Re: [PATCH] add relation and block-level filtering to pg_waldump

On Mon, Mar 21, 2022 at 4:39 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:

[snip]

I guess you did this because init fork references aren't really
> expected in the WAL, but I think it's more consistent to allow up to
> MAX_FORKNUM, not least because your documentation mentions 3 as a
> valid value. So I adjust this to allow MAX_FORKNUM. Make sense?
>

Makes sense, but I think I'd actually thought it was +1 of the max forks,
so you give me more credit than I deserve in this case... :-)

> Here are some more details I noticed, as a likely future user of this
> very handy feature, which I haven't changed, because they seem more
> debatable and you might disagree...
>
> 1. I think it'd be less surprising if the default value for --fork
> wasn't 0... why not show all forks?
>

Agreed; made it default to all, with the ability to filter down if desired.

> 2. I think it'd be less surprising if --fork without --relation
> either raised an error (like --block without --relation), or were
> allowed, with the meaning "show me this fork of all relations".
>

Agreed; reworked to support the use case of only showing target forks.

> 3. It seems funny to have no short switch for --fork when everything
> else has one... what about -F?
>

Good idea; I'd hadn't seen capitals in the getopt list so didn't consider
them, but I like this.

Enclosed is v6, incorporating these fixes and docs tweaks.

Best,

David