Re: About "Our CLUSTER implementation is pessimal" patch

From: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
To: Leonardo F <m_lists(at)yahoo(dot)it>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: About "Our CLUSTER implementation is pessimal" patch
Date: 2010-01-26 18:56:44
Message-ID: 4B5F3AEC.3060306@enterprisedb.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Leonardo F wrote:
> why is IndexInfo.ii_Expressions a list? How can an index have more than
> one expression? Sorry if it's a stupid question, but I'm not familiar with
> index expressions.

Consider multi-column indexes, ie:

CREATE INDEX i_foo ON foo (length(a), length(b));

Maybe you're confusing expression indexes with partial indexes? The
predicate for a partial index is stored in ii_Predicate, not
ii_Expressions. Although ii_Predicate is a list too; in that case it's a
list of clauses that are implicitly ANDed together.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2010-01-26 18:58:18 Re: Dividing progress/debug information in pg_standby, and stat before copy
Previous Message Josh Berkus 2010-01-26 18:53:48 Re: Dividing progress/debug information in pg_standby, and stat before copy