Re: pg_total_relation_size() and CHECKPOINT

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

"Zubkovsky, Sergey" <Sergey(dot)Zubkovsky(at)transas(dot)com> writes:
> I've detected that a result value of pg_total_relation_size() for an
> actively updated table might be significantly differ from a result that
> is returned after explicit CHECKPOINT command execution.

Uh, can you show a specific example of what you mean?

> I understand the reasons of such behavior: cache buffers must be flushed
> in order to be sure that pg_total_relation_size() result will be like we
> expect.

I wouldn't think so.  The space for a page is allocated immediately when
needed --- its *contents* might not be up to date, but that shouldn't
affect pg_total_relation_size.

			regards, tom lane