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
>
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	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