Re: Full Text Search - Slow on common words

From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Reid Thompson
Sent: Thursday, October 28, 2010 12:57 PM
To: steve(at)subwest(dot)com
Cc: Reid Thompson; pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] Full Text Search - Slow on common words

On Thu, 2010-10-28 at 12:08 -0700, sub3 wrote:
> Hi,
>
> I have a small web page set up to search within my domain based on keywords.
> One of the queries is:
> SELECT page.id ts_rank_cd('{1.0, 1.0, 1.0, 1.0}',contFTI,q) FROM page,
> to_tsquery('steve') as q WHERE contFTI @@ q
>
> My problem is: when someone puts in a commonly seen word, the system slows
> down and takes a while because of the large amount of data being returned
> (retrieved from the table) & processed by the rand_cd function.
>
> How does everyone else handle something like this? I can only think of 2
> possible solutions:
> - change the query to search for the same terms at least twice in the same
> document (can I do that?)
> - limit any searches to x results before ranking & tell the user their
> search criteria is too generic.
>
> Is there a better solution that I am missing?
>

if the keyword is that common, is it really a keyword? Exclude it.

>>

This general idea is called a stopword list. You create a list of words that are so common that searching on them is counter-productive.

http://en.wikipedia.org/wiki/Stop_words

<<