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ByteHouse Cloud Data Warehouse Version

System tables

system.tables

The system table system.tables contains information about all tables, including key attributes such as the table engine, structure (partition/sorting/primary key), storage path, data volume, and more. It is the core system table for viewing table structure and auditing table configuration.

Column names

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Field name	Data type	Field description
			\
database	String	The name of the database where the table resides.
			\
name	String	The name of the table.
			\
engine	String	The table engine name (parameters not included), fixed as "CnchMergeTree".
			\
is_temporary	UInt8	Indicates whether the table is temporary:	\
			\
		* 1 = Temporary table (automatically deleted after the session ends);	\
		* 0 = Permanent table (all examples are 0).
			\
data_path	String	The storage path of the table data in the file system.
			\
metadata_path	String	The storage path of the table metadata in the file system.
			\
metadata_modification_time	DateTime	The latest modification time of the table metadata.
			\
dependencies_database	Array(String)	List of databases the table depends on.
			\
dependencies_table	Array(String)	List of other tables the table depends on, such as materialized views based on the current table, for example 'job_174990_kafka_mv'.
			\
create_table_query	String	The SQL statement used to create the table.
			\
engine_full	String	Parameters of the table engine.
			\
as_select	String	Associated information of the `AS SELECT` statement when creating the table.
			\
partition_key	String	The partition key expression specified in the table.
			\
sorting_key	String	The sorting key expression specified in the table.
			\
primary_key	String	The primary key expression specified in the table.
			\
sampling_key	String	The sampling key expression specified in the table.
			\
storage_policy	String	The name of the storage policy used by the table.
			\
total_rows	Nullable(UInt64)	Total number of rows in the table. If the exact number of rows in the table cannot be quickly determined, the row count returns as NULL, including underlying buffer tables.
			\
total_bytes	Nullable(UInt64)	Total number of bytes in the table. If the exact number of bytes stored in the table cannot be quickly determined, the byte count returns as NULL, excluding any underlying storage.
			\
lifetime_rows	Nullable(UInt64)	NULL
			\
lifetime_bytes	Nullable(UInt64)	NULL
			\
comment	String	Comment of the table.
			\
has_own_data	UInt8	Indicates whether the table has independent data storage:	\
			\
		* 0 = No independent data;	\
		* 1 = Has independent data.

Example

Query tables in the database sales_db, returning only key fields:

SELECT 
  name AS table_name, 
  engine_full, 
  partition_key, 
  primary_key, 
  total_bytes 
FROM system.tables 
WHERE database = 'sales_db' 
LIMIT 10;

Example query results:

Last updated: 2026.03.31 16:16:45

ByteHouse Cloud Data Warehouse Version

Column names #

Example #

Column names

Example