use of data class

[Former Member]

hi

while creating tables , what is the use of data class, if data class refers to master data , what it means? If data class refers to transactional data, what does it mean? what is the internal difference if we mention data class.

[Former Member]

When the table is activated in the ABAP/4 dictionary, the table is automatically created in the database.The necessary information on whch memory area(table space) to select and the probable table size are determined from the settings for the DATA CLASS and SIZE CATEGORY.

[Former Member]

HI,

Purpose

As soon as you create a database table for the SAP system, you can influence its storage parameters by maintaining its technical configuration in the ABAP dictionary. This technical configuration is used to optimize the space requirements and access response of individual tables.

For more information, see Creating Tables.

Process Flow

We recommend you to always maintain at least the parameters Data Class and Size Categoryin the technical configuration for each table:

· Data class

The data class logically defines the tablespace where your table is stored. When you select the correct logical table type, your table is automatically assigned to the correct database area when it is created. The F1 help for data class provides information on how to select the proper value for the table.

Data class is assigned to tablespace (for data) using the TAORA table. Data class is assigned to tablespace (for indexes) using the IAORA table.

· Size category

The size category specifies the estimated space requirements of the table on the database using the categories 0 to 4. When you create a table an INITIAL extent is reserved in the database. If you need more space later, storage space is added corresponding to the selected category (NEXT extent). The F4 help on size category displays the number of data records that will fit in the assigned storage area of the database for each of the categories. A maximum of 300 extents ought to be enough for storing table contents, assuming a database block size of 8 KB.

Size category is assigned to extent size using an entry in the table DD09L and an analysis of the TGORAtable for tables or IGORA for indexes. These values of the ABAP Dictionary only represent starting values. For further database operations, use the options provided by BRCONNECT for automatically adapting the size of the NEXT extent for all tables. For example, see -f next.

This section on size category does not apply to locally managed tablespaces.

If the table is defined logically, you have to create it in the database in a second step.

Warm Regards,

Vijay

[Former Member]

HI..

<b>Data class in technical settings</b>

The data class defines the physical area of the database (for ORACLE the

TABLESPACE) in which your table is logically stored. If you choose a

data class correctly, your table will automatically be assigned to the

correct area when it is created on the database.

The most important data classes are (other than the system data):

o <b>APPL0 Master data

o APPL1 Transaction data

o APPL2 Organizational and customizing data</b>

Master data is data which is frequently read, but rarely updated.

<b>Transaction data</b> is data which is frequently updated. For example...<b>Daily transactions</b>..like sales order creations, delivery,goods receipt...Organizational und

customizing data is data which is defined when the system is initialized

and then rarely changed.

There are two more data classes available, USR and USR1. These are

reserved for user developments. The tables assigned to these data

classes are stored in a tablespace for user developments.

Note:The data class only has an effect on table storage for the database

systems<b> ORACLE and INFORMIX.</b>

[Former Member]

Hi Jyothsna,

Delivery class

The delivery class controls the transport of table data when installing or upgrading, in a client copy and when transporting between customer systems. The delivery class is also used in the extended table maintenance.

There are the following delivery classes:

A: Application table (master and transaction data).

C: Customer table, data is maintained by the customer only.

L: Table for storing temporary data.

Data class:

Data class in technical settings

The data class defines the physical area of the database (for ORACLE the TABLESPACE) in which your table is logically stored. If you choose a data class correctly, your table will automatically be assigned to the correct area when it is created on the database.

The most important data classes are (other than the system data):

APPL0 Master data

APPL1 Transaction data

APPL2 Organizational and customizing data

Master data is data which is frequently read, but rarely updated. Transaction data is data which is frequently updated.Organizational und customizing data is data which is defined when the system is initialized and then rarely changed.

There are two more data classes available, USR and USR1. These are reserved for user developments. The tables assigned to these data classes are stored in a tablespace for user developments.

Note:The data class only has an effect on table storage for the database systems ORACLE and INFORMIX.

*************Rewords some points if it is helpful.

Rgds,

P.Naganjana Reddy

[Former Member]

Hi Jyothsna,

Check this information, you can find out the differences and usage of speciifc type of data class.

<b>DATA CLASS</b>

If you choose the data class correctly, your table is automatically assigned to the correct area (tablespace or DBspace) of the database when it is created. Each data class corresponds to a physical area in which all the tables assigned to this data class are stored. There are the following data classes:

APPL0 (master data): Data which is seldomly changed. An example of master data is the data contained in an address file, such as the name, address and telephone number.

APPL1 (transaction data): Data that is frequently changed. An example of transaction data is the goods in a warehouse, which change after each purchase order.

APPL2 (organizational data): Customizing data that is defined when the system is installed and seldomly changed. An example is the table with country codes.

Hope this resolves your query.

Reward all the helpful answers.

Regards

[Former Member]

Hai Jyotsna,

Master data don't change frequently.

Where as Transactional Data Changes frequently.

You can have more info at:

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21eac5446011d189700000e8322d00/frameset.htm

Reward points if it helps you.

Regds,

Rama chary.Pammi

[Former Member]

you choose the data class correctly, your table is automatically assigned to the correct area (tablespace or DBspace) of the database when it is created. Each data class corresponds to a physical area in which all the tables assigned to this data class are stored. There are the following data classes:

APPL0 (master data): Data which is seldomly changed. An example of master data is the data contained in an address file, such as the name, address and telephone number.

APPL1 (transaction data): Data that is frequently changed. An example of transaction data is the goods in a warehouse, which change after each purchase order.

APPL2 (organizational data): Customizing data that is defined when the system is installed and seldomly changed. An example is the table with country codes.

Two further data classes, USR and USR1, are provided for the customer. These are for user developments. The tables assigned to these data classes are stored in a tablespace for user developments.

[Former Member]

Hi Jyothsna,

APPL0 Master data

APPL1 Transaction data

APPL2 Organizational and customizing data

Master data is data which is frequently accessed, but rarely updated.

Transaction data is data which is frequently updated. For eg. Daily transactions like Sales order creations, creation of customers, creation of invoice.

customizing data is data which is defined when the system is configured.

Regards,

Vara Prasad.