Re: Renaming of pg_xlog and pg_clog

* Robert Haas (robertmhaas(at)gmail(dot)com) wrote:
> On Wed, Oct 12, 2016 at 10:22 PM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
> > OK. I can live with that as well. Attached are three patches. The
> > pg_xlog -> pg_wal move, the pg_clog -> pg_transaction move, and the
> > pg_clog -> pg_xact move. Only one survivor to be chosen among the last
> > two ones.
>
> Committed 0001.

Glad to see that happen, finally.

> To be honest, I don't really like either pg_transaction or pg_xact.

> Neither name captures the fact that what we're really tracking here is
> the transaction *status*. pg_xact is slightly worse because it's a
> poor abbreviation for transaction, but I think the argument against
> even pg_transaction is similar to the one Tom previously levied
> against pg_logical - viz. "logical what?". The transaction themselves
> are not stored in the directory, just the commit status. The fact
> that commit status is saved is the source of the "c" in "clog".

This really needs to move forward also.

When it comes to the name, I tend to think of 'pg_xact' as saying "this
is where we persist info we need to keep about transactions." Today
that's just the commit status info, but I could imagine that there
might, someday, be other things that go in there. "pg_multixact" is
an example of something quite similar but does have more than just one
"thing." Also, using "pg_xact" and then "pg_subxact" and "pg_multixact"
bring them all under one consistent naming scheme.

Thanks!

Stephen