Re: What are nested transactions then? was Nested

"John Sidney-Woollett" <johnsw(at)wardbrook(dot)com> writes:
> Maybe, (don't shoot me) better procedural (pl/pgsql) error/exception
> handling ought to be a dealt with before nested transaction support?

They are largely the same problem. The representational issues for
keeping track of nested-transaction commit states are solved, at least
on paper --- see the pghackers archives. The big nut to crack is that
all of the error-handling logic in the backend is based on the
assumption that any error kills the transaction and allows all transient
state to be thrown away. Partial cleanup of transient state is simply
not there, and it's not clear how to add it without (a) a lot of new
code, (b) a big performance hit, and (c) tons of new bugs.

regards, tom lane