Blog > Don't Do This At Home #2: Count After Hydration
Can you spot the problem in the following snippet?
The problem is that, if all you need is the number of books, you just wasted a lot of memory.
find() issues a SQL
SELECT query, iterates over the resultset, and populates ("hydrates") a new
book object for each row. If there are 10,000 results to the query, Propel hydrates 10,000 Model objects... for nothing, since all you need is the number of results.
The good way to count the number of results of a query is to use the
Propel also uses
count() internally when you call
paginate(), so that only the results in the current page get hydrated.