From: | Ron <ronljohnsonjr(at)gmail(dot)com> |
---|---|
To: | pgsql-admin(at)lists(dot)postgresql(dot)org |
Subject: | Re: time taking deletion on large tables |
Date: | 2020-12-03 15:48:46 |
Message-ID: | 5f37b65c-4b3a-9f5f-85fb-2fc3c7a6f530@gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-admin pgsql-docs pgsql-in-general pgsql-performance |
On 12/3/20 8:45 AM, Atul Kumar wrote:
> Hi,
>
> The feed_posts table has over 50 Million rows.
>
> When I m deleting all rows of a certain type that are over 60 days old.
>
> When I try to do a delete like this: it hangs for an entire day, so I
> need to kill it with pg_terminate_backend(pid).
>
> DELETE FROM feed_posts
> WHERE feed_definition_id = 'bf33573d-936e-4e55-8607-72b685d2cbae'
> AND created_at > '2020-05-11 00:00:00'
> AND created_at < '2020-05-12 00:00:00';
>
> So– I need help in figuring out how to do large deletes on a
> production database during normal hours.
Presumably there is an index on created_at?
What about feed_definition_id?
> explain plan is given below
>
>
>
> "Delete on feed_posts (cost=1156.57..195748.88 rows=15534 width=6)"
> " -> Bitmap Heap Scan on feed_posts (cost=1156.57..195748.88
> rows=15534 width=6)"
> " Recheck Cond: ((created_at >= '2020-05-11 00:00:00'::timestamp
> without time zone) AND (created_at <= '2020-05-12 00:00:00'::timestamp
> without time zone))"
> " Filter: (feed_definition_id = 'bf33573d-936e-4e55-8607-72b685d2cbae'::uuid)"
> " -> Bitmap Index Scan on feed_posts_created_at (cost=0.00..1152.68
> rows=54812 width=0)"
> " Index Cond: ((created_at >= '2020-05-11 00:00:00'::timestamp without
> time zone) AND (created_at <= '2020-05-12 00:00:00'::timestamp without
> time zone))"
Have you recently analyzed the table?
--
Angular momentum makes the world go 'round.
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2020-12-03 16:16:16 | Re: time taking deletion on large tables |
Previous Message | Justin Pryzby | 2020-12-03 15:36:12 | Re: time taking deletion on large tables |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2020-12-03 16:16:16 | Re: time taking deletion on large tables |
Previous Message | Justin Pryzby | 2020-12-03 15:36:12 | Re: time taking deletion on large tables |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2020-12-03 16:16:16 | Re: time taking deletion on large tables |
Previous Message | Justin Pryzby | 2020-12-03 15:36:12 | Re: time taking deletion on large tables |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2020-12-03 16:16:16 | Re: time taking deletion on large tables |
Previous Message | Justin Pryzby | 2020-12-03 15:36:12 | Re: time taking deletion on large tables |