SAMPLE ACCOUNTING TABLES FOR DATA REORGANIZATION GREEN BOOK

Products

• Datacom
• Datacom/AD
• Datacom/DB

Issue/Introduction

Looking for the Accounting Tables:

 - High Level Accounting tables (A90 and A91)
 - High Level Accounting tables with Key Information (A92 and A93)
 - High Level Access with Key Information for Non-CICS (A94 and A95)
 - High Level Access with Key Information for Selected DBIDs (A96 and A97)
 - High Level Access with Key Information for Selected Time Periods (A98 and A99) 

Where are their definitions?

Environment

Release: ALL
Component: Datacom /AD
Component: Datacom/DB

Cause

 

Resolution

The Datacom/DB Data Reorganization Green Book was delivered in 2011. The Green Book discusses many techniques for managing and performing data row reorganizations.

Chapter 2 of the Green Book discusses using Accounting tables to measure sequential access to the data rows. The Green Book discusses five different pairs of sample Accounting tables that could be used to collect sequential data row access information. Each pair of sample tables has slightly different characteristics to allow the user to choose the Accounting table pair most applicable to his or her site.

A typical site will only need to implement one sample pair of Accounting tables. The five sample pairs are delivered as a single set of DDUPDATE transactions. The user is responsible for integrating these tables' definitions into their existing environment. More information on implementing the accounting facility can be found in the Datacom/DB Database and System Administration Guide.

 

The Green Book describes five pairs of Accounting tables as:

High Level Accounting tables (A90 and A91)

The A90 and A91 pair of Accounting tables is focused on collecting the minimal amount of information on the user tables being processed. For each day, each user table that was accessed that day has one row created in the all accesses Accounting table (A90) and one row created in the all sequential access Accounting table (A91). By comparing the data for a selected user table in A90 to the same user table in A91, we can determine the amount of sequential processing and its relative performance to the total processing and its relative performance.

High Level Accounting tables with Key Information (A92 and A93)

The A92 and A93 pair of Accounting tables is focused on collecting the minimal amount of information on the user tables processed by the key names (KNAME) being used to access the data. To do this, we add the KNAME column to the Accounting table Master Key definition. We will have multiple rows, one per key used, in the Accounting table for each user table accessed. By comparing the data for a selected table/key in A92 to the same table/key in A93, we can determine the amount of sequential processing and its relative performance to all access to the table by a specific key.

High Level Access with Key Information for Non-CICS (A94 and A95)

The A94 and A95 pair of Accounting tables is focused on collecting the minimal amount of information on the user tables processed by the key names (KNAME) being used to access the data. However, we are excluding CICS requests from the collection. To do this, we add additional selection criteria to both Accounting tables. We still have multiple rows, one per key used, in the Accounting table for each user table accessed. By comparing the data for a selected table/key in A94 to the same table/key in A95, we can determine the amount of sequential processing and its relative performance to all access to the table by a specific key.

High Level Access with Key Information for Selected DBIDs (A96 and A97)

The A96 and A97 pair of Accounting tables is focused on collecting the minimal amount of information on the user tables processed by the key names (KNAME) being used to access the user data. We are limiting the data collection to only requests for selected user databases (DBIDs). To do this, we add selection criteria. We have multiple rows, one per key used, in the Accounting table for each user table accessed. By comparing the data for a selected user table/key in A96 to the same user table/key in A97, we can determine the amount of sequential processing and its relative performance to all access to the table by a specific key.

High Level Access with Key Information for Selected Time Periods (A98 and A99)

The A98 and A99 pair of Accounting tables is focused on collecting the same amount of information as the previous Accounting tables, but we will limit the focus to just Monday through Friday and from 8:00:00 AM to 5:59:59 PM.

Download Accounting Tables A90-A99 BTG.txt file, attached to this article, containing the DDUPDATE transactions for sample Accounting tables A90-A99 mentioned in the Datacom Data Reorganization Green Book.