Thread

PostgreSQL 6.4.2 locale regexp and like problem

Petr Hubeny <psh@capitol.cz> — 1999-02-04T09:43:03Z

Hi,

I've recently found an interesting problem with using czech locale
and the regular expressions matching beginning of the line. I traced
the problem and found it is caused by the optimalization within 
function makeIndexable, especially in the way the string match_most is
constructed. What happens? The expression

text ~ '^regexp'

is rewritten into

( text ~ '^regexp' ) AND ( text >= 'regexp' ) AND ( text >= 'regexp\377' )

( N.B.: The same applies for expression "text LIKE 'match%'". )

HOWEVER, in czech locale is 'regexp\377' < 'regexp' ! So the expression
is doomed to be false.

So I'd like to ask you: Is there any general (read: locale independent)
way to create a 'match_most' string that would allow for such optimalization?

Thanks for your patience,

Psh

-- 

Mgr. Petr Hubený				ICQ UIN: 12472987