Re: Re: BUG #12990: Missing pg_multixact/members files (appears to have wrapped, then truncated)

I sure wish this had arrived two minutes earlier ...

Robert Haas wrote:

> Putting the period inside the parentheses here looks weird?
>
> +                                  "This command would create a
> multixact with %u members, which exceeds remaining space (%u
> members.)",
>
> Maybe rephrase as: "This command would create a multixact with %u
> members, but the remaining space is only enough for %u members."

WFM, will change.

> I don't think this should have a comma:
>
> +                 errhint("Execute a database-wide VACUUM in that
> database, with reduced vacuum_multixact_freeze_min_age and
> vacuum_multixact_freeze_table_age settings.")));

Ditto.

> This looks like excess brace-ifiaction:
>
> +    if (start < boundary)
> +    {
> +        return finish >= boundary || finish < start;
> +    }
> +    else
> +    {
> +        return finish >= boundary && finish < start;
> +    }

Yeah, agreed.  Will undo that change.  (I disliked the comment above the
indented single-statement, so added braces, but then moved the comment.
I should have removed the braces at that point.)

> I think this is confusing:
>
> +/*
> + * Read the offset of the first member of the given multixact.
> + */
>
> This is confusing to me because the two subdirectories of pg_multixact
> are called "members" and "offsets".  Here you are talking about the
> offset of the first member.  Maybe I'm just slow, but that seems like
> conflating terminology.  You end up with a function called
> read_offset_for_multi() that is actually looking up information about
> members.  Ick.

Yeah, I introduced the confusing terminology while inventing multixacts
initially and have regretted it many times.  I will think about a better
name for this.  (Meanwhile, on IM Robert suggested
find_start_of_first_multi_member)

--
Álvaro Herrera                http://www.2ndQuadrant.com/
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