JPH0540677A - Index file opening control system - Google Patents

Abstract

PURPOSE:To open only an index file to be used by analyzing an instruction in a user program. CONSTITUTION:An instruction analysis means 2 analyzes the instruction for a data base 5 consisting of a data file d-1 and plural index files i-1 to i-n from a user program handling the data base 5. An index file use decision means 3 decides whether or not an anlyzed instruction is the one to use the index file, and an index fife opening decision means 4 decides whether or not the index file used in the instruction is opened when it is decided that the instruction is the one to use the index file. An index file opening means 6 opens the index file to be used when it is decided that the index file to be used is not opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an index file open control system, and more particularly, in a database system, an index file is used when a user program that handles a database composed of a data file and a plurality of index files uses the index file. Regarding open control system.

[0002]

2. Description of the Related Art Conventionally, in a database system, when an instruction of a user program that handles a database composed of a data file and a plurality of index files is an open instruction that makes the database available, the data constituting the specified database is The file and all index files were open.

[0003]

In the conventional index file open control method described above, even if the user program that handles the database includes only an instruction that uses a part of the index file or an instruction that does not use the index file at all. Since all index files were opened, there was a problem that it took time to open unnecessary index files.

Further, when a failure occurs in one of the index files, even a user program that does not use the failed index file cannot handle the database, and the database cannot be recovered until the failed index file is restored. There was a problem that could not handle.

In view of the above points, an object of the present invention is to provide an index file open control system in which an instruction in a user program is analyzed and only an index file to be used is opened.

[0006]

According to the index file open control method of the present invention, in a database system, an instruction for analyzing an instruction to the database from a user program that handles a database composed of a data file and a plurality of index files. Analyzing means, and index file use determining means for determining whether or not the instruction analyzed by the instruction analyzing means is an instruction for using the index file,
Index file open determination means for determining whether the index file used by the instruction is open when the index file use determination means determines that the instruction uses the index file, and the index file open determination Index file opening means for opening the index file to be used when it is determined by the means that the index file to be used is not opened.

[0007]

In the index file open control system of the present invention,
The instruction analysis means analyzes an instruction for the database from a user program that handles a database composed of a data file and a plurality of index files, and the index file use determination means uses the index file for the instruction analyzed by the instruction analysis means. It is determined whether the index file open determination means is an instruction to use the index file by the index file use determination means and whether the index file used by the instruction is open or not. If the index file open means determines that the index file open determination means does not open the index file to be used, the index file open means opens the index file.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an index file open control system according to an embodiment of the present invention.
The index file open control system of this embodiment is composed of a user program 1, an instruction analysis unit 2, an index file use determination unit 3, an index file open determination unit 4, a database 5, and an index file open unit 6. Has been done.

The user program 1 is a user program that handles the database 5.

The database 5 is a data file d-1.
And a plurality of index files i-1 to i-n (n is a positive integer)
It consists of and.

Referring to FIG. 2, the process of the index file open control method of this embodiment is performed by a database command determining step 20 and an index file use command determining step 21.
A use index file open determination step 22, a use index file open step 23, and an instruction end determination step 24.

Next, the operation of the index file open control system of the present embodiment thus constructed will be described.

First, the instruction analysis means 2 analyzes the instruction described in the user program 1 and determines whether it is an instruction for the database 5 (step 20).

If it is determined that the command is not for the database 5, the command analysis means 2 transfers control to step 24.

When it is determined that the command is for the database 5, the index file use determining means 3 determines that the command for the database 5 is the index files i-1 to i-n.
It is determined whether the instruction uses any one of the above (step 21).

If it is determined that the instruction does not use any of the index files, the index file use determining means 3
Passes control to step 24.

If it is determined that the instruction uses any one of the index files i-1 to i-n, for example, the index file i-1, the index file open determination means 4
It is determined whether or not the index file i-1 to be used is open (step 22).

When it is determined that the index file i-1 to be used is open, the index file open determination means 4 passes control to step 24.

If it is determined that the index file i-1 to be used is not open, the index file opening means 6 opens the index file i-1 to be used (step 23), and the control goes to step 24. hand over.

In step 24, it is judged whether or not the instruction described in the user program 1 is completed. If the instruction is not completed, the control is returned to step 20 and is described in the user program 1. Step 2 for the next instruction
Repeat 0 to 24. If the command described in the user program 1 is completed, the index file open control is completed.

[0022]

As described above, according to the present invention, the instruction in the user program is analyzed to determine whether or not the instruction uses the index file, and only the index file to be used is opened. The effect is that the time required to open an unnecessary index file in the user program is reduced.

Further, since only the index file to be used is opened, even if the database contains a defective index file, a user program that does not use the index file can handle the database. ..

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an index file open control system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the index file open control system of this embodiment.

[Explanation of symbols]

 1 User Program 2 Instruction Analyzing Means 3 Index File Use Determining Means 4 Index File Open Determining Means 5 Database 6 Index File Opening Means d-1 Data Files i-1 to i-n Index Files

Claims (1)

[Claims] 1. In a database system, an instruction analyzing unit for analyzing an instruction to the database from a user program that handles a database composed of a data file and a plurality of index files, and an instruction analyzed by the instruction analyzing unit. Index file use determining means for determining whether the instruction uses the index file, and when the index file use determining means determines that the instruction uses the index file, the index file used by the instruction is opened. The index file open determination means for determining whether or not the index file is open, and the index file open means for opening the index file when the index file open determination means determines that the index file to be used is not open. Index file which is characterized by Pung-control system.