Re: Indexes growing continuously

[Mike Mascari <mascarm(at)mascari(dot)com>]

Daniele Orlandi wrote:
> 
> Hi,
> 
> I'm running PostgreSQL 6.5.3 on Linux-2.2.12 on a 2-way SMP machine.
> I noticed that even after VACUUMing there are some indexes that still
> remain very big.
> 
> For example, here's what I found for pg_attribute:
> 
> -rw-------   1 postgres postgres   122880 Apr  4 15:24 pg_attribute
> -rw-------   1 postgres postgres 17055744 Apr  4 15:24
> pg_attribute_attrelid_index
> -rw-------   1 postgres postgres 50176000 Apr  4 15:24
> pg_attribute_relid_attnam_index
> -rw-------   1 postgres postgres 20758528 Apr  4 15:24
> pg_attribute_relid_attnum_index
> 
> I know I can fix this by recreating the indexes, but I don't know how to
> do it for a system table and if it's safe.
> 
> Any hints ?

Unfortunately, this is a bug in PostgreSQL with respect to system
indexes. You can safely drop/create user indexes, but not system
ones. The only way to reclaim the space used is to dump/reload
your database. Under 7.0, I *believe* Hiroshi's REINDEX command
(please correct me someone if I'm wrong) will allow you to
reconstruct system indexes, but the root problem still exists...

Hope that helps, 

Mike Mascari