ogical data base

[Former Member]

waht is logica data base?

how r they useful to abapers?

can we create aour own logical database?

[Former Member]

Hi,

Please go thru the link below

<a href="http://help.sap.com/saphelp_47x200/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm">http://help.sap.com/saphelp_47x200/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm</a>.

Thanks,

Sriram Ponna.

[Former Member]

Hi tanuj,

1. A logical database is in fact

a program only.

2. This LDB provides two main things :

a) a pre-defined selection screen

which handles all user inputs and validations

b) pre defined set of data

based upon the user selection.

3. So we dont have to worry about from

which tables to fetch data.

4. Moreover, this LDB Program,

handles all user-authorisations

and is efficient in all respects.

5. tcode is SLDB.

*----

---

1. To get a taste of it.

2. create a new z program.

3. while creating type PNP

in logical database field.

4. paste this code and execute.

REPORT ABC.

*----

---

infotypes : 0001.

TABLES : PERNR.

*----

---

GET PERNR.

WRITE 😕 PERNR-PERNR.

5. The selection screen which u see

is coming from logical database PNP program.

6. Execute

7. U will get a list of pernr.

-

---

SAPDBPNP

this is the main program of LDB PNP

which does the main work.

SAPDB + ldb name.

8. We can create our own ldb also, using the same transaction SLDB.

regards,

amit m.

[franciscojavier_carrillom]

Hi:

A logical data base, is a data base with a special Characteristic. For example they usually have a their own selection screen, and their owns authority checks.

they usually are very interesting for the abap developers, because they give us more simplicity in a lot of developments. For example you have the pnp logical data base for the master records of employed.

For you create a logical data base, you can use the se36 transaction.

Luck

[Former Member]

Hi

Logical Databases

Logical databases are special ABAP programs that retrieve data and make it available to application programs. The most common use of logical databases is still to read data from database tables by linking them to executable ABAP programs.

However, from Release 4.5A, it has also been possible to call logical databases using the function module LDB_PROCESS. This allows you to call several logical databases from any ABAP program, nested in any way. It is also possible to call a logical database more than once in a program, if it has been programmed to allow this. This is particularly useful for programs with type 1.

Logical databases contain Open SQL statements that read data from the database. You do not therefore need to use SQL in your own programs. The logical database reads the program, stores them in the program if necessary, and then passes them line by line to the application program or the function module LDB_PROCESS using an interface work area.

Logical Databases - Views of Data

A logical database provides a particular view of database tables in the R/3 System. It is always worth using logical databases if the structure of the data that you want to read corresponds to a view available through a logical database.

The data structure in a logical database is hierarchical. Many tables in the R/3 System are linked to each other using foreign key relationships. Some of these dependencies form tree-like hierarchical structures. Logical databases read data from database tables that are part of these structures.

********************************************

Logical databases are SAP standard programs that are desinged with selections screens that helps easy retrival and access of data from various tables in and efficient manner.

You can get to know more about the logical databases from the SAP documentation or the following links.

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

Advantages of Logical database -

1) No need of programming for retrieval , meaning for data selection

2) Easy to use standard user interface, have check completeness of user input.

Disadvantages

1) Fast in case of lesser no. of tables But if the table is in the lowest level of hierarchy, all upper level tables should be read so performance is slower.

GO THROUGH LINKS -

http://www.sap-basis-abap.com/saptab.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9bfa35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/c6/8a15381b80436ce10000009b38f8cf/frameset.htm

*************************************************

GO THROUGH LINKS -

http://www.sap-basis-abap.com/saptab.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9bfa35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/c6/8a15381b80436ce10000009b38f8cf/frameset.htm

/people/srivijaya.gutala/blog/2007/03/05/why-not-logical-databases

www.sapbrain.com/FAQs/TECHNICAL/SAP_ABAP_Logical_Database_FAQ.html

www.sap-img.com/abap/abap-interview-question.htm

www.sap-img.com/abap/quick-note-on-design-of-secondary-database-indexes-and-logical-databases.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw2004s/helpdata/en/9f/db9bb935c111d1829f0000e829fbfe/content.htm

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TCODE : SE36