Oracle

Oracle SQL Profile: why multiple OPT_ESTIMATE?

By Franck Pachot . In a previous blog I’v shared my script to retrieve the OPT_ESTIMATE hints from a SQL Profile. In the example I made, I had two lines for each table: --- PROFILE HINTS from dbiInSite(…)

Oracle SQL Profiles: Check what they do before accepting them blindly

By Franck Pachot . People often ask me if I use the SQL Tuning Advisor. The answer is no, at least not through the end of it. But don’t take me wrong. SQL Tuning Advisor is a really nice(…)

Using tmux for semi-interactive demos

By Franck Pachot . You are a speaker and like to show some demos. Which kind of demo do you do? you script everything so that you just have to press ‘enter’ during the demo you prepare everything in(…)

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(…)