logical database

[Former Member]

hello SAP Gurus,

I have one doubt in logical database.

That is, is logical database extract all the data from the database tables ?

Can any one give me reply ?

Thank you very much.

[Former Member]

Hi,

Yes . it will fetch all the data from data base tables.

[Former Member]

Hi Vijaya,

Yes,

We fetch the Data from Database Tables into a Logical Database through SELECT queries,

so this Data is based on the Condition, if you don't specify a Condition then it will surely fetch whole Data.

Regards,

Sunil

[Former Member]

Hi lakshmi,

See i am providing you the all the Functionality of LDB's:

first i wll answer your question ok:

yes LDB extract all the data from the database tables.

now functionalities:

1. Providing automatic selection screen to our program.

2. Data retrieve by events.

3. Implementing authorization checks for user and data.

4. The programer need not worry about the Primary key for

each table. because LDB knows how the different tables relate to each other, and can issue the select command with proper Where clause to retrieve the data.

5. Meaningful data selection.

6. Good read access performance while retaining the hirerichal data view determined by the application logic.

These are the main functionalities of LDB's.

And if you wanna an example on LDB's how it works give me a reply i wll send you. Ok.,

<REMOVED BY MODERATOR>

thanks

Abdul Samee.

Edited by: Alvaro Tejada Galindo on Apr 30, 2008 5:23 PM

[Former Member]

Thank you very much sir.

But still i have one small doubt.That is everytime we need not to take the data from database instead of that we take from LDB.so we can reduce database load.

Can u send me example ?That will be helpful for me.

[Former Member]

Hi Lakshmi,

As u said we can reduce the database load

please check this link

http://www.geocities.com/siliconvalley/campus/6345/infotype.htm

Mode n this clause can only be used with the LDB's PCH and PNP.

This addition stops this infotype being automatically filled at the GET PERNR command.

EXAMPLE

Prerequisite

- The validity start date of the time period must be the same or before the validity end date.

- The validity start and end dates are correct date specifications (preferably from Type DATE).

Usage:

Only in PNP database reports under GET PERNR, because the personnel number for which data is being read comes from field PERNR-PERNR, while the field being used is PNP-SW-AUTH-SKIPPED-RECORD.

(RP_READ_ALL_TIME_ITY beg end) 
   DATA: BEGDA LIKE P2001-BEGDA, ENDDA LIKE P2001-ENDDA. 
   INFOTYPES:  0000, 0001, 0002, ... 
                     2001 MODE N, 2002 MODE N, ... 
     GET PERNR. 
   BEGDA = '19900101'. ENDDA = '19900131'. 
   RP_READ_ALL_TIME_ITY BEGDA ENDDA. 
   IF PNP-SW-AUTH-SKIPPED-RECORD NE '0'. 
      WRITE: / 'Authorization for time data missing'. 
      WRITE: / 'for personnel number', PERNR-PERNR. REJECT. 
   ENDIF.

Remarks

This RMAC module can be used when, for example, the time infotypes were originally defined in MODE N. This was done because the time data (from LOW-DATE to HIGH-DATE) might not all have fitted into the buffer. Now, however, they are read with shorter intervals (for example, in RPCALCx0 with payroll periods).

Please check this link

http://help.sap.com/saphelp_45b/helpdata/en/60/d8bb88576311d189270000e8322f96/content.htm

reward if helpful,

raam

[manubhutani]

hi

yes data is fetched from the LD

LD is a program in which data s fetched in an efficient way

it provids us a selection screen

for ex LD - PNP

prog is sapdbpnp it uses macros and select statements

whatever infotypes u declar in infotype statement

they get filled by this program

after get pernr event

please ask if any doubt

and please reward points