Re: [PATCH] Fix column name escaping in postgres_fdw stats import
Ayush Tiwari <ayushtiwari.slg01@gmail.com>
From: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
To: Etsuro Fujita <etsuro.fujita@gmail.com>
Cc: Alex Guo <guo.alex.hengchen@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, efujita@postgresql.org
Date: 2026-04-21T11:40:07Z
Lists: pgsql-hackers
Hi,
Thanks for the review!
On Tue, 21 Apr 2026 at 17:00, Etsuro Fujita <etsuro.fujita@gmail.com> wrote:
> On Tue, Apr 21, 2026 at 3:12 PM Alex Guo <guo.alex.hengchen@gmail.com>
> wrote:
> > On 4/21/26 4:43 AM, Ayush Tiwari wrote:
> > The new statistics import feature in postgres_fdw (commit 28972b6fc3d)
> > builds a remote query to fetch pg_stats rows, filtering by column name
> > with:
> >
> > AND attname = ANY('{col1, col2}'::text[])
> >
> > The column names are formatted with quote_identifier(), which only
> > escapes double quotes. But since the list is embedded inside a
> > single-quoted string literal, any single quote in a column name
> > breaks the literal and produces a syntax error on the remote server.
>
> > The attached patch switches to an ARRAY[] constructor with each
> > element escaped by deparseStringLiteral(), matching how schemaname
> > and tablename are already handled in the same function.
>
> Thanks for the report and patch!
>
> > It should also address the issue that was raised in [1].
>
> The root cause of this is the same as [1], so I think you should reply
> to the thread, rather than creating a new thread.
>
I faced the issue with the quoting scenario and was unaware of [1] then,
and that patch did not solve the issue regarding the quotes, which is
why I started this. Should I move this there? I've registered it in
commitfest: Fix column name escaping in postgres_fdw stats import
<https://commitfest.postgresql.org/patch/6695/>
>
> > I think the fix makes sense to me. Here, the column names are emitted as
> string content, thus deparseStringLiteral() is a better fit.
>
> +1
>
> > A small comment on the test:
> >
> > +ANALYZE VERBOSE simport_ft_quote; -- should work, not syntax
> error
> >
> > VERBOSE seems not needed.
>
> I think the option is needed; otherwise we cannot check that stats
> import was really done in the test.
>
Yeah, that was the intention.
Regards,
Ayush
Commits
Same data as JSON:
GET /api/v1/messages/:b64id/commits
the thread's linked commits as JSON, with link sources.
API reference →
-
postgres_fdw: Fix deparsing of remote column names in stats import.
- 5107398e6d5e 19 (unreleased) landed
-
Add support for importing statistics from remote servers.
- 28972b6fc3dc 19 (unreleased) cited