Database Table

[Former Member]

Hi All,

Why we always use transparent table why we not use pooled and cluster table

thanks.

[Sandra_Rossi]

Because they are obsolete since ABAP 7.53 (see ABAP documentation).

[Abinathsiva]

HI,

Transparent table is like normalized tables, ie., when you create one transparent table it will create exactly same table in Database..

A cluster and pool table cannot be read directly..

Different types of tables in SAP

[Sandra_Rossi]

Cluster(ed) and pool(ed) tables CAN be read directly: they were designed to compress data by the ABAP kernel and store data compressed, but Open SQL does the compression and decompression implicitly.

NB: the database tables which contain the clustered and pooled tables CANNOT be read directly, I mean you should decompress yourself the data, and there is no official explanation about what algorithm is used to compress the data.

[RaymondGiuseppi]

A (very) long time ago, data storage was more expensive than development and the technical limitations of databases were much lower, which led to the creation of clustered data to save space. This is no longer the case and these techniques are obsolete.

One could also discuss at length the reality of an assertion such as:Business data storage is getting cheaper, think hidden costs of business data storage...

For your question, think about performance when you want to select data on clustered fields, thus inaccessible to the relational database manager.