Updated on 2025-05-29 GMT+08:00

Global Temporary Table

max_active_global_temporary_table

Parameter description: Specifies whether global temporary tables can be created. The value of this parameter determines the memory reserved in the shared cache for hash tables required by global temporary tables. The total number of active global temporary tables in all sessions is not forcibly limited.

Parameter type: integer

Unit: none

Value range: 0 to 1000000

  • 0: The global temporary table function is disabled.
  • > 0: The global temporary table function is enabled.

Default value: 1000

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

vacuum_gtt_defer_check_age

Parameter description: Checks the differences between the global temporary table relfrozenxid and the ordinary table after VACUUM is executed. An alarm is generated if the difference value exceeds the specified parameter value. This parameter can be set at the PDB level.

Parameter type: integer

Unit: none

Value range: 0 to 1000000

Default value: 10000. In the PDB scenario, if this parameter is not set, the global setting is inherited.

Setting method: This is a USERSET parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.

enable_gtt_concurrent_truncate

Parameter description: Specifies whether to support concurrent execution of TRUNCATE TABLE and DML operations on global temporary tables and concurrent execution of TRUNCATE TABLE on global temporary tables.

Parameter type: Boolean.

Unit: none

Value range:

  • on: The preceding operations can be performed concurrently.
  • off: The preceding operations cannot be performed concurrently.

Default value: on

Setting method: This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Retain the default value.

Risks and impacts of improper settings: Change the parameter value after fully understanding the parameter meaning and verifying it through testing.