AI Features

enable_hypo_index

Parameter description: Determines whether the optimizer creates virtual indexes when executing the EXPLAIN command.

Parameter type: Boolean.

Unit: none

Value range:

• on: A virtual index is created when the EXPLAIN command is executed.
• off: No virtual index is created when the EXPLAIN command is executed.

Default value: off

Setting method: This is a USERSET parameter. Set it based on instructions in Table 2.

Setting suggestion: Retain the default value.

enable_ai_stats

Parameter description: Specifies whether to create or use intelligent statistics.

This is a USERSET parameter. Set it based on instructions in Table 2.

Value range: Boolean

• on indicates that intelligent statistics are created and used.
• off indicates that intelligent statistics are not created or used.

Default value: off

multi_stats_type

Parameter description: Specifies the type of statistics to be created when enable_ai_stats is set to on.

This is a USERSET parameter. Set it based on instructions in Table 2.

Value range: enumerated values. Valid values include "BAYESNET", "MCV", and "ALL".

• "BAYESNET": Only intelligent statistics are created.
• "MCV": Only traditional statistics are created.
• "ALL": Both traditional statistics and intelligent statistics are created.

Default value: "BAYESNET"

ai_stats_cache_limit

Parameter description: Specifies the maximum number of models that can be cached when enable_ai_stats is set to on.

This is a USERSET parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 30 to 1000.

Default value: 100

enable_operator_prefer

Parameter description: Specifies whether to enable the operator preference rule. If the estimated costs are similar, the parameterized path is preferred for table join.

This is a USERSET parameter. Set it based on instructions in Table 2.

Value range: Boolean

• on indicates that parameterized path preference is enabled.
• off indicates that parameterized path preference is disabled.

Default value: off

There are two prerequisites for this parameter to take effect:

• The parameterized path is generated.
• The estimated cost of the parameterized path is similar to that of other index scan operators.

enable_ai_watchdog

Parameter description: Enables or disables the AI watchdog function.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: Boolean

• on: enabled.
• off: disabled.

Default value: on

enable_ai_watchdog_forcible_oom_detection

Parameter description: Forcibly enables or disables the OOM detection function of the AI watchdog. If this parameter is disabled, the system automatically determines whether to enable the OOM detection function based on the current database specifications. In automatic determination mode, the OOM detection function is enabled only when max_process_memory is set to 64GB or a larger value. The OOM detection function depends on the information obtained by the memory management module. Therefore, if the memory management module is disabled or invalid, the OOM detection function is not enabled.

Parameter type: Boolean.

Unit: none

Value range:

• on: enabled.
• off: disabled.

Default value: off

Setting method: This is a SIGHUP parameter. Set it based on instructions in Table 2.

Setting suggestion: Retain the default value. If this function is enabled, the system performance may be affected.

enable_ai_watchdog_healing

Parameter description: Enables or disables the self-healing function of the AI watchdog.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: Boolean

• on: enabled.
• off: disabled.

Default value: on

ai_watchdog_max_cpu_usage

Parameter description: Specifies the expected upper limit of the database CPU usage. The value is normalized based on the multi-core situation. If this parameter is set to 0, the system does not check the CPU usage.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: a floating-point number ranging from 0 to 1.

Default value: 0.8

ai_watchdog_oom_dynamic_used_threshold

Parameter description: Specifies the expected upper limit of the dynamic memory usage of the database.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: a floating-point number ranging from 0 to 1.

Default value: 0.95

ai_watchdog_oom_growth_confidence

Parameter description: Specifies the confidence level of the OOM detection algorithm.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: a floating-point number ranging from 0.1 to 1.

Default value: 0.95

ai_watchdog_oom_malloc_failures

Parameter description: Specifies the maximum number of consecutive memory allocation failures tolerated. If the number of consecutive memory allocation failures exceeds this value, the OOM detection function may be triggered.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 1 to 32000.

Default value: 50

ai_watchdog_oom_other_used_memory_threshold

Parameter description: Specifies the expected upper limit of memory usage of other parts of the database, in MB.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: 1 to 1048576 (integer).

Default value: 20480

ai_watchdog_oom_process_threshold

Parameter description: Specifies the expected percentage of the database process usage to the value of max_process_memory. When the threshold is reached, memory leakage determination is triggered. The value can be greater than 1.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: a floating-point number ranging from 0 to 10.

Default value: 1.1

ai_watchdog_oom_shared_threshold

Parameter description: Specifies the expected upper limit of the shared memory usage of the database.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: a floating-point number ranging from 0 to 1.

Default value: 0.4

ai_watchdog_rto_restriction_time

Parameter description: Specifies the RTO threshold of the AI watchdog self-healing function. If the RTO threshold is exceeded, self-healing is not performed. The unit is second.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 0 to 36000.

Default value: 600

ai_watchdog_tolerance_times

Parameter description: Specifies the maximum number of consecutive abnormal events that can be tolerated by the AI watchdog before self-healing is started. This parameter can be used to avoid incorrect operations.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 0 to 100.

Default value: 4

ai_watchdog_tps_threshold

Parameter description: Specifies the lower limit of the expected TPS usage of the database instance. If the TPS usage is lower than the value of this parameter, the exception determination logic is triggered.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 0 to 32000.

Default value: 2

ai_watchdog_wait_time

Parameter description: Adjusts the waiting time, in seconds. To prevent the database from frequently performing self-healing operations, the database waits for a period of time after startup.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 0 to 36000.

Default value: 1800

ai_watchdog_warning_retention

Parameter description: Specifies the maximum number of alarm records that the AI watchdog can retain in the dbe_perf.ai_watchdog_detection_warnings view.

This is a SIGHUP parameter. Set it based on instructions in Table 2.

Value range: an integer ranging from 0 to 32000.

Default value: 20