How to Apply Release Update 12.2.0.1.210420 (Patch 32507738 – April 2021 RU)

Oracle recently released its April 2021 Release Update for 12cR2 (Patch 32507738). This post is to cover patching of Oracle 12cR2 database with this latest RU. (For 19.11 RU please read How to Apply Release Update 19.11.0.0.0 (Patch 32545013)).   Step-1: Install Latest OPatch First Step of Any Patching Process is to download and install…

Upgrade 12cR2 (Non-CDB) to 19c (PDB) using AutoUpgrade

In this article, we’ll perform an upgrade from 12cR2 Non container database to a 19c pluggable database using autoupgrade. If you are not aware of this autoupgrade utility, I would recommend to read my blog post on this topic Oracle 19c AutoUpgrade Utility which explains the workflow, stages and modes in autoupgrade utility. For 11gR2…

log file sync – Oracle Wait Event

When a user session commits, the session’s redo information needs to be flushed from memory to the redo logfile to make it permanent. At the time of commit, the user session will post the LGWR to write the log buffer (containing the current unwritten redo, including this session’s redo information) to the redo log file.…

log file switch – Oracle Wait Event

log file switch (archiving needed) Waiting for a log switch because the log that the LGWR will be switching into has not been archived yet. Check the alert file to make sure that archiving has not stopped due to a failed archive write. To speed archiving, consider adding more archive processes or putting the archive…

Library Cache Pin – Oracle Wait Event

Library cache pins are used to manage library cache concurrency. Pinning an object causes the heaps to be loaded into memory (if not already loaded). PINS can be acquired in NULL, SHARE or EXCLUSIVE modes and can be considered like a special form of lock. A wait for a “library cache pin” implies some other…

Library Cache lock – Oracle Wait Event

The library cache lock controls the concurrency between clients of the library cache by acquiring a lock on the object handle so that either: One client can prevent other clients from accessing the same object The client can maintain a dependency for a long time (no other client can change the object). This lock is…

Move Table Online – 12cR2

Until 11gR2 to move a table to different tablespace there were two available methods, first one was ALTER TABLE .. MOVE TABLESPACE but during this the table was locked for DML, thus downtime and the second one was DBMS_REDEFINITION which will allow to create a new table on the desired tablespace and sync the data…