Hello,
Poor system performance, because index draw~1 is not used by all queries
in MSSQL database
We can observe poor system performance on system PRD, while querying
table DRAW in customer program. Analysis with ST05 shows index DRAW~1 is
not always used by query optimizer, although the sql statement is always
the same (Please see screenshot 1 – executing with index). Actualizing
the index with ‘update statistics’ normally fix the issue and for the
next time all queries are using the index. After a certain time period
the index is not used anymore.
In lt_documentkeys_drad are approx. 17.000 entries or more possible.
For saving an document out of our Programm we call SAP BAPIS.
We have already rebuild the index DRAW~1 and update statistics in short
times (every 15 min). Even in this short time period the behaviour takes
place.
Why is index DRAW~1 not used by all queries? How can we ensure that all
statements are using index DRAW~1?
Checked SAP notes:
1016001 - SQL error 1844 for "CREATE INDEX WITH (ONLINE=ON)"
1660220 Microsoft SQL Server: Common misconceptions
1702408 Configuration Parameters for SQL Server 2012
1712785 Support for Microsoft SQL Server 2012
1744217 MSSQL: Improving the database performance
THX and Best Regards
Daniel