optimizer_features_enable

Overview

optimizer_features_enable is used to enable optimizer features for different OceanBase versions.

Privilege requirements

• Query variables

  The SHOW VARIABLES statement, or the SYS.TENANT_VIRTUAL_GLOBAL_VARIABLE view (in Oracle-compatible mode) and the information_schema.GLOBAL_VARIABLES view (in MySQL-compatible mode), can be used by the sys tenant and all user tenants to view the values of global system variables.

• Modify variables

  • The sys tenant can directly modify the values of global system variables.

  • MySQL user tenants must have the SUPER or ALTER SYSTEM privilege to modify the values of global system variables.

  • For V4.x versions, starting from V4.2.0, an Oracle user tenant must have the ALTER SYSTEM privilege to modify the values of global system variables.

Attributes

Configuration example

• Session Validity Period

  obclient> SET optimizer_features_enable='4.2.1.7';
  

• Effective globally

  obclient> SET GLOBAL optimizer_features_enable='4.2.1.7';