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Things to Consider to Avoid SQL Performance Problems on 19c (Doc ID 2773715.1)

Last updated on APRIL 03, 2024

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 19]
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Information in this document applies to any platform.


The purpose of this document is to publish some recommended fixes in hopes of avoiding SQL Performance related problems in 19c including Parallel Execution.

For Query Wrong Results, refer the below document.

<Document 2606585.1> Things to Consider to Avoid Prominent Wrong Result Problems on 19C Proactively

For SQL Plan Management, refer the below document.

<Document 2774029.1> Things to Consider to Avoid SQL Plan Management (SPM) Related Problems on 19c

For Database Performance, refer the below document.

<Document 2773012.1> Things to Consider to Avoid Database Performance Problems on 19c


This document contains the list of some known bugs impacting the SQL Performance. Some of them are included to DBRU already but some are not yet.

REMEMBER: Database Release Updates (RU) are cumulative in nature. For example, the Apr 2021 Release Update patch includes the contents of all previously Release Updates. Hence, it is always RECOMMENDED to be in the latest DBRU (Database Release Update) that contains most of the known bug fixes.

<Patch 34419443> - Database Oct 2022 Release Update (19.17) - Latest

Refer the below document for the latest DBRU information.

<Document 2521164.1> Oracle Database 19c Proactive Patch Information

For bugs that are not included to RU yet, please download and install one-off patch for your database version and OS. If you do not find a patch for your specific version and OS from MOS, please open a Service Request with details on the patch needed. Please include a list of patches already applied (opatch lsinventory -detail) as well as any other patches you intend to apply.

Some of the Optimizer bug fixes (not all) are controlled by _FIX_CONTROL setting and are DISABLED by default in 19c when installed either through one-off backport or through RUs. For one-off patches, please refer to the corresponding Patch Readme carefully and enable the fix control in order to activate the fix.



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