This setting determines if descriptors on MU and PE tables will be used in join optimization.

 

By default they will not be used.

 

Here is an example - a where clause of "value in ('A00', 'A10')"  - the value field is a PE with a descriptor on it.

The first retrieval for 'A00' may bring back ISN 1 2 8

The second retrieval for 'A10' may bring back ISN 3 8 10

ISN #8 has 2 occurrences, one with value 'A00' and one with value 'A10' -

This causes in correct SQL records when the same ISN is returned multiple times for different values.

 

If it is known for certain that there is a unique set of values in the MU across all ISNs, then this setting can safely be set to 1.

 

Default = 0.

 

Environments: Client, Windows, Unix

Configuration Manager: CONNX Settings; Current Key = CONNX/ADABAS; Key Value/Value Name =  JOINMUDESC

 

Unix Registry Setting: CONNX.JOINMUDESC