15.10 - Process Scheduling: PE and AMP UDF CPU Columns - Teradata Database

Teradata Database Resource Usage Macros and Tables

Product
Teradata Database
Release Number
15.10
Published
April 2016
Language
English (United States)
Last Update
2018-05-17
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These columns report the system level and user execution UDF CPU time value under the AMP and PE vprocs. They also provide information about whether the UDFs were doing work for the AMP or PE vprocs.

The data reported by CPUUExecPart00 for the NODE vproc includes the UDF CPU time for all UDFs running on the node.

All UDFs are invoked by either a PE or an AMP, but PDE reports UDF CPU usage to the Node partition by design, not the associated AMP and PE partitions. Therefore, the CPUUExecPart00 and CPUUServPart00 columns will report the UDF CPU usage and the CPUUServOrExecPart11 and 13 will not, where ServOrExec is either the user service (Serv) or user execution (Exec) partition. RSS code reports the UDF CPU usage by AMP and PE in the following UDF CPU columns:

  • UdfExec
  • UdfServ
The total of these UDF CPU columns can exceed 100% of elapsed centiseconds due to the CPU data gathering operation. The UDF CPU reporting for the ResUsageSvpr table is reported when the UDF completes an operation. A long running UDF will report all the CPU time at one time and that may be significantly larger than the current reporting period. This can cause spikes in the UDF CPU reporting columns.

The UDF CPU time value over multiple periods averages 100% or less.

When an external routine (such as C, C++, Java UDF, or external stored procedure) forks a child process or thread, the CPU time is not reported to these fields. As a result, the resource usage table shows a lower CPU usage than shown in the ResUsageSpma table even if the external routine consumes a large amount of CPU time. If there are child processes or threads running on your system, this may account for the larger CPU times reported in the ResUsageSpma table compared to this table. To confirm that the difference in CPU usage reported by the ResUsageSpma table is caused by child processes or threads, contact your Teradata Support Center personnel.
Column Name Mode Description Data Type
UdfServ count Reported system-level UDF CPU time value under the vproc. VprType determines if it is for an AMP or PE. If VprType is AMP, the field contains AMP CPU usage. If VprType is PE, the field contains PE usage. For other VprType, the field is 0. FLOAT
UdfExec count Reported user-level UDF CPU time value under the vproc. VprType determines if it is for an AMP or PE. If VprType is AMP, the field contains AMP CPU usage. If VprType is PE, the field contains PE usage. For other VprType, the field is 0. FLOAT