Re: [PATCH] Addition of some trivial auto vacuum logging

Royce Ausburn <royce.ml@inomial.com> writes:
>  The attached patch adds extra detail the the existing autovacuum log message that is emitted when the
log_autovacuum_min_durationthreshold is met, exposing the unremovable dead tuple count similar to what you get from
VACUUMVERBOSE.
 

> Sample log output (my addition in bold):

> LOG:  automatic vacuum of table "test.public.test": index scans: 0
>     pages: 0 removed, 5 remain
>     tuples: 0 removed, 1000 remain, 999 dead but not removable
>     system usage: CPU 0.00s/0.00u sec elapsed 0.00 sec

This proposal seems rather ill-designed.  In the first place, these
numbers are quite unrelated to vacuum duration, and in the second place,
most people who might need the info don't have that setting turned on
anyway.

I wonder whether it wouldn't be more helpful to have a pg_stat_all_tables
column that reports the number of unremovable tuples as of the last
vacuum.  I've been known to object to more per-table stats counters
in the past on the basis of space required, but perhaps this one would
be worth its keep.
        regards, tom lane