Re: add PROCESS_MAIN to VACUUM

On Tue, Mar 07, 2023 at 09:20:12AM +0900, Michael Paquier wrote:
> - * Do the actual work --- either FULL or "lazy" vacuum
> + * If PROCESS_MAIN is set (the default), it's time to vacuum the main
> + * relation. Otherwise, we can skip this part. If required, we'll process
> + * the TOAST table later.
>
> Should we mention that this part could be used for a toast table once
> we've already looped once through vacuum_rel() when toast_relid was
> set? VACOPT_PROCESS_MAIN is enforced a few lines down the road,
> still..

That did cross my mind, but I was worried that trying to explain all that
here could cause confusion.

If PROCESS_MAIN is set (the default), it's time to vacuum the main
relation. Otherwise, we can skip this part. If processing the TOAST
table is required (e.g., PROCESS_TOAST is set), we'll force
PROCESS_MAIN to be set when we recurse to the TOAST table so that it
gets processed here.

How does that sound?

--
Nathan Bossart
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