mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-12-01 12:01:58 +00:00

* prefer relative links from root

* wip

* split aggregate function reference

* split system tables

2020-06-18 11:24:31 +03:00

system.disks

Contains information about disks defined in the server configuration.

Columns:

name (String) — Name of a disk in the server configuration.
path (String) — Path to the mount point in the file system.
free_space (UInt64) — Free space on disk in bytes.
total_space (UInt64) — Disk volume in bytes.
keep_free_space (UInt64) — Amount of disk space that should stay free on disk in bytes. Defined in the keep_free_space_bytes parameter of disk configuration.

system.storage_policies

Contains information about storage policies and volumes defined in the server configuration.

Columns:

policy_name (String) — Name of the storage policy.
volume_name (String) — Volume name defined in the storage policy.
volume_priority (UInt64) — Volume order number in the configuration.
disks (Array(String)) — Disk names, defined in the storage policy.
max_data_part_size (UInt64) — Maximum size of a data part that can be stored on volume disks (0 — no limit).
move_factor (Float64) — Ratio of free disk space. When the ratio exceeds the value of configuration parameter, ClickHouse start to move data to the next volume in order.

If the storage policy contains more then one volume, then information for each volume is stored in the individual row of the table.