note 104609 modified in pdostatement.fetchall by danbrown

Note that fetchAll() can be extremely memory inefficient for large data sets. My memory limit was set to 160 MB this is what happened when I tried: <?php $arr = $stmt->fetchAll(); // Fatal error: Allowed memory size of 16777216 bytes exhausted ?> If you are going to loop through the output array of fetchAll(), instead use fetch() to minimize memory usage as follows: <?php while ($arr = $stmt->fetch()) { echo round(memory_get_usage() / (1024*1024),3) .' MB<br />'; // do_other_stuff(); } // Last line for the same query shows only 28.973 MB usage ?> --was-- Note that fetchAll() can be extremely memory inefficient for large data sets. My memory limit was set to 160 MB this is what happened when I tried: <?php $arr = $stmt->fetchAll(); // Fatal error: Allowed memory size of 16777216 bytes exhausted ?> If you are going to loop through the output array of fetchAll(), instead use fetch() to minimize memory usage as follows: <?php while ($arr = $stmt->fetch()) { echo round(memory_get_usage() / (1024*1024),3) .' MB<br />'; // do_other_stuff(); } // Last line for the same query shows only 28.973 MB usage http://php.net/manual/en/pdostatement.fetchall.php