SAP Basis interesting question and answers

What is transparent table?
Transparent Table : Exists with the same structure both in dictionary as well as in database exactly with the same data and fields.


What is a cluster table? Where and when we use these tables?
Pooled Table : Pooled tables are logical tables that must be assigned to a table pool when they are defined. Pooled tables are used to store control data. Several pooled tables can be combined in a table pool. The data of these pooled tables are then sorted in a common table in the database.


What is a pool table? Where and when we use these tables?
Cluster Table : Cluster tables are logical tables that must be assigned to a table cluster when they are defined. Cluster tables can be used to store control data. They can also be used to store temporary data or texts, such as documentation.



What is the major difference between Standard tables, Pooled tables and Clustered Tables?

A transparent table is a table that stores data directly. You can read these tables directly on the database from outside SAP with for instance an SQL statement.

Transparent table is a one to one relation table i.e. when you create one transparent table then exactly same table will create in data base and if is basically used to store transaction data.

A clustered and a pooled table cannot be read from outside SAP because certain data are clustered and pooled in one field.

One of the possible reasons is for instance that their content can be variable in length and build up. Database manipulations in ABAP are limited as well.

But pool and cluster table is a many to one relationship table. This means many pool table store in a database table which is know as table pool.

All the pool table stored table in table pool does not need to have any foreign key relationship but in the case of cluster table it is must. And pool and cluster table is basically use to store application data.

Table pool can contain 10 to 1000 small pool table which has 10 to 100 records. But cluster table can contain very big but few (1 to 10) cluster table.

For pool and cluster table you can create secondary index and you can use select distinct, group for pool and cluster table. You can use native SQL statement for pool and cluster table.

A structure is a table without data. It is only filled by program logic at the moment it is needed starting from tables.

A view is a way of looking at the contents of tables. It only contains the combination of the tables at the basis and the way the data needs to be represented. You actually call directly upon the underlying tables.

How many tables we will come across in ABAP?
Ans : 3 types : Pooled , clustered, Transparent

How many kinds of internal table are there?
Ans: 5 Types.
Standard Table,
Sorted Table,
Index Table,
Hashed Table,
Any Table ( Generic type , Rarely used )

Some more NetWeaver QA on Installation and Migration


Can I install an SAP NetWeaver 7.0 SR3 system on 32-bit platforms?

As of SAP NetWeaver 7.0 SR3 (SPS 14) you can install only dialog instances on 32-bit platforms. All remaining instances (central instance, database instance, central services instance (SCS), ABAP central services instance (ASCS)) you can install only on 64-bit platforms.

Is SAP Solution Manager 7.0 a new release following SAP Solution Manager 4.0?

SAP Solution Manager 4.0 SR4 (SPS 15) was renamed to SAP Solution Manager 7.0 to make the name compliant with SAP NetWeaver 7.0.

The new name SAP Solution Manager 7.0 brings with it the advantage of both SAP Solution Manager and SAP NetWeaver having the same release number, and is aligned with SAP's decision to streamline its product offerings. This decision also highlights the close alignment and joint go-to-market strategy of these two products.

The renaming of SAP Solution Manager 4.0 to SAP Solution Manager 7.0 is a name change only, therefore the SAP Solution Manager functionality, release schedule, installations, or other technical aspects of SAP Solution Manager will not be affected.


How can I install SAP Solution Manager Diagnostics on an SAP Solution Manager 3.2 system upgraded to SAP Solution Manager 7.0?
Proceed as follows:

1. Install the Java Add-In for ABAP with SAPinst.
2. Deploy LMSERVICE*_.SCA with SAPinst
For more information, see the installation guides at http://service.sap.com/instguides -> SAP Components -> SAP Solution Manager -> Release 7.0

Can I install an SAP NetWeaver 7.0 system as a non-Unicode system?
You can install an SAP NetWeaver 7.0 SR1 or SR2 ABAP system as a non-Unicode system. When you install an SAP NetWeaver 7.0 SR1 or SR2 dual-stack system (ABAP+Java), the ABAP part of this system can also be installed as non-Unicode. The Java part of this system can only be installed as Unicode.
As of SAP NetWeaver 7.0 SR3, you cannot install an SAP NetWeaver 7.0 ABAP system or the ABAP part of an SAP NetWeaver 7.0 SR3 dual-stack system as non-Unicode any longer.
However, non-Unicode is still supported when you perform the system copy for an SAP system upgraded to SAP NetWeaver 7.0 SR3.


Where can I find the Configuration Wizard?
The Configuration Wizard is a Java application in the SAP NetWeaver Administrator:
http://:/nwa -> Configuration Management -> Scenarios -> Configuration Wizard
or open the application with the following shortcut directly:
http://:/nwa/cfg-wizard


What are the benefits of using the Configuration Wizard?

* You only have to read a reduced number of guides and get familiar with a reduced number of tools.
* You do not need to check conflicting configuration settings and mutual dependencies between components, as the configuration wizard takes care of these dependencies.
* Reduced time and effort for setup

How can I cancel/re-execute configuration task which has "Currently executing" status?
This may happen if your web session has expired during execution of configuration task which was not able to finish in the background because it needed some user input/response. The next time you login to Configuration Wizard if the server is not restarted you will see this task with "Currently executing" status which prevents you from re-executing the task. The status can be cleared by restarting the "tc~lm~ctc~cul~startup_app" application. To do this go to
http://:/nwa -> Operation Management -> Systems -> Start & Stop -> Java EE Applications
Then stop and start the application.


What takes place during a homogeneous system copy?
The main purpose of a homogeneous system copy is to build a test, demo or training system or to move a system to a new hardware. The difference from a heterogeneous system copy is that both the database and operating system remain the same. Because of this on some platforms there is the possibility to perform the copy using database dependent methods. Please read SAP Note 89188. Please note - no matter if you change the version or bit version of either the operating system or the database, the system copy is still considered to be a homogeous system copy (e.g. system copy from Windows 2000 32-bit to Windows 2003 x64).


What takes place during a heterogeneous system copy (migration)?
The main purpose of a heterogeneous system copy is to create a copy of an already existing R/3 system on the platform where either operating system, or database, or both differ from the operating system/database of the source system.
The whole migration process consits of five main steps:
a) preparation steps on the source system
b) export of the source system data into database-independent format. In a ABAP+ Java system it#s required to both export the ABAP and the Java stack.
c) transfer of the data made during the export
d) new system installation together with data import
e) post-processing steps within the target system


Which tools are used during a migration on source and target systems?
The main programs used for the migration are - depending on the kernel release 'R3SETUP' or 'sapinst'. When working, they call some other programs for particular purposes: R3LOAD, R3LDCTL, R3SZCHK. There are also several command files or, in another words, installation templates, that have the extensions R3S (R3SETUP) or xml (sapinst).
For the kernel-tools used during a migration some rules should be followed:
a) Tools used at the export on the source system must have the same version as on the target system.
b) Tools used must all have the same kernel-version. (do not mix up kernel-tools of different releases)
c) Tools must have the same kernel release as the system which is migrated.
The Java system copy tools do not depend on the kernel-version and you can always use the latest version of these tools.For details on this please refer to note #784118.
These rules should be applied unless otherwise specified in an appropriate installation/migration note or guide. Please keep this in mind when downloading a patched version of any mentioned tool from SAP Service Marketplace.


What is the purpose of the files of different types that are used during a migration?
DDL.TPL is used for creation of table/index definition in database specific syntax, contains negative list of tables, views and indexes, assignment of TABARTs to storeage unit and next extent size of table/index. TABART stands for a data class. Fore more details on this please refer to note #46272.
SAP<.STR contains table/index definitions from ABAP Dictionary.
SAP.TPL, export directory, block and file sizes.
SAP. - (e.g.001, 002), so called dump files contains the data of all tables of a tabart in a non-platform-specific file format.
These are binary files and they should never been changed by any editor.
SAP.EXT contains initial sizes for tables and indexes. Not applicable to some RDBMS (e.g. MS SQL Server).
SAP.TOC contains position of table data within the corresponded dump file, name of the dump file , time stamp of unload, table rows number.
TOC files must never been changed besides the approval of SAP Support is given.
SAP.log contains useful information in case of error and for restart point.
SAP.TSK files used by R3load as of release 6.20. For details please refer to note # 455195


I am considering a database/operating system change. Are there any requirements that should be met before the migration starts?
A heterogeneous system copy requires a certified consultant responsible for the migration as well as the migration services if a productive system is affected. Please refer to SAP Note ' 82478 where the requirements are described in detail.


How and from where can I get all the necessary tools for a migration?
To order a Migration Kit please create customer message under XX-SER-SWFL-SHIP component and specify exact OS and DB versions as well as Kernel Release of the system you would like to migrate. A migration guide can be downloaded at: http://service.sap.com/instguides. A list of notes with the most up to date information might be found in beginning of the migration guide.


Is there anything else I need to have/ to do/ to know before doing a migration?
You also need an installation package to build up the target system and installation guide, which you can get in the same way as the Migration Kit and System Copy Guide. Please also read carefully Note #82478 and information stored under http://service.sap.com/osdbmigration.
You may find very useful information in the SAP OS/DB Migration Service and SAP OS/DB Migration Service Planning Guide (please, pay attention to chapter "Organizational Steps"), where you also can find out all prerequisites and requirements for this procedure. Please, note that the migration must be performed by a Basis consultant with special certification for OS/DB Migration.


How can I check whether a migration of a specific product/os-db-combination is supported?
Please check whether both the source and the target product/os-db-combination is supported first. Please refer to the Platform Availability Matrix on http://service.sap.com/pam for this.
In addition please check both the system copy guide and the relevant notes for any restrictions. In some exceptional cases it may be necessary to set up a pilot project for a specific system copy.
Fore more details regarding the availability of system copy procedures odf BW 3.0B/3.1 and SAP NetWeaver 04 systems please refer to: http://service.sap.com/bi --> Services & Implementation --> System Copy and Migration.
Please also refer to the following notes:
#777024 - BW3.0 and BW3.1 System Copy
#771209 - NW04: System copy (supplementary note)
#888210 - NW04s: System copy (supplementary note)
#543715 - Projects for BW Migrations and system copies
For more details on the system copy of 'SAP Web AS Java 6.40' based systems please refer to note #785848 on restrictions and procedures.


Where can I find information on how to optimize the overall runtime of a system copy?
You may refer to: HTTP://service.sap.com/systemcopy -> System Copy & Migration -> Optimization for this.


Are there any restrictions regarding system copies in general?
Yes, there are. You should always refer to the corresponding system copy guide to check the details. For instance for the system copy of ABAP+Java or Java systems of release NW 7.0 the following applies:
- "Refresh"of the database is not supported. A"refresh" of the database means that only the database is loaded with the content of a database of a different system. As in this scenario no migration controller is invoked, this is not supported.
- Copying the database only is not supported
- Copying the central instance only is not supported. The migration controller deletes all dialog instances in the database, so the system is not complete any longer.
- Reinstalling the central instance without the database is not supported.
The migration controller deletes all dialog instances in the database, so the system is not complete any longer.


Is it possible to perform a final migration of a productive system without a "test" run?
No, you should never do this. You should perform a test migration on a comparable hardware with a system which is a copy of the productive database. This is necessary both to get an idea of the overall runtime of the productive migration an to recognize major issues at the export/import before the final migration.
The same applies for the migration key. That means the migration key is generated as a self-service and should be tested before the productive migration. In case of any issues with the key generated it's not possible to create migration keys by the weekend support.

Configure ALE


Tcode: SALE
Step 1: Create Logical System
Next screen will be
Create logical systems YLS800, YLS810
Save it and back
Step 2 : Assign Client to Logical System
Dbl Click on 800 Client and give the logical system as YLS800
Dbl Click on 810 Client and give the logical system as YLS810
Step 3 : Create RFC destination
Give the RFC destination Connection type, Description and Target Host
Click on Logon/Security
Give the Language Client, User , Password
Click on Test Connection and Remote Logon
Step 4 : Create Port WE21
Select own port name and give the own port name and click on continue
Give the Description and RFC Destination created by you ie YLS810RFC
Step 5 : Create Partner Profiles WE20
Give the Partner no Parrtner type Type Agent Lang and save it
Click on Outbound Parameters
Give the Message type , Reciever Port Basic type and save it
Step 6 : Create Distribution Model
Click on Create Message type give the shorttext and Technical name and continue
Step 7 : Generate Partner Profiles
Enivornment -> Generate Partner Profiles
Give the logical system name
Step 7 :
save it , So material 858 Created
Step 8 : Send material BD10
Step 9 : Check the Idoc WE02
Click on F8
Step 10 : Execute the program RBDMOIND- Status Conversion with Successful tRFC Execution
You can check the status record status 12 appears.
Step 11. Login 810 ABAP EDITOR SE38
Execute the program RBDAPP01 - Inbound Processing of IDocs Ready for Transfer
S\tep 12 : Idoc List WE02
Check the entrty in MARA TABLE

s
Enable an SAP R/3 System send Idocs to SAP PI



Maintain the Sender R3 system 1. SM59 : Create a RFC destination to XI
2. WE21 : Create a TRFC Port ->Specify the RFC Destination Created
3. BD54 : Create a Logical System for the Idoc Receiver
4. WE20 : Create Partner Profile ->Maintain Outbound and the Inbound Parameters

Log on to XI System: 1. SM59 : RFC Destination for Sender System
2. IDX1 : Create the port to get Idoc Metadata from Sender System ( The Port Name must match the port name in the idoc header - Usually in format SAP. eg. SAPID1 [Optional Step. Not mandatory]
3. IDX2 : Maintain the Idoc Metadata. This is needed only by XI, and not by other SAP systems. IDX2 is needed because XI needs to construct IDoc-XML from the IDoc. No other SAP system needs to do that.


To Enable Acknowledgement: SXMB_ADM ->Integration Engine Configuration ->Specific Configuration ->Add New entry -> Select parameters as:
Category: RUNTIME
Parameters: ACK_SYSTEM_FAILURE
Current Value: 1


Go to SLD: 1. Create Technical System: Choose WEB AS ABAP if the system is R/3 -> Define SAP SID, Installation Number and Database Host Name a Maintain message Server Details according to Sender System -> Maintain Client Details of Sender System ->Select a Installed Product for Sender System


2. Create Business System: Choose WEB AS ABAP if the system is R/3 -> Choose the Technical System and the client Created Before -> Choose the Installed Product -> Set:
Business System Role: Application System
Related Integration Server: Integration Server


Idoc Tunneling in XI To prevent performance consuming XMLization and de-XMLization IDOCs are tunneled through SAP XI IDOC adapter meaning no XMLiziation is executed before the IDOC is passed onto the pipeline. Note the message is converted to UTF-8 codepage.
Start transaction SXMB_ADMIN on SAP XI.
Select option Configuration->Integration Engine Configuration and add two parameter EXTERNAL_MAPPER in the category IDOC.
Configure the parameter according to the conditions below:
If Message Code and Message Function are specified in the partner profile:
..ReceiverPort...
If only the Message Code is specified in the partner profile:
..ReceiverPort..
If only Message Function is specified in the partner profile:
..ReceiverPort...


Integration Builder Integration Directory:
1. Add Business System: Adapter Specific Identifiers -> 'Logical System' identical to the 'Logical System Name' in the SLD Business System
2.IDoc Receiver Communication Channel: port the same as XI System IDX1

0 comments
Archive Log Generation during Oracle Online Backup
Posted by Venky on Wednesday, May 5, 2010 at 9:36 AM


When the oracle online backup is kick started a SQL command issued which puts the tablespaces into backup active mode, then copies the datafiles to disk / tape. Once the backup is complete, anothe sql statement issued which takes the tablespace out the backup mode.
The sqls are
alter database/tablespace begin backup;
alter database/tablespace end backup;
This can be seen via v$backup dynamic view.
SQL> select * from v$backup ;

FILE# STATUS CHANGE# TIME
---------- ------------------ ---------- ---------
1 ACTIVE 831311 05-MAY-10
2 ACTIVE 831311 05-MAY-10
3 ACTIVE 831311 05-MAY-10
4 ACTIVE 831311 05-MAY-10
5 ACTIVE 831311 05-MAY-10
6 ACTIVE 831311 05-MAY-10

6 rows selected.

So, during the backup, all the tablespaces/datafiles are sealed and are not writable. Transaction changes are recorded in rego log files or sga or rollback/undo segments or something and then will be written back into the datafile when the database/tablespace is taken out of the backup mode.

We might have observed during the online backup there is a change of huge generation of redo data which may impact the database performance if the database is in archivelog mode.

Let's see what are steps taken during the online backup.

1. The tablespace is checkpointed.
2. The checkpoint SCN number in the datafile headers cease to increment with checkpoints.
3. Full images (before and after image) of the changed database blocks are written to the redologs.

When you issue

alter tablespace tbs_name begin backup;

A checkpoint is performed against the target tablespace and the datafile header is frozen, so, no more updates are allowed on the datafile header, this is for the database to know which was the last time the tablespace had a consistent image of the data.

But during the backup, the corresponding datafiles in the tablespace allow just normal read/write operations, that is IO activity is not frozen.

In case of redo log generation, each block will be recorded into the redo logs files, the first the block is changed. So, if a row is modified for the first time inside the data block since online backup is started, the complete block image is recorded in the redo log files but the subsequent transactions on the block will only record the transaction just as normal.

Above three steps are required to guarantee consistency during the file is restored and recovered. By the freezing the checkpoint SCN in the file headers, any subsequent recovery on that backup copy of the file will know that it must commence at that SCN. Having an old SCN in the file header tells recovery that the file is an old one, and that it should look for the redo log file containing that SCN, and apply recovery starting there. Note that checkpoints to the datafiles in online backup mode are not suppressed during the backup, only the incrementing of the main checkpoint SCN flag. An "Online backup checkpoint" SCN marker in the file header continues to increment as periodic or incremental checkpoints progress normally.

By initially checkpointing the datafiles that comprise the tablespace and logging full block images to redo, Oracle guarantees that any blocks changed in the datafile while in online backup mode will also be available in the redologs in case they are ever used for a recovery.

Now many one claim that during online backup there is excessive redo log generation than normal mode. It actually depends on the amound of block changes during online backup. Because the first time a block is changed logging of full images of the changed blocks in these tablespaces are recorded to the redo logs. Normally, Oracle logs an entry into the database block. But during the online backup, by logging full images of changed database blocks to the redologs, Oracle eliminates the possibility of the backup containing irresolvable split blocks. To understand this reasoning, you must first understand what a ssplit block is.

Typically, Oracle database blocks are a multiple of OS blocks. For instance, most AIX installations offer a default block size of 4MB and where as Oracle's default blcok size is of 8KB. That means the file system stores data in 4MB chunks and oracle reads or writes in 8K chunks or multiples of 8K. While backing up a datafile, backup utility (brbackup in the case of SAP) makes a copy of the datafile from the filesystem, using OS utilities such as copy, dd, cpio or ocopy. While making this copy, it is reading in OS block sized increments. If the database writer happens to be writing a DB block into the datafile at the sametime that backup utility is reading that block's constituent OS blocks, the backup copy of the DB block could contain some OS blocks from before the database performed the write, and some from after. This would be a split block.

By logging the full block image of the changed block to the redologs, it guarantees that in the event of a recovery, any split blocks that might be in the backup copy of the datafile will be resolved by overlaying them with the full legitimate image of the block from the redologs. Upon completion of a recovery, any blocks that got copied in a split state into the backup will have been resolved through application of full block images from the redologs.

0 comments
Bootstrapping SAP Web dispatcher
Posted by Venky on Saturday, April 17, 2010 at 9:08 PM


$ pwd
/sapmnt/EP1/webdisp2_710
$ sudo ./sapwebdisp -bootstrap
SAP Web Dispatcher Bootstrap
============================

This bootstrap will perform the following steps:
1. create profile file "sapwebdisp.pfl" for SAP Web Dispatcher (if not already existing)
2. create user for web based administration in file "icmauth.txt" (if not already exisiting)
3. start SAP Web Dispatcher with the created profile

After the bootstrap you can use the web based administration

Generating Profile "sapwebdisp.pfl"
Hostname of Message Server (rdisp/mshost): hostname
HTTP Port of Message Server (ms/http_port): 8100
Checking connection to message server...OK
Unique Instance Number for SAP Web Dispatcher (SAPSYSTEM): 22
HTTP port number for SAP Web Dispatcher: 8002
Create configuration for s(mall), m(edium), l(arge) system (default: medium): m
Profile "sapwebdisp.pfl" generated
Authentication file "icmauth.txt" generated
Web Administration user is "icmadm" with password "Ea9qaPtT"
Restart sapwebdisp with profile: sapwebdisp.pfl
sapwebdisp started with new pid 278536
Web administration accessible with "http://:8002/sap/wdisp/admin"

SAP Web Dispatcher bootstrap ended (rc=0)
$ *** SAP Web Dispatcher up and operational (pid: 278536) ***


SAP Table Logging


Table logging is a functionality SAP provides to automatically track changes on tables set as "LOG DATA CHANGES".
By default SAP delivers mainly config tables set like that since the main reason was to enable automatic logging of config changes.
The functionality could indeed harm your system performance but , as per OSS note 608835, you should not have problems since only config tables are set to be logged...
"Generally, you can activate logging in your system without any problems because SAP only delivers Customizing tables with activated logging. Customizing tables usually contain a relatively small amount of data which is only changed occasionally.
To be more precise: Basically all Customizing tables are delivered with activated logging because the requirements of external auditors are inconsistent as regards the logging of tables.
Tables for master and transaction data, on the other hand, are delivered by SAP without logging indicators. A large number of these tables are subject to mass changes which would cause performance problems if they were logged. You should use great caution if you want to log any of these tables.
Practice has shown that, bearing the above restrictions in mind, logging does not cause any problems in the production, Customizing and development environments.
If performance or memory problems occur unexpectedly, you can easily determine which table causes the problems:
Select the "Administration --> Number of logs (selective)" menu option (Shift+F8) in transaction scu3. Enter a time interval in the selection screen displayed and leave the table selection empty. If you now start the report, it returns a list of all logged tables with the number of recorded logs. You can then deactivate the logging of the tables most frequently logged in transaction SE13.
As described above, SAP delivers all Customizing tables with activated logging. Due to the relatively low number of changes in Customizing, it is not useful to remove the logging indicator from all tables except a selected few, especially since the requirements for the logging of pages may be changed by your external auditor from time to time."

If you want to monitor changes in application tables, you need to rely on aplication change objects. Ex: for table MARA, we don't have it set to auto changes, yet, we have the log of changes through standard change objects, programmed within the standard MM02, MM01... transactions.


* ▼ 2010 (17)
o ▼ July (1)
+ Kinds of SAP Tables
o ► May (4)
+ Some more NetWeaver QA on Installation and Migrati...
+ Configure ALE
+ Enable an SAP R/3 System send Idocs to SAP PI
+ Archive Log Generation during Oracle Online Backup...
o ► April (1)
+ Bootstrapping SAP Web dispatcher
o ► March (2)
+ SAP Table Logging
+ AIX tools for SAP Administrators Set 5
o ► February (9)
+ Near Zero Downtime Upgrade
+ Best Technical Practices for SAP Landscape Mainten...
+ Script for killing all processes matching a search...
+ NetWeaver Installation Part II
+ AIX tools for SAP Administrators Set 4
+ AIX tools for SAP Administrators Set 3
+ AIX tools for SAP Administrators Set 2
+ AIX tools for SAP Administrators Set 1
+ Identifying server node ID in multi-server node en...

* ► 2009 (1)
o ► December (1)
+ NetWeaver Installation Part I