ClickHouse/docs/en/operations/caches.md

sidebar_position	sidebar_label
65	Caches

Cache Types

When performing queries, ClickHouse uses different caches.

Main cache types:

• mark_cache — Cache of marks used by table engines of the MergeTree family.
• uncompressed_cache — Cache of uncompressed data used by table engines of the MergeTree family.

Additional cache types:

• DNS cache.
• Regexp cache.
• Compiled expressions cache.
• Avro format schemas cache.
• Dictionaries data cache.

Indirectly used:

• OS page cache.

To drop cache, use SYSTEM DROP ... CACHE statements.

Original article