ALTER DATABASE
Description
ALTER DATABASE statement changes the properties or location of a database. Please note that the usage of
DATABASE, SCHEMA and NAMESPACE are interchangeable and one can be used in place of the others. An error message
is issued if the database is not found in the system.
SET PROPERTIES
ALTER DATABASE SET DBPROPERTIES statement changes the properties associated with a database.
The specified property values override any existing value with the same property name.
This command is mostly used to record the metadata for a database and may be used for auditing purposes.
Syntax
ALTER { DATABASE | SCHEMA | NAMESPACE } database_name
SET { DBPROPERTIES | PROPERTIES } ( property_name = property_value [ , ... ] )
Parameters
-
database_name
Specifies the name of the database to be altered.
UNSET PROPERTIES
ALTER DATABASE UNSET DBPROPERTIES statement unsets the properties associated with a database.
If the specified property key does not exist, the command will ignore it and finally succeed.
(available since Spark 4.0.0).
Syntax
ALTER { DATABASE | SCHEMA | NAMESPACE } database_name
UNSET { DBPROPERTIES | PROPERTIES } ( property_name [ , ... ] )
Parameters
-
database_name
Specifies the name of the database to be altered.
SET LOCATION
ALTER DATABASE SET LOCATION statement changes the default parent-directory where new tables will be added
for a database. Please note that it does not move the contents of the database’s current directory to the newly
specified location or change the locations associated with any tables/partitions under the specified database
(available since Spark 3.0.0 with the Hive metastore version 3.0.0 and later).
Syntax
ALTER { DATABASE | SCHEMA | NAMESPACE } database_name
SET LOCATION 'new_location'
Parameters
-
database_name
Specifies the name of the database to be altered.
Examples
-- Creates a database named `inventory`.
CREATE DATABASE inventory;
-- Alters the database to set properties `Edited-by` and `Edit-date`.
ALTER DATABASE inventory SET DBPROPERTIES ('Edited-by' = 'John', 'Edit-date' = '01/01/2001');
-- Verify that properties are set.
DESCRIBE DATABASE EXTENDED inventory;
+-------------------------+------------------------------------------+
|database_description_item| database_description_value|
+-------------------------+------------------------------------------+
| Database Name| inventory|
| Description| |
| Location| file:/temp/spark-warehouse/inventory.db|
| Properties|((Edit-date,01/01/2001), (Edited-by,John))|
+-------------------------+------------------------------------------+
-- Alters the database to set a new location.
ALTER DATABASE inventory SET LOCATION 'file:/temp/spark-warehouse/new_inventory.db';
-- Verify that a new location is set.
DESCRIBE DATABASE EXTENDED inventory;
+-------------------------+-------------------------------------------+
|database_description_item| database_description_value|
+-------------------------+-------------------------------------------+
| Database Name| inventory|
| Description| |
| Location|file:/temp/spark-warehouse/new_inventory.db|
| Properties| ((Edit-date,01/01/2001), (Edited-by,John))|
+-------------------------+-------------------------------------------+
-- Alters the database to unset the property `Edited-by`
ALTER DATABASE inventory UNSET DBPROPERTIES ('Edited-by');
-- Verify that the property `Edited-by` has been unset.
DESCRIBE DATABASE EXTENDED inventory;
+-------------------------+-------------------------------------------+
|database_description_item| database_description_value|
+-------------------------+-------------------------------------------+
| Database Name| inventory|
| Description| |
| Location|file:/temp/spark-warehouse/new_inventory.db|
| Properties| ((Edit-date,01/01/2001)) |
+-------------------------+-------------------------------------------+
-- Alters the database to unset a non-existent property `non-existent`
-- Note: The command will ignore 'non-existent' and finally succeed
ALTER DATABASE inventory UNSET DBPROPERTIES ('non-existent');