Re: Renaming of pg_xlog and pg_clog

* David Fetter (david(at)fetter(dot)org) wrote:
> On Thu, Oct 20, 2016 at 02:23:32PM -0400, Tom Lane wrote:
> > Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> > > On Thu, Oct 20, 2016 at 2:09 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > >> We have the two precedents "pg_subtrans" and "pg_multixact", so
> > >> unless we want to get into renaming those too, I think "pg_trans"
> > >> and "pg_xact" are really the only options worth considering.
> > >>
> > >> Personally I'd go for "pg_trans", but it's only a weak preference.
> >
> > > Heaven forfend we actually use enough characters to make it self-documenting.
> >
> > $ ls $PGDATA
> > PG_VERSION pg_dynshmem/ pg_notify/ pg_stat_tmp/ postgresql.auto.conf
> > base/ pg_hba.conf pg_replslot/ pg_subtrans/ postgresql.conf
> > global/ pg_ident.conf pg_serial/ pg_tblspc/ postmaster.opts
> > pg_clog/ pg_logical/ pg_snapshots/ pg_twophase/ postmaster.pid
> > pg_commit_ts/ pg_multixact/ pg_stat/ pg_wal/
> >
> > I don't see one single one of those subdirectory names that I'd call
> > self-documenting.
>
> That's a problem we should do something about, even if we can't do it
> by renaming these all in one go. At the very least, we can do this
> for any new names.

I disagree that excessivly long names for files or directories are
useful and should be fully self-documenting. We should name our
directories with useful hints at what they are used for that remind
those who are knowledgable where things live. Secondary to that is
using an approach to naming which avoid implying anything about the
directories to those who are *not* knowledgable, which leads us to the
current discussion regarding the removal of directories with 'log' in
the name.

Individuals who are not knowledgable in this area are not going to get
any more benefit from a directory named 'pg_trans' or
'pg_transaction_status' than one named 'pg_clog' or 'pg_xact' and
therefore this whole line of reasoning is a red herring.

Thanks!

Stephen