> -----Original Message-----
> From: Mikheev, Vadim
>
> 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.
As long as we use no overwriting manager
1) Rollback(data) isn't needed in case of a db crash.
2) Rollback(data) isn't needed to cancal a transaction entirely.
3) We don't need to mind the transaction size so much.
We can't use the db any longer if a REDO recovery fails now.
Under overwriting smgr we can't use the db any longer either
if rollback fails. How could PG be not less reliable than now ?
regards,
Hiroshi Inoue