topic Re: Logical Dta base in Application Development and Automation Discussions

Logical Dta base

Former Member — Wed, 25 Apr 2007 06:35:52 GMT

Will logical DB improve performance

Re: Logical Dta base

Former Member — Wed, 25 Apr 2007 06:41:53 GMT

Hi,

The Logical DB contains nodes. thats why [performance wise not good.

But it contains sel-screen and default autharization check will be there.

Thanks

P.SRIKANTH

Re: Logical Dta base

Former Member — Wed, 25 Apr 2007 06:43:14 GMT

hi,

Performance will be less because it uses nested select statements.

Sudheer

Re: Logical Dta base

Former Member — Wed, 25 Apr 2007 06:44:47 GMT

hi,

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

Regards,

Priyanka.

Re: Logical Dta base

Former Member — Wed, 25 Apr 2007 06:49:46 GMT

Hi Kumar,

It depends on the requirement, what sort of data is required,

sometimes using logical database is not wise because of the performance.

If you have to fetch data from many Infotypes tables and you require logical database selection screen you should use Logical database. this is my understanding.

reward points if it helps.

Anurag Singh

Message was edited by:

Anurag Singh

Re: Logical Dta base

Former Member — Wed, 25 Apr 2007 07:42:58 GMT

Hi Kumar ,

Read my blog below for more info on LDB's :

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

Re: Logical Dta base

Former Member — Fri, 27 Apr 2007 11:42:52 GMT

The real bussiness scenario would be the same set of data (and selection screen) needed to be fetched from same database tables initially and then depending on the specific application of ur application program the final selction is done and report is outputted.....eg Report 1) Employee Personnel details (with some constraints), 2) Employee Salary details, etc SAY SOME 20 SUCH SIUATIONS....... Solution : get the valid employees from PA0000, 0001 and then for 1) Select from PA0002 , 2) Select from PA0008....In this case, using ldb saves much coding work......

But if you see for induvidual programs, still if you use ur custom logical databse with proper statements like For all entries, etc instead of select...Endselect and Innner Joins, etc u get the good performance only......

Also you can have a default selection screen and Authorization Checks (if u r writing it in the source code of ldb)....

In HR Module because of the availability of three powerful ldb's PNP, PNPCE and PCH and the default filling of infotype tables with infotype statement and authorization checks for Selected Pernr's, it is widely used.....

Re: Logical Dta base

Former Member — Mon, 07 May 2007 10:26:42 GMT

Hi,

U have to <b>award points for useful answers</b> and u have to mention it as solved if ur question is solved. Dont forget.

Regards,

Sudheer