Re: Remove xmin and cmin from frozen tuples

Josh Berkus <josh@agliodbs.com>

From: Josh Berkus <josh@agliodbs.com>
To: pgsql-hackers@postgresql.org
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, ITAGAKI Takahiro <itagaki.takahiro@lab.ntt.co.jp>
Date: 2005-09-01T04:14:42Z
Lists: pgsql-hackers
Alvaro,

> One thing that comes to mind is that this makes somewhat easier to build
> a tool to write pre-built tables, for bulk-loading purposes.  You just
> construct the binary file with the HEAP_FROZEN bit set, and then attach
> the file to a dummy table.  (Then again, you can do it today, using a
> Xmin of FrozenTransactionId.  I wonder why the Bizgres people isn't
> advocating a tool to do that.  It is very hard to do with user-defined
> types, but for BI/DW you mostly don't need those, do you?)

Hmmm ... can you expand on this a little?  We'd discussed "frozen partitions" 
but hadn't thought to get around to them for a while, expecting the kind of 
issues which Tom just raised.

-- 
Josh Berkus
Aglio Database Solutions
San Francisco