Re: Some ideas about Vacuum

Hi,

Gokulakannan Somasundaram wrote:
> because of the contention. Am i missing something 
> here? While Vacuum is reading the DSM, operations may not be able to 
> update the bits. We need to put the DSM in shared memory, if all the 
> processes are going to update it, whereas if Vacuum is going to form the 
> DSM, then it might well be in the process local memory.  I can think of 
> things like False sharing which might be avoided. But i think the main 
> stuff is contention.

Ah, I begin to understand where you are coming from now, yes. However, 
(ab-)using the WAL and archiver still doesn't look like a good idea to me.

> Even in indexes, we might end up reading dead tuples. We would mark it 
> with LP_DEAD. So the overhead is less, but its there.

That's a good point, yes.

> Ofcourse its 
> natural to think of some background jobs during OLTP, and they will be 
> affected

Agreed.

Regards

Markus