Toad World® Forums

Analyzing Unix DB2 explain


#1

I often use explain to determine relative cost of SQL query. But nowhere have I found an explaination of how to intrepret results - e.g. how do you associate the statement number in the explain to my SQL and what do the FETCH, RIDSCN, IDXSCN, etc represent?


#2

Hi Mike,
All displayed information for explain plan is based on those 2 tables
PLAN_TABLE
DSN_STATEMNT_TABLE
TOAD has hints about each block.
I suppose that you can find all related info about those tables and how explain plan works in following docs:
www.hoadb2ug.org/Docs/accessplans.pdf
www.publib.boulder.ibm.com/infocenter/dzichelp/v2r2/topic/com.ibm.db2z10.doc.perf/db2z_explaintables.htm

Thanks,
Vlas

Message was edited by: Vlas


#3

Previous post was broken so I’m resending it again.
All displayed information for explain plan is based on those 2 tables
PLAN_TABLE
DSN_STATEMNT_TABLE
TOAD has hints about each block.
I suppose that you can find all related info about those tables and how explain plan works in following docs:
www.hoadb2ug.org/Docs/accessplans.pdf
www.publib.boulder.ibm.com/infocenter/dzichelp/v2r2/topic/com.ibm.db2z10.doc.perf/db2z_explaintables.htm

Thanks,
Vlas