You can enable and disable heat map tracking at the system or session level with the ALTER SYSTEM or ALTER SESSION statement using the HEAT_MAP clause.
For example, the following SQL statement enables Heat Map tracking for the database instance.
ALTER SYSTEM SET HEAT_MAP = ON;
When Heat Map is enabled, all accesses are tracked by the in-memory activity tracking module. Objects in the SYSTEM and SYSAUX tablespaces are not tracked.
The following SQL statement disables heat map tracking.
ALTER SYSTEM SET HEAT_MAP = OFF;
When Heat Map is disabled, accesses are not tracked by the in-memory activity tracking module. The default value for the HEAT_MAP initialization parameter is OFF.
The HEAT_MAP initialization parameter also enables and disables Automatic Data Optimization (ADO). For ADO, Heat Map must be enabled at the system level. For more information about ADO, refer to "Using Automatic Data Optimization".
Oracle Database Reference for information about the HEAT_MAP initialization parameter