Re: [HACKERS] proposal: session server side variables

> ok understand

Good. So we seem to agree that GUCS are transactional?

> The logic depends on transactions and on nesting level (nesting doesn't
> depends on transactions only)

Yep, it probably also happens with LOCAL which hides the previous value 
and restores the initial one when exiting.

> void AtEOXact_GUC(bool isCommit, int nestLevel)
>
> Probably we should to use CallXactCallbacks instead - then is not a
> performance impact when there are not transactional variables.

I do not understand your point.

It is a very good thing that GUCs are transactional, and this should not 
be changed, it is a useful feature! Much more useful than non 
transactional.

Moreover I think that transactional is expensive when writing things to 
disk, but in memory the overhead is reduced, and if you need it then you 
need it.

-- 
Fabien.