13.7 Specifying the FIX attribute

The FIX attribute is an attribute assigned to a table whose row length is fixed.

Organization of this section
(1) Effects of specifying the FIX attribute
(2) Criteria
(3) Specification

(1) Effects of specifying the FIX attribute

The effects of specifying the FIX attribute for a table are discussed as follows.

Improved performance
  • The performance of retrieving a specific column becomes constant regardless of the order of the column definitions. Additionally, the column retrieval time is reduced, compared to when the FIX attribute is not specified.
  • Access performance is improved even when there are many columns because a UAP can use an interface for each row.
Improved operability
If the null value is found in the input data when a column of a table with the FIX attribute is being updated, it can be excluded as an error.
Reduction of required disk space
The physical row length is 2 bytes shorter per column than when the FIX attribute is not specified. If a table contains many columns, disk space is saved.

(2) Criteria

The FIX attribute should be specified during table definition when all the following conditions are satisfied:

When these conditions are not satisfied, the following should be evaluated:

(3) Specification

To assign the FIX attribute to a table, FIX is specified in the CREATE TABLE definition SQL (i.e., CREATE FIX TABLE is specified).