On Wed, Aug 29, 2012 at 12:52:50PM -0600, Scott Marlowe wrote: > On Wed, Aug 29, 2012 at 11:43 AM, Bruce Momjian <bruce@xxxxxxxxxx> wrote: > > On Wed, Aug 29, 2012 at 10:31:21AM -0700, Aleksey Tsalolikhin wrote: > >> On Wed, Aug 29, 2012 at 9:45 AM, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: > >> > citext unfortunately doesn't allow for index optimization of LIKE > >> > queries, which IMNSHO defeats the whole purpose. to the best way > >> > remains to use lower() ... > >> > this will be index optimized and fast as long as you specified C > >> > locale for your database. > >> > >> What is the difference between C and en_US.UTF8, please? We see that > >> the same query (that invokes a sort) runs 15% faster under the C > >> locale. The output between C and en_US.UTF8 is identical. We're > >> considering moving our database from en_US.UTF8 to C, but we do deal > >> with internationalized text. > > > > Well, C has reduced overhead for string comparisons, but obviously > > doesn't work well for international characters. The single-byte > > encodings have somewhat less overhead than UTF8. You can try using C > > locales for databases that don't require non-ASCII characters. > > I think you're confusing encodings with locales. C is a locale. You I think technically C is a non-locale. > can have a database with a locale of C and UTF-8 encoding. > > create database clocale_utf8 encoding='UTF8' LC_COLLATE= 'C' template=template0; > > \l > Name | Owner | Encoding | Collate | Ctype | > Access privileges > --------------+----------+-----------+-------------+-------------+----------------------- > clocale_utf8 | smarlowe | UTF8 | C | en_US.UTF-8 | > > > SQL_ASCII is the encoding equivalent of C locale, but it also allows > multi-byte characters. Yes, but what sort ordering do you get in that case? -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
