JPH0447367A - Data base retrieval system - Google Patents

Abstract

PURPOSE:To shorten the data base retrieval time by constituting a system so that the retrieval processing time is dependent upon the frequency in data update of a data base with respect to the data base retrieval processing. CONSTITUTION:A retrieval processing means 3 is started by a retrieval request from a user and searches a retrieval condition from a retrieval condition stack table 4 to get the designated retrieval condition and updates only data satisfying the gotten retrieval condition at the time of reading in data of a journal file 6 to update data in a retrieval result storage file 5. After the update of the retrieval result storage file 5, data in the retrieval result storage file 5 is transferred to the user as the retrieval result. Thus, the number of data updated in the period from preceding retrieval to next retrieval is normally smaller than that stored in the data base when the data base having a large number of data is frequently retrieved in the same condition, and therefore, the data base retrieval time is shortened.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a database search method.

[Conventional technology]

In conventional database search processing, journal files are used as a means of recovery in the event of a database failure. Furthermore, although there is a function to stack frequently used search conditions or search processing procedures, each time a user makes a search request, data in the database is accessed to obtain data that satisfies the search conditions.

[Problem to be solved by the invention]

The above-described conventional database search method has the disadvantage that the database search process takes time depending on the number of data items stored in the database.

[Means to solve the problem]

The database search method of the present invention includes a journal file that manages an updated image each time a specified database is updated, a search condition stack table that manages search conditions specified by the user, and a search condition stack table that manages search conditions specified by the user. It has a search result storage file in which data of the results of searching the database is stacked, a search condition registration means, and a search processing means, and the search condition registration means is activated by a search condition registration request from a user, The specified search condition is registered in the search condition stack table, the database is searched, and data matching the search condition is stored in the search result storage file, and the search processing means is activated by a search request from the user. , When searching for search conditions from the search condition stack table to obtain the specified search conditions, reading the data in the journal file and updating the data in the search result storage file, only the data that matches the obtained search conditions are updated. However, once the search result storage file has been updated, the data in the search result storage file is passed to the user as the search result.

〔Example〕

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

Referring to FIG. 1, one embodiment of the present invention includes an input/output device 1
, search condition registration means 2, search processing means 3, search condition stack table 4, search result storage file 5, journal file 6, and database 7.

FIG. 2 is a flowchart showing the operation of the search condition registration means 2. Referring to FIG. 2, search condition registration means 2
receives the search condition, search condition identifier, search database identifier, and search result storage file name and stores them in the search condition stack table 4 (Step 101), and sets the current date and time to the latest search date and time in the search condition stack table 4. settings (step 102>, then search the designated database 7 according to the search conditions, and store data matching the search conditions in the search result storage file 5 (step 103)) The process ends.

FIG. 3 is a flowchart showing the operation of the search processing means 3.

Referring to FIG. 3, the search processing means 3 first receives a search condition identifier (step 201), and then extracts the first search condition from the search condition stack table 4 (step 202).

Compare the specified search condition identifier with the retrieved search condition (step 203), and if they are different, check whether the search condition exists in the search condition stack table 4 (step 204); if there is, check the search condition stack table 4. Step 205 of retrieving the next search condition from
The process of step 203 is performed again. If it does not exist, an error will occur.

If they are the same in step 203, obtain the search conditions, search database identification name, search result storage file name, and latest search date and time from the search condition stack table 4.Step 2
06) Read journal file 6 (step 207).

Check whether the updated data read is from the search database and the update date and time is after the latest search date and time.Step 208
), if it is after the latest update date and time, it is checked whether the update type is addition (step 209).

If it is not an addition (i.e. a deletion or modification), then
Check whether there is corresponding data in the search result storage file 5 (step 210), and if there is, delete that data from the search result storage file 5 (step 211).
).

Furthermore, check whether the update type is deleted or not.Step 212
), in the case of deletion, check whether the following data exists in the journal file (step 213), if so,
Processing is performed again from step 207, and if there is no data, the update date and time of the updated data after i& of journal file 6 is set to the latest search date and time of search result storage file 5 (step 214), and then the data of search result storage file 5 is After outputting (step 215), the process ends.

If the latest update date and time are not found in step 208, proceed to step 213. If the update type is addition in step 209, check whether the updated data matches the search conditions (step 216); if not, proceed to step 213. Step 21
Perform step 3.

If there is a match, the updated data is stored in the search result storage file 5.
(Step 217>, the process of Step 213 is performed. If the type of update is not a deletion in Step 212 (that is, a change), the process of Step 216 is performed.

FIG. 4 is an example of an internal structure diagram of the search condition stack table 4, and FIG. 5 is an example of an internal structure diagram of the search result storage file 5.

〔Effect of the invention〕

As is clear from the above description, the present invention provides a configuration in which the search processing time in a database search process does not depend on the number of data items stored in the database, but on the number of data updates to the database. And so. Therefore, if you frequently search a database with a large number of data items using the same search conditions, the number of data items updated between the previous search and the next search will exceed the number of data items stored in the database. Since the number is usually small, the method of the present invention can shorten the database search time compared to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the writing style conversion method of the present invention, FIG. 2 is a flowchart showing the operation of the search condition registration means 2 in FIG. 1, and FIG. A flowchart showing the operation of the search processing means 3 in the figure, FIG. 4 is an internal structure diagram of the search condition stack table 4 in FIG. 1, and FIG. 5 is an internal structure diagram of the search result storage file 5 in FIG. 1. It is. 1... Input/output device, 2... Search condition registration means, 3.
... Search processing means, 4... Search condition stack table, 5... Search result storage file, 6... Journal file, 7... Database.

Claims (1)

[Claims] A journal file for managing an updated image each time a specified database is updated; a search condition stack table for managing search conditions specified by a user; and a search condition stack table for managing a search condition specified by a user; It has a search result storage file in which data of search results is stacked, a search condition registration means, and a search processing means, and the search condition registration means is activated in response to a search condition registration request from a user and specifies the search condition. The search processing means registers the search conditions in the search condition stack table, searches the database, and stores data matching the search conditions in the search result storage file; is activated, searches for a search condition from the search condition stack table to obtain the specified search condition, reads data in the journal file, and matches the obtained search condition when updating data in the search result storage file. A database search method characterized in that only the data to be searched is updated, and when the search result storage file has been updated, the data in the search result storage file is passed to the user as the search result.