Queries

[Former Member]

Hi Friends,

I have the following queries,can you give me the answers to the following queries.

1)what is the procedure for locking SAP Standard tables?

2)Difference between Read and select single?

3)Difference between select single and select upto 1 row?

4)Differnce between BADI and user exit?

5)How to identify the place where to incorporate the logic in user exit based on requirement?

Thanks in advance.

Regards,

Dinesh

[Former Member]

1. Have a look at below link.

<u></u><a href="http://help.sap.com/saphelp_nw04/helpdata/en/cb/168237d30d974be10000009b38f8cf/content.htm">Lock Concept</a>

2. Read can be used to read lines of internal table while select single is used to fetch a single entry from database table.

3. According to SAP Performance course the SELECT UP TO 1 ROWS is faster than SELECT SINGLE because you are not using all the primary key fields.

select single is a construct designed to read database records with primary key. In the absence of the primary key, it might end up doing a sequential search, whereas the select up to 1 rows may assume that there is no primary key supplied and will try to find most suitable index.

The best way to find out is through sql trace or runtime analysis.

Use "select up to 1 rows" only if you are sure that all the records returned will have the same value for the field(s) you are interested in. If not, you will be reading only the first record which matches the criteria, but may be the second or the third record has the value you are looking for.

The System test result showed that the variant Single * takes less time than Up to 1 rows as there is an additional level for COUNT STOP KEY for SELECT ENDSELECT UP TO 1 ROWS.

The 'SELECT SINGLE' statement selects the first row in the database that it finds that fulfils the 'WHERE' clause If this results in multiple records then only the first one will be returned and therefore may not be unique.

Mainly: to read data from

The 'SELECT .... UP TO 1 ROWS' statement is subtly different. The database selects all of the relevant records that are defined by the WHERE clause, applies any aggregate, ordering or grouping functions to them and then returns the first record of the result set.

Mainly: to check if entries exist.

4. i) BADI's can be used any number of times, where as USER-EXITS can be used only one time.

Ex:- if your assigning a USER-EXIT to a project in (CMOD), then you can not assign the same to other project.

ii) BADI's are oops based.

Also read below info.:

Business Add-Ins are a new SAP enhancement technique based on ABAP Objects. They can be inserted into the SAP System to accommodate user requirements too specific to be included in the standard delivery. Since specific industries often require special functions, SAP allows you to predefine these points in your software.

As with customer exits two different views are available:

In the definition view, an application programmer predefines exit points in a source that allow specific industry sectors, partners, and customers to attach additional software to standard SAP source code without having to modify the original object.

In the implementation view, the users of Business Add-Ins can customize the logic they need or use a standard logic if one is available.

In contrast to customer exits, Business Add-Ins no longer assume a two-level infrastructure (SAP and customer solutions), but instead allow for a multi-level system landscape (SAP, partner, and customer solutions, as well as country versions, industry solutions, and the like). Definitions and implementations of Business Add-Ins can be created at each level within such a system infrastructure.

SAP guarantees the upward compatibility of all Business Add-In interfaces. Release upgrades do not affect enhancement calls from within the standard software nor do they affect the validity of call interfaces. You do not have to register Business Add-Ins in SSCR.

The Business Add-In enhancement technique differentiates between enhancements that can only be implemented once and enhancements that can be used actively by any number of customers at the same time. In addition, Business Add-Ins can be defined according to filter values. This allows you to control add-in implementation and make it dependent on specific criteria (on a specific Country value, for example).

All ABAP sources, screens, GUIs, and table interfaces created using this enhancement technique are defined in a manner that allows customers to include their own enhancements in the standard. A single Business Add-In contains all of the interfaces necessary to implement a specific task.

The actual program code is enhanced using ABAP Objects. In order to better understand the programming techniques behind the Business Add-In enhancement concept, SAP recommends reading the section on ABAP Objects.

I hope it helps.

Best Regards,

Vibha

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