2.2.2.4 Loading Partitions

As of MySQL 9.1.0, HeatWave MySQL supports InnoDB partitions, see Partition Selection. INFORMATION_SCHEMA.PARTITIONS includes a SECONDARY_LOAD column that indicates whether a partition has been loaded. The possible values are:

• 1: The partition is loaded.

• 0: The partition is not loaded.

• NULL: The table does not have partitions.

A successfully completed load or unload operation will update INFORMATION_SCHEMA.PARTITIONS. If an operation loads or unloads the whole table, and does not specify individual partitions, then it will update all SECONDARY_LOAD columns when successfully completed.

HeatWave MySQL persists partition information. During a restart, only the previously loaded partitions will be loaded.

To load partitions into HeatWave, specify the SECONDARY_LOAD clause in an ALTER TABLE statement.

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

The SECONDARY_LOAD clause can load a subset of partitions:

mysql> ALTER TABLE tbl_name SECONDARY_LOAD PARTITION (p4, p5, p10);

To use a new partition in HeatWave after adding it to a previously loaded table:

mysql> ALTER TABLE t1 SECONDARY_LOAD;
mysql> ALTER TABLE t1 ADD PARTITION (PARTITION p4 VALUES LESS THAN (2002));
mysql> ALTER TABLE t1 SECONDARY_LOAD PARTITION (p4);

The SECONDARY_LOAD clause has these properties:

• Data is read using the READ COMMITTED isolation level.

See: Section 2.18.6, “Partition Selection Limitations”.