On 2014-04-08 09:37:33 -0400, Tom Lane wrote: > Andres Freund <and...@2ndquadrant.com> writes: > > On 2014-04-07 21:47:38 -0400, Tom Lane wrote: > >> Well, that is certainly messy. I think you could just use a local > >> HeapTupleData variable instead of palloc'ing every time, where "local" > >> means "has lifespan similar to the slot pointer". > > >> There's some vaguely similar hacking near the end of ExecDelete. > > > Yea, and some other places. I wonder if a ExecShallowMaterializeSlot() > > or something would be useful for me, that callsite and others? > > Don't like that name much, but I agree there's some room for a function > like this.
I am not the biggest fan either, for one it's really rather long, for another it's not really descriptive. One might think it's about toast or something. Do you have a better name? > I guess you're imagining that we'd add a HeapTupleData field > to TupleTableSlots, and use that for the workspace when this situation > arises? I wasn't really sure about the approach yet. Either do something like you describe (possibly reusing/recoining tts_minhdr?), or just allocate a HeapTupleData struct. > An alternative possibility would be to not invent a new function, but > just make ExecStoreTuple do this unconditionally when shouldFree=false. > Not sure if there'd be a noticeable runtime penalty. I think that's a viable alternative. > I know I've always thought > of slots as being fully independent storage, and in this case they > are not. Me to. I was initially rather confused by the memory corruptions I was seeing. I really thought that storing a tuple pointing to a buffer in the slot should "just work". 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
