mysqlnd_qc_clear_cache Flush all cache contents &reftitle.description; bool mysqlnd_qc_clear_cache Flush all cache contents. Flushing the cache is a storage handler responsibility. All built-in storage handler but the memcache storage handler support flushing the cache. The memcache storage handler cannot flush its cache contents. User-defined storage handler may or may not support the operation. &reftitle.parameters; &no.function.parameters; &reftitle.returnvalues; &return.success; A return value of &false; indicates that flushing all cache contents has failed or the operation is not supported by the active storage handler. Applications must not expect that calling the function will always flush the cache.