SORT_SEQUENCE is wrong in as400 library indexes. Can this cause performance issues?

Elias Stassinos

Member
I have 4 AS400s running JDEdwards.

Lately a performance issue occured as described here:
Performance issue

Although i am not an expert in AS400 , i tried to find out the cause. I think it came down to this:

I run the following SQL in all my systems:

<font class="small">Code:</font><hr /><pre> select sort_sequence,index_schema,count(*) from qsys2.sysindexstat group by sort_sequence,index_schema </pre><hr />

In 3 of my 4 systems all of them have sort_sequence="BY HEX VALUE"

In my 4 problematic system many indexes have sort_sequence="*LANGIDSHR"

I start to believe that this can cause performance problems as the query optimizer may leave these indexes unused and create temp indexes.

I wish somebody has an idea on where to go on from now and how.

Is there any specific setting that make all the indexes have default sort_sequence?

All my indexes are created massively so this could not happen by mistake.

How can i make all indexes be *HEX?
 
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