Re: Synchronization levels in SR

On Tue, Sep 7, 2010 at 6:02 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> On Mon, 2010-09-06 at 22:32 +0200, Boszormenyi Zoltan wrote:
>> (in commit)
>> write wal record
>> release locks/etc   <xact2 can proceed from here
>> wait for sync ack
>>
>> In the first case, the contention is obviously increased.
>> With this, we are creating more idle time in the server
>> instead of letting other transactions do their jobs as soon
>> as possible. The second method was implemented in my
>> patch. Are there any drawbacks with this?
>
> Then I respectfully suggest that you're releasing locks too early.
>
> Your proposal would allow a 2nd user to see the results of the 1st
> user's transaction before the 1st user knew about whether it had
> committed or not.
>
> I know why you want that, but I don't think its right.

Agreed. That's why I put the wait before ProcArrayEndTransaction()
is called.

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center