Re: extended operator classes vs. type interfaces - Mailing list pgsql-hackers

From Jeff Davis
Subject Re: extended operator classes vs. type interfaces
Date
Msg-id 1270924225.5250.14.camel@jdavis
Whole thread Raw
In response to Re: extended operator classes vs. type interfaces  (Yeb Havinga <yebhavinga@gmail.com>)
Responses Re: extended operator classes vs. type interfaces  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Sat, 2010-04-10 at 20:25 +0200, Yeb Havinga wrote:
> I was thinking of a case for instance for ranges a,b,c in relations 
> A,B,C respectively, where  a && b and b && c, but not a && c. Would the 
> planner consider a join path of table A and C first, then that result 
> with B. After looking in doxygen, it looks like having && defined 
> without MERGES is what prevents this unwanted behaviour, since that 
> prevents a,b and c to become members of the same equivalence class. 

Interesting, I would have to make sure that didn't happen. Most likely
there would be a new property like "RANGEMERGES", it wouldn't reuse the
existing MERGES property.

> Sorry for the spam on the list.

Not at all, it's an interesting point.

Regards,Jeff Davis



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