Category Archives: Oracle

How to make partition elimination/pruning to work

The blog was moved to: http://www.avmconsulting.net/single-post/2016/11/19/How-to-make-partition-eliminationpruning-to-work

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filter(NULL IS NOT NULL)

“filter(NULL IS NOT NULL)” in explain plan usually means what CBO found a conflict between your WHERE-clause predicates and declarative constraints on the tables involved. example – And if constraints are validated, Oracle does not physically touch the Object at … Continue reading

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Roll forward oracle database restored from storage snapshot

Most people use storage snapshots with Oracle DB these days. Its easy to restore DB to discrete point of time, i.e. to snapshots time. Here is a method of rolling forward the DB to any needed point of time using … Continue reading

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Lost control file, So what?

Recently got involved in couple conversations regarding common “RULE OF THUMB” about backing up control file, and double backup of control file backup etc.. I guess its good thing to do, its does not take much space anyway, but if … Continue reading

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ORA-01555 on standby

If you see “ORA-01555: snapshot too old” from Select what is been run on Physical standby, but same select runs on primary just fine,¬†and all relevant init.ora parameters and undo tablespace are exactly identical between primary and standby,- its odd. … Continue reading

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High CPU usage on DB host?

Its Unix 101 statement, but I have heard it wrong so many time, so decided to put a blog for it. So: If in OLTP environment, per ‘top’ %wa (IOWAIT) is major contributor for CPU busy, adding CPU would not … Continue reading

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Quckest was to find oracle alert log on linux box

Recently I had to work in a lot of new to me oracle environments. And I found a some places do not have standard for ORACLE_BASE, and no correlation between SID and Unique_name. With that – finding oracle alert log … Continue reading

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