Optimizing grouping by removing read triggers

 

For queries involving physical files or tables with read triggers, group by triggers will always involve a temporary file before the group by processing, and will therefore slow down these queries.

Read triggers are added when the Add Physical File Trigger (ADDPFTRG) command has been used on the table with TRGTIME (*AFTER) and TRGEVENT (*READ).

The query will run faster is the read trigger is removed (RMVPFTRG TRGTIME (*AFTER) TRGEVENT (*READ)).

 

Parent topic:

Grouping optimization

 

Related information

Add Physical File Trigger (ADDPFTRG) command