Performance considerations

 

Use these tips to improve performance of join logical files.

• If the physical files you join have a different number of records, specify the physical file with fewest records first (first parameter following the JOIN keyword).

• Consider using the DYNSLT keyword.

• Consider describing your join logical file so it can automatically share an existing access path.

  Join logical files always have access paths using the second field of the pair of fields specified in the JFLD keyword. This field acts like a key field in simple logical files. If an access path does not already exist, the access path is implicitly created with immediate maintenance.

 

Parent topic:

Join logical file considerations

 

Related concepts

Dynamic select/omit
Sharing existing access paths between logical files