Column Partitioning¶
The column table partition is designed to support the partition of Apache Hive™.
How to Create a Column Partitioned Table¶
You can create a partitioned table by using the PARTITION BY
clause. For a column partitioned table, you should use
the PARTITION BY COLUMN
clause with partition keys.
For example, assume there is a table orders
composed of the following schema.
id INT,
item_name TEXT,
price FLOAT
Also, assume that you want to use order_date TEXT
and ship_date TEXT
as the partition keys.
Then, you should create a table as follows:
CREATE TABLE orders (
id INT,
item_name TEXT,
price
) PARTITION BY COLUMN (order_date TEXT, ship_date TEXT);
Partition Pruning on Column Partitioned Tables¶
The following predicates in the WHERE
clause can be used to prune unqualified column partitions without processing
during query planning phase.
=
<>
>
<
>=
<=
- LIKE predicates with a leading wild-card character
- IN list predicates
Compatibility Issues with Apache Hive™¶
If partitioned tables of Hive are created as external tables in Tajo, Tajo can process the Hive partitioned tables directly. There haven’t known compatibility issues yet.