Re: When to drop indexes
Date: 1996/06/14
Message-ID: <olkPkTi00iWQI4eRFg_at_andrew.cmu.edu>#1/1
Excerpts from netnews.comp.databases.oracle: 30-May-96 When to drop
indexes by Chuck Hamilton_at_dvol.com
> For example, suppose I have a snapshot that has approx 1 millions rows
> in it. There are only two indexes on the snapshot - the snapshot index
> proper, and a user created index. The snapshot log says there's 54,000
> rows to be inserted. Should I drop the user index and rebuild it
> afterwards? Or should I leave it alone?
>
In this case, the insert size is 5% of the prior database size. My
intuition says that with a 5% insert it is best to leave the indexes in
place. With a 50% or more insert, or a full table replace, rebuilding
the index is best. On small tables (less than 100,000 rows) it doesn't
matter. On larger tables, an insert of between 10% and 50% is a gray
area. Does anyone have any hard data to check my intuition?
-Chris Received on Fri Jun 14 1996 - 00:00:00 CEST