Overview of Tajo Tables¶

Overview¶

Managed Table¶

Todo

External Table¶

Todo

Table Properties¶

All table formats provide parameters for enabling or disabling features and adjusting physical parameters. The WITH clause in the CREATE TABLE statement allows users to set those properties.

The following example is to set a custom field delimiter, NULL character, and compression codec:

CREATE TABLE table1 (
 id int,
 name text,
 score float,
 type text
) USING CSV WITH('text.delimiter'='\u0001',
                 'text.null'='\\N',
                 'compression.codec'='org.apache.hadoop.io.compress.SnappyCodec');

Each physical table layout has its own specialized properties. They will be addressed in File Formats.

Common Table Properties¶

There are some common table properties which are used in most tables.

Compression¶

Todo

Time zone¶

In Tajo, a table property timezone allows users to specify a time zone that the table uses for reading or writing.

You can specify a table time zone as follows:

CREATE EXTERNAL TABLE table1 (
 t_timestamp  TIMESTAMP,
 t_date    DATE
) USING TEXT WITH('timezone'='ASIA/Seoul') LOCATION '/path-to-table/'

In order to learn time zone, please refer to Time Zone.