System Performance Snapshot

enable_wdr_snapshot

Parameter description: Specifies whether to enable the database monitoring snapshot function.

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

Value range: Boolean

• on indicates that the database monitoring snapshot function is enabled.
• off indicates that the database monitoring snapshot function is disabled.

Default value: on

wdr_snapshot_retention_days

Parameter description: Specifies the number of days database monitoring snapshots are retained. If the number of days that the snapshots are retained exceeds the value of this parameter, the system deletes the snapshots with the smallest ID at an interval specified by wdr_snapshot_interval.

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

Value range: an integer ranging from 1 to 30. The unit is day.

Default value: 8

wdr_snapshot_query_timeout

Parameter description: Specifies the execution timeout for the SQL statements associated with database monitoring snapshot operations. If the SQL statement execution is not complete and no result is returned within the specified time, the snapshot operation fails.

This is a SIGHUP parameter. Set it based on instructions provided in Table 1. The value 0 indicates that this parameter does not take effect.

Value range: an integer ranging from 0 to 2147483647. The unit is s.

Default value: 100s

wdr_snapshot_interval

Parameter description: Specifies the interval at which the backend thread Snapshot automatically performs snapshot operations on the database monitoring data.

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

Value range: an integer ranging from 10 to 60. The unit is min.

Default value: 1h

enable_asp

Parameter description: Specifies whether to enable the active session profile function.

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

Value range: Boolean

• on: The function is enabled.
• off: The function is disabled.

Default value: on

asp_sample_num

Parameter description: Specifies the maximum number of samples allowed in the LOCAL_ACTIVE_SESSION view. Only the sysadmin user can access this parameter.

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

Value range: an integer ranging from 10000 to 100000

Default value: 100000

asp_sample_interval

Parameter description: Specifies the sampling interval.

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

Value range: an integer ranging from 1 to 10. The unit is s.

Default value: 1s

asp_flush_rate

Parameter description: When the number of samples reaches the value of asp_sample_num, the samples in the memory are updated to the disk based on a certain proportion. asp_flush_rate indicates the update proportion. If this parameter is set to 10, the update ratio is 10:1.

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

Value range: an integer ranging from 1 to 10

Default value: 10

asp_flush_mode

Parameter description: Specifies the mode for the ASP to update data to the disk. The value can be file (default value), table (system catalog), or all (system catalog and file). Only the sysadmin user can access this parameter.

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

Value range: a string, which can be table, file, or all

Default value: table

asp_retention_days

Parameter description: Specifies the maximum number of days for reserving ASP samples when they are written to the system catalog.

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

Value range: an integer ranging from 1 to 7. The unit is day.

Default value: 2

asp_log_filename

Parameter description: Specifies the file name format when writing files using ASP. Only the sysadmin user can access this parameter.

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

Value range: a string

Default value: asp-%Y-%m-%d_%H%M%S.log