JP2836093B2 - Database search device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database search apparatus, in particular, a relational database search for extracting a field from a plurality of physical files and performing a conditional search of a virtual file created by a joining operation. Drain the device.

[Conventional technology]

Conventionally, this type of database search apparatus generates a physical file of a real image file of a virtual file from a first physical file and a second physical file by a combining operation as shown in FIG. Is searched for.

[Problems to be solved by the invention]

In the above-described conventional database search device, since the physical file of the real image of the virtual file is generated, the capacity of the physical file may become enormous.
When the capacity of the physical file is large, there is a disadvantage that a large amount of auxiliary storage area for storing is required. In addition, since the condition search process is executed by accessing the generated physical file, there is a disadvantage that the time required for the condition search process increases as the capacity increases.

[Means for solving the problem]

The relational database search device according to the present invention is capable of extracting a field from a plurality of physical files and performing a condition search on a virtual file created by a combining operation. A search condition specification field setting means for setting a field to be set, and an image of a field set by the search condition specification field setting means in the virtual file and position information of a record of a physical file corresponding to a record of the virtual file. A real image file generating means for generating a physical file of a real image of a virtual file, and a search processing means for performing a conditional search by accessing the physical file generated by the real image file generating means. .

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which a combining operation is performed on a first physical file 31 and a second physical file 32, and respective fields are extracted into a virtual file 51 created. 14 shows a case where a condition search process is performed. FIG. 1 has a search condition specification field setting mechanism 1, an actual image file generation mechanism 2 and a search processing mechanism 3, and when performing a condition search process, first, prior to the processing, the search condition specification field setting mechanism 1 Then, the user is caused to set a search condition specification field 11 for which field of the virtual file 51 to specify the search condition, and the search condition specification feed setting information 21 is stored in the storage device. Next, the real image file generation mechanism 2 executes the first physical file
31 and the second physical file 32 are accessed, and the search condition specification field setting information in the record of the virtual file 51
A real image file 41 including a field image of a field indicated by 21 and positional information of records of the first physical file 31 and the second physical file 32 corresponding to the record of the virtual file 51 is generated on the auxiliary storage device.
Next, the search processing mechanism 3 receives the search condition 12 from the user, accesses the real image file 41, performs a search process, and stores the search result information 22 in the storage device or the auxiliary storage device. As a result of this search, when information of another field is required, the first and second physical files 31 and 32 are referred to from the record position information.

FIG. 2 is an example of a real image file in FIG. 1 and a first physical file as a search condition designating field.
Field 11 of 31 and field 22 of the second physical file 32
This shows a case where is set. As shown in this example,
The image of the field stored in the real image file 41 is only the image of the field set as the search condition specification field and the record number of the corresponding physical file, and the size of the real image file is shown in FIG. Smaller than real image files. Since the search process is performed by accessing the real image file, the present invention, in which the real image file is small, can be performed faster than the conventional case.

〔The invention's effect〕

As described above, the present invention provides a relational beta-based search processing apparatus capable of performing a conditional search of a virtual file created by extracting fields from a plurality of physical files and performing a joining operation. A search condition specification field setting mechanism for setting a field to be set, an image of a field set as a field for specifying a search condition among records of the virtual file, position information of a record of the physical file corresponding to the record of the virtual file, and By having a real image file generating mechanism for creating a physical file of a real image of a virtual file consisting of a virtual file and a search processing mechanism for performing a search process, the size of the real image file for performing the search process is made larger than in the conventional method. Can be made smaller, reducing the amount of auxiliary storage used. Come, there is an effect that can further perform a search processing at high speed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of one embodiment of the present invention, FIG. 2 is a format diagram of an example of a real image file of FIG. 1, and FIG. 3 is an example of a real image file generated by a conventional database search device. FIG. 1 ... search condition specification field setting mechanism, 2 ... real image file generation mechanism, 3 ... search processing mechanism, 31 ... first physical file, 32 ... second physical file, 41 ... real image file, 51 … Virtual files.

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 17/30 JICST scientific and technical literature file

Claims (1)

(57) [Claims] 1. A virtual file created by combining fields by extracting fields from a plurality of physical files.
In a relational database search apparatus capable of performing a condition search, a search condition specification field setting means for setting a field for specifying a search condition, and a search condition specification field setting means of a virtual file. Real image file generating means for generating a physical file of a real image of a virtual file comprising field image and position information of a record of a physical file corresponding to a record of the virtual file; and a physical file generated by the real image file generating means. A database search device comprising: search processing means for performing a condition search by accessing a file.