Skip to content
ClickHouse Docs
ClickHouse DocsClickHouse Docs
49.6kGet Started

system.codecs

View as MarkdownEdit this pageReport an issueSet up docs MCP

Description

Contains information about compression and encryption codecs.

You can use this table to get information about the available compression and encryption codecs

Columns

  • name (String) — Codec name.
  • method_byte (UInt8) — Byte which indicates codec in compressed file.
  • is_compression (UInt8) — True if this codec compresses something. Otherwise it can be just a transformation that helps compression.
  • is_generic_compression (UInt8) — The codec is a generic compression algorithm like lz4, zstd.
  • is_encryption (UInt8) — The codec encrypts.
  • is_timeseries_codec (UInt8) — The codec is for floating point timeseries codec.
  • is_experimental (UInt8) — The codec is experimental.
  • tier (Enum8(‘Production’ = 0, ‘Obsolete’ = 4, ‘Experimental’ = 8, ‘Beta’ = 12, ‘PrivatePreview’ = 16)) — Support level for this codec (e.g. ‘Production’, ‘Beta’ or ‘Experimental’).
  • description (String) — A high-level description of the codec.

Example

Querysql
SELECT * FROM system.codecs WHERE name='LZ4'
Responsetext
Row 1:
──────
name:                   LZ4
method_byte:            130
is_compression:         1
is_generic_compression: 1
is_encryption:          0
is_timeseries_codec:    0
is_experimental:        0
tier:                   Production
description:            Extremely fast; good compression; balanced speed and efficiency.
Navigation