Questions

[Former Member]

1.what is delivery class?

2.Explain about technical settings?

3.What is Buffering? How many types are there and explain it?

4.What approach you prefer for creating a table?

[Former Member]

Hi

1.what is 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.

G: Customer table, SAP may insert new data records, but may not overwrite or delete existing data records. The customer namespace must be defined in table TRESC. (Use Report RDDKOR54 here).

E: System table with its own namespaces for customer entries. The customer namespace must be defined in table TRESC. (Use Report RDDKOR54 here.)

S: System table, data changes have the same status as program changes.

W: System table (e.g. table of the development environment) whose data is transported with its own transport objects (e.g. R3TR PROG, R3TR TABL, etc.).

2.Explain about technical settings?

Data class

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.

Size category

The size category determines the probable space requirement for a table in the database.

You can select the categories 0 to 4 for your table. Each category is assigned a specific fixed storage area value in the database. When you create a table, initial space is saved for it in the database. If more space is required later as a result of data that has been entered, the storage space is increased in accordance with the category selected.

Press F4 on the field Size category to see the number of data records that can be maintained for the individual categories of your table without complications ensuing. These complications could be for example a reorganization becoming necessary because the maximum space to be reserved for the table was exceeded due to the maintained size category.

3.What is Buffering? How many types are there and explain it?

We have 3 types of buffering

There are the following types of buffering:

o single-record buffering

o generic area buffering

o full buffering

Single-record buffering should be selected when :

o For large tables where there are frequent single-record accesses (using SELECT SINGLE ...). The size of the records being accessed should be between 100-200 KB.

o For comparatively small tables for which the access range is large, it is normally advisable to opt for full buffering. Only one database access is required to load such a table for full buffering,

while single-record buffering calls for a very large number of table accesses.

And also check this matter.

Single-record buffering: Only the records of a table that are really accessed are loaded into the buffer

Single-record buffering should be used particularly for large tables where only a few records are accessed with SELECT SINGLE. The size of the records being accessed should be between 100 and 200 KB.

Full buffering is usually more suitable for smaller tables that are accessed frequently. This is because only one database access is necessary to load such a table with full buffering, whereas several database accesses are necessary for single-record buffering.

Check this link :

http://help.sap.com/saphelp_nw04/helpdata/en/f7/e4c5a8a84a11d194eb00a0c929b3c3/content.htm

<b>Reward points for useful Answers</b>

Regards

Anji

[Former Member]

Hi

1.what is 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.

G: Customer table, SAP may insert new data records, but may not overwrite or delete existing data records. The customer namespace must be defined in table TRESC. (Use Report RDDKOR54 here).

E: System table with its own namespaces for customer entries. The customer namespace must be defined in table TRESC. (Use Report RDDKOR54 here.)

S: System table, data changes have the same status as program changes.

W: System table (e.g. table of the development environment) whose data is transported with its own transport objects (e.g. R3TR PROG, R3TR TABL, etc.).

2.Explain about technical settings?

Data class

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.

Size category

The size category determines the probable space requirement for a table in the database.

You can select the categories 0 to 4 for your table. Each category is assigned a specific fixed storage area value in the database. When you create a table, initial space is saved for it in the database. If more space is required later as a result of data that has been entered, the storage space is increased in accordance with the category selected.

Press F4 on the field Size category to see the number of data records that can be maintained for the individual categories of your table without complications ensuing. These complications could be for example a reorganization becoming necessary because the maximum space to be reserved for the table was exceeded due to the maintained size category.

3.What is Buffering? How many types are there and explain it?

We have 3 types of buffering

There are the following types of buffering:

o single-record buffering

o generic area buffering

o full buffering

Single-record buffering should be selected when :

o For large tables where there are frequent single-record accesses (using SELECT SINGLE ...). The size of the records being accessed should be between 100-200 KB.

o For comparatively small tables for which the access range is large, it is normally advisable to opt for full buffering. Only one database access is required to load such a table for full buffering,

while single-record buffering calls for a very large number of table accesses.

And also check this matter.

Single-record buffering: Only the records of a table that are really accessed are loaded into the buffer

Single-record buffering should be used particularly for large tables where only a few records are accessed with SELECT SINGLE. The size of the records being accessed should be between 100 and 200 KB.

Full buffering is usually more suitable for smaller tables that are accessed frequently. This is because only one database access is necessary to load such a table with full buffering, whereas several database accesses are necessary for single-record buffering.

Check this link :

http://help.sap.com/saphelp_nw04/helpdata/en/f7/e4c5a8a84a11d194eb00a0c929b3c3/content.htm

<b>Reward points for useful Answers</b>

Regards

Anji

[Former Member]

<b>Delivery Class</b>

The delivery class controls the transport of table data for installation, upgrade, client copy and

when transporting between customer systems. The delivery class is also used in the extended

table maintenance.

There are the following development classes:

A: Application table (master and transaction data).

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

L: Table for storing temporary data.

G: Customer table, SAP may insert new data records but may not overwrite or delete

existing ones.

E: System table with its own namespace for customer entries. The customer namespace

must be defined in table TRESC.

S: System table, data changes have the status of program changes.

W: System table (e.g. table of the development environment) whose data is transported

with its own transport objects (e.g. R3TR PROG, R3TR TABL, etc.).

<b>Technical Settings</b>

The technical settings of a table define how the table will be handled when it is created in the

database, that is whether the table will be buffered and whether changes to data records of the

table will be logged.

The most important parameters are:

Data class: The data class [Page 31] defines the physical area of the database

(tablespace) in which the table should be created.

Size category: The size category [Page 32] defines the size of the extents created for the

table.

When the table is created in the database, the required information about the memory area to be

selected and the extent size is determined from the technical settings.

Buffering permission: The buffering permission [Page 33] defines whether the table may

be buffered.

Buffering type: If the table may be buffered, you must define a buffering type (full, singlerecord,

generic). The buffering type [Page 34] defines how many table records are

loaded into the buffer when a table entry is accessed.

Logging: This parameter defines whether changes to the table entries should be logged.

If logging [Page 41] is switched on, each change to a table record is recorded in a log

table.

<b>Buffering Permission</b>

You must define whether and how a table is buffered in the technical settings for the table. There

are three possibilities here:

Buffering not permitted: Table buffering is not permitted, for example because application

programs always need the most recent data from the table or the table is changed too

frequently.

Buffering permitted but not activated: Buffering is permitted from the business and

technical points of view. Applications which access the table execute correctly with and

without table buffering. Whether or not table buffering will result in a gain in performance

depends on the table size and access profile of the table (frequency of the different types

of table access). Table buffering is deactivated because it is not possible to know what

these values will be in the customer system. If table buffering would be advantageous for

the table size and access profile of the table, you can activate it in the customer system

at any time.

Buffering activated: The table should be buffered. In this case you must specify a

buffering type

<b>Buffering Types</b>

The buffering type defines which table records are loaded into the buffer of the application server

when a table record is accessed. There are the following buffering types:

Full buffering [Page 35]: All the records of the table are loaded into the buffer when one

record of the table is accessed.

Generic buffering [Page 37]: When a record of the table is accessed, all the records

having this record in the generic key fields (part of the table key that is left-justified,

identified by specifying a number of key fields) are loaded into the buffer.

Single-record buffering [Page 39]: Only the records of a table that are really accessed

are loaded into the buffer.

And, finally for creating a Table,

> First assign a name to a field and then create it Data element and then finally it's Domain.

Regards,

Pavan