RE: Avoid repeated PQfnumber() in pg_dump - Mailing list pgsql-hackers

From houzj.fnst@fujitsu.com
Subject RE: Avoid repeated PQfnumber() in pg_dump
Date
Msg-id OS0PR01MB5716E0112B1BAF4AD544EF4594129@OS0PR01MB5716.jpnprd01.prod.outlook.com
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In response to Re: Avoid repeated PQfnumber() in pg_dump  (Daniel Gustafsson <daniel@yesql.se>)
Responses Re: Avoid repeated PQfnumber() in pg_dump  (Daniel Gustafsson <daniel@yesql.se>)
List pgsql-hackers
On July 15, 2021 5:35 AM Daniel Gustafsson <daniel@yesql.se> wrote:
> > On 14 Jul 2021, at 10:54, houzj.fnst@fujitsu.com wrote:
>
> > Since PQfnumber() is not a cheap function, I think we'd better invoke
> > PQfnumber() out of the loop like the attatched patch.
>
> Looks good on a quick readthrough, and I didn't see any other similar
> codepaths in pg_dump on top of what you've fixed.

Thanks for reviewing the patch.
Added to the CF: https://commitfest.postgresql.org/34/3254/

> > After applying this change, I can see about 8% performance gain in my
> > test environment when dump table definitions which have many columns.
>
> Out of curiosity, how many columns are "many columns"?

I tried dump 10 table definitions while each table has 1000 columns
(maybe not real world case).

Best regards,
houzj



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