Re: vacuumdb: add --dry-run

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Corey Huinker <corey.huinker@gmail.com>

Cc: Chao Li <li.evan.chao@gmail.com>, pgsql-hackers@postgresql.org

Date: 2025-11-19T22:44:03Z

Lists: pgsql-hackers

Commits

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Add ParallelSlotSetIdle().
- 750816971b35 19 (unreleased) landed
vacuumdb: Add --dry-run.
- d107176d27c7 19 (unreleased) landed
vacuumdb: Move some variables to the vacuumingOptions struct.
- cf1450e57799 19 (unreleased) landed
Log a note at program start when running in dry-run mode
- c05dee191125 19 (unreleased) cited

On Wed, Nov 19, 2025 at 05:23:48PM -0500, Corey Huinker wrote:
> Now with zero hangs and some test cases. I didn't create a function (yet)
> as it seemed trivial.

I still think it could be worth moving the dry-run code into
run_vacuum_command() (which might entail moving the calls to
ParallelSlotSetHandler() there, too).  We can probably piggy-back on the
"if (echo)" branch in that function.

Also, we can probably skip the executeCommand() calls for
--analyze-in-stages.

-- 
nathan