JPS61290532A - Data base retrieving system - Google Patents

Abstract

PURPOSE:To eliminate a store structure limit of a data base, so that a user can satisfy a processing request immediately with respect to the data base, by providing a virtual sub-schema, and controlling a data base retrieval request expected by the user. CONSTITUTION:A list 18 of an access path is read from a virtual sub-schema 15, based on a retrieval request, and a data base retrieval instruction in the list 18 of the access path, and an instruction for executing a transfer to a store area 17 are connected to a data base control system 12. Subsequently, by using one data base retrieval instruction in the list 18 of the access path, the data base retrieval instruction is issued to the control system 12. A retrieved record is accumulated in the stored are 17 in a simple retrieval mechanism 16 from the control system 12 by using an instruction for a transfer use in the list 18 of the access path. Next, whether the list 18 of all the access paths has been processed or not is checked, and when it is completed, it is informed to a user that one list of a record to be retrieved has been completed, and when it is not completed yet, the issue of the data base retrieval instruction is continued.

Description

Detailed Description of the Invention: Technical Field 1 The present invention relates to a database search method, and particularly to a database management system in which each record is stored hierarchically with parent-child dependent relationships based on logical relationships with other records. Concerning a simple database search method.

11 盈I Conventionally, a simple database search method in a hierarchical database management system with a parent-child dependency relationship is such that the search mechanism directly refers to the schema and subschema, which are the structure definitions of the database prepared by the database management system. Either a method is adopted in which the search mechanism determines a search route by determining the record where the requested information is located, or a method in which the user suggests the location of the desired data and the search route between records.

Among these types of conventional methods, in the former method, a database management system and a search mechanism search all records of parent and child records for a database that has a hierarchical structure with multiple parents or child records. Since it is impossible to derive dependent relationships due to the existence of records at the same level that have no logical relationship to each other, the storage structure of the database must be significantly restricted in order to be able to respond to all of the various search requests. The disadvantage is that it requires simplification. In addition, the latter method requires a lot of specialized knowledge to operate a database with a complex logical structure and a special physical structure according to the purpose, so it is difficult for non-database experts to use the latter method. The drawback is that users cannot immediately satisfy processing requests to the database.

An object of the present invention is to provide a database search method that does not impose any restrictions on the storage structure of the database and allows users who are not database experts to immediately satisfy processing requests for the database. do.

The database search method of the present invention converts the sequence of records to be searched, which is declared in advance by the user, into the sequence of approach routes for actually searching the records. In response to a database search request, the database is sequentially searched while referring to this sequence of approach routes, the searched records are edited and accumulated, and finally the sequence of records to be searched that has been declared in advance by the user is completed. The feature is that the user is notified of the completion of the search at the point in time.

Ki■ Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a database management system to which the database search method of the present invention is applied. In the database management system of this embodiment, in addition to the database 11, database control system 12, and schema/subschema 13 that generally exist in a hierarchical database management system having parent and child subordinates, A virtual subschema conversion mechanism 14, which is a means for converting the sequence of records to be declared into an sequence of approach paths for actually searching the records, and a sequence of approach paths 18 created by the virtual subschema conversion mechanism 14. Virtual subschema 1 that stores
5, means for searching the database using a database search command provided by the database control system 12 while referring to the sequence of approach routes 18 stored in the virtual subschema 15 in response to a user's database search request. A simple database search mechanism 16 exists.

Within the database simple search mechanism 16, there is a storage area 17 in which the database control system 12 edits and stores the actual records of the search and the array of records to be searched declared by the user.

FIG. 2 is a flowchart showing the creation process of the virtual subschema 15 by the virtual subschema conversion mechanism 14.

First, referring to the schema/subschema 13, it is determined whether the sequence of records to be searched declared by the user is valid for both the parent and child subordinate arms and the search route (step 21).
. If the declaration is valid, the database control system 12
A database search command for the database, a control pointer for sequentially executing a group of these database search commands, and a storage area for editing and accumulating the sequence of records to be searched provided in the simple search mechanism 16 for searching records. A sequence 18 of approach routes consisting of commands for transferring to 17 is created (steps 22, 2.3). Finally, the approach route sequence 1 created by the above steps
8 is stored in the virtual subschema 15 (step 24)
.

FIG. 3 is an example of the sequence of approach routes 18 stored in the virtual subschema 15 through the process shown in FIG. It consists of a control pointer 32 and an instruction 33 for transferring to the storage area 17.

FIG. 4 is a flowchart of the search processing portion from the database search triggered by the user's database search request by the database simple search mechanism 16 to the notification of the completion of the search to the user. First, the virtual subschema 15 of the approach route sequence 18 is read from the search request (step 41). Next, in order to enable a database search, the database control system 12 sends the database search command 31 stored in the approach route sequence 18 read from the virtual subschema 15 and the command 33 for transferring to the storage area 17. (step 42).

Next, the database control system 12 uses one database search command stored in the approach route array 18.
The database search command 31 is issued to the database search command 31 (step 43).

Furthermore, the searched records are stored in the storage area 17 in the simple search mechanism 16 from the database control system 12 according to the transfer instruction 33 stored in the approach route array 18 (step 44), and then It is checked whether all the approach route sequences 18 have been processed, and if the processing of all the approach route sequences 18 has been completed, the process proceeds to step 46. If there are still uncompleted approach route sequences 18, the process proceeds to step 46. Control is transferred to step 43 (step 45).

Finally, the user is notified that one sequence of records to be searched has been completed (step 46).

1.11 According to the present invention, a virtual subschema that holds the sequence of approach routes is provided, and the database simple search mechanism uses the virtual subschema to control the database search request expected by the user. This has the effect that there are no restrictions on the storage structure of the database, and users who are not database experts can immediately satisfy processing requests for the database, allowing users to easily perform a variety of database processes.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a database management system to which the database search method of the present invention is applied;
2 is a flowchart showing the creation process of the virtual subschema 15 by the virtual subschema conversion mechanism 14 of the database management system shown in FIG. 1, and FIG. 3 shows the approach route stored in the virtual subschema 15 by the process shown in FIG. As an example of the arrangement, FIG. 4 shows a portion of the search processing from the database search triggered by the user's database search request by the database simple search mechanism 16 of the database management system shown in FIG. 1 until the user is notified of the completion of the search. This is a flowchart. Explanation of symbols of main parts 11...Database 12...Database control system 13...
...Schema/subschema 14...Virtual subschema conversion mechanism 15-...Virtual subschema 16...Database simple search mechanism 17...
... Record storage area 18 ... Arrangement of approach routes 31 ... Database search command 32 ...
・Control pointer

Claims (1)

[Claims] A database search method in a database management system in which each record is stored hierarchically with a parent-child dependent relationship based on logical relationships with other records, and the search is declared in advance by the user. a first means for generating a sequence of approach routes for actually searching this record from a sequence of records to be searched; and a second means for searching the database according to the arrangement of the approach routes, the second means editing and storing records searched according to the arrangement of the approach routes.