Summary Mode | Resource Usage Macros/Tables | Teradata Vantage - 17.00 - Summary Mode - Teradata Database

Teradata Vantageā„¢ - Resource Usage Macros and Tables

Advanced SQL Engine
Teradata Database
June 2020
User Guide

You can use Summary Mode to reduce the system overhead from logging tables that produce multiple rows per logging period. Summary Mode helps reduce overhead by combining data from multiple rows into one or more summary rows based on specific criteria for each table. For example, if you want to log information provided in the ResUsageSvpr table but do not need data for each individual vproc, use Summary Mode to produce one row per vproc type instead of one row per vproc.

The ResUsageSpma table, in comparison, provides node level summary of key fields from most of the other resource usage tables. When more details are required than the ResUsageSpma table provides, the next level of information is provided by using Summary Mode logging for the table of interest. This helps minimize the cost of the data logging.

You can select Summary Mode for each table individually. For details on how Summary Mode affects that particular table, see the description for each table.

For example, for the ResUsageSvpr table in Summary Mode, all the individual vproc rows of the same vproc type are combined into a single row. Since the data values are added together, you need to divide the summary row data value by the number of rows that made up the Summary Mode row to get the average per vproc. For example, divide the AMP summary row data value by the number of AMPs on that node to determine the average value per AMP. A similar computation needs to be done to derive the average value per PE from the summary row data value.

To determine the number of AMP, PEs, and all other vproc types on your system, you can use the ResUsageSpma table or use the Vproc Manager utility.

Resource usage columns that represent a maximum statistic are not summed together. Instead the maximum value from the rows is used. For example, the ResUsageSvpr table MsgWorkQLenMax column in the Summary Mode row for the AMPs will contain the maximum value from all the AMP rows that would have been logged in non-Summary Mode. The columns that represent a minimum statistic are summarized by storing the minimum value from all the constituent rows.

Summary Mode has either no effect on the values of the Housekeeping Columns or it is specifically detailed in the description of each affected field.

To enable Summary Mode, see Enabling RSS Logging.

For more information on Summary Mode, see Summary Mode in Resource Usage Tables.