Re: [HACKERS] WIP: Faster Expression Processing v4
| От | Tom Lane |
|---|---|
| Тема | Re: [HACKERS] WIP: Faster Expression Processing v4 |
| Дата | |
| Msg-id | 9137.1489616217@sss.pgh.pa.us обсуждение |
| Ответ на | Re: [HACKERS] WIP: Faster Expression Processing v4 (Andres Freund <andres@anarazel.de>) |
| Ответы |
Re: [HACKERS] WIP: Faster Expression Processing v4
|
| Список | pgsql-hackers |
Andres Freund <andres@anarazel.de> writes:
> On 2017-03-15 17:33:46 -0400, Tom Lane wrote:
>> We could make the planner mark each table scan node with the highest
>> column number that the plan will access, and use that to drive a
>> slot_getsomeattrs call in advance of any access to tuple contents.
> probably isn't sufficient - we build non-virtual tuples in a good number
> of places (sorts, tuplestore using stuff like nodeMaterial, nodeHash.c
> output, ...). I suspect it'd have measurable negative consequences if
> we removed the deforming logic for all expressions/projections above
> such nodes. I guess we could just do such a logic for every Plan node?
[ scratches head... ] What deforming logic do you think I'm proposing
removing?
regards, tom lane
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