Different types of tables........Explain

[Former Member]

Hai Gurus,

Explain the following tables and give difference between them...

<b>1. Transparent table

2. Pooled table

3. Cluster table.</b>

Send it immediately very urgent....

[Former Member]

hi,

<b>Transparent Table</b>

1) Exists with the same structure both in dictionary as well as in database exactly with the same data and fields.

2) one to one relationship

<b>Pool Tables</b>

1) Many to One Relationship.

2) Table in the Dictionary has the different name, different number of fields, and the fields have the different name as in the R3 Table definition.

3) It can hold only pooled tables.

<b>cluster Tables:</b>

1) These are logical tables that are arranged as records of transparent tables.

2) One cannot use Native SQL on these tables (only Open SQL).

3) They are not manageable directly using database system tools.

These two table are used to store system data and onother for configural data.

if u want to fetch the data from DB table u need to go for trasperent tables only.

Bcoz transperent tables are one - one relation.

Thanks,

Madhukar

[Former Member]

<b>Transparent table, Pool table and cluster table</b> are data dictionary table objects <b>sorted table, indexed table and hash table</b> are internal tables.

<b>Table pools</b> (pools) and table clusters (clusters) are special table types in the ABAP Dictionary. The data from several different tables can be stored together in a table pool or table cluster. Tables assigned to a table pool or table cluster are referred to as pooled tables or cluster tables.

A <b>table</b> in the database in which all records from the pooled tables assigned to the table pool are stored corresponds to a table pool.

The <b>definition of a pool</b> consists essentially of two key fields (Tabname and Varkey) and a long argument field (Vardata). Table Clusters Several logical data records from different cluster tables can be stored together in one physical

record in a table cluster.

A <b>cluster</b> key consists of a series of freely definable key fields and a field (Pageno) for distinguishing continuation records. A cluster also contains a long field (Vardata) that contains the contents of the data fields of the cluster tables for this key. If the data does not fit into the long field, continuation records are created. Control information on the structure of the data string is still written at the beginning of the Vardata field.

<b>Hashed tables </b>

This is the most appropriate type for any table where the main operation is key access. You cannot access a hashed table using its index. The response time for key access remains constant, regardless of the number of table entries. Like database tables, hashed tables always have a unique key. Hashed tables are useful if you want to construct and use an internal table which resembles a database table or for processing large amounts of data.

reward points if it is usefull ....

Girish

[Former Member]

Hi,

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

Regards,

Priyanka.

[Former Member]

<b>When you need it urgent , then you have to reward points in the same manner.....</b>

[Former Member]

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.

Major diff between standard,cluster and pool table:</b></b>

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.

Reward points if useful.

[Former Member]

Hi Suresh,

<b>Table types:</b>

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

<b>Pooled Table :</b> 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.

<b>Cluster Table :</b> 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.

<b>Differences between table types:</b>

<b>I. Transparent tables</b> (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.

<b>II. Pool Tables</b> (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

<b>III. Cluster Tables</b> (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

Thanks,

Vinay

[Former Member]

<b>Transparent Tables</b>

There is a physical table on the database for each transparent table.

The names of the physical table and the logical table definition in the

ABAP/4 Dictionary agree. All the business and application data is store

in transparent tables.

<b>Pooled table</b>

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.

<b>Cluster table</b>

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 category. This permits object-by-object storage or

object-by-object access. In order to combine tables in clusters, at

least part of the keys must agree. Several cluster tables are stored in

one corresponding table on the database.

[Former Member]

Hi,

1. First thing to understand is this that

Either Pooled data, or cluster Data.

Both have SOME PHYSICAL table in the database.

(The table name will be different)

2. POOL TABLE

Suppose we have 15 different

tables in ABAP Dictionary

and only 1 table in physcial table.

So, the data of all these 15 tables

will be stored in the 1 physical table.

(it will be stored in a raw data format,

but it will be provided to the programs

in a structured way)

This concept is called POOL.

If all these 15 tables have 10 records each,

Then,

In the poooled table there will be

15 x 10 = 150 records.

Each record of the physical table

contains,

name of the table

Primary key value of the table

so that to identify the record.

3. CLUSTER

In a cluster table,

there is 1 physical table.

Each record contains a RAW Data.

The format of raw data is such

that it contains (NESTED DEEP STRUCTURE)

ie.

this raw data of 1 record,

contains data of many INTERNAL TABLES.

(These tables are just defined as structure

in database dictionary so that its definition

is there while saving and extracting)

Eg.

Salary of 1 employee, 1 month

will have 1 record in database table.

But this 1 record raw data will contain

information about these many internal tables.

Company data

salary figures

bank figures data

Provident fund data

etc. etc.

refer this link

http://www.is-edu.hcmuns.edu.vn/WebLib/Books/Database/0-672-31217-4/ch03/ch03.htm#TableClustersandCl...

Regards

Message was edited by:

skk