Re: Getting acces to MVCC version number
Jean-Luc Lachance <jllachan@nsd.ca>
From: Jean-Luc Lachance <jllachan@nsd.ca>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-sql@postgresql.org, pgsql-general@postgresql.org
Date: 2002-09-23T15:47:01Z
Lists: pgsql-hackers, pgsql-general, pgsql-sql
That is great! Thanks for the info. Tom Lane wrote: > > Jean-Luc Lachance <jllachan@nsd.ca> writes: > > How about making available the MVCC last version number just like oid is > > available. This would simplify a lot of table design. You know, having > > to add a field "updated::timestamp" to detect when a record was updated > > while viewing it (a la pgaccess). > > That way, if the version number do not match, one would know that the > > reccord was updated since last retrieved. > > > What do think? > > I think it's already there: see xmin and cmin. Depending on your needs, > testing xmin might be enough (you'd only need to pay attention to cmin > if you wanted to notice changes within your own transaction). > > regards, tom lane