On Mon, Feb 13, 2023 at 12:38:12PM -0500, Tom Lane wrote:
! Peter writes:
! > "rows=1" in the "Hash Anti Join" line is WRONG. It should be
! > 300. Or at least some thousands.
!
! FWIW, this behaves better in v14 and up. In older versions there's
! an ambiguity about what relpages=reltuples=
On Mon, Feb 13, 2023 at 12:38:12PM -0500, Tom Lane wrote:
! Peter writes:
! > "rows=1" in the "Hash Anti Join" line is WRONG. It should be
! > 300. Or at least some thousands.
!
! FWIW, this behaves better in v14 and up. In older versions there's
! an ambiguity about what relpages=reltuples=
Peter writes:
> "rows=1" in the "Hash Anti Join" line is WRONG. It should be
> 300. Or at least some thousands.
FWIW, this behaves better in v14 and up. In older versions there's
an ambiguity about what relpages=reltuples=0 means; it's the state
when ANALYZE has never yet examined the table
CREATE DATABASE ttc
WITH
OWNER = admin
ENCODING = 'UTF8'
LC_COLLATE = 'de_DE.UTF-8'
LC_CTYPE = 'de_DE.UTF-8'
TABLESPACE = pg_default
CONNECTION LIMIT = -1
IS_TEMPLATE = False;
select version();
PostgreSQL 12.13 on amd64-portbld-freebsd13.1, compiled by FreeBSD clang
TL;DR Version:
==
For a table where all rows have been deleted, under certain conditions
the planner does assume that it contains the values that were
previousely present, and will therefore assume that nothing needs to
be added, while in fact everything needs to be added.
-
This
