Chapter 04 abap dictionary tables in relational databases1

ABAP Dictionary Tables in Relational Databases

March-2005ABAP Dictionary Tables in Relational

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Objectives

• The participants will be able to: – Describe the different types of tables in the SAP

ABAP Dictionary.– Explain the technical settings for optimizing the

storage and maintenance requirements.– Describe performance benefits through indexing.


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SAP Table Types


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Transparent Table (TRANSP)

Structure (INTTAB)

Pool Table Cluster Table

View

Transparent Tables


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Master Data

SAP stores both master data and transaction data exclusively in transparent tables.

Transactional Data

Table Types TRANSP in the Database


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DB

PROFILE

Transparent (TRANSP) tables have a 1:1 correlation between the ABAP Dictionary and the physical database.

Mapping a Table of Type INTTAB


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DB xx

PROFILE

INTTAB tables are field strings (structures) which do not hold data.

They are not mapped to the database and have no underlying database tables.

Pool and Cluster Tables: Overview


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Pool Table Cluster TableCluster Table

Pooled tables can be used to store control data (e.g. screen sequences, program parameters or temporary data).

Cluster tables contain continuous text (e.g. documentation).

Technical Settings


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Master, Transaction Organization &

Customizing, UserData class

Number of data records in DB storage

Single records buff, generic area buffered, fully buffered

On or off

Size category

Buffering

Log data changes

Data Class


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User dataMaster data

Organization and Customizing dataTransaction data

DB

Size Categories


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A table’s size category identifies the amount of disk space on the database that is allocated to the table.

Buffering Type


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None

Single Record Generic

Full

KF1 KF2 KF3 F4 F5 F6 KF1 KF2 KF3 F4 F5 F6

KF1 KF2 KF3 F4 F5 F6

Logging


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On the technical settings screen you can specify “Log data changes” to automatically generate a log file of details on the structure of a table, a list of the data changes made during a certain period, and statistics.

Maintaining Technical Settings


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Data Class

Size Category

Buffering Type

Logging

Demonstration•Observation of the technical settings of the SAP Table MARA and familiarization with the technical settings of a transparent table.


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Practice

•Observation of the technical settings of the SAP Table MARA and familiarization with the technical settings of a transparent table.


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Database Utility


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ABAP ABAP Dictionary

Dictionary

DB

The Database (DB) Utility is a tool used in SAP to serve as a interface between the database management software (i.e., ORACLE, INFORMIX, DB2, INGRES, etc.) and the ABAP Dictionary

Index


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To improve performance, SAP automatically creates a primary index (id 0) for transparent tables based on the primary key. You can also define your own secondary indexes for transparent tables.

Database Indexes


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Index Table

Last NameLast Name First NameFirst Name PointerPointer

Adams Anthony

IDID Last NameLast Name First NameFirst Name SalarySalary

Zelkova Zephyr

Employee Names Employees

Burrows

Jones

Furia

Peters

Treske

Gregory

Gerry

Fred

Tim

Jimmy

Beth

Carolin

The Telephone Book Analogy


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Think of an index like a telephone book

The Telephone Book Analogy (Contd.)


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The Index Range Scan


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Sometimes an index doesn’t point to a single record, so it has to go for the Index Range Scan

The Unique Index Scan


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If each index record matches exactly one record in the table, and if all the fields of the index are specified in the query, a unique index scan can be performed.

Evaluating the Various Types of Scans


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Unique Index ScanUnique Index Scan

Index Range ScanIndex Range Scan

Full Table ScanFull Table Scan

A unique index scan is generally faster than an index range scan, because it has less data to sort through and retrieve.

Summary• There are 5 different table types in the SAP ABAP Dictionary: Transparent tables,

Structures, Pool tables, Cluster tables & Views.• Technical settings allow you to optimize the storage requirements and table

access behavior of database tables.• Defining a data class has the effect of storing the table in a defined area of the

database when the table is created.• A table’s size category identifies the amount of disk space on the database that is

allocated to the table. • Buffering is only recommended for tables with data that typically does not change

or get updated.• To improve performance, SAP automatically creates a primary index (id 0) for

transparent tables based on the primary key. You can also define your own secondary indexes for transparent tables.


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Questions• What are the different table types ?• What is data class ?• What is size category ?• What is buffering ?


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Documents

Chapter 04 abap dictionary tables in relational databases1