Before loading a table into HeatWave, identify table columns to exclude. Columns to exclude are:
Columns with unsupported data types. It is required that these columns are excluded; otherwise, the table cannot be loaded. For a list of data types that HeatWave supports, see Section 10.1, “Supported Data Types”.
Columns that are not relevant to the queries you intend to run. Excluding irrelevant columns is not required but doing so reduces load time and the amount of memory required to store table data.
To exclude a column, specify the
SECONDARY column attribute in a
CREATE TABLE or
ALTER TABLE statement, as shown
NOT SECONDARY column attribute
prevents a column from being loaded into the HeatWave cluster when
executing a table load operation.
mysql> CREATE TABLE orders (id INT, description BLOB NOT SECONDARY);
mysql> ALTER TABLE orders MODIFY description BLOB NOT SECONDARY;
Queries that access columns defined with the
SECONDARY attribute are executed on the MySQL DB
system by default.