Describe table metadata feature

You can use certain Impala show and describe commands to get information about table metadata. You can also query metadata tables.

The following table lists SHOW and DESCRIBE commands supported by Impala.


Command Syntax	Description	Impala Support
`SHOW CREATE TABLE table_name`	Reveals the schema that created the table.	yes
`SHOW FILES IN table_name`	Lists the files related to the table.	yes
`SHOW PARTITIONS table_name`	Returns the Iceberg partition spec, just the column information, not actual partitions or files.	yes
`DESCRIBE [EXTENDED] table_name`	The optional EXTENDED shows all the metadata for the table in Thrift serialized form, which is useful for debugging.	yes
`DESCRIBE [FORMATTED] table_name`	The optional FORMATTED shows the metadata in tabular format.	no
`DESCRIBE HISTORY table_name [BETWEEN timestamp1 AND timestamp2]`	Optionally limits the output history to a period of time.	yes

The output of DESCRIBE HISTORY includes the following columns about the snapshot. The first three are self-explanatory. The is_current_ancestor column value is TRUE if the snapshot is the ancestor of the table:

creation_time
snapshot_id
parent_id
is_current_ancestor

Impala examples

DESCRIBE HISTORY ice_t FROM '2022-01-04 10:00:00';
DESCRIBE HISTORY ice_t FROM now() - interval 5 days;
DESCRIBE HISTORY ice_t BETWEEN '2022-01-04 10:00:00' AND '2022-01-05 10:00:00';