IBM abap interview Questions phse - B

Time stamp – whenever the table is activated, a time stamp is created and stored activation of table in ABAP/4 dictionary affects time stamp of all reports using it. When the program is called we can determine whether to execute it or regenerate it by comparing the time stamps Type of stamp – CRSTAMP – most recent activation of table - ABSTAMP – comparison of reports - DYSTAMP – comparison with screens.

Runtime object – of a table collects the information about the data elements, domain field definition in a form optimal for program access. It is created when the table is generated for first time.

Mass activation program – Activate large sets of objects Simultaneously. ADV – 1 – large no of tables are affected by the change of domains or data elements at a time, so reactivated only once. 2 – related objects and its associated value table could be activated together else we should maintain sequence correctly. Activation Procedure – Step 1 – internal and external characteristics check (naming convention. Relation between check table and value table. Step 2 – partially active objects are checked whether external characteristics are arranged in order

Changing the structure – deleting the table in database. Activate the revised table in the dictionary. Table in database is created. Data in table is lost. Changing the database catalog by ALTER TABLE. Data is preserved indexes – recreated. Converting of tables – original table is renamed and temporarily buffered, revised table is activated in ABAP/4 dictionary and created in database Data from temporary table is reconstructed.

Conversion procedure – - 1 Generating a program - 2 Renaming the database table Prefix of QCM is added to table name - 3 Activating revised version - 4 reloading data - 5 secondary index - we need at least 16 MB RAM for conversion

Lock Mechanism – prevents a new database operation being started an existing one has been correctly completed. When conversion is done, lock is created automatically and released only when conversion is successful. Clearing of locks – restart adjustment – attempt is made to continue conversion at the point of termination – Cancel adjustment – lock entry is simply deleted from table

Restart log – progress of each step of conversion is noted in restart log,

Adjust structures – - A – structured adjustment is activated by changing database catalog - U – structured adjustment is activated by converting tables

Type of versions – - Versions in ABAP Dictionary – active or partially active / revised - Temporary versions - Historical versions

Type of status - New – newly created , not activated - Activated – activated version of object used by other components during runtime - Partially active – not yet been fully activated - Revised – version changed after activation, but not yet re-activated - Deactivated – match code Id is not proposed for selection by F4 help function

Version Management functions – - Canceling changes – reset revised version to active version - Storing changes – active version will be temporarily stored in version - Switching changes – switch between active and revised versions

Version catalog – list of all existing versions of an object - Revised version – produced when we edit an existing object - Active version – produced when we activate an object - Temporary version – produced when we copy the active version temporarily to the database with store version functions - Historical versions – created when 1. Correction is created 2 correction is released

Function provided - Display old versions - Retrieving historical or temporary versions - Comparing versions in same system - Comparing versions in different systems

Buffering – created locally on application server, changes in buffer are loaded in log table. Synchronization mechanism runs (1 –2 min) log table is read and buffer contents changed by other servers are invalid. Synchronization of all buffers in application servers is by asynchronous procedure

Tables that can be buffered – transparent and pooled tables

Possible buffering types - full buffering – either, whole table or none of the table is located in the buffer (Tables up to 30 kb done in client dependent fully buffered tables) - Generic buffering – generic areas of the table are fully buffered. - - Generic key – left justified section of primary key of a table. - - generic area – all records for which fields of generic key correspond - Single record buffering – records actually being accessed are loaded to buffers, large records where few records are accessed.

When to reset a buffer? A) If consistencies occurred between the buffer contents and the database.

What is Database Utility? A) Interface between ABAP/4 dictionary and relational database in SAP system. It allows to create, delete and convert objects from ABAP/4 dictionary in the database.

Processing types :- Direct – Changes carried out immediately. Background – background job is scheduled. Enter mass processing - entries are generated with relevant function in system table TBATG.

Repository Information System: - tool that makes data stored in ABAP/4 dictionary available. Find - search for objects from a specific object class that meets certain search criteria. Where-used list: -used to determine the use of an object in other objects.

Layers for data and data descriptions: · External layer – plane at which user sees and interacts with the data · ABAP/4 layer – data formats used by ABAP/4 processor. · Database layer – data formats used in the database.

Table spaces and extents: - · Table space - physical storage area in the database. · Database – determines in which table space the table is stored when it is created in the database. · Size category – describes the probable space requirement of the table in the database.

Transport system: - · Allows you to transport changes made to a particular development object. · Allows transporting objects from one SAP sys to another.

Table pool: - used to combine several logical tables in ABAP/4 dictionary, created for each match code object.

Table clusters: - · Combine several logical tables in ABAP/4 dictionary. Several logical rows from different cluster tables are brought together in a single physical record. · Used to store control data, temporary data or texts e.g. documentation.

Work bench organiser: - provides assistance for organizing development projects by allowing you to distribute project work for individual developers or teams among different change requests.

Request: - Objects from the areas of customizing and ABAP/4 development workbench are managed and recorded in separate requests.

Request overview: - When we start the workbench organizer, we are presented with a request overview that shows all change requests available and allows us to access several levels of detail, right down to the level of the object list itself.

Task: - Developments, correction and repairs recorded in tasks.

Change request: - Tasks are transported using change requests.

Development class: - Indicates which area the object belongs to. (Set of repository objects, which are mutually different.)

Production system: - Development projects are carried out here.

Transport log: - Enables you to immediately find out which objects were transported, by whom and why.

Transport system: -Used for moving objects from SAP development system to production system or between different systems.

System types: - § Development system (development work). § Quality assurance system: - Development and customizing settings are tested here. § Production system: - After successful testing, cust. Setting released here. § Training or demo systems: - For presentation of completed developments. § Relationship between system types. Special development Integration Consolidation Recipient System Û System Þ System Þ System Transports of Transportable Automatic Originals change requests Delivery

Special development system: - used for programming critical paths of development projects.

Integration system: - developing applications and testing systems.

Consolidated (production) system: - receives transports from integration system. It contains released versions.

Recipient system: - receive transportable change requests as soon as they are imported successfully into consolidation system.

Transport layer: - describes the transport route for distributing the developer class objects among various systems in the group. All development classes are distributed via same route belong to same transport layer.

Correction system: - prevents parallel, uncoordinated changes to the same object, even if many copies of the objects exists, connected by SAP system. It saves all changes to repository and customizing objects in original system on a version database. It is activated each time the user edits Repository object.

Request category: - § CUST – client-specific customizing. § SYST – SAP Repository and customizing for all clients.

Request Types: - § Transport request – List of objects to be transported. § Repair request – List of changed objects, which are not original. § Local change request – List of local objects. § Correction request – List of all changed original objects. § Object list – List of all transport objects. § Customizing request – List of all changed client specific-customizing objects.

Request source client: - Client in which requests and all assigned tasks are edited.

Request target client: - Client where request is imported.

Private object: - Exempt from the correction system.

Local object: - Exempt from both correction and transport systems.

Restrictions on transport system: - § Cannot overwrite, add to or delete original objects that are under repairs. § Can transport to consolidation system only with transport type K. § Can transport to recipient systems only from consolidation system to which recipient systems have subscribed.

Protecting a Transport Request: - Lock the objects listed in requests so prevents users from correcting it.

Task & Request Status: - § DOCUMENT – still editing a task or request and have not protected or released yet (not locked). § LOCKED – shows that you have tried to lock a task or request, but not all objects are locked. § LOCKED ALL – objects in task or transport layer-locked successfully. § RELEASED – task or request released. § OPEN – released but not yet transported.

Tables associated with CTS: - § TSYST – list of available systems. § DEVL – ABAP/4 Development Workbench transport layers. § TWSYS – consolidation routes for change requests. § TASYS – recipient system.