This is probably 50% an SQL question, and 50% a Perl question, but hopefully the monks will forgive me for my impurity :). I am trying to execute the following loop to update a Postgresql table: 

for (1..$#{$columns}) {
 $sth = $dbh->prepare("UPDATE yeast1 set $tables[$_] = temp/$tables[$_
+-1] where yeast1.orf = temp.orf; INSERT INTO profile_index VALUES ('$
+tables[$_-1]', '$columns->[$_]')");
 $sth->execute;
 $sth = $dbh->prepare("UPDATE yeast1 set $tables[$_-1] = 999 where $ta
+bles[$_-1] IS NULL");
 $sth->execute;
}

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Yeast1 is a large table: 6265 rows and about 100 columns so far, and growing to about 400. This loop presently takes hours to complete, and gets longer as I load more data into yeast1. Does anyone know how I can optimize this DBI query? thanks, Evan $sth = $dbh->prepare("UPDATE yeast1 set $tables$_-1 = 999

In reply to Perl DBI Performance by Evanovich

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