Re: Full Table Scans

Tom Kyte has a good mantra for this, that goes something like this; "not all full table scans are bad, not all index scans are good"

Why do you want to reduce the full scans? Is anyone complaining about performance? If so, start with them and see what process they are undertaking. Probably use an extended trace on their session and understand what is causing the bottleneck.

If you are just trying to be proactive, perhaps start with Statspack and examine SQLs that are performing a lot of buffer accesses but are only returning a small number of rows. These SQLs may perform FULL table scans, or they may not. Some of the worst performance problems I've seen have been from forced index scans. Received on Tue Feb 08 2005 - 05:48:47 CST