Re: New VACUUM FULL

Alvaro Herrera <alvherre@commandprompt.com> wrote:

> Hmm.  With this patch, if I do "vacuumdb -f" it will not vacuum the
> special system catalogs that can only be vacuumed with INPLACE, correct?

No. It will vacuum normal tables with FULL (rewrite), and system catalogs
with FULL INPLACE. FULL vacuums for system catalogs always fall back to
INPLACE vacuum silently.

But certainly we cannot recommend to use daily database-wide VACUUM FULLs
because they have higher costs than repeated FULL INPLACE vacuums.
FULL (rewrite) will not be cheaper for tables that have little dead tuples.
Just an idea, something like "vacuumdb -f --threshold=<some baseline>"
might be useful for users running daily "vacuumdb -f".

Regards,
---
Takahiro Itagaki
NTT Open Source Software Center