Don't allow yourself to screw up with sql-sync to the production environment.

drushrc.php

<?php

$options['shell-aliases']['syncdb'] = '!drush --verbose --yes sql-sync --create-db @pac12.prod @self';

policy.drush.inc

<?php

/**
 * @file
 *   Policy commandfile.
 *
 *   Validates commands as they are issued and returns an error
 *   or changes options when policy is violated.
 */

/**
 * Implement of drush_hook_COMMAND_validate().
 *
 * Prevent catastrophic braino when syncing databases.
 */
function drush_policy_sql_sync_validate($source = NULL, $destination = NULL) {
  if ($destination == '@pac12.prod') {
    return drush_set_error(dt('You may never overwrite the production database.'));
  }
}

/**
 * Implement of drush_hook_COMMAND_validate().
 *
 * Prevent catastrophic braino when rsyncing files.
 */
function drush_policy_core_rsync_validate($source = NULL, $destination = NULL) {
  if (preg_match('/^@pac12.prod/', $destination)) {
    return drush_set_error(dt('You may never overwrite the production files.'));
  }
}