Re: Efficient String searching

Like an implementation of Boyer-Moore-...?

-----Original Message-----
From: pgsql-admin-owner@postgresql.org
[mailto:pgsql-admin-owner@postgresql.org]On Behalf Of Stephan Szabo
Sent: September 25, 2001 10:43 AM
To: Robert.Farrugia@go.com.mt
Cc: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] Efficient String searching


On Tue, 25 Sep 2001 Robert.Farrugia@go.com.mt wrote:

> Hi,
> 
> I have the following problem.  When doing string searches using the ilike
> command, no indexes are being used.  This is giving performance problems,
> whereas it takes longer to sequentially search the whole table.  Am i
> missing something about searching for strings ?  Are there any efficient
> methods than using regular expressions or like ?

Unless your pattern is anchored at the start, indexes don't get used.  In
addition, if you're in a locale other than C, indexes don't get used.
It depends on the kind of string searches you're doing.  If you're looking
for words in a longer string, you probably want to look at a full text
indexing solution.  IIRC, there's one in contrib and a few others made by 
people on the lists.


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