Re: parallel mode and parallel contexts

On Tue, Jan 6, 2015 at 4:37 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> So when you say "Only the top frame of the transaction state stack is
> copied" you don't mean the top, you mean the bottom (the latest
> subxact)? Which then becomes the top in the parallel worker? OK...

The item most recently added to the stack is properly called the top,
but I guess it's confusing in this case because the item on the bottom
of the stack is referred to as the TopTransaction. I'll see if I can
rephrase that.

> Those comments really belong in a README, not the first visible
> comment in xact.c

OK.

> You need to start with the explanation that parallel workers have a
> faked-up xact stack to make it easier to copy and manage. That is
> valid because we never change xact state during a worker operation.

OK.

--
Robert Haas
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