system.dns_cache

System table containing information about cached DNS records.

Querying in ClickHouse Cloud

The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the clusterAllReplicas function. See here for further details.

Description

Contains information about cached DNS records.

Columns

• hostname (String) — Hostname.
• ip_address (String) — IP address.
• ip_family (Enum8(‘IPv4’ = 0, ‘IPv6’ = 1, ‘UNIX_LOCAL’ = 2)) — IP address family.
• cached_at (DateTime) — Record cached timestamp.

Example

Query

SELECT * FROM system.dns_cache;

hostname	ip_address	ip_family	cached_at
localhost	::1	IPv6	2024-02-11 17:04:40
localhost	127.0.0.1	IPv4	2024-02-11 17:04:40

See also

• disable_internal_dns_cache setting
• dns_cache_max_entries setting
• dns_cache_update_period setting
• dns_max_consecutive_failures setting