hi gurus

[Former Member]

hello gurus..plz answer this questions

What is data Dictionary ?

What is the difference between open sql & native sql ?

Difference between Pooled, cluster & transparent tables?

[ferry_lianto]

Hi,

What is data dictionary ?

Data dictionary describes the logical structures of the objects used in application development and shows how they are mapped to the underlying relational database in tables/views.

What is the difference between open sql & native sql?

ABAP Native SQL allows you to include database-specific SQL statements in an ABAP program. Most ABAP programs containing database-specific SQL statements do not run with different databases. If different databases are involved, use Open SQL. To execute ABAP Native SQL in an ABAP program, use the statement EXEC. Open SQL (Subset of standard SQL statements), allows you to access all database tables available in the R/3 System, regardless of the manufacturer. To avoid conflicts between database tables and to keep ABAP programs independent from the database system used, SAP has generated its own set of SQL statements known as Open SQL.

Difference between pooled, cluster & transparent tables?

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.

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

Regards,

Ferry Lianto

[Former Member]

Data dictionary holds the data definations or metadata. Ex: table defenations, type defenations etc.

Transparent table has a one to one relation with the field in the database and fields in the dictionary. The no of fields and field names are same in the data dictionary and database tables. But in case of pooled or cluster table, many to one relationship exists between the tables in the dictionary and database. The no of fields and field names are also different.