On Sat, Apr 19, 2008 at 6:10 PM, Oleg Bartunov <oleg@sai.msu.su> wrote:
> On Sat, 19 Apr 2008, Tom Lane wrote:
>
>> Craig Ringer <craig@postnewspapers.com.au> writes:
>>>
>>> Tom Lane wrote:
>>>>
>>>> I don't really see the problem. I assume from your reference to pg_trgm
>>>> that you're using trigram similarity as the prefilter for potential
>>>> matches
>>
>>> It turns out that's no good anyway, as it appears to ignore characters
>>> outside the ASCII range. Rather less than useful for searching a
>>> database of translated strings ;-)
>>
>> A quick look at the pg_trgm code suggests that it is only prepared to
>> deal with single-byte encodings; if you're working in UTF8, which I
>> suppose you'd have to be, it's dead in the water :-(. Perhaps fixing
>> that should be on the TODO list.
>
> as well as ltree. they are in our todo list:
> http://www.sai.msu.su/~megera/wiki/TODO
>
Hi Oleg
In your TODO list says that UTF8 was added to ltree, is this code
currently available for download?
Regards,
José
>>
>> But in any case maybe the full-text-search stuff would be more useful
>> as a prefilter? Although honestly, for the speed we need here, I'm
>> not sure a prefilter is needed at all. Full text might be useful
>> if a LIKE-based match fails, though.
>>
>>>> (And besides, speed doesn't seem like the be-all and end-all here.)
>>
>>> True. It's not so much the speed as the fragility when faced with small
>>> changes to formatting. In addition to whitespace, some clients mangle
>>> punctuation with features like automatic "curly"-quoting.
>>
>> Yeah. I was wondering whether encoding differences wouldn't be a huge
>> problem in practice, as well.
>>
>> regards, tom lane
>>
>>
>
> Regards,
> Oleg
> _____________________________________________________________
> Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
> Sternberg Astronomical Institute, Moscow University, Russia
> Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
> phone: +007(495)939-16-83, +007(495)939-23-83
>
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