On 8/23/24 09:33, Matthew Tice wrote:
>
>
> On Fri, Aug 23, 2024 at 10:26 AM Adrian Klaver
> <adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>> wrote:
> https://www.postgresql.org/docs/current/pgstattuple.html
> <https://www.postgresql.org/docs/current/pgstattuple.html>
>
> pgstattuple_approx(regclass) returns record
>
> pgstattuple_approx is a faster alternative to pgstattuple that
> returns approximate results.
>
> Not sure how you get exact count out of that?
>
>
> Maybe the wording is a little confusing to me. Under the section
> for pgstattuple_approx:
> "pgstattuple_approx tries to avoid the full-table scan and returns exact
> dead tuple statistics along with an approximation of the number and size
> of live tuples and free space."
Yeah, see what you mean.
The part that bears more investigating for this case is:
"It does this by skipping pages that have only visible tuples according
to the visibility map (if a page has the corresponding VM bit set, then
it is assumed to contain no dead tuples).
Wondering if PostgreSQl-compatible covers this?
--
Adrian Klaver
adrian.klaver@aklaver.com
