Re: postgres_fdw: Use COPY to speed up batch inserts
Matheus Alcantara <matheusssilv97@gmail.com>
From: "Matheus Alcantara" <matheusssilv97@gmail.com>
To: "Dewei Dai" <daidewei1970@163.com>, "Matheus Alcantara"
<matheusssilv97@gmail.com>, "Masahiko Sawada" <sawada.mshk@gmail.com>
Cc: "Andrew Dunstan" <andrew@dunslane.net>, "jian he"
<jian.universality@gmail.com>, "Tomas Vondra" <tomas@vondra.me>,
"pgsql-hackers" <pgsql-hackers@postgresql.org>
Date: 2026-01-05T13:43:52Z
Lists: pgsql-hackers
Attachments
- v9-0001-postgres_fdw-speed-up-batch-inserts-using-COPY.patch (text/plain) patch v9-0001
Hi, thank you for reviewing this patch! On Sat Jan 3, 2026 at 9:45 AM -03, Dewei Dai wrote: > 1 - in function `execute_foreign_modify_using_copy` > The `res` object obtained from the first call to `pgfdw_get_result` > is not freed, maybe you can use `PQclear` to release it > Fixed. > 2 - in function `execute_foreign_modify_using_copy` > After using `copy_data`,it appears it can be released by > calling `destroyStringInfo`. > I'm wondering if we should call destroyStringInfo(©_data) or pfree(copy_data.data). Other functions use the pfree version, so I decided to use the same. (I actually tried to use destroyStringInfo() but the postgres_fdw tests kept running for longer than usual, so I think that using the pfree is correct) > 3 - in function `convert_slot_to_copy_text` > The value returned by the OutputFunctionCall function can be > freed by calling pfree > We have other calls to OutputFunctionCall() on postgres_fdw.c and I'm not seeing a subsequent call to pfree. IIUC the returned valued will be allocated on the current memory context which will be free at the end of query execution, so I don't think that a pfree here is necessary, or I'm missing something? > 4 - in function `execute_foreign_modify_using_copy` > ```Send initial COPY data if the buffer reach the limit to avoid large > ``` > Typo: reach -> reaches > Fixed -- Matheus Alcantara EDB: https://www.enterprisedb.com