Poor Performance Issue (Excessive Parsing) after Upgrading to 18c
(Doc ID 2691189.1)
Last updated on JULY 15, 2020
Applies to:Oracle Database - Enterprise Edition - Version 184.108.40.206.0 and later
Information in this document applies to any platform.
Some SQL statements take much more time to complete, following an upgrade to Oracle Database 18c. Further examination (e.g., ADDM Report information about a high percentage of parse time, Time Model Statistics in the AWR Report) indicates that the additional time is spent within the parse phase.
Setting OPTIMIZER_ADAPTIVE_PLANS to FALSE has not helped.
The SGA Breakdown Difference Section of the AWR Report may indicate a large increase in space used by the SQLA pool.
You have recently upgraded the database to Release 18c, or higher.
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