RE: SQL Optimizer Issue

I had an opportunity to deal with these types of questions and it was never
the same answer but rather "it depends".

I recommend taking advantage of free tech call with Centerfield DB2 expert:

http://www.centerfieldtechnology.com/comptechcall.asp

DISCLAIMER: I work for Centerfield.

Elvis

-----Original Message-----
 Subject: SQL Optimizer Issue

Posted for a colleague:
 
What I was told:  A SEQUEL select statement is run over a very large (50-60
Million records), select by name and a plan field.  MOST of the time results
are returned quickly but for "some" names the statement does not use the
existing index and thus creates one, which causes about a 20-30 minute
response time.  IBM support to date has not been able to help and they ahve
submitted a PMR to IBM but no response yet and it is becoming (is) an issue.
 
Example:
 
Name=Smith   Plan=B, quick response
Name=Jones Plan=C, takes forever
 
I was told that they have also tried it as a straight interactive SQL and
get the same issue.  They have not been able to find any rhyme or reason as
to why "some" names/plan combinations take so long.  Anyone run across this
or have any ideas?