From: | Alexander Korotkov <aekorotkov(at)gmail(dot)com> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Itagaki Takahiro <itagaki(dot)takahiro(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: levenshtein_less_equal (was: multibyte charater set in levenshtein function) |
Date: | 2010-10-04 20:19:18 |
Message-ID: | AANLkTinL406w209Nh5MSxjyAVVh3UTGWknpL_VQAgWMk@mail.gmail.com |
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Lists: | pgsql-hackers |
I've reworked patch with your suggestion. In this version I found a little
slowdown in comparison with previous version:
SELECT * FROM words WHERE levenshtein_less_equal(a, 'extensize', 2) <= 2;
48,069 ms => 57,875 ms
SELECT * FROM words2 WHERE levenshtein_less_equal(a, 'клубничный', 3) <= 2;
100,073 ms => 113,975 ms
select * from phrases where levenshtein_less_equal('kkkknucklehead
courtliest sapphires be coniferous emolument antarctic Laocoon''s deadens
unseemly', a, 10) <= 10;
22,876 ms => 24,721 ms
test=# select * from phrases2 where levenshtein_less_equal('таяй
раскупорившийся передислоцируется юлианович праздничный лачужка присыхать
опппливший ффехтовальный уууудобряющий', a, 10) <= 10;
55,405 ms => 57,760 ms
I think it is caused by multiplication operation for each bound
movement. Probably,
this slowdown is ignorable or there is some way to achieve the same
performance.
----
With best regards,
Alexander Korotkov.
Attachment | Content-Type | Size |
---|---|---|
levenshtein_less_equal-0.3.patch | text/x-patch | 15.2 KB |
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