How do I rename an existing table in Hive?
Rename table syntax in Hive. ALTER TABLE RENAME TO ; As mentioned in the syntax, mention your current table name after the ALTER TABLE command and specify the new table name after the RENAME TO command.
Can we alter table in Hive?
Hive provides us the functionality to perform Alteration on the Tables and Databases. We can perform multiple operations with table schema like renaming the table name, add the column, change or replace the column name, etc. …
How do I update table data in Hive?
There are many approaches that you can follow to update Hive tables, such as: Use Temporary Hive Table to Update Table. Set TBLPROPERTIES to enable ACID transactions on Hive Tables. Use HBase to update records and create Hive External table to display HBase Table data.
What is Hive Tblproperties?
The TBLPROPERTIES clause allows you to tag the table definition with your own metadata key/value pairs. Some predefined table properties also exist, such as last_modified_user and last_modified_time which are automatically added and managed by Hive.
Can we change the data type of a column in a Hive table?
It’s simple usually to change/modify the exesting table use this syntax in Hive. Here you can change your column name and data type at a time. If you don’t want to change col_name simply makes old_col_name and new_col_name are same.
How do I rename my Hive database?
We can also alter the database as below.
- Alter in Database Properties. Example: ALTER ( DATABASE | SCHEMA ) database name SET database properties ( property name = property value, );
- Alter the Owner. Example: ALTER (DATABASE| SCHEMA) database name SET OWNER [USER|ROLE ] user or role ;
- Alter the HDFS Location.
Can we rename columns in Hive?
You can replace the column name and the datatype using the ALTER command. Refer to the command below: hive> ALTER TABLE REPLACE COLUMNS ( INT, STRING); Replace columns removes all existing columns and add the ones mentioned.
How do you update an external table?
Updating external tables in Oracle
- Define a view on the external table.
- On this view, define INSTEAD OF triggers for insert, update and delete.
- Write PL/SQL code in these triggers to perform the required processing.
Which version of Hive supports update?
Since Hive Version 0.14, Hive supports ACID transactions like delete and update records/rows on Table with similar syntax as traditional SQL queries. You need to enable Hive ACID support and create a transactional table.
Can we update Hive external table?
2 Answers. There are two types of tables in Hive basically. One is Managed table managed by hive warehouse whenever you create a table data will be copied to internal warehouse. You can not have latest data in the query output .
What does MSCK repair table do?
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. User needs to run MSCK REPAIR TABLE to register the partitions.
What can be altered using alter command in Hive?
You can use the Apache Hive ALTER TABLE command to change the structure of an existing table. You can add, modify existing columns in Hive tables.
How do I rename a table in hive?
Based on the Hive doc below: ALTER TABLE table_name RENAME TO new_table_name; This statement lets you change the name of a table to a different name. As of version 0.6, a rename on a managed table moves its HDFS location as well.
How to add or change a column in hive using JDBC?
Given below is the JDBC program to change a column. Save the program in a file named HiveAlterChangeColumn.java. Use the following commands to compile and execute this program. Change column successful. The following query adds a column named dept to the employee table. The JDBC program to add a column to a table is given below.
How to rename a managed table in HDFS?
But the later version moves its HDFS location if you rename on a managed table. As mentioned in the syntax, mention your current table name after the ALTER TABLE command and specify the new table name after the RENAME TO command. Let’s look at an example that uses the ALTER TABLE statement to rename the table.
Why can’t I rename a partition in hive?
There was an issue with old version of Hive with renaming partition. This might be an issue for your case too. Please see this link for detail. You need to set below two property before executing the rename partition command if you are using Older version of Hive. Now run the query by setting this property.