$sth->prepare_cached loop

[hmadhi]

Will the following loop cause separate queries to the database?

my %kpi_thres = (
                "PDP"=>80,
                "GAS"=>70,
                "RAU"=>75 
      );

$SQL=qq{select * from abc where date=?};

foreach $kpi (keys(%kpi_thres)) 
{

            my $sth_ne = $dbh->prepare_cached($SQL);
            $sth_ne->execute($currDateTime);
}

[tilly]

What will happen will vary depending on the database.

With Oracle, you will prepare the query once. And then send 3 execute statements to it. Which saves you the effort of compiling the query. Since compilation is expensive in Oracle, this is a win.

In MySQL the caching is done client side. So you wind up preparing and executing the query 3 times. Since MySQL makes preparing the query cheap, this doesn't cost very much.

[hmadhi]

Thanks for the reply, I am using Oracle.