Re: how to investigate GIN fast updates and cleanup cycles?

On Fri, Aug 28, 2015 at 11:18 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> It looks like a VACUUM will do the cleanup during the first ginbulkdelete
> call, so you could probably handle this by running a manual "VACUUM
> VERBOSE" with the smallest possible maintenance_work_mem, and canceling it
> as soon as you see something reported about the GIN index.

Since I'm back to running VACUUM VERBOSE by hand, can you clarify for me
how reducing maintenance_work_mem (currently 512MB) will speed it up? Will
it work in smaller chunks? So just do something like:

set maintenance_work_mem = '32MB';
VACUUM VERBOSE my_table';

How do I determine the smallest value possible? Just start small (32MB?)
and see if it fails, and increase until it doesn't?