Re: Why does a normally fast query run so slow when the table is in a partition?

On 02/03/2011 07:29 AM, Bill Thoen wrote:
> Got it solved!
>
Great.
> The problem was one of two things,or maybe both. I had somehow gotten
> over 15 million records into the master table and even though I
> "deleted" them and run VACUUM ANALYZE over the table, they were still
> taking up space in the table.

If you want to delete every record in the table, use truncate (truncate
table only tablename;), it is far faster than delete all and clears out
the unused space.

"Vacuum analyze" just does a vacuum and an analyze. Vacuum does not
reclaim space but merely identifies "holes" in the table that can be
reused. "Vacuum full" will reclaim the space but is very slow. "Cluster"
is almost always the preferred way of reclaiming space.

Both "vacuum full" and "cluster" require an exclusive lock.

Cheers,
Steve