develooper Front page | perl.dbi.users | Postings from February 2012

Re: same query, two different approaches, vastly different performance

Thread Previous | Thread Next
From:
Puneet Kishor
Date:
February 13, 2012 17:16
Subject:
Re: same query, two different approaches, vastly different performance
Message ID:
08DF4A15-E447-4AC7-BE5A-968B731B933A@gmail.com

On Feb 13, 2012, at 7:12 PM, Mike Blackwell wrote:

> Check the postgres-performance list archives.  I believe the difference is due to the query planner having less info available with parameters vs inline args.  
> 



ahhhh... that makes sense. I would like to confirm this, because, if true, then it is a strike against statements prepared with bind values.


> 
> 
> On Feb 13, 2012, at 19:07, Puneet Kishor <punk.kish@gmail.com> wrote:
> 
> 
> On Feb 13, 2012, at 6:57 PM, David Nicol wrote:
> 
>> did you find
>> 
>> http://stackoverflow.com/questions/1566717/postgresql-like-query-performance-variations
>> 
>> in your research?
> 
> 
> Thanks for that link, but I don't think that applies in my case. I have two exact queries, with a postfix wildcard search. One, I prepare with the search term embedded in the query. The other is prepared with a bind variable and the search term is added during $sth->execute.
> 
> The first one uses the index. The second does a full-table scan.
> 
> Strange, but true.
> 
> 
> 
> --
> Puneet Kishor


Thread Previous | Thread Next


nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About