Re: Avoid MVCC using exclusive lock possible?

Andrew Sullivan a écrit :

>On Sun, Feb 29, 2004 at 10:43:34AM -0500, Tom Lane wrote:
>
>
>>general I think our VACUUM-based approach is superior to the
>>Oracle-style UNDO approach, because it pushes the maintenance overhead
>>out of foreground transaction processing and into a schedulable
>>background process. Certainly any Oracle DBA will tell you that huge
>>
>>
>
>I completely agree with this. If the recent work on lowering the
>overall cost ov VACUUM on loaded systems pays off, then I think there
>can be no argument that the work-now, vacuum-later strategy is the
>best approach, simply because it deals with the outlying and
>unexpected cases better than the alternatives. I know too many
>people who have been burned by running out of rollback segments when
>some use pattern emerged that they hadn't planned for.
>
>A
>
I agree too. The VACUUM aproach is better as it reduces fragmentation
and chained rows due to columns size change.