pcp_invalidate_query_cache pcp_invalidate_query_cache 1 PCP Command pcp_invalidate_query_cache invalidate query cache contents pcp_invalidate_query_cache options pcp_invalidate_query_cache places a query cache invalidation request on the shared memory area. The request is processed by one of Pgpool-II child process, which corresponds to each pgpool client session, when a message from the client is processed. This means that if there's no client connecting to Pgpool-II, or all clients are sitting idle, the request will not be processed until next message arrives. Although this command does not modifies the statistics data shown by , part of the statistics data is affected since this command invalidate the contents of query cache. num_cache_hits and num_selects continue to increase after the query cache invalidated. used_hash_entries, num_cache_entries and used_cache_entries_size starts off with 0. free_cache_entries_size will increase. If is false, this command emits an error and exits. See .