Re: Option to not use ringbuffer in VACUUM, using it in failsafe mode

On Sat, 1 Apr 2023 at 13:24, Melanie Plageman <melanieplageman(at)gmail(dot)com> wrote:
> Your diff LGTM.
>
> Earlier upthread in [1], Bharath had mentioned in a review comment about
> removing the global variables that he would have expected the analogous
> global in analyze.c to also be removed (vac_strategy [and analyze.c also
> has anl_context]).
>
> I looked into doing this, and this is what I found out (see full
> rationale in [2]):
>
> > it is a bit harder to remove it from analyze because acquire_func
> > doesn't take the buffer access strategy as a parameter and
> > acquire_sample_rows uses the vac_context global variable to pass to
> > table_scan_analyze_next_block().
>
> I don't know if this is worth mentioning in the commit removing the
> other globals? Maybe it will just make it more confusing...

I did look at that, but it seems a little tricky to make work unless
the AcquireSampleRowsFunc signature was changed. To me, it just does
not seem worth doing that to get rid of the two globals in analyze.c.

I pushed the patch with just the vacuum.c changes.

David