Oracle Patch types

Oracle Patch types

Interim patches - contain a single bug fix or a collection of bug fixes provided as required

Diagnostic patches - intended to help diagnose or verify a fix

Bundle Patch Updates (BPUs) - a cumulative collection of fixes for a specific product or component

Patch Set Updates (PSUs) - a cumulative collection of high impact, low risk, and proven fixes for a specific product or component and Security Patch Updates

Security Patch Updates (SPU) - a cumulative collection of security bug fixes.  SPUs were formerly known as Critical Patch Updates (CPU).

System Patch - contains several sub-patches in a format that can be used by OPatchAuto.

Merge Label Request (MLR) - a merge of two or more fixes. MLR creation requires a label for the new set of merged code and a Patch Set Exception.

What to install?

RU - Release Update

Release Update

RU - Release Update

Oracle recommends that you keep your database software current by applying Release Updates (RUs).

RUs are listed in Primary Note for Database Proactive Patch Program (Doc ID 888.1)

Release Updates (RUs) are release quarterly: Third Tuesday of January, April, July and October. 

Each RU will be given a maximum of six Monthly Recommended Patches (MRPs), released monthly.

RUs are highly tested bundles of critical fixes which enable you to avoid known issues. 

They usually contain the following type of fixes: security, regression (bug), optimizer, and functional.

Monthly Recommended Patches (MRP)

Starting with update 19.17, Oracle is providing MRPs for Linux x86-64 to provide proactive patching between Release Updates.

Which patches to install for Oracle 19?

A. Oracle Database 19c Important Recommended One-off Patches (Doc ID 555.1)

This documents lists the latest patches for Oracle 19
for example:

19.22 DB RU - Patch 35943157

19.21 DB RU - Patch 35643107 

19.20 DB RU - Patch 35320081

19.19 DB RU - Patch 35042068

B. Primary Note for Database Proactive Patch Program (Doc ID 888.1)

This documents lists patches for All oracle versions.
for example: