Re: Yet another LIKE-indexing scheme

Jules Bean <jules@jellybean.co.uk>

From: Jules Bean <jules@jellybean.co.uk>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
Date: 2000-09-06T08:49:14Z
Lists: pgsql-hackers
On Sat, Sep 02, 2000 at 01:39:47PM -0400, Tom Lane wrote:
> > So what happens with "WHERE name like 'Czec%`" ?
> 
> Our existing code fails because it generates WHERE name >= 'Czec' AND
> name < 'Czed'; it will therefore not find names beginning 'Czech'
> because those are in another part of the index, between 'Czeh' and
> 'Czei'.  But WHERE name >= 'Cze' AND name < 'Czf' would work.

(OK, I haven't read the previous discussion.  Guilty, m'lud)

Why should it?  If 'ch' is one letter, then surely 'czech' isn't LIKE
'czec%'.  Because 'czec%' has a second c, wheres, 'czech' only has one
'c' and one 'ch'?

Jules