A new version 2.0 of the XPLAN_ASH utility introduced here is available for download.You can download the latest version here.The change log tracks the following changes:- Access check- Conditional compilation for different database versions- Additional activity summary- Concurrent activity information (what is/was going on at the same time)- Experimental stuff: Additional I/O summary- More pretty printing- Experimental stuff: I/O added to Average Active Session Graph (renamed to Activity Timeline)- Top Execution Plan Lines and Top Activities added to Activity Timeline- Activity Timeline is now also shown for serial execution when TIMELINE option is specified- From 18.104.22.168 on: We get the ACTUAL DOP from the undocumented PX_FLAGS colu
Note: This blog post actually serves three purposes:
So this will be my Oracle related Christmas present for you: A prototype implementation that extends the DBMS_XPLAN.DISPLAY_CURSOR output making it hopefully more meaningful and easier to interpret. It is a simple standalone SQL*Plus script with the main functionality performed by a single SQL query. I've demoed this also during my recent "optimizer hacking sessions".
DBMS_XPLAN.DISPLAY_CURSOR together with the Rowsource Statistics feature (enabled via SQL_TRACE, GATHER_PLAN_STATISTICS hint, STATISTICS_LEVEL set to ALL or controlled via the corresponding hidden parameters "_rowsource_execution_statistics" and "_rowsource_statistics_sampfreq") allows since Oracle 10g a sophisticated analysis of the work performed by a single SQL statement.