Re: [HACKERS] RTE_NAMEDTUPLESTORE, enrtuples and comments - Mailing list pgsql-hackers

From Robert Haas
Subject Re: [HACKERS] RTE_NAMEDTUPLESTORE, enrtuples and comments
Date
Msg-id CA+TgmoY4QkyvNXtwk4CNAkSAFpkMM5VunUnq-x8gMoyuW4VbuQ@mail.gmail.com
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In response to Re: [HACKERS] RTE_NAMEDTUPLESTORE, enrtuples and comments  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [HACKERS] RTE_NAMEDTUPLESTORE, enrtuples and comments  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Tue, Jun 13, 2017 at 11:53 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> How does it break those properties?  I don't think enrtuples is being
>> modified by planning or execution as things stand.
>
> But it needs to be changeable, unless you like the proposition that we
> can never replan a query inside a trigger on the basis of new information
> about how big the transition table is.  Even if you're okay with that
> particular restriction, the NamedTupleStore stuff is supposed to be
> flexible enough to accommodate other use-cases, and some of them will
> surely not be okay with an immutable estimate for the store's size.

Hmm, true.  But even if we extracted enrtuples from the
RangeTbleEntry, there wouldn't be any mechanism to actually trigger
such a replan, would there?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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