---
name: "pcp_invalidate_query_cache"
section: "1"
platform: "linux"
package: "pgpool2"
version: "4.6.1-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/pcp_invalidate_query_cache"
---

# pcp\_invalidate\_query\_cache(1)

invalidate query cache contents

## NAME

pcp\_invalidate\_query\_cache - invalidate query cache contents

## SYNOPSIS

**pcp\_invalidate\_query\_cache** \[*options*...\]

## DESCRIPTION

**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 SHOW POOL\_CACHE ([**SHOW\_POOL\_CACHE**(1)](/SHOW_POOL_CACHE/1.md)), 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 memory\_cache\_enabled is false, this command emits an error and exits.

## OPTIONS

See [**pcp\_common\_options**(1)](/pcp_common_options/1.md).