will change this behavior. If the value of $timeout is 0, Apache:DBI will validate the database connection using the ping( ) method for every database access. This is the default. Setting $timeout to a negative value will deactivate the validation of the database handle. This can be used for drivers that do not implement the ping( ) method (but it's generally a bad idea, because you don't know if your database handle really works). Setting $timeout to a positive value will ping the database on access only if the previous access was more than $timeoutseconds earlier.
$data_source is the same as in the connect( ) method (e.g., DBI:mysql:...).