When dealing with doctrine 1.2 and medium data, you will probably see something like this:
Fatal error: Allowed memory size of X bytes exhausted (tried to allocate X bytes)
To avoid this you should care about the following points:
1. If you only want to read data fetch it as an array. Nobody needs an overloaded active record while read only.
2. Select only the data you need – especially when using multiple inner joins.
$q->select('u.id, u.email, u.slug') $q->from('User u')
3. Use pagination while using active records
4. Use free on objects you dont need any longer when using php <= 5.2.5