This page is a brain dump from using perl. Mostly with postgres and the few problems that I have encountered.

Firstly, this is something that caught be by surprise. When you execute a statement, such as the one below, the result set will be held in memory by the perl process.

$sth = $dbh->execute( "select * from t" );

It does not matter which type of fetch you do following this, the result will end up in the perl process. See the following note:

DBD::Pg cursors

This is a shame since it means that very large select result would be inefficient and potentially cause the system to swap.