Re: Estimation problem with a LIKE clause containing a / - Mailing list pgsql-performance

From Gregory Stark
Subject Re: Estimation problem with a LIKE clause containing a /
Date
Msg-id 87prykpc3q.fsf@oxford.xeocode.com
Whole thread Raw
In response to Re: Estimation problem with a LIKE clause containing a /  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Estimation problem with a LIKE clause containing a /
List pgsql-performance
"Tom Lane" <tgl@sss.pgh.pa.us> writes:

> What I am tempted to do about this is have make_greater_string tack "zz"
> onto the supplied prefix, so that it would have to find a string that
> compares greater than "123/zz" before reporting success.  This is
> getting pretty klugy though, so cc'ing to pgsql-hackers to see if anyone
> has a better idea.

Hm, instead of "zz" is there a convenient way to find out what actual
character sorts last amongst all the single characters in the locale's
encoding?

Doesn't really strike at the core reason that this is so klugy though. Surely
the "right" thing is to push the concept of open versus closed end-points
through deeper into the estimation logic?

--
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com
  Ask me about EnterpriseDB's RemoteDBA services!

pgsql-performance by date:

Previous
From: "Steinar H. Gunderson"
Date:
Subject: Re: Join performance
Next
From: "Scott Marlowe"
Date:
Subject: Re: dell versus hp