2.3.1 Query Prerequisites

The following prerequisites apply for offloading queries to HeatWave:

• The query must be a SELECT statement. INSERT ... SELECT and CREATE TABLE ... SELECT statements are supported, but only the SELECT portion of the statement is offloaded to HeatWave. See Section 2.3.7, “CREATE TABLE ... SELECT Statements”, and Section 2.3.8, “INSERT ... SELECT Statements”.

• All tables accessed by the query must be defined with RAPID as the secondary engine. See Section 2.2.2.2, “Defining the Secondary Engine”.

• All tables accessed by the query must be loaded in HeatWave. See Section 2.2, “Loading Data to HeatWave”.

• autocommit must be enabled. If autocommit is disabled, queries are not offloaded and execution is performed on the MySQL DB System. To check the autocommit setting:

  mysql> SHOW VARIABLES LIKE 'autocommit';
  +---------------+-------+
  | Variable_name | Value |
  +---------------+-------+
  | autocommit    | ON    |
  +---------------+-------+

• Queries must only use supported functions and operators. See Section 2.12, “Supported Functions and Operators”.

• Queries must avoid known limitations. See Section 2.17, “HeatWave Limitations”.

If any prerequisite is not satisfied, the query is not offloaded and falls back to the MySQL DB System for processing by default.