Server System Variables This variable controls whether updates to a view can be made when the view does not contain all columns of the primary key defined in the underlying table, if the update statement contains a  LIMIT clause. (Such updates often are generated by GUI tools.) An update is an  UPDATE  or  DELETE  statement. Primary key here means a  PRIMARY KEY , or a  UNIQUE  index in which no column can contain  NULL . The variable can have two values: For future use. Whether to execute queries using a secondary engine. For use with HeatWave. See HeatWave User Guide. The  validate_password  component implements a set of system variables having names of the form  validate_password. xxx . These variables affect password testing by that component; see Section 6.4.3.2, “Password Validation Options and Variables” . The version number for the server. The value might also include a suffix indicating server build or configuration information.  -debug  indicates that the server was built with debugging support enabled. 914 • version_comment • version • validate_password. xxx • use_secondary_engine • 0  or  NO : Prohibit the update. • 1  or  YES : Issue a warning only (not an error message). This is the default value. Scope Global, Session Dynamic Yes SET_VAR  Hint Applies Yes Type Boolean Default Value 1 Introduced 8.0.13 System Variable use_secondary_engine Scope Session Dynamic Yes SET_VAR  Hint Applies Yes Type Enumeration Default Value ON Valid Values OFF ON FORCED System Variable version_comment