Re: citext LIKE search bug

On Thu, Sep 19, 2019 at 12:19:34AM -0400, Tom Lane wrote:
> Morris de Oryx <morrisdeoryx@gmail.com> writes:
> > I'm using citext fields, and am working through how to build indexes that
> > the planner recognizes. I found this paragraph in the PG 11 release notes:
> 
> > "Allow creation of indexes that can be used by LIKE comparisons on citext
> > columns (Alexey Chernyshov)
> > To do this, the index must be created using the citext_pattern_ops operator
> > class."
> > https://www.postgresql.org/docs/11/release-11.html
> 
> > As far as I can tell, this doesn't work, or at least not in my case with an
> > expression index.
> 
> Hm.  I found the original submission in the archives [1], and Alexey
> explicitly *didn't* claim that that patch was sufficient to enable LIKE
> index optimizations on citext.  Indeed it obviously isn't, since it just
> created some weirdly-named operators without connecting them up to the
> LIKE plumbing in any way.  So this seems like a case of the REL11 release
> notes author (probably Bruce) not reading too closely, which doesn't seem
> like entirely his fault since the commit message was totally content-free
> about what the point of the patch was [2].

I have no idea how I would have generated any release note item with
that commit or the commit diff.  I must have asked someone, but I don't
remember who.  The item was in my initial version of the relesae notes,
so it was not added later.  Sorry.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
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