function system_update_8403 in Drupal 8

Delete all cache_* tables. They are recreated on demand with the new schema.

File

core/modules/system/system.install, line 2440

Install, update and uninstall functions for the system module.

Code

function system_update_8403() {
  foreach (Cache::getBins() as $bin => $cache_backend) {

    // Try to delete the table regardless of which cache backend is handling it.
    // This is to ensure the new schema is used if the configuration for the
    // backend class is changed after the update hook runs.
    $table_name = "cache_{$bin}";
    $schema = Database::getConnection()
      ->schema();
    if ($schema
      ->tableExists($table_name)) {
      $schema
        ->dropTable($table_name);
    }
  }
}