Re: idle in txn query cancellation

On Sat, 2010-02-13 at 22:37 +0100, Andres Freund wrote:
> On a related note I would also like to get rid of the restriction that
> a normal query cancellation will only be done if no subtransactions
> are stacked. 
> But I guess its too late for that? (I have a patch ready, some cleanup
> would be needed)
> The latter works by:
> - adding a explicit error code (which should be done regardless of
> this 
> discussion)
> - avoiding to catch such error at a few places (plperl, plpython)
> - recursively aborting the subtransactions once the mainloop is
> reached
> - relying on the fact that the cancellation signal will get resent
> - possibly escalating to a FATAL if nothing happens after a certain
> number of tries

Such an action needs to have a good, clear theoretical explanation with
it to show that the interaction with savepoints is a good one.

I toyed with the idea of a new level between ERROR and FATAL to allow
ERRORs to be handled by savepoints still in all cases.

-- Simon Riggs           www.2ndQuadrant.com