topic Re: ddic table in Application Development and Automation Discussions

ddic table

Former Member — Tue, 31 Jul 2007 12:25:00 GMT

Dear friends,

I wanna know about ddic table .Actually what it means,is there any difference exists between ddic table and transparent table

and

There exist ONE TO ONE relationship between ddic table and transparent table

Can u please expain me what does it means in simple words with example???

Regards,

Parag

Re: ddic table

Former Member — Tue, 31 Jul 2007 12:36:11 GMT

Hi,

In DDIC there are two types of tables,

Transparent Tables

Pooled and Clustered Tables

Reward if helpful.

Re: ddic table

Former Member — Tue, 31 Jul 2007 13:05:19 GMT

Transparent Table : Exists with the same structure both in dictionary as well as in database exactly with the same data and fields.

Pooled Table : Pooled tables are logical tables that must be assigned to a table pool when they are defined. Pooled tables are used to store control data. Several pooled tables can be cominied in a table pool. The data of these pooled tables are then sorted in a common table in the database.

Cluster Table : Cluster tables are logical tables that must be assigned to a table cluster when they are defined. Cluster tables can be used to strore control data. They can also be used to store temporary data or texts, such as documentation.

difference between Standard tables, Pooled tables and Clusterd Tables

A transparent table is a table that stores data directly. You can read these tables directly on the database from outside SAP with for instance an SQL statement.

Transparent table is a one to one relation table i.e. when you create one transparent table then exactly same table will create in data base and if is basically used to store transaction data.

A clustered and a pooled table cannot be read from outside SAP because certain data are clustered and pooled in one field.

One of the possible reasons is for instance that their content can be variable in length and build up. Database manipulations in Abap are limited as well.

But pool and cluster table is a many to one relationship table. This means many pool table store in a database table which is know as table pool.

All the pool table stored table in table pool does not need to have any foreign key relationship but in the case of cluster table it is must. And pool and cluster table is basically use to store application data.

Table pool can contain 10 to 1000 small pool table which has 10 to 100 records. But cluster table can contain very big but few (1 to 10) cluster table.

For pool and cluster table you can create secondary index and you can use select distinct, group for pool and cluster table. You can use native SQL statement for pool and cluster table.

A structure is a table without data. It is only filled by program logic at the moment it is needed starting from tables.

A view is a way of looking at the contents of tables. It only contains the combination of the tables at the basis and the way the data needs to be represented. You actually call directly upon the underlying tables.

Go through this link

http://web.mit.edu/sapr3/dev/sap_table_types.htm

I. Transparent tables (BKPF, VBAK, VBAP, KNA1, COEP)

Allows secondary indexes (SE11->Display Table->Indexes)

Can be buffered (SE11->Display Table->technical settings) Heavily updated tables should not

be buffered.

II. Pool Tables (match codes, look up tables)

Should be accessed via primary key or

Should be buffered (SE11->Display Table->technical settings)

No secondary indexes

Select * is Ok because all columns retrieved anyway

III. Cluster Tables (BSEG,BSEC)

Should be accessed via primary key - very fast retrieval otherwise very slow

No secondary indexes

Select * is Ok because all columns retrieved anyway. Performing an operation on multiple

rows is more efficient than single row operations. Therefore you still want to select into

an internal table. If many rows are being selected into the internal table, you might still

like to retrieve specific columns to cut down on the memory required.

Statistical SQL functions (SUM, AVG, MIN, MAX, etc) not supported

Can not be buffered

IV. Buffered Tables (includes both Transparent & Pool Tables)

While buffering database tables in program memory (SELECT into internal table) is generally

a good idea for performance, it is not always necessary. Some tables are already buffered

in memory. These are mostly configuration tables. If a table is already buffered, then a

select statement against it is very fast. To determine if a table is buffered, choose the

'technical settings' soft button from the data dictionary display of a table (SE12). Pool

tables should all be buffered.

regards,

srinivas

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Re: ddic table

Former Member — Tue, 31 Jul 2007 15:03:42 GMT

DDIC stands for Data Dictionary

There exist ONE TO ONE relationship between ddic table and transparent table..

It means :

There is a physical table on the database for each transparent table. The names of the physical tables and the logical table definition in the ABAP/4 Dictionary correspond and

one field in dictionary correspond to one field in physical database.

When the table is activated, a physical table definition is created in the database for the table definition stored in the ABAP Dictionary. The table definition is translated from the ABAP Dictionary to a definition of the particular database in One to One Relationship..

Pooled table

Pooled tables can be used to store control data (e.g. screen sequences, program parameters or temporary data). Several pooled tables can be combined to form a table pool. The table pool corresponds to a physical table on the database in which all the records of the allocated pooled tables are stored.

Cluster table

Cluster tables contain continuous text, for example, documentation. Several cluster tables can be combined to form a table cluster. Several logical lines of different tables are combined to form a physical record in this table type. This permits object-by-object storage or object-by-object access. In order to combine tables in clusters, at least parts of the keys must agree. Several cluster tables are stored in one corresponding table on the database.

Reward if useful

Regards

Prax

Re: ddic table

Former Member — Wed, 01 Aug 2007 01:20:25 GMT

/message/3767615#3767615 [original link is broken]

Re: ddic table

Former Member — Wed, 01 Aug 2007 06:57:17 GMT

Just search in SE11 transaction for DD* for the Database table, which will help you for system tables of DDIC.

Following are the tables having the DDIC table properties -

DD01L Domains

DD01T R/3 DD: domain texts

DD02L SAP Tables

DD02T R/3 DD: SAP table texts

DD03L Table Fields

DD03T DD: Texts for fields (language dependent)

DD04L Data elements

DD04T R/3 DD: Data element texts

DD05S Foreign key fields

DD06L Pool/cluster structures

DD08L R/3 DD: relationship definitions

DD09L DD: Technical settings of tables

DD30L Search helps

DD30T Search help texts

ECLOG_HEAD Table for Log Header

E070 Change & Transport System: Header of Reque

E071 Change & Transport System: Object Entries

Hope this helps.

Regards,

Pavan