Re: pg_waldump: support decoding of WAL inside tarfile

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Amul Sul <sulamul@gmail.com>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-09-29T15:15:31Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Move tar detection and compression logic to common.
- c8a350a43982 19 (unreleased) landed
pg_verifybackup: Enable WAL parsing for tar-format backups
- b3cf461b3cf9 19 (unreleased) landed
pg_waldump: Add support for reading WAL from tar archives
- b15c1513984e 19 (unreleased) landed
pg_waldump: Preparatory refactoring for tar archive WAL decoding.
- f8a0cd267170 19 (unreleased) landed
pg_verifybackup: Verify tar-format backups.
- 8dfd31290279 18.0 cited

On Thu, Sep 25, 2025 at 4:25 AM Amul Sul <sulamul@gmail.com> wrote:
> > Another thing that isn't so nice right now is that
> > verify_tar_archive() has to open and close the archive only for
> > init_tar_archive_reader() to be called to reopen it again just moments
> > later. It would be nicer to open the file just once and then keep it
> > open. Here again, I wonder if the separation of duties could be a bit
> > cleaner.
>
> Prefer to keep those separate, assuming that reopening the file won't
> cause any significant harm. Let me know if you think otherwise.

Well, I guess I'd like to know why we can't do better. I'm not really
worried about performance, but reopening the file means that you can
never make it work with reading from a pipe.

-- 
Robert Haas
EDB: http://www.enterprisedb.com