Обсуждение: PostgreSQL full text vs. MySQL

Hey all,

I have been a MySQL user for a number of years,
but just read about PostgreSQL version 8.3 and was
especially intrigued and interested in the full
text search implementation using lexemes.

I'm currently doing the specs for a PHP app that
will involve up to the millions records to search,
and it will need full text capability.

I am wondering if I could get some opinions on
PostgreSQL's full text versus MySQL's and
specifically I have not been able to find
documentation that MySQL supports lexeme type full
text, able to locate root words the way PostgreSQL
8.3 does.

Is this the case? I could certainly justify the
switch to PostgreSQL if I can make a solid case to
the client for doing so.

I realize this is a PostgreSQL list, so let's try
to be fair ;)

Thanks!
--
Skip Evans
Big Sky Penguin, LLC
503 S Baldwin St, #1
Madison, WI 53703
608-250-2720
http://bigskypenguin.com
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Skip Evans wrote:
> I am wondering if I could get some opinions on PostgreSQL's full text
> versus MySQL's and specifically I have not been able to find
> documentation that MySQL supports lexeme type full text, able to locate
> root words the way PostgreSQL 8.3 does.

MySQL's full-text search is:
1. Isam-based only (afaik), so no transactions for you.
2. Much simpler than PostgreSQL's full-text searching

Whether #2 is good/bad depends if you want simple or flexible. If you're
starting to think about stemming or custom requirements already, I think
you're probably ruling out MySQL anyway. From my (admittedly limited)
knowledge of MySQL fti, you're able to replace the standard list of
stopwords and set a minimum number of letters to count as a word and
that's about it.

The PostgreSQL system lets you chain dictionaries together, have
multiple dictionaries per configuration or write a custom parser if
really required. Complicated, but flexible.

--
   Richard Huxton
   Archonet Ltd