Re: Select Statement

Yes, when committed updates to one of the tables you are querying are in a rollback segment that needs to be used for a data modification operation such as insert, update, or delete, a select may get killed with a snapshot too old message if those read consistent values are needed by you query.

The good news is that at least you get an error rather than wrong information, and you can usually work around the problem with additional resources:

Some combination of having bigger rollback segments (or sometimes more segments and extents of the same total size) and reducing the total volume of data modifications during your query can usually solve the problem.

I don't know of any switch that will cause data modifications to wait for your query to finish in this situation.

Mark W. Farnham
President
Rightsizing, Inc.
mwf_at_coat.com Received on Thu Feb 29 1996 - 16:32:22 CST