Tag Archives: top_tip

Harnessing the Power of Optimizer Hints

Last week I was lucky enough to have participated in the Trivadis Performance Days 2017 conference and several people have asked if I would share the slides from one of my sessions. The session in question was called “Harnessing the power … Continue reading

Posted in Optimizer | Tagged , , | Leave a comment

Using DBMS_XPLAN.DISPLAY_CURSOR to examine Execution Plans

In last week’s post I described how to use SQL Monitor to determine what is happening during the execution of long running SQL statements. Shortly after the post went up, I got some requests on both social media and via … Continue reading

Posted in Optimizer, Syntax | Tagged , , , | 7 Comments

Getting the most out of Oracle SQL Monitor

I’m often asked what is the best tool for viewing execution plans and for me the answer is always SQL Monitor (included in the Oracle Tuning Pack). It really is the most invaluable tool if you need to determine what … Continue reading

Posted in Optimizer | Tagged , , , , | 4 Comments

Overriding DBMS_STATS Parameter Settings

Since it’s introduction in Oracle Database 8i, the DBMS_STATS package is Oracle’s preferred method for gathering statistics. With each new database release the DBMS_STATS package is extended to accommodate new approaches to gather statistics and new types of statistics. Over … Continue reading

Posted in New Features, Optimizer, Oracle Database 12c New Features | Tagged , , | Leave a comment

Longer Identifiers in Oracle Database 12c Release 2

Prior to Oracle Database 12c Release 2, all object names had been limited to just 30 bytes. This limitation lead to some interesting problems, especially if you wanted to use descriptive names for the database objects you were creating.

Take for example the dictionary tables we wanted to create in 12.1 to help manage SQL Plan Directives. The first table was DBA_SQL_PLAN_DIRECTIVES, with 23 characters, which wasn’t problem. However, the second table we wanted was DBA_SQL_PLAN_DIRECTIVES_OBJECTS. Continue reading

Posted in New Features, Oracle Database 12c New Features | Tagged , | 2 Comments