SQL Laravel 5.7 unique() on collection really slow

Question

I'm trying to calculate the number of unique records based on a mobile column that has an index via the Laravel collect and unique method. I have 200,000 rows and have a column called optout_csv_schedule_id that has an index on it along with the mobile. Right now, it's been running over 15 minutes for the query to execute, how can I improve the performance of this as I need to calculate the number of unique numbers out of the 200,000, my current query is:

/**
 * Get valid lead count
 */
protected function getValidLeadCount($schedule_id)
{
    $optoutConnectionLogs = OptoutConnectionLog::where('optout_csv_schedule_id', $schedule_id)
                                               ->get();

    // no leads
    if (!$optoutConnectionLogs) {
        return 0;
    }

    // count total unique leads
    $uniqueLeads = collect($optoutConnectionLogs)->unique('mobile')->count();
    return $uniqueLeads;
}

Answer 1

It seems to be difficult to calculate the number of unique numbers out of the 200,000 in Laravel. Try to change as follows:

protected function getValidLeadCount($schedule_id)
{
    $uniqueLeads = OptoutConnectionLog::where('optout_csv_schedule_id', $schedule_id)
                                                 ->distinct('mobile')
                                                 ->count('mobile');
    return $uniqueLeads;
}