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Message-ID: <1013bd5d-5356-497b-ae06-c02dc53caf92@aklaver.com>
Date: Wed, 21 Jan 2026 08:59:17 -0800
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Subject: Re: pgBadger and postgres_fdw
To: Colin 't Hart <colinthart@gmail.com>
Cc: PostgreSQL General <pgsql-general@lists.postgresql.org>
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From: Adrian Klaver <adrian.klaver@aklaver.com>
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On 1/21/26 08:12, Colin 't Hart wrote:

> 6. The 19 slowest queries in a 4 hour period are between 2 and 37 
> minutes, with an average of over 10 minutes; they are all `fetch 100 
> from c2`.
> 
> The slowness itself isn't my question here; it was caused by having too 
> few cores in the new environment, while the application was still 
> assuming the higher core count and generating too many concurrent processes.
> 
> My question is how to identify which connections / queries from 
> postgres_fdw are generating the `fetch 100 from c2` queries, which, in 
> turn, may quite possibly lead to a feature request for having these 
> named uniquely.

My guess not.

See:

https://github.com/postgres/postgres/blob/master/contrib/postgres_fdw/postgres_fdw.c

Starting at line ~5212

fetch_size = 100;

and ending at line ~5234

/* Construct command to fetch rows from remote. */
	snprintf(fetch_sql, sizeof(fetch_sql), "FETCH %d FROM c%u",
			 fetch_size, cursor_number);

So c2 is a cursor number.

> 
> Thanks,
> 
> Colin
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com