On 2014-04-07 15:58:31 -0400, Tom Lane wrote: > Andres Freund <and...@2ndquadrant.com> writes: > > I've the need to persist a the result of an index_getnext() in a tuple > > slot. I don't want to unneccessarily duplicate the tuple data itself, so > > I'd like to use ExecStoreTuple(buffer = real_buffer) notion. But since > > the next index_getnext()/index_endscan() will overwrite/release the > > heaptuple I need to copy the HeapTupleData(). > > It'd be rather useful to be able to do ExecStoreTuple(tuple, slot, > > some_buffer, true), i.e. hav ethe HeapTupleData struct freed *and* the > > buffer pinned. There's an Assert preventing that though. > > There's an assumption that if you are asking to pin a buffer, the tuple > pointer you're passing is pointing into that buffer (and is therefore not > something that could be pfree'd). If it isn't pointing into a buffer, > the tuple slot is not the place to be keeping the buffer reference.
Yea. I *have* a HeapTupleData struct pointing into the buffer. It's just that the lifetime of the indexscans's xs_ctup isn't sufficient for my case. So I have to allocate a new HeapTupleData struct, *again* pointing into the buffer. I'd like to manage the lifetime of that HeapTupleData struct (*not* the entire HeapTupleHeader blob) via the slot. That doesn't sound too crazy to me? Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
