apps-dba journal

A working journal for Oracle DBAs.

October 27, 2026  · 

Oracle DBA Lesson 65 Part 1 — Reduce Undo Pressure from Temporary Work

Temporary undo stores the undo for changes on temporary objects in a temporary tablespace. For a workload that stages and discards many...

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October 27, 2026

Oracle DBA Lesson 64 Part 2 — Choose an Undo Remedy from the Failing Workload

A long report losing its required history and a transaction unable to allocate undo need different investigations. Use the affected wor...

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October 27, 2026

Oracle DBA Lesson 64 Part 1 — Find Which Container Owns the Undo

For permanent-table transactions in Oracle Database 19c, establish the CDB undo mode , the container that owns the undo storage , and t...

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October 27, 2026

Oracle DBA Lesson 63 Part 2 — Explain What a Concurrent Reader Sees

Oracle's default READ COMMITTED isolation gives each ordinary query a committed view consistent to the time that statement opens. ...

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Oracle DBA Lesson 65 Part 1 — Reduce Undo Pressure from Temporary Work

Temporary undo stores the undo for changes on temporary objects in a temporary tablespace. For a workload that stages and discards many...