Doctrine_manual-1-2-en

Chapter 28: Improving Performance 366
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memory unless you manually break the circular reference chains. Doctrine provides a free()
function on Doctrine_Record, Doctrine_Collection, and Doctrine_Query which
eliminates the circular references on those objects, freeing them up for garbage collection.
Usage might look like:
Free objects when mass inserting records:
for ($i = 0; $i < 1000; $i++)
{
$object = createBigObject();
$object->save();
$object->free(true);
}
You can also free query objects in the same way:
for ($i = 0; $i < 1000; $i++)
{
$q = Doctrine_Query::create()
->from('User u');
}
$results = $q->fetchArray();
$q->free();
Or even better if you can reuse the same query object for each query in the loop that would
be ideal:
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$q = Doctrine_Query::create()
->from('User u');
for ($i = 0; $i < 1000; $i++)
{
$results = $q->fetchArray();
$q->free();
}
Other Tips
Helping the DQL parser
There are two possible ways when it comes to using DQL. The first one is writing the plain
DQL queries and passing them to Doctrine_Connection::query($dql). The second one
is to use a Doctrine_Query object and its fluent interface. The latter should be preferred for
all but very simple queries. The reason is that using the Doctrine_Query object and it's
methods makes the life of the DQL parser a little bit easier. It reduces the amount of query
parsing that needs to be done and is therefore faster.
Efficient relation handling
When you want to add a relation between two components you should NOT do something like
the following:
The following example assumes a many-many between Role and User.
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