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Re: Behavior of a pg_trgm index for 2 (or < 3) character LIKE queries - Mailing list pgsql-hackers

From Alexander Korotkov
Subject Re: Behavior of a pg_trgm index for 2 (or < 3) character LIKE queries
Date
Msg-id CAPpHfdtGkbXjrPkxziRdc9dNnurGAYgivYLNV0_LoBQ329fS7A@mail.gmail.com
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In response to Re: Behavior of a pg_trgm index for 2 (or < 3) character LIKE queries  (Sawada Masahiko <sawada.mshk@gmail.com>)
Responses Re: Behavior of a pg_trgm index for 2 (or < 3) character LIKE queries  (Amit Langote <amitlangote09@gmail.com>)
Re: Behavior of a pg_trgm index for 2 (or < 3) character LIKE queries  (Amit Langote <amitlangote09@gmail.com>)
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On Thu, May 30, 2013 at 12:49 PM, Sawada Masahiko <sawada.mshk@gmail.com> wrote:
following emails are discussed about partial match of pg_trgm.  I hope
will this help.
<http://www.postgresql.org/message-id/CAHGQGwFJshvV2nGME19wdTW9teFw_w7h2ns4E+YYsjkB9WdWDQ@mail.gmail.com>
as you may know, if search string contains multibyte characters
trigram key is converted to CRC of 4 byte and it is used as key.
(but only use upper 3 byte from CRC)
so we can do partial matching if KEEPONLYALNUM is enabled.

Please, read the further discussion on that thread. We can't do partial matching because of CRC independently of KEEPONLYALNUM.

------
With best regards,
Alexander Korotkov.

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