From: | Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> |
---|---|
To: | Tomas Vondra <tomas(dot)vondra(at)postgresql(dot)org> |
Cc: | pgsql-committers(at)lists(dot)postgresql(dot)org |
Subject: | Re: pgsql: Sample postgres_fdw tables remotely during ANALYZE |
Date: | 2023-01-12 11:17:46 |
Message-ID: | 20230112111746.uoowzww6lt2ypldg@alvherre.pgsql |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-committers |
On 2022-Dec-30, Tomas Vondra wrote:
> Sample postgres_fdw tables remotely during ANALYZE
>
> When collecting ANALYZE sample on foreign tables, postgres_fdw fetched
> all rows and performed the sampling locally. For large tables this means
> transferring and immediately discarding large amounts of data.
>
> This commit allows the sampling to be performed on the remote server,
> transferring only the much smaller sample. The sampling is performed
> using the built-in TABLESAMPLE methods (system, bernoulli) or random()
> function, depending on the remote server version.
>
> Remote sampling can be enabled by analyze_sampling on the foreign server
> and/or foreign table, with supported values 'off', 'auto', 'system',
> 'bernoulli' and 'random'. The default value is 'auto' which uses either
> 'bernoulli' (TABLESAMPLE method) or 'random' (for remote servers without
> TABLESAMPLE support).
You left out the Discussion line, so here's the link:
https://postgr.es/m/151e835f-55d6-ddbc-b5b4-07ee606aba44@enterprisedb.com
--
Álvaro Herrera 48°01'N 7°57'E — https://www.EnterpriseDB.com/
"Nunca se desea ardientemente lo que solo se desea por razón" (F. Alexandre)
From | Date | Subject | |
---|---|---|---|
Next Message | Amit Langote | 2023-01-12 13:30:25 | Re: pgsql: Improve handling of inherited GENERATED expressions. |
Previous Message | Andrew Dunstan | 2023-01-12 10:52:00 | Re: pgsql: Improve handling of inherited GENERATED expressions. |