DB2 FOR LUW / DB2FORLUW / 910 - DB2

In some situations, statement compilation may fail to use the 
statistics collected for a global temporary table.  This may 
lead to a non optimal access plan.  For example, in the sequence 
of: 
    1. declare global temporary table 
    2. insert data into the global temporary table 
    3. runstats on the global temporary 
    4. use the global temporary table in a query 
the statement compilation in step4 may not use the statistics 
collected in step3.

Users Affected: all using DGTTs in DPF environment 
 
Problem Description: 
In some situations, statement compilation may fail to use the 
 
statistics collected for a global temporary table.  This may 
lead to a non optimal access plan.  For example, in the sequence 
of: 
    1. declare global temporary table 
    2. insert data into the global temporary table 
    3. runstats on the global temporary 
    4. use the global temporary table in a query 
the statement compilation in step4 may not use the statistics 
collected in step3. 
 
Problem Summary: 
See PRoblem description above

- After observing the problem, repeating the RUNSTATS operation 
typically clears the problem. 
- Querying the global temporary table prior to the RUNSTATS 
operation, for example with "select 1 from session.t1 fetch 
first 1 row only", typically avoids the problem.

See LOCAL FIX

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

18.02.2010
18.02.2010
18.02.2010