On Mon, Jan 6, 2014 at 11:47 AM, Andres Freund <and...@2ndquadrant.com> wrote: > On 2014-01-06 11:08:41 -0500, Robert Haas wrote: >> On Mon, Jan 6, 2014 at 9:47 AM, Andres Freund <and...@2ndquadrant.com> wrote: >> > On 2014-01-06 09:43:45 -0500, Robert Haas wrote: >> >> > I actually vote for not allowing doing so at all by erroring out when >> >> > accessing a plpgsql variable created in an aborted subxact, unless you >> >> > explicitly signal that you want to do do so by calling some function >> >> > deleting the information about which subxact a variable was created >> >> > in. I have seen several bugs caused by people assuming that EXCEPTION >> >> > BLOCK/subtransaction rollback had some kind of effects on variables >> >> > created in them. And we just don't have much support for doing anything >> >> > in that direction safely. >> >> >> >> So, you want to let users do things that are unsafe, but only if they >> >> ask nicely? That hardly seems right. >> > >> > Well, no. If they have to use that function explicitly *before* the >> > subxact aborted, we can copy & detoast the value out of that context >> > safely. >> >> Oh, I see. I think that's pretty icky. Users won't expect (and will >> complain about) such restrictions. > > Yea. But at least it would fail reliably instead of just under > concurrency and other strange circumstances - and there'd be a safe way > out. Currently there seem to be all sorts of odd behaviour possible. > > I simply don't have a better idea :(
Is "forcibly detoast everything" a complete no-go? I realize there are performance concerns with that approach, but I'm not sure how realistic a worry it actually is. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
