View Materialized View Structure (DESC MATERIALIZED VIEW)

Description

The DESC command is used to view the column structure of a materialized view, including field names, data types, and comments. DESC EXTENDED can further display detailed metadata of the materialized view, such as creation time, query definition, source table information, and more.

For more details, see Materialized View.

Syntax

DESC [EXTENDED] [schema_name.]<mv_name>

Parameter Description

Parameter	Required	Description
EXTENDED	No	Display extended information, including materialized view metadata, query definition, source tables, and other details
schema_name	No	The name of the schema. If not specified, the current schema is used by default
mv_name	Yes	The name of the materialized view to view

Return Column Description

Basic Mode (without EXTENDED)

Column Name	Description
column_name	Column name
data_type	Data type
comment	Column comment

Extended Mode (with EXTENDED)

After the basic column information, the following metadata rows are also returned:

Field	Description
workspace	Workspace name
schema	Schema name
name	Materialized view name
creator	Creator
created_time	Creation time
last_modified_time	Last modified time
type	Object type, value is MATERIALIZED VIEW
view_text	The full query statement of the materialized view (with schema prefix)
view_original_text	The original query statement of the materialized view
is_materialized	Whether it has been materialized, value is true
source_tables	List of dependent source tables
format	Storage format, e.g., PARQUET
statistics	Data statistics (row count and bytes)

Examples

Example 1: View the column structure of a materialized view

DESC doc_test.mv_test_sales;

Result:

+-------------+-----------+---------+ | column_name | data_type | comment | +-------------+-----------+---------+ | id | int | | | name | string | | +-------------+-----------+---------+

Example 2: View extended information of a materialized view

DESC EXTENDED doc_test.mv_test_sales;

Result (partial):

+------------------------------+------------------------------------------+---------+ | column_name | data_type | comment | +------------------------------+------------------------------------------+---------+ | id | int | | | name | string | | | | | | | # detailed table information | | | | workspace | quick_start | | | schema | doc_test | | | name | mv_test_sales | | | creator | qiliang | | | type | MATERIALIZED VIEW | | | view_original_text | SELECT id, name FROM doc_test.employees; | | | is_materialized | true | | | format | PARQUET | | | statistics | 5 rows 2610 bytes | | +------------------------------+------------------------------------------+---------+

Notes

• DESC is equivalent to DESCRIBE; the two can be used interchangeably.
• The DESC syntax for materialized views is the same as for regular tables. See DESC TABLE for details.
• The source_tables field returned by DESC EXTENDED records all source tables that the materialized view depends on, which can be used for data lineage analysis.

Related Commands

• DESC TABLE: View regular table structure
• SHOW TABLES WHERE is_materialized_view=true: List all materialized views
• REFRESH MATERIALIZED VIEW: Refresh a materialized view