Re: Does VACUUM FULL need ANALYZE ?

[Venkata Balaji N <nag1010@xxxxxxxxx>]

On Sun, Jun 21, 2015 at 6:02 AM, Eoin O'Hehir <eoin.ohehir@xxxxxxxxxxxxxxxxx> wrote:

Eoin O'Hehir <eoin.ohehir@xxxxxxxxxxxxxxxxx>

8:59 PM (0 minutes ago)

to pgsql-admin-ow.

Hi,

I'd be grateful for some insight into the VACUUM functionality in 9.3. I read through the documentation and searched around a bit but could not find a definitive answer to this.

I'm setting up a weekly DB maintenance job for a 9.3 server.

Part of this will be a VACUUM FULL.

Is there any point in adding the ANALYZE option to the command ?

According to the 9.3 documentation, "VACUUM FULL rewrites the entire contents of the table into a new disk file with no extra space, allowing unused space to be returned to the operating system.". If the table is completely recreated then do I need to specifically ask for ANALYZE to happen or are the statistics updated automatically as the rows are written to the new version of the table ?

VACUUM FULL will only remove the bloats and releases the bloated space to the disk. ANALYZE updates the statistics which will make significant difference in the query's cost calculation.

Regards,

Venkata B N

Fujitsu Australia