> > I've read this paper ~2 years ago. My plans so far were:
> > 
> > 1. WAL in 7.1
> > 2. New (overwriting) storage manager in 7.2
> > 
> 
> Oh, so Vadim has overwriting storage manager concept for 7.2.
> Vadim, how will you keep old rows around for MVCC?

Just like you told about it - some outstanding files for old
versions. Something like Oracle' rollback segments.
And, for sure, this will be the most complex part of smgr and
that's why I think that we can't use their smgr if we're
going to keep MVCC.

As for WAL, WAL itself (as collection of routines to log changes,
create checkpoints etc) is 90% done. Now it has to be integrated
into system and the most hard part of this work are access methods
specific redo/undo functions. If we're going to use our access
methods then we'll have to write these functions for no matter
what WAL implementation will be used.

Vadim
 

Mon, 15 May 2000 13:23:29 -0700
"Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
RE: WAL versus Postgres (or: what goes around, comes ar
	   ound)