Showing posts with label mount hbase table in hive. Show all posts
Showing posts with label mount hbase table in hive. Show all posts

Friday, December 28, 2012

Query Hbase tables using hive/ Mount an Hbase table into hive


You can use Hbase as the data store for your hive table. On hive table creation we need to specify a mapping for the same.  What all needs to be provided
1.       The hbase table name
2.       The mapping between hbase Column Family:Qualifier to hive Columns
If you are mapping a hbase column Family itself to a hive column then the data type of that hive column has to be Map. Also in the DDL the table has to me specified as External

Example of mapping a hbase table (employee_hbase) to a hive table employee_hive

CREATE EXTERNAL TABLE employee_hive(key INT, value1 STRING,value2 Map<STRING,STRING>)
STORED BY 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
WITH SERDEPROPERTIES ("hbase.columns.mapping" = ":key,cf1:val,cf2:")
TBLPROPERTIES("hbase.table.name" = "employee_hbase");