Re: Renaming of pg_xlog and pg_clog

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: Stephen Frost <sfrost@snowman.net>, Michael Paquier <michael.paquier@gmail.com>, David Steele <david@pgmasters.net>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2016-10-20T18:02:27Z
Lists: pgsql-hackers
On Thu, Oct 20, 2016 at 1:39 PM, Bruce Momjian <bruce@momjian.us> wrote:
> On Thu, Oct 20, 2016 at 12:29:47PM -0400, Robert Haas wrote:
>> > 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.
>>
>> I don't dispute the fact that you tend to think of it that way, but I
>> think it's a real stretch to say that "pg_xact" is a clear name from
>> the point of view of the uninitiated.  Now, maybe the point is to be a
>> little bit deliberately unclear, but "xact" for "transaction" is not a
>> lot better than "xlog" for "write-ahead log".  It's just arbitrary
>> abbreviations we made up and you either know what they mean or you
>> don't.  We could call it "pg_xkcd" and we wouldn't be removing much in
>> the way of clarity.
>
> What is your suggestion for a name?  If you have none, I suggest we use
> "pg_xact".

I'm not sure.  pg_transaction_status would be clear, but it's long.
Is pg_xact actually better than pg_clog?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


Commits

  1. Rename "pg_clog" directory to "pg_xact".

  2. Improve error reporting in pg_upgrade's file copying/linking/rewriting.