Re: plan time of MASSIVE partitioning ...

Boszormenyi Zoltan <zb@cybertec.at>

From: Boszormenyi Zoltan <zb@cybertec.at>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@commandprompt.com>, Stephen Frost <sfrost@snowman.net>, Hans-Jürgen Schönig <postgres@cybertec.at>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers Hackers <pgsql-hackers@postgresql.org>
Date: 2010-09-08T17:05:59Z
Lists: pgsql-hackers
Tom Lane írta:
> Boszormenyi Zoltan <zb@cybertec.at> writes:
>   
>> This applies to anything else that may need to be converted
>> from list to tree to decrease planning time. Like ec_members
>> in EquivalenceClass.
>>     
>
> AFAIR, canonical pathkeys are the *only* thing in the planner where pure
> pointer equality is interesting.  So I doubt this hack is of any use for
> EquivalenceClass, even if the lists were likely to be long which they
> aren't.
>
> 			regards, tom lane
>   

No, for EquivalanceClass->ec_member, I need to do something
funnier, like implement compare(Node *, Node *) and use that
instead of equal(Node *, Node *)... Something like nodeToString()
on both Node * and strcmp() the resulting strings.

-- 
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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
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