On 2019-09-12 21:04:25 +0200, Peter J. Holzer wrote:
> On 2019-09-12 12:54:55 -0400, Tom Lane wrote:
> > It's not taking the partial-index filter into account in that, I
> > suspect, which skews the results in this case --- but that would be
> > hard to account for accurately.
>
> Hmm. Wouldn't th
On 2019-09-12 12:54:55 -0400, Tom Lane wrote:
> "Peter J. Holzer" writes:
> > we'll consider just three columns, which we unimaginatively call a, b,
> > and c. There are also three indexes:
>
> > t_a_idx btree (a) WHERE a IS NOT NULL
> > t_b_idx btree (b) WHERE b IS NOT NULL
> > t
"Peter J. Holzer" writes:
> we'll consider just three columns, which we unimaginatively call a, b,
> and c. There are also three indexes:
> t_a_idx btree (a) WHERE a IS NOT NULL
> t_b_idx btree (b) WHERE b IS NOT NULL
> t_a_b_idx btree (a, b) WHERE a IS NOT NULL AND b IS NOT NULL
[PostgreSQL 11.5 (Ubuntu 11.5-1.pgdg18.04+1) on x86_64-pc-linux-gnu]
I have a table with many columns and many indexes (actually many tables
with many columns and many indexes), but for the sake of this posting,
we'll consider just three columns, which we unimaginatively call a, b,
and c. There ar
