Re: Savepoints
Vadim Mikheev <vmikheev@sectorbase.com>
From: "Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
To: "'Bruce Momjian'" <pgman@candle.pha.pa.us>, PostgreSQL-development <pgsql-hackers@postgreSQL.org>
Date: 2002-01-23T23:22:42Z
Lists: pgsql-hackers
> I have talked in the past about a possible implementation of > savepoints/nested transactions. I would like to more formally outline > my ideas below. Well, I would like to do the same -:) > ... > There is no reason for other backend to be able to see savepoint undo > information, and keeping it private greatly simplifies the > implementation. Yes... and requires additional memory/disk space: we keep old records in data files and we'll store them again... How about: use overwriting smgr + put old records into rollback segments - RS - (you have to keep them somewhere till TX's running anyway) + use WAL only as REDO log (RS will be used to rollback TX' changes and WAL will be used for RS/data files recovery). Something like what Oracle does. Vadim