On Sun, Nov 13, 2011 at 11:16 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> While investigating bug #6291 I was somewhat surprised to discover
> $SUBJECT.  The cause turns out to be this kluge in alter_table.sql:
>
>        select virtualtransaction
>        from pg_locks
>        where transactionid = txid_current()::integer

...

> that plasters on the appropriate epoch value for an
> assumed-to-be-current-or-recent xid, and returns something that squares
> with the txid_snapshot functions.  Then the test could be coded without
> kluges as

That fixes the test, but it doesn't fix the unreasonability of this situation.

We need a function called transactionid_current() so a normal user can write

       select virtualtransaction
       from pg_locks
       where transactionid = transactionid_current()

and have it "just work".

We need a function whose behaviour matches xid columns in pg_locks and
elsewhere and that doesn't need to have anything to do with txid
datatype.

-- 
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to