system.codecs

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Description

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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.
• 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.

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Example

SELECT * FROM system.codecs WHERE name='LZ4'

Row 1:
──────
name:                   LZ4
method_byte:            130
is_compression:         1
is_generic_compression: 1
is_encryption:          0
is_timeseries_codec:    0
tier:                   Production
description:            Extremely fast; good compression; balanced speed and efficiency.