Oracle

The future of SQL*Plus and some oddities

By Franck Pachot . Rumors are coming after OOW14. Oracle is working on a new SQL*Plus version. Not only a new version. It’s a completely new development. Here is what we know currently about the future of sqlplus an(…)

How to disable all database links

By Franck Pachot . A frequent scenario: you refresh test from production with a RMAN duplicate. Once the duplicate is done, you probably change dblinks so that they address the test environment instead of the production one. But are(…)

Oracle cloud control / SQL Details / Statistics

By Franck Pachot . A question that I had several times: in Enterprise Manager, in the screen about one SQL statement, the ‘statistics’ tab shows the number of executions, elapsed time, etc. Question is: which time window does it(…)

Oracle: an unexpected lock behavior with rollback

By Franck Pachot . Here is an odd Oracle behavior I observed when a transaction that acquired a lock is rolled back. Note that this is related to a specific combination of locks that should not be encountered in(…)

From 8.0 extended rowid to 12c pluggable db: Why Oracle Database is still a great software

By Franck Pachot . Do you know why Oracle Database is a leader in the database market since 30 years? Do you know any other software that is still the leading solution after decades? I think that it is(…)

What about ALTER INDEX … SHRINK SPACE ?

By Franck Pachot . I have recently published a script to check index fragmentation. But then, do you COALESCE or REBUILD? Well, there also is another option: ALTER INDEX SHRINK SPACE. Let’s compare all those index defragmentation operations.

Oracle IOT: when to use Index Organized Tables

By Franck Pachot . When can we use IOT? That’s a question I had when giving recently the Oracle DBA essentials workshop. the DBA Essential is very dense and there is only half a day about performance. We(…)

Oracle system statistics: Display AUX_STATS$ with calculated values and formulas

By Franck Pachot . System statistics can be gathered in NOWORKLOAD or WORKLOAD mode. Different values will be set depending on that and the others will be calculated – derived from them. We can see defined values from SYS.AUX_STATS$(…)

How to measure Oracle index fragmentation

By Franck Pachot . At Oracle Open World 2014, or rather the Oaktable World, Chris Antognini has presented ‘Indexes: Structure, Splits and Free Space Management Internals’. It’s not something new, but it’s still something that is not(…)

How to measure Exadata SmartScan efficiency

By Franck Pachot . A thread on OTN Forum about Exadata came to the following question: “But how can I monitor if it is effectively used or not?”. This is a common question. There are 3 exclusive features coming(…)