Horton

Re: Use pg_pwritev_with_retry() instead of write() in dir_open_for_write() to avoid partial writes?

Andres Freund <andres@anarazel.de>

View thread View on postgr.es
From: Andres Freund <andres@anarazel.de>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Nathan Bossart <nathandbossart@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-02-14T01:10:56Z
Lists: pgsql-hackers 
Hi,

On 2023-02-12 09:31:36 -0800, Andres Freund wrote:
> Another thing: I think we should either avoid iterating over all the IOVs if
> we don't need them, or, even better, initialize the array as a constant, once.

I just tried to use pg_pwrite_zeros - and couldn't because it doesn't have an
offset parameter.  Huh, what lead to the function being so constrained?

- Andres

Commits

  1. Revise pg_pwrite_zeros()

  2. Use pg_pwrite_zeros() in walmethods.c

  3. Introduce pg_pwrite_zeros() in fileutils.c

  4. Move pg_pwritev_with_retry() to src/common/file_utils.c

  5. Restore pg_pread and friends.

  6. Remove dead pread and pwrite replacement code.