System-wide performance issues in Sybase ASE 15.0.2 ESD #3 or later
Issue:
· Performance of Adaptive Server is degraded after the version upgrade. It could be because of unusually high levels of CPU usage with no clear cause, while running a multiengine Adaptive Server.
· Or the procedure cache is filled with idle cached plans, but the CPU usage is not high.
Suggested Workaround:
· Shutdown the Adaptive Server and restart it with trace flag 757 set in the RUN_server file.
Risks:
· No risks have been noted as per Sybase
Sybase URL:
Using 'Compatibility Mode' In Sybase ASE 15.0
Issue:
· Performance of Adaptive Server is degraded after the version upgrade.
Suggested Workaround:
· Compatibility Mode is an optimizer related feature. With Compatibility Mode enabled, queries will be optimized according to the optimizer logic as in ASE 12.5, and the query plans identical or at least very similar to those in 12.5.
Risks:
· Performance of Adaptive Server may degrade. No effect on data.
Sybase URL:
Using ‘Optimization Goal' in Sybase ASE 15.0
Issue:
- Performance of Adaptive Server is degraded after the version upgrade.
Suggested Workaround:
Three optimization goals that can be set at server, session or query level.
- allrows_mix – the default goal, the most useful goal in a mixed-query environment. It balances the needs of OLTP and DSS query environments.
- allrows_oltp – the most useful goal for purely OLTP queries.
- allrows_dss – the most useful goal for operational DSS queries of medium-to-high complexity (which is the best goal for processing huge data with few user-sessions).
Risks:
- Performance of Adaptive Server may degrade. No effect on data.
Sybase URL:
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