Re: Possible solution for LIKE optimization
Oleg Bartunov <oleg@sai.msu.su>
From: Oleg Bartunov <oleg@sai.msu.su>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Giles Lean <giles@nemeton.com.au>, Peter Eisentraut <peter_e@gmx.net>, PostgreSQL Development <pgsql-hackers@postgresql.org>
Date: 2001-08-07T19:39:33Z
Lists: pgsql-hackers
On Mon, 6 Aug 2001, Tom Lane wrote: > Giles Lean <giles@nemeton.com.au> writes: > > Implementations of strxfrm() that I've looked at have had result data > > that is three or four times larger than then input string -- quite a > > penalty in some situations. > > Especially so given that we don't have TOAST for indexes, so the indexed > value can't exceed about 2700 bytes (for btree and an 8K block size). > You are allowed to compress first, so that's not a hard limit, but it > could still be a problem. > > I like the non-locale-aware-opclass idea much better than the original. Does this means that if implemented we could create indexes for different columns with/without locale support ? It's pain currently that I had to enable locale support while actually I need it only for several columns. Gnu sort on Linux 10 times slow if I use LC_ALL other than C ! Regards, Oleg > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org > Regards, Oleg _____________________________________________________________ Oleg Bartunov, sci.researcher, hostmaster of AstroNet, Sternberg Astronomical Institute, Moscow University (Russia) Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/ phone: +007(095)939-16-83, +007(095)939-23-83