modify config in file config/web.php or config/console.php
'components' => [
'yac' => [
'class' => 'Knowbox\Libs\YacCache',
],
...
then you may use yac cache on DB schemaCache
[
'class' => 'yii\db\Connection',
'charset' => 'utf8',
'enableSchemaCache' => true,
'schemaCacheDuration' => 3600,
'schemaCache' => 'yac',
...
or other things in yii2 way, follow the guide