Sorry, I don't understand your exact question about pg_stats. In any case I
cannot make strict assumptions about data, because that greatly varies from
project to project (it's a SaaS) and over time. To give an idea the table
has some tens of millions of rows, each project has from a few thousands
Marco Colli writes:
> Unfortunately I don't get actual improvements. I use PG 11 and I run the
> following commands:
> ALTER TABLE subscriptions ALTER tags SET STATISTICS 1000;
> ANALYZE subscriptions;
> However the bias remains pretty much the same (slightly worse after). Any
> idea?
So what hav
Thanks Tom for the clear explanation.
Unfortunately I don't get actual improvements. I use PG 11 and I run the
following commands:
ALTER TABLE subscriptions ALTER tags SET STATISTICS 1000;
ANALYZE subscriptions;
However the bias remains pretty much the same (slightly worse after). Any
idea?
On S
Marco Colli writes:
> Let's say that you have a simple query like the following on a large table
> (for a multi-tenant application):
> SELECT "subscribers".* FROM "subscribers" WHERE "subscribers"."project_id"
> = 123 AND (tags @> ARRAY['de']::varchar[]);
> If you run EXPLAIN ANALYZE you can see
> Is one of those estimates way off reality, or is it only the conjunction
which is deranged?
The estimate is wrong *even with a single tag*, without the conjunction
(e.g. expected 3500, actual 20). Then the conjunction can make the bias
even worse...
On Sun, Feb 2, 2020 at 3:23 PM Justin Pryzby
On Sun, Feb 02, 2020 at 03:18:19PM +0100, Marco Colli wrote:
> Hello!
>
> Let's say that you have a simple query like the following on a large table
> (for a multi-tenant application):
> SELECT "subscribers".* FROM "subscribers" WHERE "subscribers"."project_id"
> = 123 AND (tags @> ARRAY['de']::va
Hello!
Let's say that you have a simple query like the following on a large table
(for a multi-tenant application):
SELECT "subscribers".* FROM "subscribers" WHERE "subscribers"."project_id"
= 123 AND (tags @> ARRAY['de']::varchar[]);
If you run EXPLAIN ANALYZE you can see that stats are complete
