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sql-ref-syntax-ddl-alter-database.md

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ALTER DATABASE
ALTER DATABASE
Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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');

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