Tom Lane wrote:
> We should not *force* people to have an index. If the master table very
> seldom changes, then an index on the referencing table will be a net
> loss (at least as far as the foreign-key ops go). You'll pay for it on
> every referencing-table update, and use it only seldom.
Not only that but it's non standard ... people porting code over which
correctly defines an explicit index when appropriate would end up with
two of them.
> Possibly there should be an entry in the "performance tips" chapter
> recommending that people consider adding an index on the referencing
> column if they are concerned about the speed of updates to the
> referenced table. But I dislike software that considers itself smarter
> than the DBA.
This is a much better idea.
--
Don Baccus
Portland, OR
http://donb.photo.net, http://birdnotes.net, http://openacs.org