Examining and optomizing a query
Posted on 2006-04-28
I have some simple quesitons about my DB2 query. Like "is it using an index when it joins table a to table b?" I've been looking all day for references that tell how to do this. I've found didly.
Here are some of the google searches I've done:
db2 query optimization
db2 query plan
db2 explain query
db2 explain results
Nearly every hit is either a page trying to sell a training class or a third party software tool. Neither are options I can use.
I did find references to the EXPLAIN statement and how to run it. Seemed promising. There was nothing about what to do once the statement is executed. Lots of stuff gets put into the "explain tables" but I've found precious little information about how to interpret the results.
Please do not post examples of how to do what I need. I'm looking for references. Please post links to GOOD sites that explian SQL profiling/explaining/optimizing for DB2 databases.