JPH0488532A - Key definition storing system for data base - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a database management system (DBMS),
In particular, it relates to a database key definition storage method that defines a sequence of one or more columns as a composite key.

[Prior Art] As a conventional technology related to a database management system, for example, there is a method of using a composite key consisting of a sequence of multiple columns, as described in "Database System Overview" by C1J, Date (Maruzen Co., Ltd., 1984). Techniques regarding definition methods are known.

On the other hand, the conventional dictionary
), for example, Belkis W, Leong-
A technique described in "Data Dictionary/Directory System" (Ohm Publishing, 1986) co-authored by Hong et al. is known.

This conventional technology stores and manages metadata (hereinafter referred to as definition information) regarding data types, structures, etc. of columns or keys in the dictionary.
Since the formats for describing definition information for columns and keys are different, the definition information for columns and keys is stored and managed in dedicated dictionaries, respectively.

Hereinafter, an example of a database management method according to this type of conventional technology will be explained with reference to the drawings.

FIG. 4 is a block diagram showing an example of a dictionary in a conventional DBMS and a system for managing it, and FIG. 5 is a diagram explaining the structure of a dictionary that stores definition information of tables, columns, and keys. . 4 and 5, 400 is a definition processing section, 41.0 is a control section, 420 is a table definition processing section, 430 is a column definition processing section, 44
0 is the key definition processing section, 500 is the dictionary 1H 51
Q is the table dictionary, 520 is the column dictionary, 5
30 is a key dictionary.

As shown in FIG. 4, the DBMS according to the prior art is composed of a definition processing unit 400 and a dictionary 500, and the dictionary 500 has a dedicated dictionary 51 for storing definition information of tables, columns, and keys.
0, 520, and 530. In addition, the definition processing unit 400 stores these dictionaries 510
Definition processing units 420 to 440 that perform processing for ~530
and a control section 410 that performs overall control.

Dictionaries 510, 520, and 530 that store definition information of tables, columns, and keys store information necessary to define attributes of tables, columns, and keys, respectively, as shown in FIG. has been done. That is, in the table dictionary 510, the name of the table is defined as, for example, "name list", and in the column dictionary 520, the column name of the table 5 is defined.
22, data type 523, etc. are defined.

However, in the aforementioned dictionary, for example, component 533.5 is a column in key dictionary 530.
34 or 535 stores the value of the column name 522, which is a column in the column dictionary 520 for specifying the column, and the respective dictionaries have a reference relationship with each other.

[Problems to be Solved by the Invention] As described above, a DBMS according to the prior art stores key definition information in a dedicated key dictionary 530 and stores column definition information in a dedicated column dictionary 520 for management. are doing. Since the key definition information specifies a sequence of one or more columns, there is a reference relationship between the two dictionaries.

So, for example, row 5 in column dictionary 520
When attempting to modify the value of the column name 522 of 24 from "full name" to "last name", the value of component l in row 536 in the key dictionary 530 also changes from "full name" to "last name". Needs to be fixed. This process must be performed because it is necessary to maintain consistency in the reference relationships between dictionaries.

Processing for this purpose is generally complex and requires a large amount of processing, so in systems where column and key definitions are frequently changed, the processing performance of the entire system is degraded.

That is, in the prior art, dictionaries are provided for each column and key, and the reference relationships between these dictionaries must always be matched, so the size of the entire dictionary becomes large (or small). However, there is a problem in that it is difficult to improve the processing performance of the entire system.

An object of the present invention is to solve the problems of the prior art and reduce the size of the dictionary by merging dictionaries that exclusively store column and key definition information, and organizing and simplifying the structure of the dictionaries. Provides a database key definition storage method that can reduce the amount of time required, facilitate processing when changing column and key definitions, and improve overall system processing performance. It's about doing.

[Means for Solving the Problems] According to the present invention, the object is to store column definition information in a database that stores and manages composite key definition information consisting of one or more column sequences in a dictionary. In the dictionary to be stored, provide an area for storing information that specifies the sequence of one or more other columns in one table as a column attribute, and an area for storing an attribute that specifies whether it is a key or not. This is further achieved by making the area for storing information specifying the sequence of the other columns of the - or more one table into an array type.

Further, the purpose is to provide, as a column attribute, an area for storing a column identifier that specifies the position in the dictionary where the definition information of the column is stored in the dictionary that stores the definition information of the column, and the above-mentioned - This is achieved by storing the column identifier in an area that stores information specifying the sequence of other columns of one or more tables.

[Operation] According to the present invention, by taking the above-mentioned means, dictionaries that were required exclusively for storing column and key definition information are merged, and column and key definition information is stored in one dictionary. This eliminates the need to match reference relationships between different dictionaries, and improves system performance.

[Embodiment] Hereinafter, an embodiment of a database key definition storage method according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, and FIG.
The figure is a diagram explaining the structure of the dictionary, and FIG. 3 is a flowchart explaining the operation.

In FIGS. 1 and 2, 100 is a definition processing unit, 110
1 is a control unit, 120 is a table definition processing unit, 130 is a column definition processing unit, 140 is a key definition processing unit, 200 is a dictionary, 210 is a table dictionary, and 220 is a column dictionary.

An embodiment of the present invention shown in FIG. 1 is a DBMS to which the present invention is applied, which includes a definition processing section 100 and a dictionary 2.
00.

The dictionary 200 includes a table dictionary 210 that stores table definition information, and a column dictionary 220 that stores column and key definition information.

The definition processing unit 100 also includes a table definition processing unit 120 that processes definition information of the table dictionary 210, a column definition processing unit 130 that processes definition information about columns in the column dictionary 220, and a column definition processing unit 130 that processes definition information about columns in the column dictionary 220. It is composed of a key definition processing section 140 that processes definition information, and a control section 110 that controls these processing sections 120 to 140. The control unit 110 controls the activation of each processing unit, etc., in order to maintain the consistency of the reference relationships of each dictionary.

Next, the data structures of the table dictionary 210 and column dictionary 220 will be explained with reference to FIG.

The table dictionary 210 stores table definition information in a two-dimensional table format, and each row defines one table.

Further, the columns of the table dictionary 210 include a table identifier 211 that stores an identifier that identifies a row in the table dictionary 210, and a table name 212 that stores information that identifies a table.
It is composed of etc.

The column dictionary 220 stores column and key definition information in a two-dimensional table format, and each row defines one column.

The columns of the column dictionary 220 also include a column identifier 221 that stores an identifier that identifies a row in the column dictionary 220, a column name 223 that stores information that identifies the column, and information that identifies the table to which the column belongs. Table identifier to be stored 22
2. a data type 224 indicating the type of value stored in the column;
a key attribute 225 that stores an attribute that specifies whether the column is a key; and, if the column is a composite column consisting of a sequence of one or more columns, information that specifies the sequence of columns. It is composed of array-type components 226 and the like that are stored in a one-dimensional array.

Next, the process of defining a key using the column dictionary 220 in an embodiment of the present invention configured as described above will be described with reference to the flow shown in FIG.

(1) The operator who performs the definition operation inputs, as key information, a column name list consisting of a table name, a key name, and one or more column names that specify the constituent elements of the key (step 301).

(2) The control unit 110 starts the table definition processing unit 120,
The table dictionary 210 is searched using the table name, and table definition information is read. In this processing, if the input table name is not in the dictionary, abnormal termination is executed (steps 302 and 316).

(3) In step 302, if there is table definition information and the table definition information is read, the column dictionary 220 is searched using the table identifier 211 of the read table definition information and the key name, and the existing column Load definition information. In this process, if there is definition information for an existing column, the process moves to step 313, which will be described later (step 303).

(4) In the process of step 303, if there is no existing column definition information, set the table identifier 222 in the new column definition information to the table identifier 211 of the table definition information read in step 303 (step 304) .

(5) Set the key name in the column name 223 of the new column definition information, and set "compound type" in the data type 224 of the new column definition information. Furthermore, set O to counter i,
Initialize the counter (steps 305-307).

(6) Add 1 to the value of the counter l, search the column dictionary 220 using the table identifier 211 of the table definition information read in step 303 and the first column name in the column name list, and define the member column. Load information. In this process, if the definition information of the member column is not in the column dictionary, abnormal termination is executed (steps 308.309.3).
16).

(7) In step 309, if the definition information of a member column exists in the column dictionary and the definition information of this member column is read, the member column read in step 309 is added to the first component 226 of the new column definition information. The column identifier 221 of the definition information is set (step 310).

(8) Next, the value of counter 1 is compared with the number n of constituent elements of the column list, and if l is smaller than n, the process from step 308 is repeatedly executed, and the column name forming the column list is The column names are converted into column identifiers by the number of column identifiers (step 311).

(9) In step 311, if l is greater than n, that is, after all column names have been converted to column identifiers, the column that specifies the position where the new column definition information is stored from the management information of the column dictionary 220. Obtain the identifier and set the new column definition information to the column identifier 221 (step 312)
.

(10) Set the key attribute 225 of the new column definition information set in step 312 or the existing column definition information read in step 303 to "YES". This step updates the definition information of an existing column or creates the definition information of a new column (Step 3
I3).

(+1) Write the new or existing column definition information to a predetermined position in the column dictionary 220 specified by the column identifier 221 of the new or existing column definition information, and successfully process the key definition operation. End (steps 314 and 315).

According to the embodiment of the present invention described above, the key definition information stored in the conventional key dictionary is edited as column and key definition information in a format that corresponds to the columns that constitute the key, and the key definition information is stored in the column dictionary 220. Since it is stored in
A key dictionary can be made unnecessary.

This organizes and simplifies the structure of the dictionary,
Dictionary size can be reduced. Further, when changing the definition of a column or key, the consistency of reference relationships can be easily maintained, and the amount of processing required for this purpose can be reduced.

Furthermore, according to the embodiments of the present invention, by changing the handling of keys from entities to column attributes, the correspondence between columns and keys is simplified, and the system becomes more operable and flexible with respect to changes in column and key definitions. can be improved.

[Effects of the Invention] As explained above, according to the present invention, the structure of the dictionary can be organized and simplified, the size of the dictionary can be reduced, and the consistency of reference relationships between column and key definitions can be easily maintained. can be maintained, the amount of processing can be reduced, and the operability and flexibility of the system with respect to changes in column and key definitions can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, and FIG.
The figure is a diagram explaining the structure of the dictionary, Figure 3 is a flowchart explaining the operation, and Figure 4 is a diagram explaining the structure of the dictionary.
FIG. 5 is a block diagram showing an example of a dictionary in a BMS and a system for managing it. FIG. 5 is a diagram illustrating the structure of a dictionary that stores definition information of tables, columns, and keys. 100...Definition processing unit, 110...Control unit, 120...Table definition processing unit, 130...
Column definition processing unit, 140...Key definition processing unit, 2
00...Dictionary, 210...
Table dictionary, 220... Column dictionary. Figure 1 Figure 2 100: Definition processing unit 200: Dictionary diagram 500: Dictionary diagram

Claims (1)

[Claims] 1. In a database that stores and manages definition information of a composite key consisting of a sequence of one or more columns in a dictionary, in a dictionary that stores column definition information, column attributes are stored. The column is characterized by comprising an area for storing information specifying the sequence of other columns of one or more self-tables, and an area for storing an attribute specifying whether the column is a key or not as an attribute of the column. Key definition storage method for the database. 2. The key definition storage method for a database according to claim 1, wherein the area for storing information specifying the sequence of other columns of the one or more self-tables is of an array type. 3. The dictionary that stores the definition information of the column has, as a column attribute, an area that stores a column identifier that specifies the position in the dictionary where the definition information of the column itself is stored; 3. The key definition storage method for a database according to claim 1, wherein the column identifier is stored in an area that stores information specifying sequences of other columns in a table.