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

Last updated on SEPTEMBER 23, 2024

Applies to:

Purpose

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.

For SQL Plan Management, refer the below document.

For Database Performance, refer the below document.

Scope

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.

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.

Example:

Details

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