Re: Index bloat problem?

Bill,

> Honestly, this seems like an inordinate amount of
> babysitting for a production application.  I'm not
> sure if the client will be willing to accept it.

Well, then, tell them not to delete 75% of the rows in a table at once.  I
imagine that operation brought processing to a halt, too.

If the client isn't willing to accept the consequences of their own bad data
management, I'm not really sure what you expect us to do about it.

> Admittedly my knowledge of the inner workings of an
> RDBMS is limited, but could somebody explain to me why
> this would be so?  If you delete a bunch of rows why
> doesn't the index get updated at the same time?

It does get updated.  What doesn't happen is the space getting reclaimed.  In
a *normal* data situation, the dead nodes are recycled for new rows.   But
doing a massive delete operation upsets that, and generally needs to be
followed by a REINDEX.

> Is
> this a common issue among all RDBMSs or is it
> something that is PostgreSQL specific?

Speaking from experience, this sort of thing affects MSSQL as well, although
the maintenance routines are different.

--
Josh Berkus
Aglio Database Solutions
San Francisco