public inbox for [email protected]  

help / color / mirror / Atom feed

From: Sami Imseih <[email protected]>
To: dinesh salve <[email protected]>
Cc: Tom Lane <[email protected]>
Cc: [email protected]
Cc: Jeff Davis <[email protected]>
Subject: Re: explain plans for foreign servers
Date: Wed, 3 Dec 2025 16:40:26 -0600
Message-ID: <CAA5RZ0skXF+d7SANSnMi3xMTs9zr6dZadyc5OEtPiMnw-rGizw@mail.gmail.com> (raw)
In-Reply-To: <CAP+B4TDxE3gbrixL9qR9F+CK_N_N0-HmXSL55QXVZNAorRHSHQ@mail.gmail.com>
References: <CAP+B4TD=iy-C2EnsrJgjpwSc7_4pd3Xh-gFzA0bwsw3q8u860g@mail.gmail.com>
	<CAA5RZ0vXiOiodrNQ-Va4FCAkXMpGA=GZDeKjFBRgRvHGuW7s7Q@mail.gmail.com>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<CAP+B4TDxE3gbrixL9qR9F+CK_N_N0-HmXSL55QXVZNAorRHSHQ@mail.gmail.com>

> I have refactored the commit on the latest version of PG and added a few more tests.

Thanks for the update!

> To simplify the roll out of this feature, I decided to work on analyze=false use case first.

I did not go through the entire patch yet, but a few things stood out
from my first pass.

1/
RegisterExtensionExplainOption is called during _PG_init, which is fine, but I
also wonder if we can call this during postgresExplainForeignScan as well?

The reason being is for _PG_init to be invoked, the user must load postgres_fdw
(LOAD, session_preload_libraries, shared_preload_libraries), which from my
experience is not very common in postgres_fdw. Users ordinarily just
"CREATE EXTENSION..."

So this needs to be documented [0]

2/

Does this behave sanely with multiple fdw connections? Can we add
tests for this?

+
+                               /*
+                                * add one of the tables to
foreign_scan_table to get the
+                                * serverId for remote plans
+                                */
+                               if (list_length(foreign_scan_table) == 0)
+                                       foreign_scan_table =
lappend_oid(foreign_scan_table, rte->relid);
+

[0] https://www.postgresql.org/docs/current/postgres-fdw.html

--
Sami Imseih
Amazon Web Services (AWS)

view thread (11+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: explain plans for foreign servers
  In-Reply-To: <CAA5RZ0skXF+d7SANSnMi3xMTs9zr6dZadyc5OEtPiMnw-rGizw@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox