JPH07141239A - Record processing system for index sequential organized file - Google Patents

Abstract

PURPOSE:To update plural records having the same key item in an index sequential organized file which does not have a primary key. CONSTITUTION:The position of an optional record in the index sequential organized file 1 which is counted from the head of the record having the same key item is held in a counter before update processing. When the update processing is specified, the processing is positioned at the record to be updated on the basis of a number which is counted previously after direct reading processing using the keys. Consequently, the optical record can be updated without restrictions such as the updating of only the record physically at the head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a record processing method for an index sequential file, and more particularly to a record processing method for an index sequential file having no primary key.

[0002]

2. Description of the Related Art In a conventional record processing method for an index sequential organization file, update processing is performed by direct reading with a designated key. According to this method, when there are a plurality of the same key items, the record physically located at the head is updated.

[0003]

It is attempted to recognize that there are a plurality of records having the same key item in the index sequential organization file. In this case, it is impossible to update all the records having the same key item only by directly reading with the key. Therefore, it becomes necessary to recognize in advance which record is to be updated among a plurality of existing records before performing the update process.

[0004]

A record processing method for an indexed sequential organization file according to the present invention is a counter for internally holding the update target record from the beginning of a record having the same key item. It is characterized in that the registration update processing is performed by having the above.

[0005]

First, the time of registering a new record will be described. If a record with the same key already exists, the number of existing data is counted, and then the data is physically registered at the last position. If it does not exist, set the counter to 0
(The number of cases counted does not directly affect the registration process, but it is used when the data processed immediately before is displayed again on the screen).

Second, the replacement and deletion of existing records will be described. In advance, locate the record to be updated by the record reference process (sequential reading). At the same time, the number of records counted from the beginning of the record having the same key is counted (counter = 0 if not present). If you specify replacement or deletion after locating the record by reference processing, the key is read directly and then the record you want to replace or delete is repositioned based on the counted number (displayed also on the screen). After that,
Perform normal replacement and deletion processing.

[0007]

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

FIGS. 1 and 2 show an update process for indexed sequential organization files 1 and 2 in an embodiment of the present invention. Keys shall allow duplicates.

FIG. 1 shows a registration process when a record having the same key already exists. At this time, the counter of the number of records with the same key (item of number type.
The default value is 0) (in this case, the counter value is 1). Others perform normal update processing for the index sequential organization file.

FIG. 2 shows a replacement process when there are a plurality of records having the same key. The key A is directly read in advance (positioned at the record of the key A / data a at this point), and then the reference process (sequential reading) is repeated until the record of the data a1 is displayed with the same key. At this time, 1 is set in the counter.

After the positioning by the reference processing, the replacement processing is designated. At this time, based on the value of the counter = 2, the key A and the data a1 are repositioned to the record and displayed again on the screen. After that, the data part is rewritten from the data a1 to the data a2. After that, the normal replacement process for the index sequential organization file is performed.

The deletion process is performed according to the replacement process. That is, after locating the record to be deleted by reference processing,
Specify deletion and reposition and redisplay the target record. After that, normal deletion processing is performed on the index sequential organization file.

[0013]

As described above, according to the present invention, since the record having the same key item is internally retained as to which record from the beginning, the physical record among records having the same key is stored. It is possible to update any record without restriction that only the first record can be updated.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a record registration process in an index sequential organization file according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a record replacement process on an index sequential organization file according to an embodiment of the present invention.

[Explanation of symbols]

 1 Index sequential file 2 Index sequential file

Claims (3)

[Claims] 1. A registration update process is performed by having a counter that internally holds the number of the update target record from the beginning of a record having the same key item. A record processing method for indexed sequential files. 2. When registering a new record, if a record with the same key already exists, after counting all existing data, the record is physically made at the last position, and the record with the same key is recorded. A record processing method for an indexed sequential organized file, characterized in that if it does not exist, the counter is set to 0 before registration. 3. When replacing or deleting an existing record, the record reference process is performed to position the record to be updated in advance, and at the same time, counting from the beginning of the record having the same key is counted. In addition, if you specify replacement or deletion after positioning the record by reference processing, after reading directly by the key, it is repositioned to the record you want to replace or delete based on the counted number of records. Record processing method for organized files.