Module clickhouse

sql_query_analyzer::preprocessor

Module clickhouse 

Source
Expand description

ClickHouse-specific SQL preprocessing.

Handles ClickHouse DDL constructs not supported by sqlparser:

  • CODEC(...) - Column compression codecs
  • TTL ... - Data expiration rules
  • SETTINGS ... - Table-level settings

§Codec Syntax

ClickHouse supports various compression codecs:

CREATE TABLE t (
    col1 String CODEC(ZSTD),
    col2 UInt64 CODEC(Delta, LZ4),
    col3 DateTime CODEC(DoubleDelta, ZSTD(3))
)

§TTL Syntax

CREATE TABLE t (...)
ENGINE = MergeTree
TTL event_date + INTERVAL 90 DAY

Functions§

preprocess
Preprocess ClickHouse SQL.