ALTER TABLE ALTER COLUMN SET/DROP PARQUET ENCODING/COMPRESSION

Sets or removes per-column Parquet encoding and compression configuration on existing tables. These settings only affect Parquet partitions and are ignored for native partitions.

SET

Override the default Parquet encoding, compression, or both for a column.

Set encoding only

ALTER TABLE sensors ALTER COLUMN temperature SET PARQUET ENCODING rle_dictionary;

Set compression only (with optional level)

ALTER TABLE sensors ALTER COLUMN temperature SET PARQUET COMPRESSION zstd 3;

Set both encoding and compression

ALTER TABLE sensors ALTER COLUMN temperature SET PARQUET ENCODING rle_dictionary COMPRESSION zstd 3;

DROP

Reset per-column overrides back to the server defaults.

Drop both encoding and compression overrides

ALTER TABLE sensors ALTER COLUMN temperature DROP PARQUET ENCODING COMPRESSION;

Drop encoding only (keeps compression override)

ALTER TABLE sensors ALTER COLUMN temperature DROP PARQUET ENCODING;

Drop compression only (keeps encoding override)

ALTER TABLE sensors ALTER COLUMN temperature DROP PARQUET COMPRESSION;

Supported encodings and codecs

See the CREATE TABLE reference for the full list of supported encodings, compression codecs, and their valid column types.