Re: Internal fragmentations statistics Was: VACUUM FULL memory requirements

Le mardi 15 décembre 2009 à 00:04:47, Evan Rempel a écrit :

> Is there a command/tool that will report on how FULL a table is getting?
> If there is, how intrusive is it? How computationally heavy is it?
>
> We have a database that is approx 100 million rows with
> approx 2 million insert/updates per day. Each day old data
> is purged from the database. The end result is a mostly static
> footprint with regards to disk space used, but I would like to
> know how much room is usable inside the tables as well as the
> OS file system (that part is easy).
>

pgstattuple contrib module give such an information. But it requires an
exclusive lock on the table it's looking at, so it's quite intrusive. For more
details, the 8.4 documentation is interesting:
http://www.postgresql.org/docs/8.4/interactive/pgstattuple.html