Re: interpret vacuum verbose output

Shankar K <shan0075@yahoo.com> writes:
> I'm trying to evaluate the frequecy to run vacuum
> analyze on key tables.  so if anyone could help me to
> interpret the output of vacuum analyze verbose output
> that would be great.

> INFO:  Removed 55448 tuples in 2367 pages.
>     CPU 0.04s/0.11u sec elapsed 0.41 sec.
> INFO:  Pages 11266: Changed 4, Empty 0; Tup 231: Vac
> 55448, Keep 0, UnUsed 205434.

This says that you have 231 live tuples versus 55448 that were removed ---
in other words, less than one-half of one percent of your table was
current data.  You need to vacuum this table a LOT more often than
you are doing.

You will need a VACUUM FULL and a REINDEX to get the table and index
physical sizes down to something reasonable, after which a more rigorous
schedule of plain vacuums ought to keep things in shape.

            regards, tom lane