Unloading a table from MySQL HeatWave may be necessary to replace an existing table, to reload a table, to free up memory, or simply to remove a table that is no longer used.

To unload a table manually, specify the SECONDARY_UNLOAD clause in an ALTER TABLE statement:

mysql> ALTER TABLE tbl_name SECONDARY_UNLOAD;

The following example unloads the data_table_1 table.

mysql> ALTER TABLE data_table_1 SECONDARY_UNLOAD;

Data is removed from MySQL HeatWave only. The table contents on the DB System are not affected.

As of MySQL 9.1.0, MySQL HeatWave supports partitions for DB System tables. INFORMATION_SCHEMA.PARTITIONS includes a SECONDARY_LOAD column that indicates whether a partition is loaded. Review how to Load Partitions.

See the following to learn more:

When an unload operation successfully unloads the last partition, it unloads the whole table.

To unload partitions, specify the SECONDARY_UNLOAD clause in an ALTER TABLE statement.

mysql> ALTER TABLE tbl_name SECONDARY_UNLOAD PARTITION (p0, p1, ..., pn);

The following example unloads the p0 partition from data_table_1.

mysql> ALTER TABLE data_table_1 SECONDARY_UNLOAD PARTITION (p0);

If a partition unload fails, the table becomes stale.