Patent Application
20060122985
The present application is based on, and claims priority from, Japanese Application Number 2004-309439, filed Oct. 25, 2004, the disclosure of which is hereby incorporated by reference herein in its entirety.
The embodiments of the present invention relate to a data structure, a database system, a method and a computer-readable medium storing a program for data management and/or conversion.
Relational databases have been used for storing associated data and for searching for desired stored data.
Examples include the following references: “The Associative Model of Data White Paper” (Lazy Software, September 2000), JP 2001-209647 A, and WO 00/29980, all of which are incorporated by reference herein in their entireties.
However, in some of the methods disclosed in the above references, it is not easy to change the structure (schema) of the already completed relational databases.
In other methods disclosed in the above references, descriptive contents of the data become complex, and the data are not always uniquely parsed prior to storing, therefore the original data may not be accurately reproduced from the stored data when necessary.
Furthermore, in the methods disclosed in the above references, when a database is distributed among a plurality of servers, it is not easy to distribute loads among said servers.
In accordance with an embodiment of the present invention, a database system is provided for creating a database of a directory tree form by associating each of one or more association nodes with one or more topic nodes, each of the one or more topic nodes having data belonging thereto, and an association attribute being defined to represent each of associations between the associated association nodes and topic nodes. The database system comprises a directory tree creating element for creating an association node entry for each of the association nodes and an association attribute entry for each of the association attributes, and for creating a directory tree by correlating the entries in accordance with an association between the respective association node and the respective association attribute; and a data correlating element for correlating the data belonging to one of the topic nodes with the created association attribute entry in accordance with an association between the topic node and the respective association attribute.
In accordance with an embodiment of the present invention, a data management method is provided for creating a database of a directory tree form by associating each of one or more association nodes with one or more topic nodes, each of the one or more topic nodes having data belonging thereto, and an association attribute being defined to represent each of associations between the associated association nodes and topic nodes. The method comprises creating an association node entry for each of the association nodes and an association attribute entry for each of the association attributes; creating a directory tree by correlating the entries in accordance with an association between the respective association node and the respective association attribute; and correlating the data belonging to one of the topic nodes with the created association attribute entry in accordance with an association between the topic node and the respective association attribute.
In accordance with an embodiment of the present invention, a computer-readable medium storing therein a program is provided. The program is for use in a database system including a computer for creating a database of a directory tree form by associating each of one or more association nodes with one or more topic nodes, each of the one or more topic nodes having data belonging thereto, and an association attribute being defined to represent each of associations between the associated association nodes and topic nodes. The program when executed in the database system causes the computer to perform the steps of creating an association node entry for each of the association nodes and an association attribute entry for each of the association attributes; creating a directory tree by correlating the entries in accordance with an association between the respective association node and the respective association attribute; and correlating the data belonging to one of the topic nodes with the created association attribute entry in accordance with an association between the topic node and the respective association attribute.
In accordance with an embodiment of the present invention, a computer-readable memory having stored thereon a data structure is provided. The data structure comprises a topic node field for storing therein object data belonging to a plurality of objects; an association node field for storing therein association data describing associations among said objects; and an association attribute field for storing therein role data representing attributes of roles played by the objects with respect to the associated associations.
In accordance with an embodiment of the present invention, a method is provided for converting a first data structure having a plurality of nodes connected by a plurality of links to a second data structure having a plurality of associated topic and association nodes. The method comprises converting each of the nodes of the first data structure to one of the topic nodes of the second data structure; converting each of the links of the first data structure to one of the association nodes of the second data structure; in the second data structure, associating each of the association nodes with two of the topic nodes corresponding to the nodes which in the first data structure are connected by the link corresponding to said association node; and in the second data structure, assigning an association attribute to each association between the associated association and topic nodes to represent attributes of roles played by the nodes with respect to the associated links in the first data structure.
The objects, features and advantages of the embodiments of the present invention will become apparent upon consideration of the following detailed description of the specific embodiments thereof, especially when taken in connection with the accompanying drawings.
The embodiments of the present invention are illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout.
FIGS. 3(a)-(b) are diagrams each showing schematically an example of a method of expressing associations between associated nodes in accordance with an embodiment of the present invention.
FIGS. 51(A)-(B) are diagrams each illustrating schematically a newly added subtree in the DB server of the DB system shown in
FIGS. 53(A)-(B) are diagrams each illustrating schematically the subtree exchange/movement between the DB servers of the DB system shown in
FIGS. 54(A)-(B) are views showing the updating of the directory tree table (
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawing. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of letters to identify steps of a method or process is simply for identification and is not meant to indicate that the steps should be performed in a particular order.
Data containing various components are parsed, and the parsed data are stored.
It is desired that when necessary the original data are accurately reproduced from the stored data.
In general, in a partial set R⊂A×B of Cartesian product of sets A×B, notation of aRb with respect to an ordered pair (a, b) E R means that “a has a relation R with b”. As a simple example of original data that need to be stored and later reproduced, “playwright Shakespeare wrote drama Hamlet” will now be considered.
The original data are in a binary relation. That is, the original data “playwright Shakespeare wrote drama Hamlet” can be expressed in the “aRb” format, in which a is “playwright Shakespeare”, R is “author-work”, and b is “drama Hamlet”.
Thus, the original data are stored in a database as “a”, “R” and “b”, and can be reproduced when necessary.
However, when the number of data components increases, i.e., when the original data are not in a binary relation but in an n-ary relation, a series of such associated data are expressed in a hypergraph structure, and processing of the data is not simple.
Accordingly, a method of decomposing any n-ary relation into a number of binary relations, parsing the data into a combination of the binary relations, and storing the parsed data in a database is employed.
As a first example, “playwright Shakespeare wrote drama Hamlet in England in about 1600” will now be considered.
This example shows a quaternary relation which is decomposed into a combination of six binary relations as shown in Table 1, because 4C2=6.
In other words, with any given n, a combination of nC2 binary relations is necessary to express an n-ary relation.
Next, “playwright Shakespeare wrote drama Twelfth Night in about 1600” will be considered as a second example. This example shows a tertiary relation which is decomposed into a combination of 3 binary relations, i.e., n=3, and 3C2=3. The result is shown in Table 2.
In this case, storage of information of the first example and information of the second example in the same database causes a problem in that the same binary relation composed of “playwright Shakespeare”—“author-creation time”—“about 1600” is stored.
Another problem is the impossibility of judging which one of the combinations of the binary relations used to express the data of the first and second examples should be employed to reproduce the original information. In other words, the data, e.g., the first and second examples, are not uniquely parsed and stored.
These problems can be solved by adding an identifier to each of the binary relations. However, there is a drawback because data structure and processing will become more complex.
It is known to store binary or tertiary or any n-ary data in relational databases.
A relational database includes one or more fields in which data items are stored. A simple example of a relational database is a table in which fields or data elements are arranged in columns, and data items are arranged in rows. As used herein, a “field” or a “data element” is understood as a logical definition of data, whereas a “data item” is understood to be an actual unit of data stored in a field.
Return now to the first example “playwright Shakespeare wrote drama Hamlet in England in about 1600”.
(1) “Who”, (2) “what”, (3) “when”, (4) “where”, (5) “why”, and (6) “how” can be specified as data elements or fields.
Corresponding to these fields, data items of (1) “playwright Shakespeare”, (2) “drama Hamlet”, (3) “about 1600”, (4) “England”, (5) “NULL”, and (6) “wrote” can be stored.
However, the following problems are inherent in the method of storing data using relational databases.
(1) It is not easy to add data elements later when new data come in. Addition is not a problem in the case of data composed of stereotyped components. In the case of inputting data containing various components, however, it is necessary to change the schema of the database for adding data elements each time new data come in with a new data component or components. Schema changing is generally difficult especially when data is inputted on-line.
(2) Since the later addition of new fields or data elements is not easy, during the initial database construction, the schema may be constructed with the maximum number of fields or data elements. However, many of the fields are unlikely to contain any data item. This inevitably leads to a reduction in the efficiency of memory use.
To solve such problems, a data storage method based on “Associative Model of Data” developed by “Lazy Software” Inc. (England) has been proposed as a model alternative to the conventional relational database model.
According to this associative data model, information is processed in terms of association between objects, and this association is expressed in a “Source-Verb-Target” syntax.
This model solves some of the problems inherent in the storage method based on relational databases.
However, the associative data model has the following problems. In the case of processing a complex data relation, the model's method of expressing a relation between data is complex and not intuitive. As discussed above, when an n-ary relation is expressed in the form of a binary tree, the data are not uniquely parsed and stored. In addition, an operator can optionally change the data structure when the data is stored in the database. Thus, original information may not be accurately reproduced.
As described above, the relational database has conventionally been known as the method of storing multiple data associated with one another.
According to this method, fields or data elements are preset, and data items are stored in such fields.
The method is advantageous in that the data relation can be easily understood and/or expressed. However, addition of new fields or data elements to the already constructed database, i.e., modification of the structure (schema) of the already constructed database, is not easy.
If new fields or data items are added later, NULL entries will generated with respect to the stored data, causing a problem about a reduction in the memory use efficiency.
On the other hand, in the case of “Associative Model of Data” proposed by the Lazy Software Inc., the problems about the difficulty in adding new data items and the reduction in the memory use efficiency are solved. However, the data descriptive contents become complex, and the data structure is not intuitive, causing another problem in that the parsed/stored data is not unique.
Thus, associative network data 101 is converted to data model 102. In an embodiment of the present invention, data model 102 is constructed anew. In a simple example, data model 102 is represented in the form of an association role table including three fields, i.e., one “A node” field, one “T node” field and one “Association Role” field, and information extracted from associative network data 101 are entered as data items in the rows (records) of such an association role table (referred to as “AR table” hereinafter) as shown in Table 3. In an embodiment, the AR table which is defined as part of a relational database is managed using a relational database management system.
Accordingly, new attribute information regarding certain data (topic node) is defined as another associative data, and expressed as data associated with a row of the AR table by using a combination of corresponding A and T nodes and the links between the nodes (i.e., basic components in the data model in accordance with an embodiment of the present invention), whereby new attribute information can be added without changing the existing table structure (database schema).
Furthermore, identifiers are assigned to the A and T nodes to uniquely identify the nodes. For the identifiers, an identifier table (referred to as “ID table” hereinafter) is defined and contains node types representing node attribute types and node names representing attribute values, i.e., specific contents of the nodes (Table 5).
The ID table is managed by the relational database management system as in the case of the AR table.
In an embodiment of the present invention, a T node is newly added as data describing a specific meaning of an association represented by a certain A node, and these two nodes, i.e., the preexisting A node and the new T node, are associated with each other by an association role predefined as “reification”.
By further defining/describing an association between the new T node and another new T node added similarly for another A node, it is possible to express a relation between the associations represented by the two original A nodes.
The new T node and the association role “reification” particularly introduced to describe the meaning of an A node can be stored/managed by the AR table.
By managing the nodes using the ID table and the AR table, a data expression method capable of expressing not only the associations between the A and T nodes but also the associations between the A nodes is realized.
In the prior method, nC2 binary relations are necessary to express a piece of an n-ary data. According to an embodiment of the present invention, however, only n relations will be required to express the same n-ary data.
In other words, when a data set composed of n data components having one common association (
The resulting AR table is given in Table 4.
“A1” used in
Multiple A nodes with multiple, different identifiers are added when the data components have multiple, different common associations.
Furthermore, for the A and T nodes to which the identifiers have been assigned, an ID table having a “Node Type” field and a “Node Name” field as data attributes is created as shown in Table 5.
FIGS. 3(a)-3(b) show an example in which T nodes T1 and T2 are associated with each other by an A node A1 and T nodes T1 and T3 are associated with each other by an A node A2 (
Similarly, the A node A2 is associated with a new T node T12 based on an association role “reification”, and an association between the two T nodes T11 and T12 is defined by using the A node A11 (
Thus, a relation between the two original A nodes A1 and A2 can be expressed by using an AR table similar to that shown in Table 6.
Data Storage Method/Data Structure
Hereinafter, the data storage method and the data structure in accordance with an embodiment of the present invention will be described.
As a specific example, “playwright Shakespeare wrote drama Hamlet in England in about 1600” will be considered as first data.
The first data represent a quaternary relation having data components of (1) “playwright Shakespeare”, (2) “drama Hamlet”, (3) “about 1600”, and (4) “England”. When the first data are parsed using the prior method into binary relations, a combination of six binary relations will be required as shown in Table 7, because 4C2=6.
The parsed data are converted according to an embodiment of the present invention. The first record (row) of Table 7 is converted as described below.
Data component “playwright Shakespeare” in the topic node 1 indicates “playwright” in this information. Thus, the data component is parsed into “playwright” and “Shakespeare”, wherein “Shakespeare” is set as a T node, and “author” is set as an association role. As described later, “playwright” is set as a T node.
For the link “author-work” indicating an association, an A node is added for “authorship of Hamlet” so as to indicate that the series of information belong to the same group.
Since “authorship of Hamlet” is used to indicate that the series of information belong to the same group, other expressions are allowed as long as the information can be differentiated from information of the other group.
Thus, the first record (row) of Table 7 is converted as shown in Table 8.
Similarly, “drama Hamlet” in the topic node 2 is converted as shown in Table 9 because it is “work” in this information. Additionally, “drama” is set as a T node.
Next, similar conversion of the second record (row) of Table 7 is shown in Table 10.
Here, the data items “authorship of Hamlet”, “Shakespeare” and “author” can be omitted because they are redundant. Thereafter, all the records (rows) of Table 7 are similarly converted, redundant data are omitted, and the result is shown in Table 11.
Accordingly, when a data set composed of four data components having one common association is expressed in binary relations using the prior method, six records are necessary, because 4C2=6. However, it can be understood that only four records are necessary according to an embodiment of the present invention.
In an embodiment, when a data set having four data components are parsed and stored in a database, one new node (A node) common for the data set is added, an association role is then defined for each data component, and the database having “A node”, “T node” and “association role” fields is defined. Thus, the data structure in accordance with the embodiment of the present invention can be constructed anew.
Here, an identifier “A1” is assigned to the A node “authorship of Hamlet”. It can be understood that the data having common identifiers “A1” belong to one group. Additionally, identifiers “T11” to “T14” are assigned to four T nodes “Shakespeare”, “Hamlet”, “about 1600” and “England”, respectively.
Thus, an AR table is created for the first data as shown in Table 12.
An A node (identifier A1) indicating “authorship of Hamlet” is set as “authorship-related information”, and node types of the T nodes to which the identifiers T11 to T14 have been assigned are set as “playwright”, “drama”, “time” and “country”. Accordingly, an ID table is created as represented by Table 13.
As second data, a statement that “Japanese translation with drama Hamlet as original work was published by OO Publishing Company in February 2003” will be considered in a further example.
The second data are parsed as follows according to an embodiment of the present invention. Here, an A node common for all data component is “Japanese translation of Hamlet”, and an identifier “A2” is assigned thereto. The result is shown in Table 14.
An identifier “T12” has been assigned to Hamlet which is an original work. Thus, when an identifier “T22” is assigned to the translation Hamlet, and identifiers “T23” and “T24” are assigned to the publication date and the publisher, an AR table for the second data is shown in Table 15.
Additionally, an ID table is created as represented by Table 16.
The first and second data, and other such data are stored in the same database. Thus, an AR table and an ID table similar to Tables 17 and 18 are eventually obtained.
Furthermore, as shown in
Node types of these two new T nodes are set as “authorship information”, and node names are set as “authorship of Hamlet” and “Japanese translation of Hamlet”, respectively.
An A node indicating an association between the nodes T31 and T32 is newly added with an identifier A3, and a node type is set as “original work-translation information”.
Roles of the nodes T31 and T32 in the association are “original work information” and “translation information”. Through the aforementioned processing, an AR table and an ID table are added as represented by Tables 19 and 20, respectively. In an embodiment of the present invention, Tables 19, 20 are appended to Tables 17, 18, respectively.
To directly store the first and second data in the same relational database, an item (data attribute), e.g., corresponding to “Hamlet” as a translation version or “OO Publishing Company”, must be newly added as a new field. This addition, in accordance with the prior method, is not easy because the table structure of the database must be changed accordingly.
However, according to an embodiment of the present invention, by adding a new row, i.e., a new record rather than a new field, to the existing AR table as shown above, it is possible to differentiate the first data from the second data, by storing data having different data attributes as different groups.
The first and second data are expressed as shown in
An embodiment of the present invention provides a method of easily representing data having complex structure and a storage/management method using relational databases.
Next, an exemplary search for desired data in the database of an embodiment of the present invention will be described.
For example, a user wishes to know the publisher of the Japanese translation of drama Hamlet written by playwright Shakespeare.
At step 110: The user inputs search conditions as “drama” (or “work”) written by “playwright” (or “author”), “Shakespeare”.
At step 120: One or more groups of data satisfying the search conditions are retrieved.
At step 130: Data corresponding to “drama” among the retrieved one or more groups of data are displayed.
At step 140: The user selects a desired drama name, i.e., “Hamlet”, from the displayed data.
At step 150: The database is searched again, with “Hamlet” and “translation” as the new search conditions.
At step 160: Further one or more groups of data satisfying the new search conditions are retrieved.
At step 170: Data regarding “publisher” and “publication date” among the retrieved one or more groups of data are displayed.
At step 180: The user selects a desired publisher from the displayed data.
A detailed description will be given below.
The user inputs “Shakespeare” and “author” as search conditions, and searches for data.
In this particular example, there is a node name “Shakespeare” of a T node and an association role “author” in the database. An identifier of the T node (e.g., T11) whose association role is “author” is retrieved by referring to the AR table (e.g., Table 17) in the database. Subsequently, one or more groups of identifiers of A nodes corresponding to the T node (e.g., T11) whose node name is “Shakespeare” are retrieved by referring to node name attributes stored in the ID table (e.g., Table 18).
Within the search result including the retrieved one or more groups of A node identifiers, another search condition, i.e., a T node identifier whose association role is “work”, is selected from the AR table (e.g., Table 17).
Data, i.e., node names, regarding the selected T node, i.e., drama(s) corresponding to the association role “work” are displayed from the ID table (e.g., Table 18) based on the selected identifier.
For example, dramas or node names “Hamlet”, “Taming of the Shrew”, “Merchant of Venice”, “Midsummer Night's Dream”, “King Lear” and the like are displayed. The user selects a desired drama, or node name, i.e., “Hamlet”.
Subsequently, using the identifier “T12” of the selected node name “Hamlet” as a key, the system in accordance with an embodiment of the present invention searches for an A node identifier containing an identifier “T12” as a T node ID and having an association role “translation” at the same time from the AR table (e.g., Table 17).
Accordingly, one or more groups of data associated with the A node identifiers satisfying the search conditions are retrieved.
Node names of T nodes having “publication” and “publication date” as association roles are displayed from the retrieved one or more groups of data by referring to the ID table (e.g., Table 18).
The user can now select a desired publisher from the displayed data, i.e., “OO Publishing Company” which has indeed published a translation of drama Hamlet recently in “February 2003”.
The process of
In the described specific example, a single attribute is defined as an association role. However, each association role is not limited to only one, single attribute.
In other words, an association role can have a plurality of attributes. In the above examples, more detailed attributes can be defined by adding and specifying genres such as “tragic drama”, “comedy”, “romance”, “historical drama” and the like to the association role “drama”.
Features of Data Storage Method/Data Structure
As described above, according to the data storage method and the data structure of an embodiment of the present invention, by using the widely used relational database form, the data can be stored and managed while the hypergraph structure representing a relation of a series of data having tertiary or more complex relations, generally n-ary mutual relations, is maintained.
According to the method of directly mapping the associative network data in the table (s) of a relational database in accordance with an embodiment of the present invention, it is possible to solve the prior problem that it is impossible to efficiently store/manage data having tertiary or more complex relations, generally n-ary relations.
It is also possible to solve the prior problem that modifications, such as addition of attribute data to the data stored in the database, necessitate changing of the structure of the relational database table, causing a loss of flexibility and requiring much labor.
Furthermore, it is possible to give specific meanings to a series of associations by using additional identifiers usually assigned to data and additional association roles in the framework of the same database schema.
First Database System
Hereinafter, a first database of an embodiment of the present invention will be described.
Referring to
In the description below, terminology may be partially or slightly different from the terminology used above to describe the data storage method and the data structure with reference to
In case of discrepancies, the meanings of the terms used in the below description of the DB system 1, will control.
Throughout the drawings referenced below, similar components will be denoted by similar reference numerals.
Hardware Configuration
Referring to
In other words, the DB server 12 and the PC 102 include components as computers provided with functions of performing communication with the other communication node.
Data Structure
The DB server 12 is constructed to allow data storage and searching for stored data in accordance with the data storage method and the data structure of an embodiment of the present invention described above with reference to
The data structure and the data search mechanism in the DB server 12 will now be described.
Referring to
The association attribute R may be any attribute for defining an association between the T and A nodes. However, for a specific and clear description presented below, a specific example in which the association attribute R is an association role R (as detailed in the aforementioned description of the data storage method and the data structure of an embodiment of the present invention) will be considered.
The data associations shown in
Among A nodes A1 to An shown in
Similarly, T nodes T2-1, T2-2 and Tn-1 associated with the A node A2, and the A node A2 are interconnected by links.
The same holds true for the A node An. T nodes Tn-1 to Tn-4 associated with the A node An, and the A node An are interconnected by links.
In other words,
The links 851, 852, 853, 854, 855 from the T node T1-1 through the A node A1, the T node T2-1, the A node A2 and the T node Tn-1 to the A node An in
In a specific example,
(1) The T nodes T1-1 to T1-m1 and T2-1 are associated with the A node A1, and association roles R1-1 to R1-m1 and R1-0 are defined in associations (links) between the T nodes T1-1 to T1-m1 and T2-1 and the A node A1.
(2) The T nodes T2-1 to T2-m2 and the T node omitted from
(3) Similarly thereafter, the T node omitted from
(4) The T nodes Tn-1 to Tn-mn and the T node omitted from
In other words, in the DB server 12, each of the T nodes is associated with one or more A nodes, and each of the A nodes is associated with one or more T nodes, whereby the plurality of T nodes can be associated with one another via the A nodes, and the plurality of A nodes can be associated with one another via the T nodes.
In the DB server 12, a plurality of combinations of the A and T nodes associated as shown in
Referring to
The T node T2-3 is connected to both of the A nodes A2 and An by links, which means that the T node T2-3 is associated with both of the A nodes A2 and An.
When, like in this case, a series of information associated by the A nodes A1, A2 and An have a common association, a new association node A3 can be defined.
For example, when the A node A1 is information regarding the original work of Hamlet, the A node A2 is information regarding the translation of Hamlet, and the A node An is information regarding the performance of Hamlet, associative data represented by the A nodes A1, A2 and An have a commonality as data regarding Hamlet.
Thus, to indicate that the data associated by the A nodes A1, A2 and An have the commonality, the new association node A3 is defined and stored in the database.
As shown by broken line in
Similarly, to specifically describe the associations of the A nodes A2 and An, new T nodes T3-2 and T3-n are defined and stored in the database.
For example, data “authorship of Hamlet” is defined as topic contents in the T node T3-1, data “Japanese translation of Hamlet” is defined as topic contents in the T node T3-2, and data “performance of Hamlet” is defined as topic contents in the T node T3-n. These data are stored in the database.
Additionally, an association role R is defined between the new A node A3 and each of the T nodes T3-1 to T3-n, and stored in the database.
For example, “original work information” is defined as an association role R between the new A node A3 and the T node T3-1, “translation information” is defined as an association role R between the new A node A3 and the T node T3-2, and “performance information” is defined as an association role R between the new A node A3 and the T node T3-n. These data are stored in the database.
Similarly, for example, association roles R predefined as “reification” by the system are defined between the A nodes A1, A2 and An and the T nodes T3-1, T3-2 and T3-n.
In the DB server 12, the data of the A and T nodes associated by the structure shown in
Each of the entries (or records or rows) of the AR table shown in
In other words, each of the entries of the AR table includes the identifier of the A node at one end of one of the links shown in
Such entries are created for all the links (links between the T node T1-1 and the A node A1 and between the T node Tn-mn and the A node An) shown in
Each T node has its contents (name of the T node, data of the T node itself, data referred to by the T node, and the like). Further, for each T node, in addition to the identifier (ID) stored in each entry of the AR table, an attribute of the T node (node type (NT); topic attribute) is defined. Hereinafter, a specific example in which each T node has only its name (node name (N)) as its contents will be considered.
Each entry of the T node ID table shown in
Such entries are created for all the T nodes T1-1 to Tn-mn shown in
Each entry of the A node ID table shown in
Such entries are created for all the A nodes A1 to An shown in
It is to be noted that similar forms can be employed to store the associations between the A and T nodes and the data of the A and T nodes shown in
Depending on use, configuration or processing task of the DB server 12, as shown in
Similarly, in the AR table, each entry may further include contents of the T node.
Data Search
As shown in
In the DB server 12, one or more combinations of the association role Rret defined for Tret, an attribute of the A node used for searching (node type NT; ANT1 and ANT2 in
As shown in
The search conditions can further contain an attribute NT of the T node (third condition data) as described later.
Among the search conditions, one or more combinations (R1, N1), (R2, N2), . . . (Rn, Nn) of the association role R and the node name N of the T node included in the Filter are used as filters for searching, and thus will be referred to as search filters hereinafter.
Among the search conditions, the attributes of the A node (ANT1, ANT2, . . . ) can be omitted.
Referring to
In a step S22, detailed in
In a step S24, detailed in
In a step S202, the DB server 12 creates a response to the searcher's query based on an identifier (node ID) and the node name (Nret) of the T node Tret obtained as a search result through the processing in S24.
For the response, only the node name Nret, various data referred to by the node Tret, or various data indicating the node Tret can be used.
In a step S204, referring to
The DB server 12 ends the process when the searcher's query has been terminated, or returns to the processing in S200 otherwise.
Referring to
In this association node list, among the A nodes obtained from the AR table (
It is to be noted that when the attributes of the A nodes are omitted from the search conditions ((ANT1, ANT2, . . . )=NULL), in the processing in S220, all the identifiers of the A nodes obtained from the AR table (
In a step S222, the DB server 12 determines whether processing has been carried out or not for all the search filters (Ri, Ni).
The DB server 12 proceeds to processing in S24 (
In step S224, the DB server 12 searches the T node ID table (
It is to be noted that when the search conditions contain attributes of T nodes (node type; NT) and the search filters are represented by (Ri, Ni, NTi), in the processing in S224, the DB server 12 only needs to retrieve entries containing the node names Ni and the node types NTi of the search filters (Ri, Ni, NTi) from the ID table, and to create a set of T node identifiers contained in the retrieved entries as a node ID set T.
In a step S226, the DB server 12 determines whether the node ID set T obtained in the processing in S224 is empty or not.
When the node ID set T is empty, the DB server 12 performs processing for terminating the search process (display a “zero matches found” message or the like to the searcher), and ends the search process. Otherwise, the DB server 12 proceeds to processing in S228.
In step S228, the DB server 12 searches the AR table (
That is, the DB server 12 retrieves all the entries containing the association roles Ri of the search filters (Ri, Ni) and the T node identifiers included in the node ID set T obtained in the processing in S224 from the AR table, and stores the A node identifiers contained in the retrieved entries in the association node list A (A={Aj| role=Ri, T node identifier=Ti (all i), A node identifier ε A in AR table}).
In a step S230, the DB server 12 determines whether the association node list A obtained in the processing in S228 is empty or not.
When the association node list A is empty, the DB server 12 performs processing for terminating the search process, and ends the search process. Otherwise, the DB server 12 proceeds to processing in S232.
In step S232, the DB server 12 reads the search filter included in the search conditions but not processed and returns to the processing in S222.
Referring to
That is, the DB server 12 retrieves all the entries containing the association roles Rret included in the search conditions and A node identifiers included in the association node list A obtained in the processing in S22 (S228) from the AR table, and creates a set of T node identifiers (T node ID set T) contained in the retrieved entries (T={Tm| role=Rret, A node identifier E A in AR table}).
In a step S242, the DB server 12 determines whether the T node ID set T obtained in the processing in S240 is empty or not.
When the T node ID set T is empty, the DB server 12 performs termination processing to end the search process. Otherwise, the DB server 12 proceeds to S244.
In step S244, the DB server 12 searches the T node ID table (
That is, the DB server 12 retrieves from the ID table all the entries containing any of the T node identifiers Tm contained in the T node ID set T created in the processing in S240, and creates a set P of node names Nm and T node identifiers Tm contained in the entries (P={(Tm, Nm)|T node identifier=Tm (all m) in ID table}).
In a step S246, the DB server 12 determines whether the set P of the T node identifiers and the T node names obtained in the processing in S244 is empty or not.
The DB server 12 performs termination processing to end the search process when the set P of the T node identifiers and the T node names is empty. Otherwise, the DB server 12 proceeds to processing in S202.
This set P is used for creating the response to the searcher in the processing in S202 shown in
DB Program 2
In
Referring to
The DB management unit 20 includes a management operation receiver 200, an AR entry creation unit 202, an ID entry creation unit 204, an AR database management unit (ARDB management unit) 206, and an ID database management unit (IDDB management unit) 208.
The DB unit 24 includes an AR database (ARDB) 240, a T node ID database (IDDB) 242, and an A node IDDB 244.
The DB search unit 26 includes a search operation receiver 260, a search condition creation unit 262, a search control unit 264, an AR database search unit (ARDB search unit) 266, and an ID database search unit (IDDB search unit) 268.
For example, the DB program 2 is carried on and read from the recording medium 130 (
With these components, the DB program 2 is used to create an AR database (
In the DB unit 24, the ARDB 240 stores the AR table shown in
The IDDB 242 stores the T node ID table shown in
The IDDB 244 stores the A node ID table shown in
The T node ID table and the A node ID table do not need to be always created separately, but they may be integrally created in one database.
In the DB management unit 20, the management operation receiver 200 receives an operation of managing or modifying data stored in the AR table and the ID table from the input/output device 126 (
The management operation receiver 200 receives user's operation for designating an A node and a T node, an association between the A node and the T node, an association role R defined between the A node and the T node (links), identifies (ID) assigned to the A node and the T node, a node name (N) assigned to the T node, and an attribute (FIG. 9) defined for the T node, and outputs the operation to the AR entry creation unit 202 and the ID entry creation unit 204.
For example, the management operation receiver 200 displays a user interface (UI) image representing the A node and the T node, an association therebetween as shown in
The AR entry creation unit 202 creates entries of the AR table shown in
The ARDB management unit 206 adds the entries of the AR table input from the AR entry creation unit 202 to the AR table stored in the ARDB 240.
The ARDB management unit 206 modifies contents of the AR table stored in the ARDB 240 according to user's operation input from the management operation receiver 200.
The ARDB management unit 206 retrieves the entries of the AR table stored in the ARDB 240 according to search requests by the ARDB search unit, and outputs the entries to the ARDB search unit 266.
The ID entry creation unit 204 creates entries for the T node and A node ID tables shown in
The IDDB management unit 208 adds the entries of the T node ID table input from the ID entry creation unit 204 to the T node ID table stored in the IDDB 242.
The IDDB management unit 208 adds the entries of the A node ID table input from the ID entry creation unit 204 to the A node ID table stored in the IDDB 244.
The IDDB management unit 208 modifies contents of the ID table stored in the IDDBs 242 and 244 according to user's operation input from the management operation receiver 200.
The IDDB management unit 208 retrieves the entries of the ID table stored in the IDDBs 242 and 244 according to search requests by the IDDB search unit 268, and outputs the entries to the IDDB search unit 268.
In the DB search unit 26, the search operation receiver 260 receives searcher's operation for designating search conditions (
The search operation receiver 260 outputs the received operation to the search condition creation unit 262.
For example, when the search operation receiver 260 accepts search conditions in a form of a natural language query, the search condition creation unit 262 parses the query statement to take out words.
Next, the search condition creation unit 262 searches the AR table and the ID table stored in the ARDB 240 and the IDDBs 242 and 244 through the ARDB search unit 266, the IDDB search unit 268, the ARDB management unit 206 and the IDDB management unit 208, and extracts words used as search conditions.
Further, the search condition creation unit 262 combines the extracted words according to the structure of the query sentence, retrieves the search conditions in the form of (Rret, (ANT1, ANT2, . . . ), ((R1, N1), (R2, N2), . . . (Rn, Nn)) shown in
It is to be noted that when the searcher directly designates the search conditions in the form of (Rret, (ANT1, ANT2, . . . ), ((R1, N1)), (R2, N2), . . . ., (Rn, Nn))) shown in
The search condition creation unit 262 may be a tool for assisting retrieval of the search conditions (Rret, (ANT1, ANT2, . . . ), ((R1, N1), (R2, N2), . . . , (Rn, Nn))) by the searcher.
The search control unit 264 controls the ARDB search unit 266 and the IDDB search unit 268 according to the search conditions (Rret, (ANT1, ANT2, . . . ), ((R1, N1), (R2, N2), . . . , (Rn, Nn))) input from the search condition creation unit 262 (search operation receiver 260) to perform searching in the ARDB 240 (AR table;
When a search result (set P;
The ARDB search unit 266 searches the ARDB 240 (AR table;
The IDDB search unit 268 searches the IDDBs 242 and 244 (ID tables;
Overall Operation
Hereinafter, an overall operation of the DB server 12 (DB program 2;
Creation of AR Table and ID Table
To begin with, a process of creating an AR table and ID tables by the DB management unit 20 of the DB program 2 will be described.
For example, data associated as shown in
The data shown in
(1) “A node A1” and “T node T11” are associated together, an association role R “Author” is defined therebetween, and a node name “Shakespeare (different person of the same name)” is assigned to the “T node T11”.
(2) “A node A9” and “T nodes T92 and T41” are associated together, association roles R “Work” and “Author” are defined therebetween, and node names “The Merchant of Venice” and “Shakespeare” are assigned to the “T nodes T92 and T42”.
(3) “A node A4” and “T nodes T41 and T42” are associated together, association roles R “Author” and “Work” are defined therebetween, and a node name “Hamlet” is assigned to the “T node T42”.
(4) “A node A13” and “T node T42” are associated together, and an association role R “Script” is defined therebetween.
(5) “A node A19” and “T node T42” are associated together, and an association role R “Original Work” is defined therebetween.
(6) “A node A10” and “T node T42” are associated together, and an association role R “Original Work” is defined therebetween.
(7) “A node A10” and “T nodes T103 and T101” are associated together, association roles R “Publication” and “Translation” are defined therebetween, and a node name “OO Publishing Company” is assigned to the “T node T103”.
(8) “A node A19” and “T node T191” are associated together, and an association role R “Translation” is defined therebetween.
The management operation receiver 200 receives input data, and outputs the data to the AR entry creation unit 202 and the ID entry creation unit 204.
The AR entry creation unit 202 creates each entry of the AR table from the data shown in
It is to be noted that in the drawings below, NULL indicates that there is no attribute (node type)/name (node name).
The ARDB management unit 206 sequentially adds the entries of the AR table input from the AR entry creation unit 202 to the AR table stored in the ARDB 240.
As a result of the processing by the AR entry creation unit 202 and the ARDB management unit 206, an AR table shown in
The ID entry creation unit 204 creates entries of the T node ID table from the data shown in
The IDDB management unit 208 sequentially adds the entries of the T node ID table input from the ID entry creation unit 204 to the ID table stored in the IDDB 242.
As a result of the processing by the ID entry creation unit 204 and the IDDB management unit 208, a T node ID table shown in
The ID entry creation unit 204 creates entries of the A node ID table from the data shown in
The IDDB management unit 208 sequentially adds the entries of the ID table input from the ID entry creation unit 204 to the A node IDDB table stored in the IDDB 244.
As a result of the processing by the ID entry creation unit 204 and the IDDB management unit 208, an A node ID table similar to that shown in
Data Search
For example, when the searcher inputs a search condition “what is the name of the publisher that publishes a translation of the original work of drama Hamlet which is one of the works that the Playwright Shakespeare wrote as an author?” in a form of a query statement to the input/output device 126 (
In the second half of the query statement “the works that the Playwright Shakespeare wrote as an author”, to retrieve data regarding “Work”, the search condition creating unit 262 sets an association role Rret of the T node Tret to be a search result as “Work”.
The search condition creation unit 262 creates a search filter (R1=“Author”, N1=“Shakespeare”) from the second half. “Shakespeare wrote as an author”.
Further, the search condition creation unit 262 creates search conditions (Rret, (ANT1), ((R1, N1)))=(Work, (NULL), ((Author, Shakespeare))) corresponding to the second half of the query statement from the association role (Rret=“Work”) of the T node Tret and the search filter (R1=“Author”, N1=“Shakespeare”).
In the first half of the query statement “what is the name of the publisher that publishes a translation of the original work of drama Hamlet?”, to retrieve information regarding “Publisher that publishes”, the search condition creating unit 262 sets an association role Rret of the T node Tret to be a search result as “Publication”.
The search condition creation unit 262 creates a first search filter (R1=“Original Work”, N1=“Hamlet”) from the condition that an “original work” of drama “Hamlet” included in the first half, and creates a second search filter (R2=“Translation”, N2=“NULL (not specified)”) from “Translation” included in the first half.
Further, the search condition creation unit 262 creates search conditions (Rret, (ANT1), ((R1, N1), (R2, N2)))=(Publication, (NULL), ((Original Work, Hamlet), (Translation, NULL))) corresponding to the first half of the query statement from the association role (Rret=“Publication”), the first search filter (“R=“Original Work”, N1=“Hamlet”) and the second filter (R2=“Translation”, N2=“NULL”).
Based on the search conditions created by the search condition creation unit 262, the search control unit 264 searches the ARDB 240 (AR table;
First, from the search conditions obtained from the second half of the query statement, the search control unit 264 performs the following.
(1) The search control unit 264 refers to the T node ID table stored in the IDDB 242 (
(2) The search control unit 264 refers to the AR table (
(3) The search control unit 264 refers to the AR table to retrieve T node identifiers (ID; generally plural) corresponding to A nodes whose association roles R are “Work” among the A node identifiers obtained in the processing of (2), and obtains T42 and T92 as a result of this processing.
(4) The search control unit 264 refers to the ID table, and sets node names of identifiers corresponding to the T node identifiers obtained by the processing of (3) together with T node identifiers (ID) as search results.
That is, the search control unit 264 performs searching based on the search conditions (Work, (NULL), ((Author, Shakespeare))) obtained from the second half of the query statement by the processing of (1) to (4), and obtains search results (T42, Hamlet), and (T92, the Merchant of Venice).
Next, based on the search conditions obtained from the first half of the query statement and the search results corresponding to the second half, the search control unit 264 performs the following.
(5) From the search results (T42, Hamlet) and (T92, the Merchant of Venice) corresponding to the second half of the query statement, the search control unit 264 selects (T42, Hamlet) whose node name corresponds to the first search filter (original work, Hamlet), and obtains its node identifier (ID) T42.
(6) The search control unit 264 refers to the AR table to retrieve all the A node identifiers in which association roles are “Original Work” and T node identifiers match the node identifiers (ID) obtained by the processing of (5), and obtains A10 and A19 as a result.
(7) The search control unit 264 refers to the AR table to retrieve all identifiers whose roles are “Translation” among the A node identifiers obtained by the processing of (6), and obtains A10 and A19 as a result.
(8) The search control unit 264 refers to the AR table to retrieve T node identifiers corresponding to the A nodes whose roles are “Publication” among the A node identifiers obtained by the processing of (7), and obtains T103 as a result (when there are translations from a plurality of publishers, a plurality of T nodes are obtained).
(9) The search control unit 264 refers to the ID table, and sets node names of node IDs corresponding to the T node identifiers obtained by the processing of (8) together with node identifiers as search results (T103, OO Publishing Company).
That is, the search control unit 264 performs searching based on the search conditions (Publication, (NULL), ((Original Work, Hamlet), (Translation, NULL))) obtained from the first half of the query statement by the processing of (5) to (9), and obtains the search results (T013, OO Publishing Company).
(10) The search control unit 264 displays the search results in the input/output device 126 (
Second Database System 3
Referring to
Thus, the DB program 2 does not need to be always executed on one computer, but it may be distributed to a plurality of computers interconnected through a network to be executed.
Third DB System 4
Hereinafter, the third DB system 4 of an embodiment of the present invention configured to store and search association information based on a directory structure will be described.
Referring to
It is to be noted that when any one of a plurality of components, such as the DB servers 6-1 to 6-n, is not specified, it may be simply referred to as the DB server 6.
Hardware of the retrieval device 40, the DB management server 5 and the DB server 6 employs a configuration shown in
When the DB server 6 includes a search function as in the case of the DB server 12 (
Furthermore, in the DB system 4, a replica server (mirror sever; DB server 6′) may be provided corresponding to each DB server 6.
Hereinafter, the DB serves 6-1 to 6-n may be referred to as DB servers A to N.
Next, data representation in the DB system 4 of
As described above with reference to
The A nodes A2-1 and A2-2 indicate a node for defining a node type (class) and a node as its instance (node corresponding to an entity). Thus, the nodes A2-1 and A2-2 are special nodes in that they enable association of T nodes not based on roles independently defined by a user according to a purpose but based on two roles of “Class” and “Instance” predefined by the system.
The associative data of the graphical representation shown in
That is, the associative data shown in
In other words, in the case shown in
It is to be noted that in the DIT form shown in
“Entry” is defined to arrange/classify data regarding objects of the real world according to object classes and to represent the data as directory information, or defined as data stored in the directory.
“Directory information tree” is defined to represent, when entries (directory information) are managed in a hierarchical manner, the hierarchical relation in a tree structure.
In other words, squares in
As described above, an entry is a set of data regarding an object, and data regarding this object is called “Attribute”.
The attribute includes “Attribute Type” and one or more values, “Attribute Value(s)”. Referring to
In the entry directly below “ou=association #1”, each attribute of the entry is defined, for example, in a manner that an attribute value of an attribute type objectclass is an association node, an attribute value of an attribute type cn (common name) is location, . . .
As shown in
In the case shown in
For example, as shown in
Accordingly, the associative data partitioned according to the directory tree can be partitioned and stored in the DB servers 6-1 to 6-n as shown in
To manage the associative data partitioned and stored in the DB servers 6-1 to 6-n (A to N) as shown in
Referring to
As shown in
Accordingly, classification types and classification values indicating attributes or the like used for classifying the stored associative data can be defined for the directory trees (or subtrees) stored in the DB servers 6-1 to 6-n (A to N) shown in
To manage the associative data stored in the DB servers 6-1 to 6-n (A to N), as shown in
It is to be noted that “Classification Type” shown in
“Classification Value” corresponds to an instance in the LDAP data model.
Specific examples of entries that can be top entries shown in FIGS. 27 to 30 include, but are not limited to:
(1) a root entry of a subtree containing a specific classification value (instance) of a certain classification type (association type; node type of A node); and
(2) a root entry of a subtree containing associative data containing a certain specific classification value (instance).
Here, the case is described in which “Classification Type” corresponds to the association type and “Classification Value” corresponds to the instance thereof. However, this is only an example in which
For example, the subtree a shown in
For example, “Location Information” shown as an entry classification type containing a top entry dn_B of the data table shown in
This entry indicates that all the associative data having “Location (located-in)” as classification values are stored in the DB server 6-2 (B).
As other examples of classification values of the classification type “Location Information”, a classification value “Adjacent (next-to)” and the like can be cited.
Alternatively, “Building” written as an entry classification type containing the top entry dn_(N−1) shown in
This entry indicates that all the associative data having “Store 1” as classification values are stored in the DB server 6-(n-1) (N−1).
Creation and Search of Associative Data
Hereinafter, creation of the associative data represented in the directory structure of the DIT form described above with reference to FIGS. 25 to 30, and searching for the created associative data will be described.
First DB Management Program 50
Referring to
With these components, the DB management program 50 creates the associative data represented in the directory structure of the DIT form as shown in
The DB management program 50 partitions and stores the created associative data in the DB servers 6-1 to 6-n as shown in
Additionally, the DB management program 50 properly provides data (tree data) contained in the directory tree table and the data table, which is necessary for searching to the retrieval device 40 (
In the DB management program 50, the UI unit 500 provides a GUI environment for the user of the DB management server 5 or the PC 102, and displays a GUI image similar to that shown in
The UI unit 500 accepts user's operation of registering, managing or modifying the associative data on the displayed GUI image, outputs the operation to the components of the DB management program 50, such as the data registration unit 502 and the associative data creation and management unit 510, and controls the operations thereof.
Additionally, the UI unit 500 displays/outputs the data created by each component of the DB management program 50 to the input/output device 126.
It is to be noted that the UI unit 500 may be installed in the DB management server 5 or the PC 102, and the functions may be provided to the user in the PC 102.
The associative data creation and management unit 510 controls operations of the directory tree table creation unit 522 and the data table creation unit 532 or the like, creates associative data represented in the directory structure of the DIT form as shown in
In response to a request, the associative data creation and management unit 510 outputs data (tree data) contained in the directory tree table and the data table and used for retrieval by the retrieval device 40 to the tree data provision unit 512.
Additionally, according to user's operation, the associative data creation and management unit 510 partitions the associative data represented in the directory structure of the DIT form as shown in
The data registration unit 502 transmits the associative data input from the associative data creation and management unit 510 to the DB servers 6-1 to 6-n through the data transmission unit 504, and requests registration of the associative data.
The tree information provision unit 512 provides the tree data input from the associative data creation and management unit 510 in response to a request from the retrieval device 40.
The directory tree table creation unit 522 creates a directory tree table shown in
The directory tree table management unit 524 stores the directory tree table input from the directory tree table creation unit 522 in the directory tree table DB 526.
In response to a request, the directory tree table DB 526 outputs the directory tree table stored in the directory tree table DB 526 to the associative data creation and management unit 510.
It is to be noted that while the DB management unit 20 performs the processing of creating the AR table and the ID table from the associative data in the DB program 2 shown in
The data table creation unit 532 creates a data table shown in
The data table management unit 534 stores the data table input from the data table creation unit 532 in the data table DB 536.
Additionally, in response to a request, the data table management unit 534 outputs the data table stored in the data table DB 536 to the associative data creation and management unit 510.
Hereinafter, an overall process of the DB management program 50 will be described.
Referring to
The user performs an operation on the displayed GUI image, and inputs data regarding newly added associative data to each field.
In a step S302, the associative data creation and management unit 510 identifies an association (theme; e.g., “Work of Shakespeare”) based on the associative data input during the processing of the step S300.
In a step S304, the associative data creation and management unit 510 identifies a node type (classification type; e.g., “Authorship Information”) of the associative data, and sets this type as an entry attribute.
In a step S306, the associative data creation and management unit 510 refers to the data table through the data table management unit 534, and determines a subtree into which the created entry is classified based on the theme and the node type identified in the processing of steps S302 and S304.
In a step S310, the associative data creation and management unit 510 refers to the directory tree table through the directory tree table management unit 524, and determines a DB server 6 in which the subtree obtained in the processing of the step S306 is stored.
In a step S312, the associative data creation and management unit 510 creates a corresponding entry based on the data regarding the associative data input through the UI unit 500.
In a step S314, the associative data creation and management unit 510 transmits the added associative data entry to the DB server 6 determined in the processing of the step S310 through the data registration unit 502 and the data transmission unit 504. The DB server 6 judges whether the received associative data entry has been stored or not.
It is to be noted that the associative data creation and management unit 510 uses the data in the DB server 6 in pre-processing upon storage in the DB server 6.
Each entry dn (distinguished name) is allocated to this data, and all the entries in the DIT can be uniquely identified by the dn. Accordingly, the presence of an identical entry can be judged.
The DB management program 50 ends the process upon reception of a result that the added associative data entry has been stored from the DB server 6, or proceeds to processing of a step S316 otherwise.
In the step S316, the associative data creation and management unit 510 registers the added associative data entry in the determined DB server 6.
In a step S340, the user operates the DB management server 5 (
The associative data creation and management unit 510 receives the operations through the UI unit 500.
In a step S342, the user operates the DB management server 5 (
The associative data creation and management unit 510 receives the operation through the UI unit 500.
In a step S344, the associative data creation and management unit 510 judges whether the classification type, the classification value and the top entry indicated by the operations received in the processing in S340 and S342 have all been set for the specified subtree or not.
The associative data creation and management unit 510 reads the data table through the data table management unit 534, and ends the process when all data have been set for the specified subtree, or proceeds to processing in S346 otherwise.
In the step S346, the associative data creation and management unit 510 outputs the received setting values (specified subtree, classification type, classification value and top entry) to the data table management unit 534.
The data table management unit 534 sets the setting values input from the associative data creation and management unit 510 in the data table, and stores them in the data table DB 536.
Referring to
In a step S362, the associative data creation and management unit 510 obtains the directory tree table (
In a step S364, the UI unit 500 receives setting of the top entry and the referring entry of the subtree after the partitioning in accordance with user's operation on the displayed directory structure.
In a step S366, the associative data creation and management unit 510 judges whether or not to set a replica server for the DB server 6 in which the partitioned subtree is stored based on user's operation of partitioning the directory information tree.
The DB management program 50 proceeds to processing in S368 when the replica server is set, or proceeds to processing in S370 otherwise.
In the step S368, the associative data creation and management unit 510 determines the replica server when the setting of the replica server is configured in the processing in S366.
In the step S370, when the top entry and the referring entry of the subtree after the partitioning and the replica server are set, the associative data creation and management unit 510 outputs a name of the replica server to the directory tree table management unit 524.
The directory tree table management unit 524 reflects the data input from the associative data creation and management unit 510 on writing in a designated part of the directory tree table DB 526.
In a step S372, the associative data creation and management unit 510 judges whether the update process of the direction tree table has been completed or not for all the DB servers 6.
The DB management program 50 returns to the processing in S364 when the update process has not been completed for all the DB servers 6.
Next, an overall process of the DB management server 5 will be described.
Referring to
In a step S402, the UI unit 500 outputs the data regarding the input associative data to the associative data creation and management unit 510.
The associative data creation and management unit 510 receives the data.
In a step S404, the associative data creation and management unit 510 outputs classification data (classification type/classification value) used for classifying the associative data such as a theme and a node type among the data regarding the received associative data to the data table management unit 534.
In a step S406, the data table management unit 534 receives the data used for classifying the associative data from the associative data creation and management unit 510, and returns top entries of corresponding subtrees to the associative data creation and management unit 510.
The associative data creation and management unit 510 receives the top entries of the subtrees.
It is to be noted that when there are no corresponding subtrees, the top entry (i.e., root entry) of the DB server 6-1 is returned to the associative data creation and management unit 510 in place of the top entries of the corresponding subtrees.
In the processing in S406, data corresponding to the classification type and the classification value stored in the data table (
That is, the associative data creation and management unit 510 supplies a combination of a node type and a specific instance to the data table management unit 534, whereby the data table management unit 534 can obtain the top entries of the subtrees corresponding to the data used for classifying the associative data. Additionally, for example, “Category” as a classification type and “Work of Shakespeare” as a classification value can be supplied to the data table management unit 534.
In a step S408, the associative data creation and management unit 510 outputs the top entries of the subtrees obtained in the processing in S406 to the directory tree table management unit 524.
The directory tree table management unit 524 receives the top entries of the subtrees.
In a step S410, the directory tree table management unit 524 searches the directory tree table DB 526 by using the received top entries of the subtrees, and determines DB servers 6 for storing the subtrees. Data indicating the determined DB servers 6 are returned to the associative data creation and management unit 510.
In a step S412, the associative data creation and management unit 510 outputs the associative data of the DIT form and the data indicating the determined DB servers 6 to the data registration unit 502.
The data registration unit 502 transfers the input associative data to the determined DB servers 6 and registers the data.
In steps S416 to S422, a registration result (normal or abnormal end) is notified from the data registration unit 502 to the UI unit 500, and displayed to the user.
Second DB Program 60
Referring to
With these components, the DB program 60 receives registration of associative data represented in a directory structure of a DIT form and properly partitioned from the DB management server 5 (DB management program 50;
The DB program 60 provides the registered associative data in response to the search request from the retrieval device 40.
The DB program 60 modifies the registered associative data under control of the DB management server 5.
In the DB program 60, the data transmission unit 604 receives the associative data, a registration request thereof and a modification request thereof from the DB management server 5, and outputs them to the data management unit 600.
The search execution unit 606 searches for the associative data with the data management unit 600 in accordance with search conditions (LDAP operation created by a search condition creation unit 420 of a search program 42 described later and shown in
Further, the search execution unit 606 returns the associative data obtained from the data management unit 600 as a search result to the retrieval device 40 that sent the search request.
The data management unit 600 stores the associative data (FIGS. 26 to 28) sent from the DB management server 5 or the other DB server 6 in response to the registration request and the modification request from the DB management server 5 in the information DB 602.
Additionally, in response to retrieval by the retrieval device 40, the data management unit 600 reads the associative data from the information DB 602 and outputs the data to the search execution unit 606.
First Search Program 42
Referring to
With these components, the search program 42 performs search processing for the DB server 6, and displays associative data obtained as a result of the search to the searcher.
In the search program 42, a search operation receiver 260 receives a search operation which the searcher inputs to the input/output device 126 (
The search condition creation unit 420 (directory tree search means) analyzes contents of the search operation input from the search operation receiver 260, then obtains tree data matching the contents of the search operation (data necessary for search in the directory tree table and the data table (
Specifically, in accordance with a classification type and a classification value of associative data obtained by analyzing the contents of the search operations, the search condition creation unit 420 receives the data table (
Then, the search condition creation unit 420 searches for the contents in the directory tree table (
Further, the search condition creation unit 420 creates a command and a parameter of an LDAP operation to be executed by the DB server 6 by using the contents of the search operation and attributes (classification type and value) used for classifying the associative data obtained from the data table, and outputs the command and the parameter as search conditions to the search control unit 264.
The search control unit 264 (data search means) outputs the search conditions input from the search condition creation unit 420 to the DB server 6, and controls the search for the associative data.
The search result output unit 422 displays/outputs the associative data returned as a result of the search from the DB server 6 to the input/output device 126 (
Hereinafter, an overall process of the search program 42 will be described.
Referring to
In a step S442, the search operation receiver 260 creates a search request message (described later with reference to
In a step S444, the search condition creation unit 420 judges whether a classification type and a classification value are specified or not in the search request message.
The search condition creation unit 420 proceeds to processing in S446 when the classification type and the classification value are specified, or proceeds to processing in S454 otherwise.
In a step S446, the search condition creation unit 420 sends the classification type and the classification value to the DB management server 5, and determines a top entry of a corresponding subtree.
In a step S448, the search condition creation unit 420 judges whether the subtree has been determined or not in the processing in S446.
The search program 42 proceeds to processing in S450 when the subtree has been determined, or proceeds to processing in S454 otherwise.
In the step S450, the search condition creation unit 420 sends the determined top entry to the DB management server 5, and determines a DB server 6 in which a subtree corresponding to the top entry is stored.
In a step S452, the search condition creation unit 420 sets the determined top entry of the subtree as a search start entry (query base).
In the step S454, the search condition creation unit 420 receives a directory tree table from the DB management server 5, refers to the received directory tree table to set the top entry (root entry) as a query base through the subtrees stored in all the DB servers, and determines a DB server 6 that stores the root entry.
In a step S456, the search control unit 264 obtains data regarding the search request, the query base and the like from the search condition creation unit 420, and creates an LDAP operation command for the determined DB server 6.
in a step S458, the search control unit 264 executes search processing on the DB server 6 by using the created LDAP operation command, and receives and outputs a result thereof.
Hereinafter, the overall process of the search program 42 will be further described in connection with the process of the DB management program 50.
Referring to
In a step S522, the search operation receiver 260 transmits a search request message to the search condition creation unit 420.
In a step S526, the search condition creation unit 420 transmits a classification type and classification value contained in the search request message to the associative data creation and management unit 510 of the DB management program 50.
It is to be noted that the processing in S526 corresponds to the processing of transmitting the classification type/value to the DB management server 5 from the search condition creation unit 420 in the step S446 shown in
In a step S528, the associative data creation and management unit 510 outputs the classification type/value received from the search condition creation unit 420 to the data table management unit 534.
In a step S530, the data table management unit 534 refers to the data table by using the classification type/value input from the associative data creation and management unit 510 to obtain a top entry corresponding to the input classification type/value.
The data table management unit 534 returns the obtained top entry to the associative data creation and management unit 510.
In a step S532, the associative data creation and management unit 510 outputs the top entry obtained in the processing in S530 to the directory tree table management unit 524.
In steps S534 and S536, the directory tree table management unit 524 returns the DB server 6 corresponding to the input top entry through the associative data creation and management unit 510 to the search condition creation unit 420.
In a step S538, the search condition creation unit 420 creates search conditions, and outputs the search conditions together with a name of the determined DB server 6 or the like to the search control unit 264.
In a step S540, the search control unit 264 creates an LDAP command, and accesses the determined DB server 6 to perform search.
In steps S542 to S546, a search result is returned from the DB server 6 and displayed to the user.
Associative Data and Search Example (1) in DB System 4
Hereinafter, how associative data are registered and the registered associative data are retrieved in the DB system 4 will be described by taking a specific example.
In the directory structure shown in
This directory structure is referred to as a “flat directory structure”.
The user performs an operation of sequentially registering associative data with respect to the GUI image (
With this operation, the following data are input to the DB management server 5 in the following form
(association name, association type, name, role):
(authorship of Hamlet, authorship information, Shakespeare, author),
(authorship of Hamlet, authorship information, Hamlet, work),
(authorship of the Merchant of Venice, authorship information, Shakespeare, author),
(authorship of the Merchant of Venice, authorship information, the Merchant of Venice, work),
(Japanese translation of Hamlet, translation information, Hamlet, original work),
(Japanese translation of Hamlet, translation information, Japanese translation of Hamlet, translation),
(Japanese translation of Hamlet, translation information, publication, OO Publishing Company),
As a result of the registration operation by the user, associative data are generated in a directory structure of a DIT form similar to that shown in
It is to be noted that in the directory structure of the DIT form shown in
In this directory structure, entries are disposed below the virtual root entry corresponding to five A nodes (“Authorship of Hamlet”, “Authorship of the Merchant of Venice”, “Japanese Translation of Hamlet”, “Chinese Translation of Hamlet”, and “Performance of Hamlet”; A4, A9, A10, A19, and A13 (see
Additionally, in the directory structure, entries corresponding to association roles of the A nodes are disposed below the entries corresponding to the A nodes, and data regarding T nodes (T41, T42, T92, T101, T103, and T191; see
The associative data shown in
As described above, by registering the associative data below the entries in accordance with the association types (node types), the hierarchical structure is realized based on the association types (node types).
As shown in
That is, “Shakespeare's Work” can be defined as a common theme for the nodes contained in the associative data shown in
In the case shown in
For example, the entry “Shakespeare's Work” and the entries “Authorship of Hamlet (A4)” to “Chinese Translation of Hamlet (A19)” or below are stored as subtrees in the DB server 6-1, and the entries “Performance of Hamlet (A13)” or below are stored as subtrees in the DB server 6-2 or the like, whereby the associative data can be partitioned into subtrees in accordance with the directory structure. The subtrees thus obtained can be partitioned and stored in the DB servers 6-1 to 6-n.
In such a case, the directories of “Shakespeare's Work” and “Performance of Hamlet” are set as top entries, classification types and values are defined for these top entries, the defined classification types and values are managed in the data table shown in
In another example, in the hierarchical directory structure of the associative data shown in
It is to be noted that the top entries are root (top) entries in the subtrees, and thus only one top entry is defined for each subtree stored in the DB server 6. A classification type/value is defined for this top entry.
Thus, in the example shown in
A referring relation of the subtrees thus partitioned is managed by using the directory table shown in
Furthermore, when “Authorship Information” is defined as an association type (node type) for the A4 node (“Authorship of Hamlet”) and the A9 node (“Authorship of the Merchant of Venice”) among the five A nodes shown in
For example, in the hierarchical structure of the associative data shown in
In such a case, the entries of “Shakespeare's Work”, “Translation Information” and “Performance Information” are set as top entries, classification types and values are defined for the top entries, the defined classification types and values are managed in the data table shown in
When the searcher (user) executes the search program 42 (
Furthermore, the search program 42 creates search conditions (command and parameter for LDAP operation) matching the search operation and the tree information, and performs a search in the DB server 6 which stores the directory information matching the search conditions to obtain a search result.
The search result thus obtained is displayed to the user of the search program 42.
Associative Data and Search Example (2) in DB System 4
Hereinafter, how the associative data are registered and the registered data is retrieved in the DB system 4 will be described in more detail by taking a specific example of sales information indicating commercial goods, stores and programs for promoting sale of commercial goods.
By user's operation of the DB management server 5 or the PC 102 shown in
That is, based on the registered data of the associative data input by the user, an entry for integrating directory information regarding “Sales Information” is disposed directly below a virtual root entry. Below this entry, an entry regarding the sales information of “Kanto Region” is disposed.
Regarding the sales information of “Kanto Region”, entries having “Location Information”, “Offer Information” and “Participation Information” as association types (node types) are disposed. Below these entries, entries corresponding to association roles such as “Store”, “Area”, “Offering” and “Organizer” are disposed. As attributes of these entries (attributes are stored in the DB servers 6, but independent management tables are not defined or created to manage the attributes), data regarding members that play roles of “Store A”, “Shinjuku” and the like (corresponding to node IDs and node names of the T node ID table (
It is to be noted that “Role” shown in
In the example shown in
As shown in
Below these entries, entries corresponding to roles of “Store”, “Offering”, “Area”, “Organizer” and the like are disposed. As attributes of the entries, data regarding members which play roles of “Store B”, “Store C”, “Osaka”, “Campaign A” and the like are registered.
For example, the sales information shown in
The top entries and the referring entries of the sales information stored in the DB servers 6-1 to 6-3, the top entries of the partitioned directory tree (or subtree), and the classification type/value of the directory information stored in the subtree are managed by the DB management server 5 based on the directory tree table and the data table shown in
The GUI image shown in
Search for Sales Information of Only Kanto Region
To begin with, search for the sales information of only the Kanto region shown in
It is to be noted, however, that
The searcher (user) performs an operation of search for, for example, “stores affiliated with store B through participation in a certain sales program in Kanto region” on the GUI image (
For example, as shown in
Further, the retrieval device 40 searches for contents of the directory tree table (
It is to be noted that
The LDAP operation (LDAP command and parameter) for searching for “stores affiliated with store B through participation in certain sales program in Kanto region” is generated from the search conditions input by the operator, the top entry of the subtree obtained from the tree information, and the information indicating its storage in the DB server 6-2 (B), and search is performed in the DB server 6-2 (B).
(1) Entries whose lower entry “Role” is “Participant” and whose lower entry “Member” is “Store B” are obtained from all the entries in which “Association type” (node type of A node shown in
As a result of this processing, “Program A” is obtained as a sales program in which the store B participates.
(2) Entries whose lower entry “Role” is “Organizer” and whose lower entry “Member” is “Program A” are obtained from all the entries in which “Association type” is “Participation Information”, and member attribute values (member names) are obtained from those of the lower entries in which “Role” is “Participant”.
As a result of this processing, “Store A” and “Store B” are obtained as stores which participate in the sales program “Program A”. The retrieval device 40 selects “Store A” different from “Store B” contained in the contents of the search operation (
Searching for Sales Information of in Specific Areas
Next, searching for the sales information of the Kanto and other regions shown in
The searcher (user) performs an operation of searching for, for example, “stores participating in campaign in which store A participates by offering commercial goods irrespective of regions (in all regions)” on the GUI image (
The retrieval device 40 analyzes contents of searcher's search operation, and searches the data table (
Further, the retrieval device 40 searches the directory tree table (
An LDAP operation (LDAP command and parameter) for search for “stores participating in campaign in which store A participates by offering commercial goods irrespective of regions (in all regions)” is generated from the search conditions input by the operator, the top entry obtained from the tree information, and the information indicating its storage in the DB server 6-1 (A), and search is performed in the DB server 6.
The LDAP operation includes the following search operations.
(1) Entries whose lower entry “Member” is “Store A” and whose lower entry “Role” is “Offeree” are obtained from all the entries in which “Association type (node type of A node shown in
As a result of this processing, “Commercial Goods A” are obtained as commercial goods offered by the store A.
(2) Entries whose lower entry “Member” is “Commercial Goods A” and whose lower entry “Role” is “Participant” are obtained from all the entries in which “Association type” is “Participation Information”, and member attribute values (member names) are obtained from those of the lower entries in which “Role” is “Organizer”.
As a result of this processing, “Campaign A” is obtained as a campaign program to which the commercial goods A are offered.
(3) Entries whose lower entry “Member” is “Campaign A” and “Role” is “Organizer” are obtained from all the entries in which “Association type” is “Participation Information”, and member attribute values (member names) are obtained from those of the lower entries in which “Role” is “Participant”.
As a result of this processing, the retrieval device 40 retrieves “Commercial Goods A” and “Commercial Goods C” as commercial goods offered by the store which participates in the campaign A.
(4) Entries whose lower entry “Member” is “Commercial Goods A” and whose lower entry “Role” is “Offering” or whose lower entry “Member” is “Commercial Goods C” and whose lower entry “Role” is “Offering” are obtained from all the entries in which “Association type” is “Offer Information”, and member attribute values (member names) are obtained from those of the lower entries in which “Role” is “Offeree”.
As a result of this processing, “Store A” and “Store C” are obtained as stores for offering the commercial goods A and C to the campaign A, and the retrieval device 40 selects, out of “Store A” and “Store C”, the “Store C” different from the “Store A” contained in the contents of the search operation (
Dynamic Modification of Directory Structure and Load Distribution Among DB Severs
As described above, in the DB system 4 (
Thus, in the DB system 4, for example, even when access to a certain entry stored in the DB server 6 becomes excessive for one reason or another, measures are easily taken for load distribution such as addition of a replica server (mirror server) for storing the entry, and transfer of the entry and its subordinate entries (set of a certain entry and its subordinate entries may be referred to as subtree, hereinafter) together to the other DB server 6.
Hereinafter, description will be made of a dynamic modification of the directory structure and a subtree exchange/movement that are suited to load distribution among the DB servers 6 and prevention of a degradation in system performance of the DB system 4 by using the features of the DB system 4.
The following method is employed for the dynamic modification of the directory structure, and the subtree exchange/movement among the DB servers 6 in the DB system 4:
(1) creation of new subtrees (provision of new subtrees) in the same DB server 6, and
(2) transfer of subtrees from the high-load DB server 6 to the low-load DB server 6, or exchange between a frequently accessed subtree of the high-load DB server 6 and an infrequently accessed subtree of the low-load DB server 6 (subtree exchange/movement).
Provision of New Subtree
To begin with, provision of new subtrees in the DB system 4 will be described.
Consideration will be given to a case, as shown in
It is to be noted that the filter queryFiler corresponds to search conditions of the LDAP, and conditions of “Role”=“Offering”, “Member”=“Commercial Goods C” and the like constitute a filter queryFiler in the search operation described thus far.
In the filter queryFiler, complex conditions can be represented by a logical product of some conditions.
The DB server 6 counts the number of times of matching of each entry with the search conditions for each search operation, and results of such counting are totaled in the DB management server 5, whereby a set of frequently accessed entries and superordinate entries thereof can be obtained under specific search conditions.
For example, in the directory structure before the provision of the new subtree (
When such access concentration is detected, a superordinate entry (groupDN) is provided to a set of the access-concentrated entries, and those entries are built up as a new subtree. Thus, access to the entry set can be localized, and a degradation in performance of the DB system can be prevented.
Furthermore, preparation can be made for moving the access-concentrated subtrees between one DB server 6 and the other.
When a subtree is newly created by providing the superordinate entry (groupDN), the DB management server 5 (
In the case of receiving the search condition management table to create search conditions, when search including above-mentioned specific filter (queryFilter) as a logical product in its query filter occurs in the subtrees below the changed entry (query base: queryBaseDN), the retrieval device 40 performs the search by using filters excluding the specific filter (queryFilter) not for the subtrees below the original search starting entry (query base; queryBaseDN) but for subtrees below a newly-created search starting entry (new query base; groupDN). Accordingly, it is possible to shorten a time necessary for the search.
When the filter does not contain the specific filter (queryFilter), the original entry (queryBaseDN) is set as a search starting entry, and search is performed in a range of all the subordinate subtrees.
After the provision of new subtrees, as in the case of not using the search condition management table, when a top entry for search cannot be obtained from the data table (
Movement/Exchange of Subtree
FIGS. 53(A) and 53(B) exemplify subtree exchange/movement between the DB servers 6-1 and 6-2 (A and B) of the DB system 4 shown in
Consideration will be given to a case, as shown in
The number of times of access to each entry is counted by the DB server 6, and results of such counting are totaled by the DB management server 5, whereby a frequently accessed subtree can be obtained. Simultaneously, a loading state of the DB server 6 can be obtained. Additionally, a subtree on which access concentrates can be obtained by using the search condition management table shown in
When such access concentration (nonuniformity) is detected, as shown in
However, considering access concentration/nonuniformity at a macro level (e.g., case in which the number of times of being searched is small, thereby lowering of access and load), it is not always necessary to use the search condition management table for the subtree movement/exchange.
The provision of new subtrees (search condition management table) is designed to achieve a high speed (high efficiency) of search processing thereafter in accordance with a degree of access concentration under specific search conditions which has occurred until a certain point of time.
On the other hand, the subtree movement/exchange solves a problem that considerably uneven distribution of loads occurs due to an increase/decrease in the absolute number of times (frequency) of access to each server or subtree not dependent on search conditions or not limited to specific search conditions.
It is to be noted that such subtree exchange is carried out for the subtrees newly provided as shown in FIGS. 51(A) and (B) and the existing subtrees.
When the updating is performed, the DB management server 5 updates the contents of the directory tree table for the DB servers 6-1 and 6-2 (A and B) as shown in FIGS. 54(A) and (B) (in this case, however, there is no change in the contents of the directory tree table for the DB server 6-1 (A)).
For example, when access concentrates on the directory dn_1 of the DB server 6-1 (A) shown in
The aforementioned subtree movement/exchange is performed in accordance with the following procedure.
(1) Measurement of access frequency: the DB server 6 measures the numbers of times (frequencies) of access to the entries from entry directly below the virtual root entry to entry in an upper position by one layer the first level of the basic component (
(2) Selection of subtree of movement/exchange source: when considerably uneven access (concentration) to subtrees below a plurality of entries belonging to the same level is detected in each DB server 6, the DB management server 5 selects subtrees below the entries as subtrees of the movement/exchange source.
(3) Selection of DB server of movement/exchange destination: upon the selection of the subtree of the movement/exchange source, the DB management server 5 selects the other DB server 6 in which the subtrees of the movement/exchange source are not stored as subordinate entries and whose access frequency (load) is lower as a whole than that of the DB server 6 which has stored the subtrees of the movement/exchange source.
Third DB Program 62
Referring to
With these components, the DB program 62 realizes functions necessary for provision of new subtrees and movement/exchange in addition to the functions similar to those of the second DB program 60.
In the DB program 62, the data transmission unit 620 transmits the associative data necessary for subtree movement/exchange shown in FIGS. 53(A) and 53 (B) according to control from the DB management server 5.
The access monitoring unit 624 measures the number of times (frequency) of access to each entry of the directory information stored in the DB server 6, and transmits the measured value to the DB management server 5.
Second DB Management Program 56
Referring to
With these components, the DB management program 56 realizes functions necessary for provision of new subtrees and movement/exchange in addition to the functions similar to those of the first DB management server 50.
In the DB management program 56, the DB monitoring unit 570 totals the number of times (frequencies) of access to entries sent from the DB servers 6 and data (query base, and filter) regarding the search operation of the LDAP used for the access, and stores the totaled value in the monitoring DB 572.
The DB monitoring unit 570 outputs the stored totaled value of the access frequencies and the data regarding the search operation to the reconfiguration process unit 560.
The reconfiguration process unit 560 controls the data transfer control unit 562 in accordance with the totaled value of the number of times of access to the entries input from the DB monitoring unit 570, and performs processing for the provision of new subtrees shown in FIGS. 51(A) and (B).
The reconfiguration process unit 560 controls the data transfer control unit 562 in accordance with the totaled value of the number of times of access to the entries, and performs processing necessary for the movement/exchange of subtree shown in FIGS. 53(A) and (B).
Moreover, the reconfiguration process unit 560 controls the data table management unit 534 to perform processing necessary for the modification of the directory tree table (
The search condition management unit 580 creates the search condition management table shown in
Additionally, the search condition management unit 580 outputs the stored search condition management table to the search condition provision unit 584.
The search condition provision unit 584 provides the search condition management table input from the search condition management unit 580 to the retrieval device 40 (search program 44;
Hereinafter, the counting of the numbers of accessing times will be described in more detail.
Referring to
In a step SS562, the DB monitoring unit 570 starts measurement of the number of times of access to each entry of the DB server 6.
In a step S564, the DB server 6 receives an LDAP search operation command from the search control unit 264.
In a step S566, the DB monitoring unit 570 retrieves search conditions contained in the search operation command input to the DB server 6.
In a step S568, the DB monitoring unit 570 retrieves data of entries matching search conditions from the DB server 6.
It is to be noted that the processing in S564 to S568 is carried out for totaling data regarding the search operation performed by the DB server 6, and the totaled value is sent from the DB server 6 to the DB monitoring unit 570.
In a step S570, the DB monitoring unit 570 judges whether a predetermined measuring time for totaling the data regarding the search operation has elapsed or not.
The DB management program 56 proceeds to processing in S572 if the measuring time has elapsed, or proceeds to processing in S564 otherwise.
In a step S572, the DB monitoring unit 570 ends the measurement of the number of accessing times.
In a step S574, the DB monitoring unit 570 calculates the numbers of times of access to all the entries and the loading states of all the DB servers 6 during the measuring time from the start to the end of the measurement.
In a step S576, the reconfiguration process unit 560 detects presence of access concentration for all the entries based on the measuring result calculated by the DB monitoring unit 570.
In a step S578, the DB monitoring unit 570 judges whether or not to continue the process.
The DB management program 56 proceeds to processing in S560 if the process is continued, or ends the process otherwise.
For example, access concentration on an entry or a subtree is determined by the following method of (1) or (2).
(1) An access concentration index (access concentration index=number of entries satisfying search conditions/number of entries present at specific level (
When the number of execution times of each search operation is larger than a preset number and a calculated access concentration index is equal to or lower than a threshold value, occurrence of access concentration with respect to the search conditions is determined.
(2) The DB servers 6 that store the partitioned subtrees are set as targets of measurement, the number of times (frequency) of processing in which a top entry of each subtree and all the entries belonging to the same level as that of the top entry are used as query bases in accordance with a search request is set as a frequency of access to the subtree, and access concentration is determined by a method similar to that of (1).
Second Search Program 44
Referring to
The search program 44 transforms the search conditions by using the search condition management table in addition to functions similar to those of the first retrieval device 40.
In the search program 44, the search condition transformation unit 440 receives the search condition management table (
When the filter and the query base contained in the search conditions match the conditions shown in the search condition management table, the search condition transformation unit 440 modifies the original search starting entry (query base; queryBaseDN) to a new search starting entry (new query base; groupDN), and controls the search condition creation unit 420 to transform the filter into a new filter in which the filter (queryFilter) shown in the search condition management table is removed from the filter of the search conditions.
Operation of DB System 4 when Subtree is Newly Created
Hereinafter, an overall operation of the DB system 4 when subtrees are newly created will be described.
As described above with reference to
When such access concentration is determined, by providing a top entry (groupDN) in the set of entries on which access concentrates, and constructing its subordinate entries as a new subtree, it is possible to localize the access to the set of entries and to prevent a degradation in performance of the DB system.
The DB server 6 notifies the DB management server 5 of the number of times of access to each entry and a filter used for the accessing.
The DB management server 5 counts the numbers of times (frequencies) of access to the entries and the filters used for the accessing from the DB server 6.
When access to the subtree of a certain DB server 6 is frequent, as shown in FIGS. 51(A) and (B), the DB management server 5 controls the DB server 6 to create new subtrees.
The DB management server 5 modifies the contents of the search condition management table (
The DB management server 5 provides the modified search condition management table to the retrieval device 40.
When creating search conditions based on the search operation in response to searcher's (user's) search requests, the retrieval device 40 performs transformation by using the search condition management table provided from the DB management server 5, and performs a search in the DB server 6.
Operation of DB System 4 when Subtree is Moved/Exchanged
Next, an overall operation of the DB system 4 when the subtrees are moved/exchanged will be described.
As described above with reference to
The DB server 6 measures the number of times each entry is used as a query base, and notifies the DB management server 5 of the result.
The DB management server 5 counts the number of times each entry is set as query bases for the top entry of each DB server 6 and all the entries of the other DB servers at the same level as that of the top entry, and calculates an access frequency of each subtree.
When access to the subtree of a certain DB server 6 is frequent, as shown in FIGS. 53(A) and (B), the DB management server 5 controls the DB server 6 to move/exchange the subtree.
Additionally, the DB management server 5 modifies the contents of the directory tree table (
The DB management server 5 provides the modified directory tree and data tables to the retrieval device 40.
The retrieval device 40 performs a search in the DB server 6 by using the provided directory tree and data tables in accordance with searcher's (user's) search operation.
It should be noted that although some disclosed embodiments of the present invention are implemented in form of software instructions that are contained in a computer-readable medium and executable by a computer, the present invention is not limited to such arrangement. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, the invention is not limited to any specific combination of hardware circuitry and software.
It should be further noted that the disclosed embodiments of the present invention provide the following advantages.
(1) The disclosed embodiments provide a data model and a database system allowing easy addition of various kinds of information, especially data elements or fields, without the need of changing the schema of the database.
(2) The disclosed embodiments further provide a data model and a database system allowing data to be uniquely parsed, stored and retrieved for reproduction.
(3) The disclosed embodiments also provide a database system and management method and software allowing loads to be easily distributed among a plurality of processing devices.
(4) The disclosed embodiments additionally provide a data model and a database system and management method and software allowing users to search for registered information.
(5) The disclosed embodiments further provide a method of converting preexisting databases to a data model and a database system that allows easy addition of various kinds of information, especially data elements or fields, without the need of changing the schema of the database.
While there have been described and illustrated specific embodiments of the invention, it will be clear that variations on the details of the embodiment specifically illustrated and described may be made without specifically departing from the true spirit and scope of the invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-309439 | Oct 2004 | JP | national |
