# 0 => Nested loop joins will be preferred (where
# possible) over sortmerge joins and hash joins.
# 1 => If the transaction isolation mode is not
# "repeatable read", optimizer behaves as in (2)
# below. Otherwise it behaves as in (0) above.
# 2 => Use costs regardless of the transaction isolation
# mode. Nested loop joins are not necessarily
# preferred. Optimizer bases its decision purely
# on costs.
I'm from Oracle database and I'm trying to learn about informix database. I'd like to say thanks for all that helped me at this moment
Well, I'd like understand, what's this parameter OPTCOMPIND....
My database's set to 2...
It's mean that all SQL executed in database will be process by costs ?
I'd like to put my database in statistics (like Oracle) It's possible ?
With optcompind equal 2 will use the cost based on statistics.
But, on Informix you must manually start the process where gather the statistics. To do that , study about the SQL command UPDATE STATISTICS.
You found a lot information on the manuals. (the manuals are free for charge, and ALL are available to download on the IBM Informix Support site)
In www.iiug.org you can find scripts to "automate" the update statistics, they must follow the best or recommended practices to be successfull. They are very important, make the difference between work and not!
try to find some scripts like tbl_updstats or something like.