Re: One-time plans
| От | Tom Lane |
|---|---|
| Тема | Re: One-time plans |
| Дата | |
| Msg-id | 10645.1175530835@sss.pgh.pa.us обсуждение исходный текст |
| Ответ на | One-time plans ("Simon Riggs" <simon@2ndquadrant.com>) |
| Ответы |
Re: One-time plans
|
| Список | pgsql-hackers |
"Simon Riggs" <simon@2ndquadrant.com> writes:
> ISTM we've just invented the concept of one-time plans to allow CREATE
> INDEX to work effectively with HOT.
> I'd like to extend that thought back over towards constraint exclusion.
> Currently we don't allow STABLE functions to be used for constraint
> exclusion because that mean plans were valid only if they are
> immediately executed.
> It seems like a very small act to force the plan to be one-time only
> when we have successfully used a STABLE function to exclude a table.
No. STABLE functions are not stable enough for that --- you'd have to
assume they are unchanging across the whole transaction.
regards, tom lane
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