| layout | title | displayTitle | license |
|---|---|---|---|
global |
REPAIR TABLE |
REPAIR TABLE |
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.
|
MSCK REPAIR TABLE recovers all the partitions in the directory of a table and updates the Hive metastore. When creating a table using PARTITIONED BY clause, partitions are generated and registered in the Hive metastore. However, if the partitioned table is created from existing data, partitions are not registered automatically in the Hive metastore. User needs to run MSCK REPAIR TABLE to register the partitions. MSCK REPAIR TABLE on a non-existent table or a table without partitions throws an exception. Another way to recover partitions is to use ALTER TABLE RECOVER PARTITIONS.
{% highlight sql %} MSCK REPAIR TABLE table_identifier {% endhighlight %}
table_identifier-
Specifies the name of the table to be repaired. The table name may be optionally qualified with a database name.
Syntax:[ database_name. ] table_name
{% highlight sql %} -- create a partitioned table from existing data /tmp/namesAndAges.parquet CREATE TABLE t1 (name STRING, age INT) USING parquet PARTITIONED BY (age) location "/tmp/namesAndAges.parquet";
-- SELECT * FROM t1 does not return results SELECT * FROM t1;
-- run MSCK REPAIR TABLE to recovers all the partitions MSCK REPAIR TABLE t1;
-- SELECT * FROM t1 returns results SELECT * FROM t1;
+ -------------- + ------+
| name | age |
+ -------------- + ------+
| Michael | 20 |
+ -------------- + ------+
| Justin | 19 |
+ -------------- + ----- +
| Andy | 30 |
+ -------------- + ----- +
{% endhighlight %}