Re: forcing a rebuild of the visibility map

On Thu, Jun 16, 2016 at 2:33 AM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> Option name DISABLE_PAGE_SKIPPING is good to me.
> I'm still working on this, but here are some review comments.
>
> ---
> +CREATE FUNCTION pg_truncate_visibility_map(regclass)
> +RETURNS void
> +AS 'MODULE_PATHNAME', 'pg_truncate_visibility_map'
> +LANGUAGE C STRICT
> +PARALLEL UNSAFE; -- let's not make this any more dangerous
> +
>
> "REVOKE ALL ON FUNCTION pg_truncate_visibility_map(regclass) FROM
> PUBLIC;" is missing in pg_visibility/pg_visibility--1.0--1.1.sql.

OK, thanks. I'll fix that.

> I think that VACUUM with VERBOSE option can show the information for
> how many frozen pages we skipped like autovacuum does. Thought?
> Patch attached.

I'm not sure. The messages VACUUM emits are already quite long and
hard to read, and adding more lines to them might make that problem
worse. On the other hand, having more details can be helpful, too.

--
Robert Haas
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