I did blog in the past weeks about Fallback Strategies with Flashback Database. But two of my reference customers came across an interesting issue when they tried to fallback: Oracle 12.2 underscores appear in the SPFILE – magically – and prevent the fallback using the existing SPFILE.
Oracle 12.2 underscores appear in SPFILE – be aware when you flashback
In one case it happened during a test, in the other case it happened during a live fallback after the Data Guard Broker has interfered with the upgrade causing real trouble.… [Read More]
There is a fancy new command to unplug a PDB in Oracle Database 188.8.131.52:
ALTER PLUGGABLE DATABASE pdb1 UNPLUG INTO 'pdb1.pdb';
The nice thing with this command differing in the file ending of ‘
pdb‘ instead of ‘
xml‘ as you used it in Oracle 12.1 (and the ‘
xml‘ option is still available of course): Instead of just creating an
xml description file it
zips everything together into a PDB archive.… [Read More]
We discussed an interesting upgrade case last week together with our upgrade colleagues in Support – and learned the double-hop (or triple-hop) upgrade case is not described in the documentation somewhere.
What is a multiple-hop upgrade?
Triple Jump – Willie Banks – Olympics 1988 Seoul
Actually this describes the case where somebody can’t upgrade directly and has to do several upgrades in a sequence to reach the targeted release.… [Read More]
At the DOAG Conference in November in Nürnberg in November 2016 a customer asked me right after my talk about “Upgrade to Oracle Database 12.2. – Live and Uncensored” why the DBA_REGISTRY_HISTORY does not get updated when he applies a Bundle Patch and follows all instructions including the “./datapatch -verbose” call.… [Read More]
I while back I blogged about issues with “rowsets“, a new Oracle 12c feature which unfortunately had two known wrong result (WQR) bugs:
Switch off “_rowsets_enabled” in Oracle Database 12c
UPDATE: _rowsets_enabled in Oracle Database 12c
What does “rowsets” actually mean?
I’d like to thank Sankar, our Development manager for providing this explanation which sheds some light on how important this feature actually is:
“Rowsets is a SQL execution performance enhancement introduced in Oracle RDBMS release 12.1 and further extended in a future release of the Oracle Database.
… [Read More]
Credits to Chris Smids from Proximus in Belgium 🙂 Thanks, Chris!!!
Upgrade to Oracle 184.108.40.206 is slow in phase: #65 ?
You are wondering why phase: #65 of the database upgrade to Oracle Database 220.127.116.11 takes quite a while. You dig down into the catupgrd0.log and recognized this statement taking a while:
dbms_output.put_line('catuposb, update 4 - rows updated ' || rows_updated);
END; -- end of update for system internally generated objs
The cause for this issue is buried in the script catuposb.sql hitting stale histograms which did not get refreshed even if you gathered dictionary stats before the upgrade as recommended.… [Read More]
A while back we added this slide to our big slide deck:
The story behind this slide
A large and important customer in the US tested a patch set upgrade – but when they approached the production upgrade from 18.104.22.168 to 22.214.171.124 on a large RAC cluster they’ve had to cancel the attempt and revert to the previous state.… [Read More]