From: Jason Farmer <jfarmer@getloaded.com>
To: pgsql-sql@postgresql.org
Subject: Using In Clause For a Large Text Matching Query
Date: Thu, 29 Jun 2006 16:00:50 -0400
Message-ID: <44A43172.3040202@getloaded.com> (raw)
Hello all, my first post to the pgsql mailing list!
There may be a completely better way to do this; if so please help point
me in the right direction!
What I'm trying to do is run a query to partially match 300+ text fields
to a PG table of about 200,000 rows. The idea is to pull out a portion
of text from the original text fields and do a partial text match on
anything in my PG table containing that substring.
I liked the idea of using a where IN(group) to do my comparisons, as in
select col1 from table1 where col1 in ('text1','text2')
however, this requires an exact string match. Is there any way to do a
substring match inside of my IN group? Or can anyone think of a better
way to do something like this?
Heres an example of something of how I'd like this to work:
Portion of 300 Original Text fields:
"brown cat"
"green dog"
2 rows of 200k+ Database table:
"brown kitty"
"green doggy"
We can assume a certain portion of the text is included in the DB table,
so I want to be able to do a substring match on "brown" and "green" and
in this case return both "brown kitty", and "green doggy". However the
problem is, if I run the query on each of my 300 rows to scan 200,000
rows in my DB is entirely too slow. So I was hoping to use the IN clause
to create an IN group of about 300 items to scan the DB once.
I hope this makes sense, but if anything sounds confusing please let me
know, and I will be sure to clarify! Thanks for any help or direction
anyone can provide!!
- Jason Farmer
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To: pgsql-sql@postgresql.org
Cc: jfarmer@getloaded.com
Subject: Re: Using In Clause For a Large Text Matching Query
In-Reply-To: <44A43172.3040202@getloaded.com>
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