4.2.6.3 Load Tables

You can load tables into HeatWave using the SECONDARY_LOAD clause.

Before You Begin

• Define the secondary engine.

Loading Tables Statement

To load a table into MySQL HeatWave, specify the SECONDARY_LOAD clause in an ALTER TABLE statement and use the following syntax.

ALTER TABLE table_name SECONDARY_LOAD [PARTITION (...)] [GUIDED {ON | OFF}];

Specify the following clauses in the ALTER TABLE statement:

• table_name: Specify the name of the table to load to MySQL HeatWave.

• PARTITION: Available as of MySQL 9.1.0. To learn more about partitions, see Load Partitions. If including partitions in the command, add them as needed.

• GUIDED: Available as of MySQL 9.4.1. Allows you to disable and enable Guided Load as needed. Set to OFF to disable Guided Load. By default, Guided Load is enabled.

The SECONDARY_LOAD clause has these properties:

• Data is read using the READ COMMITTED isolation level.

Guided Load

Available as of MySQL 8.2.0, the Guided Load feature performs a set of checks and validations before loading data.

These checks include the following:

• Automatically exclude tables and columns that cannot be loaded and set them with the NOT SECONDARY attribute.

• Automatically set SECONDARY_ENGINE to rapid.

As of MySQL 9.4.1, you have the option to disable Guided Load if you want to skip these checks.

Loading Data Examples

The following example loads the airport_geo. The Guided Load feature is enabled by default.

mysql> ALTER TABLE airport_geo SECONDARY_LOAD;

Warning (code 3877): Command executed during preprocessing: 'ALTER TABLE `airportdb`.`airport_geo` MODIFY `geolocation` point NOT NULL COMMENT '' NOT SECONDARY'.
Warning (code 3877): Command executed during preprocessing: 'ALTER TABLE `airportdb`.`airport_geo` SECONDARY_ENGINE=RAPID'.
Warning (code 3877): 1 InnoDB parallel read thread was requested to load airportdb.airport_geo (session variable value: 4).

The following example loads the airport_geo and disables Guided Load.

mysql> ALTER TABLE airport_geo SECONDARY_LOAD GUIDED OFF;

What's Next

• Learn how to load partitions.