Tables

[Former Member]

Hi,

What are the different types of tables we had and what is their significance? (Ex:Transparent Table, Cluster Table)

Thanks.

[Former Member]

Hi,

Types of tables : Transparent tables, Cluster tables, Pooled tables etc. For more information just do an F1 on the tables field in se11. You will have detailed description of the tables.

Thanks & regards,

Prakash Ghantasala

[Former Member]

Hi,

There are three categories of database tables in the ABAP Dictionary.

Transparent Table:

A physical table definition in the database for the table definition which is stored in the ABAP Dictionary for transparent tables when the

table is activated. The table definition is translated from the ABAP

Dictionary to a definition of the particular database.

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.

See the documetation at:

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21f083446011d189700000e8322d00/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/81/415d363640933fe10000009b38f839/frameset.htm

A transparent table in the dictionary has one to one relationship with a table in the database.

For each transparent table in the data dictionary there is one associated table in the database.The database table has the same name, the same number of fields and fields have same names as the transparent table definition. Transparent tables are used to hold application data. Application data is master data or transaction data used by an application.

e.g. master data - table of customers

Transaction data - order placed by the customers.

Pooled table in R/3 has a many to one relationship with a table in the database. For one table in the database there are many tables in the R/3 data dictionary.R/3 uses pooled tables to hold large number of very small tables. You might create a table pool if yoou need to create hundreds of small tables that each hold only a few rows of data.

A cluster table is similar to pool table . It has many to one relationship with the table in the database.

They are used to hold the data from a few(approximatelly 2 to 10) very large tables. They would be used when these tables have a part of their primary keys in common and if data in these tables are all accessed simultaneously.A cluster is advantageous in the case where data is accessed from multiple tables simultaneously and those tables have at least one of their primary key fields in common.Cluster table reduce number of database reads and thereby improves performance.

[mahaboob_pathan]

there are 3 different types of tables

transactional data-----> inflow and outflow of data.

masterdata-----> enduser will create.if we want to describe a particular ojbject.

control data---->stored in single and some times 2 tables. funtional ppl will create when the time of confuguration.data will be stored in 'T' tables

[Former Member]

Pooled tables and Cluster tables are not created in the database.

The data of these tables is stored in the corresponding table pool or table cluster at the database level.

It is not necessary to create indexes and technical settings for pooled and cluster tables.

Difference between transparent tables, pooled tables & Cluster Table.-

Transparent tables:

Transparent tables in the dictionary has a one-to-one relation with the table in database. Its structure corresponds to single database field. Table in the database has the same name as in the dictionary. Transparent table holds application data.

Pooled tables.

Pooled tables in the dictionary has a many-to-one relation with the table in database. Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level.

Cluster Tables

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.

pooled and cluster tables

http://help.sap.com/saphelp_47x200/helpdata/en/cf/21f083446011d189700000e8322d00/frameset.htm

Views

Contents of a view are dynamically generated when called from a program.

Hope this helps.

[Former Member]

Hi,

1. Table pool is used for storing large number of unrelated logical tables in one physical table. Table cluster is used for storing small number of related logical tables in one physical table.

2. Tables in a cluster must have a significant part of the key common, but tables in a table pool do not have that restriction.

3. One record of a table pool represent one record of any one of the pooled table whereas one record of table cluster represent data from one or more records of all cluster tables (If it fits in one page).

Cluster table contains large amount of data.

This cluster table in database is stored as the combination two or more small database tables.

For example BSEG is a cluster table..

You can find all the Fields of this table in different small tables BSIS, BSAS etc...

The following are the table types used in SAP :

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

regards

sri.