JP2716014B2 - Execution object storage method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database system in an electronic computer, and more particularly, to an execution object which is information indicating an access procedure (access method) of a database (single or plural database files) is determined and stored in advance. The present invention relates to an execution object storage method for executing a database access according to an execution object when executing a database access.

[0002]

2. Description of the Related Art In a database system, ISO (I
international Organization
SQL (Structured Query La), which is a standard for standardization
NML and other DMLs (Data Man
ipulation Language. In general, complicated conditions can be specified by using a data manipulation language. However, a process for finding an optimal access procedure from procedures for accessing target data from a database is complicated and requires many processes.

[0003] Here, when technologies in this field are classified from the viewpoint of the timing of executing the processing for finding such an optimal access procedure, there are the following two systems in the prior art.

[0004] The first method is a method for finding an optimal access procedure when executing DML. In this method, DML
Although high-speed execution cannot be expected, there is an advantage that the influence of an environmental change such as a change in data definition can be eliminated.

The second method is a method in which an optimum access procedure is obtained in advance before executing DML, and processing is performed according to the access procedure when executing DML. Information indicating an access procedure used in this method is called an "execution object". Such an execution object is generated in advance and stored in preparation for DML execution, and when the DML is executed, access to the database is performed according to the execution object. Is called an “executable object storage method”.

[0006] The execution object storage method enables high-speed execution of DML, but has a disadvantage that execution objects need to be re-created due to environmental changes such as changes in data definitions.

[0007] The present invention is directed to the above-mentioned "executable object storage method".

Hereinafter, the configuration and operation of the conventional execution object storage method will be described with reference to FIG.

Referring to FIG. 2, a conventional execution object storage method is a DDL (Data Description).
n Language. Data definition language) 201, business program source list 202, object control means 203, business program 204, DDL processor 205, compiler 206, execution object loader 207, directory file 208, execution object library 209, , Execution object 2
10, an object execution unit 211, and a plurality of database files 212 (databases). In FIG. 2, double arrows indicate the flow of processing, and other arrows indicate the flow of information.

Generally, a data group handled by one business program can be divided and stored in a plurality of data files (the "data file" is a concept including a subfile in the file). is there. The "function of dividing a data group into a plurality of data files and storing" in this manner is called a "division function" or a "partitioning function". The execution object storage method targeted in the present specification (the execution object storage method shown in FIG. 1 and FIG. 2)
Is assumed to be applied to a database system having such a function.

In the present specification, a plurality of database files (including subfiles in the database file)
The function of storing a data group by dividing into data ranges is called a “range dividing function”, and each database file or subfile to be divided and stored is called a “range”. In this range division function, in which range certain data is stored is determined by the value of a specific item in the data. This item is called a “range key item”.

The range dividing function will be described below with reference to an example shown in FIG.

In the example shown in FIG.
3 to 305. Here, which of the ranges 303 to 305 stores the data 301 is determined by the value of the range key item 302 which is one of the items of the data 301. In this example, when the value of the range key item 302 is “Tokyo head office”, the data 301 is stored in the range 303, and when the value of the range key item 302 is “Osaka branch office”, the data 3 is stored.
01 is stored in the range 304 and the range key item 302
Is “Nagoya branch office”, the data 301 is stored in the range 305. The range dividing function implements the function of controlling the storage of the data 301 in this way.

The range dividing function is effective when the number of data is large, and has an effect of enabling a degenerate operation when an external storage device fails or a parallel execution when all data are processed.

Next, it is configured as shown in FIG.
The operation of the execution object storage method applied to the database system having the above-described range division function will be described.

The DDL processor 205 interprets the DDL 201 specified by the user (including range definition information that is definition information relating to a range), and based on the interpretation, stores data format definition information (stored in the database file 212). Information indicating the format of the data, including information resulting from the range definition information)
08.

The compiler 206 interprets the business program source list 202 to generate the business program 204, and performs the following processing related to "generation of execution object".

A DML described in the business program source list 202 is obtained.

With reference to the directory file 208, an optimal access procedure for the plurality of database files 212 is determined based on the DML obtained in the above and the data format definition information in the directory file 208.

An execution object having the access procedure determined in step (1) is generated, and the execution object is stored in the execution object library 209.

In this example, the generation of the execution object is performed at the time of compiling the business program source list 202 by the compiler 206. However, the execution object may be generated any time before the execution of the business program 204. In addition, the business program 20
The execution object may be generated by a compiler (such as a precompiler) other than the compiler 206 that generates the execution object 4.

When the business program 204 is started, the object control means 203 is started.

The activated object control means 203
Activates the execution object loader 207 to expand (load) the execution object 210 (the execution object in the execution object library 209) corresponding to the business program 204 in the memory.

When the DML is executed during the execution of the business program 204, the object execution unit 211 is started. The object execution unit 211 accesses a database (a plurality of database files 212) according to the execution object 210.

[0025]

In the above-described conventional execution object storage method, since information resulting from the range definition information is included in the execution object, an environment related to the range is changed (for example, the number of ranges is increased). Is performed, it is necessary to re-create the execution object.

For example, when a conventional execution object storage method is applied to a database system having a range division function as shown in FIG.
To 305 have “base” as the range key item 302 (“base”, “region”, “organization”, and “product group”)
In many cases, items that are meaningful to the user, such as the range key items, are set as range key items. Object 210 needed to be recreated.

More specifically, referring to the example of FIG. 3, when a new base, for example, a Sendai branch office is to be established, it is necessary to add a range corresponding to the Sendai branch office. Had to be recreated.

In particular, when the number of business programs is large, it takes a long time to re-create an execution object, and the above-mentioned problem has become serious.

In view of the above, an object of the present invention is to handle an execution object by dividing it into a range object and a DML object, and to change the range definition information in the DDL by changing the range environment such as adding a range. Even in this case, by eliminating the need to perform the work of recreating the DML object, an execution object storage method that can easily cope with a change in the range environment with respect to the creation of the execution object (join processing of the range object and the DML object ( Object storage method using object merging).

[0030]

According to the present invention, there is provided an execution object storing method, comprising: a database having a plurality of ranges as an area on an external storage device for storing data; and data format definition information relating to data in the database. In a database system comprising: a directory file that is an area on an external storage device for storing data; and a DDL processor that stores data format definition information regarding data in the database in the directory file based on DDL interpretation. A range object library that is an area on the external storage device that stores the object, a DML object library that is an area on the external storage device that stores the DML object, and information indicating the correspondence between the data and the range by the range key item. Ah The DDL processor that generates a range object based on the range definition information described in the DDL and stores the range object in the range object library; a DML described in a business program source list and a data format in the directory file A compiler that generates a DML object based on the definition information and stores the DML object in the DML object library; and, when a certain business program is executed, expands a range object corresponding to the business program from the range object library to a memory. A range object loader, and a DML object loader for expanding a DML object corresponding to the business program from the DML object library into a memory when the business program is executed. An object merging means for combining a range object expanded in memory by the range object loader with a DML object expanded in memory by the DML object loader to generate an execution object; By activating the DML object loader, the DML object corresponding to the business program is expanded in the memory, and by activating the range object loader, the range object corresponding to the data to be accessed by the business program is stored in the memory. Object control means for controlling the generation of an execution object by expanding and activating the object merge means; and a request for accessing the database from a certain business program. An object execution unit that, when received, accesses the database in accordance with an execution object corresponding to the business program.

[0031]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an execution object storage method according to an embodiment of the present invention.

The execution object storage method of this embodiment is as follows.
DDL 101 and business program source list 102
, Object control means 103, business program 1
04, the DDL processor 105, and the compiler 106
, Range object loader 107, DML object loader 108, and object merging means 109
, A directory file 110, a DML object library 111, a range object 112,
DML object 113 and execution object 114
, An object execution unit 115, and a plurality of database files 116 (databases) (the range object 112, the DML object 113, and the execution object 114 are loaded in the memory). In FIG. 1, double arrows indicate the flow of processing, and other arrows indicate the flow of information.

As described above, it is assumed that the execution object storage method of this embodiment is applied to a database system having a "range division function", and each database file 116 corresponds to each range. (Hence, the database is composed of a plurality of database files 116). However, it is also possible to set a sub-file in the database file 116 as a range. In this case, one database file 116 may constitute a database.

In the execution object storage method of this embodiment, the range (here, the database file 11
6) In order to process the DML in parallel for each (to execute a plurality of business programs 104 having different access ranges in parallel), the range object 1 for each range
12 and the execution object 114 are generated, and the object execution unit 115 is activated for each range. However, it is needless to say that the execution object storage method of the present invention can be applied to the case where the execution object 114 is not divided and generated for each range (in this case, the range object 112 and the execution object 114 in FIG. 1). , And the object execution unit 115
Is one for each).

FIG. 4 is a flowchart showing the processing of the object control means 103. This processing includes a range object loader activation step 401, an all range object load completion determination step 402, a DML object loader activation step 403, an object merging means activation step 404, and an all execution object generation completion determination step 405.

FIG. 5 is a diagram for explaining a specific operation of the DDL processor 105 when the range object (the range object 511 in FIG. 5) in the directory file 110 (the directory file 510 in FIG. 5) is initially generated. is there.

FIG. 6 shows a case where the range object (the range object 611 in FIG. 6) in the directory file 110 (the directory file 610 in FIG. 6) is changed (when the range object is changed when the range definition information is added). FIG. 3 is a diagram for explaining a specific operation of the DDL processor 105.

Next, the operation of the execution object storing method of the embodiment constructed as described above will be described.

First, the operation before the execution of the business program 104 will be described.

The DDL processor 105 interprets the DDL 101 specified by the user (including range definition information which is definition information relating to a range), and based on the interpretation, stores the data format definition information (stored in the database file 116). Information indicating the data format, including information resulting from the range definition information)
10 is stored.

At this time, the DDL processor 105 transmits a database (a plurality of database files 11
In the information (execution object) indicating the procedure for accessing (6), a part depending on the range definition information is registered in the directory file 110 as a range object. However, if the DDL 101 specifies the change of the existing data format definition information, the data format definition information and the range object registered in the directory file 110 are changed according to the specification of the DDL 101 (see FIG. 6).

Registration (storage) of a range object
The destination is not limited to the directory file 110 but may be arbitrary (for example, it can be registered in an independent library called "range object library". See the invention of claim 1). However, in the execution object storage method of the present embodiment, it is desirable to manage the data format definition information and the range object in common from the viewpoint of generation management and the like, and the registration destination of the range object is the directory file 110 (“ The “range object library” is realized in an area in the directory file 110).

The compiler 106 interprets the business program source list 102 to generate the business program 104, and performs the following processing related to "generation of an execution object".

The DML described in the business program source list 102 is obtained. Referring to the directory file 110, a plurality of database files 11 are created based on the DML obtained in the above and data format definition information in the directory file 110.
6 is determined as an optimal access procedure (access method).

D having the access procedure determined in
An ML object is generated, and the DML object is stored in the DML object library 111. Here, for the contents related to the range (content depending on the range definition information), the above-described processing is controlled so as not to be included in the DML object (as described above, the content depending on the range definition information is the range). Object).

The generation of the DML object is performed by the compiler 106 in the execution object storage method of this embodiment.
This is performed at the time of compiling the business program source list 102 (at the time of generating the business program 104).
The DML object may be generated by a compiler (a precompiler or the like) other than the compiler 106 that generates the business program 104 from the business program source list 102.

Second, the operation at the time of executing the business program 104 will be described.

The business program 104 activates the object control means 103 at the time of activation.

The activated object control means 103
Performs the following control (see FIG. 4).

First, the range object loader 10
7, the range object 1 for each range for all ranges corresponding to the business program 104
12 is loaded (loaded) into the memory from the directory file 110 (steps 401 and 402).

Next, the DML object loader 10
8, the DML object 113 corresponding to the business program 104 is expanded (loaded) from the DML object library 111 into the memory (step 403).

Further, the object merging means 10
9 is executed for each range object 112, thereby merging each range object 112 and the DML object 113 to generate an execution object 114 for each range for all ranges (step 404).
And 405).

When the business program 104 executes the DML during the execution of the business program 104, the business program 104 activates the object execution unit 115 for each execution object 114.

Each object execution unit 115 accesses a plurality of database files 116 according to the corresponding execution object 114.

Next, referring to FIG. 5 and FIG.
A specific operation of the processor 105 will be described.

First, a specific operation at the time of initial generation of a range object (range object 510) will be described with reference to FIG.

DDL 501 in FIG. 5 is the DDL in FIG.
101 is an example of the relational database, and is composed of database file definition information 502, table definition information 503, and range definition information 504. This DDL 501 is a DDL for generating a database for storing sales information.

The database file definition information 502 includes
Three database files 116 are defined, DBFILE1, DBFILE2, and DBFI, respectively.
It defines the name LE3.

The table definition information 503 defines data called a sales table, and items included in the data are items such as a product name, a sales amount, a sales base, and a sales date.

The range definition information 504 defines the following contents. The data of the sales table is divided into three ranges using the item of the sales base as the range key item. The database files 116 corresponding to each range are DBFILE1, DBFILE2, and DFILE.
BFILE3. DBFILE1, DBFILE2, and DBFI
The range key item values corresponding to LE3 are “Tokyo head office”, “Osaka branch office”, and “Nagoya branch office”, respectively.

Generally, the range definition information can include the following information (range definition information at the time of changing the range object (see FIG. 6).
Some information does not exist). Identification information of the range definition information (range definition information 5
04 “Sales table range”) Data name to be range-divided (“Sales table” in range definition information 504) Range key item value (“Sales base” in range definition information 504) Range for each range Correspondence information between identification information and range key item values (“ran” in range definition information 504)
ge (1) "and" Tokyo Head Office ") Correspondence information between range identification information for each range and a database file name (may be a subfile name) (" range "in range definition information 504)
(1) ”and“ DBFILE1 ”etc.)

When started, the DDL processor 105 generates data format definition information 511 from the database file definition information 502, table definition information 503, and range definition information 504 described in the DDL 501,
The data format definition information 511 is stored in a directory file 510 (an example of the directory file 110 in FIG. 1).
To be stored.

Further, the DDL processor 105 generates a range object 512 from the range definition information 504, and stores the range object 512 in the directory file 510.

Second, with reference to FIG. 6, a specific operation when the range object (range object 610) is changed will be described. Here, an operation procedure when a range object is changed based on the addition of range definition information will be described.

The DDL 601 in FIG. 6 (DDL1 in FIG. 1)
01) includes database file definition information 602 and range definition information 604 as a definition of a relational database change. This DD
L601 is a DDL for adding one more range to the database created as shown in FIG.
It is.

The database file definition information 602 is
One database file 116 is defined and DB
FILE4 is defined.

The range definition information 604 defines the following contents. Add ranges for sales table data. Database file 116 corresponding to the range
Is DBFILE4. The database file 116 (DBFILE
The range key item value corresponding to 4) is “Sendai branch office”.

When the DDL processor 105 is started, the DDL processor 105 follows the directory file 610 according to the database file definition information 602 and the range definition information 604.
The data format definition information 611 in (an example of the directory file 110 in FIG. 1 and corresponding to the directory file 510 in FIG. 5) is changed.

Further, the DDL processor 105 determines the directory file 610 according to the range definition information 604.
Is changed in the range object 612 inside.

At this time, it is needless to say that the contents of the DML object library 111 need not be changed.

[0072]

As described above, according to the present invention, in a database system employing an execution object storage method, execution objects are defined as range objects and DM objects.
When the range definition information in the DDL is changed due to a change in the range environment such as the addition of a range, it is not necessary to re-create the DML object by dividing and handling the LML object. There is an effect that a change in the range environment can be easily handled.

Further, by generating a range object and an execution object for each range and activating the object execution unit for each range (see the invention of claim 2), it is possible to process the DML in parallel for each range. There is an effect that a plurality of business programs having different access ranges can be executed in parallel.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an execution object storage method according to the present invention.

FIG. 2 is a block diagram showing a configuration of an example of a conventional execution object storage method.

FIG. 3 is a diagram for explaining a range division function.

FIG. 4 is a flowchart showing a process of an object control unit in FIG. 1;

FIG. 5 is a diagram for explaining a specific operation of the DDL processor in FIG. 1;

FIG. 6 is a diagram for explaining a specific operation of the DDL processor in FIG. 1;

[Explanation of symbols]

 101, 501, 601 DDL 102 Business program source list 103 Object control means 104 Business program 105 DDL processor 106 Compiler 107 Range object loader 108 DML object loader 109 Object merging means 110, 510, 610 Directory file 111 DML object library 112, 512 612 Range object 113 DML object 114 Execution object 115 Object execution unit 116 Database file 502, 602 Database file definition information 503 Table definition information 504 604 Range definition information 511, 611 Data format definition information

Claims (7)

(57) [Claims] 1. An area on an external storage device for storing data, the database having a plurality of ranges, and an area on the external storage device for storing data format definition information relating to data in the database. In a database system comprising a directory file and a DDL processor for storing data format definition information on data in the database in the directory file based on a DDL interpretation, a range which is an area on an external storage device for storing a range object An object library, a DML object library that is an area on an external storage device for storing the DML object, and information indicating a correspondence between data and a range by a range key item, based on range definition information described in the DDL. hand The DDL processor for generating a range object and storing it in the range object library; and a DML described in a business program source list.
And a compiler that generates a DML object based on the data format definition information in the directory file and stores the DML object in the DML object library, and a range object corresponding to the business program when a business program is executed. A range object loader that expands from a range object library to a memory; a DML object loader that expands a DML object corresponding to the business program from the DML object library to a memory when a certain business program is executed; Object that generates an execution object by combining the range object and the DML object expanded in the memory by the DML object loader. When a certain business program is started, a DML object corresponding to the business program is expanded in a memory by starting the DML object loader, and the business program is accessed by starting the range object loader. A range object corresponding to the data to be developed in the memory, an object control means for controlling generation of an execution object by activating the object merging means, and a request for accessing the database from a certain business program is received. An execution unit for accessing the database in accordance with an execution object corresponding to the business program. 2. A DDL processor for generating a range object for each range, an object merging unit for combining the DML object with a range object for each range generated by the DDL processor, and generating an execution object for each range, 2. The execution object storage method according to claim 1, further comprising an object execution unit that is activated every time. 3. The execution object storing method according to claim 1, wherein the range is a database file. 4. The execution object storage method according to claim 1, wherein the range is a subfile in the database file. 5. The system according to claim 1, wherein the range object library is realized in an area in the directory file, and the data format definition information and the range object are managed in common in the directory file.
Execution object storage method described. 6. The execution object storage method according to claim 3, wherein the range object library is realized in an area in the directory file, and the data format definition information and the range object are managed in common in the directory file. 7. The execution object storage method according to claim 4, wherein the range object library is realized in an area in the directory file, and the data format definition information and the range object are managed in common in the directory file.