Why is this loop over mysql resultset slow? (1.4ms per cycle)
- by pawpro
The $res contains around 488k rows the whole loop takes 61s! that's over 1.25ms per cycle! What is taking all that time?
while($row = $res->fetch_assoc())
{
$clist[$row['upload_id']][$row['dialcode_id']][$row['carrier_id']]['std'] = $row['cost_std'];
$clist[$row['upload_id']][$row['dialcode_id']][$row['carrier_id']]['ecn'] = $row['cost_ecn'];
$clist[$row['upload_id']][$row['dialcode_id']][$row['carrier_id']]['wnd'] = $row['cost_wnd'];
$dialcode_destination[$row['upload_id']][$row['carrier_id']][$row['dialcode_id']]['other_destination'] = $row['destination_id'];
$dialcode_destination[$row['upload_id']][$row['carrier_id']][$row['dialcode_id']]['carrier_destination'] = $row['carrier_destination_id'];
}
Now resultset of 10 rows, smaller arrays and performance 30 times higher (0.041ms) not the fastest still but better.
while($row = $res->fetch_assoc())
{
$customer[$row['id']]['name'] = $row['name'];
$customer[$row['id']]['code'] = $row['customer'];
}
