RE: [HACKERS] Savepoints...

> -----Original Message-----
> From: root(at)sunpine(dot)krs(dot)ru [mailto:root(at)sunpine(dot)krs(dot)ru]On Behalf Of Vadim
> Mikheev
> Sent: Thursday, June 17, 1999 12:58 PM
> To: Hiroshi Inoue
> Cc: PostgreSQL Developers List
> Subject: Re: [HACKERS] Savepoints...
>
>
> Hiroshi Inoue wrote:
> >
> > > - lmgr will remember command id when lock was acquired;
> >
> > Does this mean that many writing commands in a transaction
> > require many command id-s to remember ?
>
> Did you mean such cases:
>

Yes.

> begin;
> ...
> update t set...;
> ...
> update t set...;
> ...
> end;
>
> ?
>
> We'll remember command id for the first "update t" only
> (i.e. for the first ROW EXCLUSIVE mode lock over table t).
>

How to reduce lock counter for ROW EXCLUSIVE mode lock
over table t?

And more questions.

HEAP_MARKED_FOR_UPDATE state could be rollbacked ?

For example

..
[savepoint 1]
select .. from t1 where key=1 for update;
[savepoint 2]
select .. from t1 where key=1 for update;
[savepoint 3]
update t1 set .. where key=1;

Rollback to savepoint 3 OK ?
Rollback to savepoint 2 OK ?
Rollback to savepoint 1 OK ?

Regards.

Hiroshi Inoue
Inoue(at)tpf(dot)co(dot)jp