src/app/dbtext/storage/DbtextCollectionManager.php
public function clearCache(string $namespace = null) {
		if (null !== $namespace) {
			$this->cacheStore->remove(self::APP_CACHE_PREFIX . $namespace, array());
			return;
		}
		
		$this->cacheStore->clear();
	}
public function clearCache(string $namespace = null) {
		if (null !== $namespace) {
			$this->cacheStore->remove(self::APP_CACHE_PREFIX . $namespace, array());
			return;
		}
		
		$this->cacheStore->clear();
	}
If no namespace is provided, the whole dbtext cache is cleared.

@param string $namespace