JPH0612455A - Record retrieval device - Google Patents

Abstract

PURPOSE:To provide the record retrieval device where the retrieval time is not extended regardless of increase or reduction of the number of records in a file. CONSTITUTION:This device consists of a file storage means 4 where retrieval object files are stored, a specific item retrieval and extraction means 2 which rerieves and extracts a specific item from retrieval object files stored in the file storage means 4, a comparison file selecting means 1 which selects a file to be compared from files extracted by the specific item retrieval and extraction means 2, and a file comparing means 3 which compares the file selected by the comparison file selecting means 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a record search device, and more particularly to a record search device for a plurality of files.

[0002]

2. Description of the Related Art In a conventional record search apparatus, when a record matching a specified search keyword or search condition is searched and extracted from a plurality of files, the search time of each search target file is minimized in advance. The target records were extracted while sequentially comparing in the order set so that the comparison result was created as an intermediate file.

[0003]

However, in the above-mentioned conventional example, since the comparison order of the respective files to be searched is determined in advance, when the comparison order is set, the search time is optimized so as to be the minimum. However, if the number of records in each file increases or decreases, the search time becomes long.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a record retrieving apparatus which improves the inconvenience of the conventional example, and in particular does not cause a delay in retrieval time even if the number of records in a file increases or decreases.

[0005]

Therefore, according to the present invention, there is provided a file storage means in which a file to be searched is stored,
A specific item search / extractor for performing a search / extraction for a specific item with respect to the search target file stored in the file storage unit, and a comparison for selecting a file to be compared from the files extracted by the specific item search / extractor The file selection means and the file comparison means for comparing the files selected by the comparison file selection means are provided. This aims to achieve the above-mentioned object.

[0006]

The specific item search and extraction means performs the search and extraction for the specific item for all the search target files stored in the file storage means. The comparison file selection means is
Files are selected from the files extracted by the specific item search / extraction means in order of increasing number of racodes. The file comparison means compares the files in the order selected by the comparison file selection means, and extracts the target record.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment shown in FIG. 1, a file storage unit 4 in which a search target file is stored, and a specific item search / extract unit 2 that searches and extracts a specific item from a search target file stored in the file storage unit 4. , A comparison file selecting means 1 for selecting a file to be compared from the files extracted by the specific item searching and extracting means 2 and a file comparing means 3 for comparing the files selected by the comparison file selecting means 1. When,
The output means 5 outputs the search / extraction result of the file comparison means 3. Here, the comparison file selection means 1 has a function of sequentially selecting the files extracted by the specific item search extraction means 2 from the file having the smallest number of records. Further, it is assumed that the file storage means stores four files A, B, C, and D as search target files, as shown in FIG. The search target file A is composed of a plurality of records having the common items a, b, c, and d, and the search target file B is composed of a plurality of records having the common items a, h, and f. The target file C is composed of a plurality of records having common items A, G, C, and R, and is a search target file D.
Is composed of a plurality of records having common items a, n, le, and w. Next, the operation of this embodiment will be described. Here, a case will be described in which item A is used as a search keyword and records that are common to all files are extracted. ． First, the specific item search / extract unit searches the file A stored in the file storage unit under the condition of the specific extraction item, and as shown in FIG. 3, a record group (numbers 1, 2, 3) that matches the condition. , 4, 6) is a file a. Next, the specific item search / extract unit searches the file B stored in the file storage unit under the condition of the specific extraction item, and as shown in FIG. 3, a record group (numbers 2, 3) that matches the condition. , 4, 5, 6, 7, 8,
Let 9) be a file b. Further, the specific item search / extracting unit searches the file C stored in the file storage unit under the condition of the specific extraction item, and as shown in FIG. 3, a record group (numbers 1, 2, 4) that matches the condition. ，
6, 7, 8, 10, 11, 12, 13) is a file c. Subsequently, the specific item search / extract unit searches the file D stored in the file storage unit under the condition of the specific extraction item, and as shown in FIG. 3, a group of records (numbers 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 20, 30, 40) is a file d. Here, assuming that the number of records in the file a is [a], the number of records in the file b is [b], the number of records in the file c is [c], and the number of records in the file d is [d], as shown in FIG. And [a] <[b] <[c] <[d]. ． The comparison file selection means finds one of the files to be compared first among the files a, b, c and d created by the specific item search / extraction means. Here, in the files a, b, c, and d, the number [x] of the final search target records when the record having the common item a is searched is [x] ≦ [a] <[b] <[ There is a relationship of c] <[d]. Since the processing time is shorter when the number of records to be searched is smaller, the file a having the record number closest to the number [x] of the last extracted records is selected as one of the first files to be compared. . Further, the comparison file selection means obtains another file to be compared with the file a. Here, the probability that the file a is included in the file b is {a−b}, the probability that the file a is included in the file c is {a−c}, and the probability that the file a is included in the file d is {a−d}. When these are expressed, since these have a relation of {ab} <{ac}} {ad}, the file b that is the combination to be extracted in the most squeezed state is selected first. ． The file comparison means compares the file a and the file b as shown in FIG. 3, and creates the file ab.
Here, the file ab is composed of a record group of numbers 2, 3, 4, and 6. ． The comparison file selection means selects the file c as a file to be compared next. ． The file comparison means compares the file ab and the file c as shown in FIG. 3, and creates the file abc. Here, the file abc is composed of a record group of numbers 2, 4, and 6. ． The comparison file selection means selects the file d as a file to be compared next. ． The file comparison means compares the file abc with the file d as shown in FIG. 3, creates the final extracted file x, and outputs it to the output means 5. Here, the file x is composed of a record group of numbers 2, 4, and 6. In other words, the file with the smallest number of records as a result of searching with the condition of the specific extraction item of each search target file,
Then compare the file with the fewest records first,
The first intermediate file created is compared with the file with the next smallest number of files, a second intermediate file is created, and the final search target record is determined by repeating the sequential comparison until the final search target file. Extract. In this way, the records can be automatically searched under the optimum conditions by sequentially comparing the files with the smallest extraction results.

[0008]

Since the present invention is constructed and functions as described above, according to the present invention, it is possible to automatically perform a record search under the optimum conditions automatically, and therefore, even if the number of records in a file increases or decreases. It is possible to provide an unprecedented excellent record search device that does not cause a delay in search time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the embodiment of FIG.

FIG. 3 is an explanatory diagram showing another operation of the embodiment of FIG.

[Explanation of symbols]

 1 comparison file selection means 2 specific item search extraction means 3 file comparison means 4 file storage means 5 output means

Claims (2)

[Claims] 1. A file storage unit in which a search target file is stored, a specific item search and extraction unit that searches and extracts a specific item from a search target file stored in the file storage unit, and the specific item search. A comparison file selection means for selecting a file to be compared from the files extracted by the extraction means, and a file comparison means for comparing the files selected by the comparison file selection means. Record retrieving device. 2. The record according to claim 1, wherein the comparison file selection means has a function of sequentially selecting files having a smaller number of records among files extracted by the specific item search / extraction means. Search device.