Copy paste error
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/17/multivariate-statistics-examples.html
Description:
CREATE STATISTICS stts (dependencies) ON a, b FROM t;
ANALYZE t;
EXPLAIN (ANALYZE, TIMING OFF) SELECT * FROM t WHERE a = 1 AND b = 1;
QUERY PLAN
-------------------------------------------------------------------------------
Seq Scan on t (cost=0.00..195.00 rows=100 width=8) (actual rows=100
loops=1)
Filter: ((a = 1) AND (b = 1))
Rows Removed by Filter: 9900
The result of the explain is a copy paste of previous example, so this
example looks like the statistic doesn't improve things
On Thu, Feb 13, 2025 at 7:44 AM PG Doc comments form <noreply@postgresql.org>
wrote:
The following documentation comment has been logged on the website:
Page:
https://www.postgresql.org/docs/17/multivariate-statistics-examples.html
Description:CREATE STATISTICS stts (dependencies) ON a, b FROM t;
ANALYZE t;
EXPLAIN (ANALYZE, TIMING OFF) SELECT * FROM t WHERE a = 1 AND b = 1;
QUERY PLAN-------------------------------------------------------------------------------
Seq Scan on t (cost=0.00..195.00 rows=100 width=8) (actual rows=100
loops=1)
Filter: ((a = 1) AND (b = 1))
Rows Removed by Filter: 9900The result of the explain is a copy paste of previous example, so this
example looks like the statistic doesn't improve things
Look more closely, and read the surrounding text. It talks about the
problem being the rows estimate.
David J.
Man... I looked at it 50 times before I posted that report. Sorry!
Totally correct. Nothing to see here.
On Thu, 13 Feb 2025 at 14:49, David G. Johnston <david.g.johnston@gmail.com>
wrote:
Show quoted text
On Thu, Feb 13, 2025 at 7:44 AM PG Doc comments form <
noreply@postgresql.org> wrote:The following documentation comment has been logged on the website:
Page:
https://www.postgresql.org/docs/17/multivariate-statistics-examples.html
Description:CREATE STATISTICS stts (dependencies) ON a, b FROM t;
ANALYZE t;
EXPLAIN (ANALYZE, TIMING OFF) SELECT * FROM t WHERE a = 1 AND b = 1;
QUERY PLAN-------------------------------------------------------------------------------
Seq Scan on t (cost=0.00..195.00 rows=100 width=8) (actual rows=100
loops=1)
Filter: ((a = 1) AND (b = 1))
Rows Removed by Filter: 9900The result of the explain is a copy paste of previous example, so this
example looks like the statistic doesn't improve thingsLook more closely, and read the surrounding text. It talks about the
problem being the rows estimate.David J.