Difference between V1, V2, V3 updates

V1 Synchronous update - Used for LIVE tables, after the records get updated system will send an acknowledgement. This degrades processing performance.

V2 Asynchronous update – LUW's will be Updated in front end without any acknowledgement. 

V3 Asynchronous with background updating – Updating happens in Background.

We use this concept in LO Extraction update modes.

Direct delta update mode uses V2 update. Recommended only when less number of records are there.

Queued delta is recommended for most of the cases and it will use V3 update. LUW’s will be updated to Extractor queue (LBWQ) in the form of tokens (pointers). We need to run a background job (V3 collective run) to push the data to delta queue from LIVE tables. All the records will be moved at once so no problem with sequence.

Unserialized V3 update also uses V3 update, only recommended when sequence of data is not important. DSO is not recommended as target when we use this update. 

Common Issues with Open Hub

1. Error message: 'Destination not supported' (Error Code RSBO 102)

when creating an open hub destination

Firstly the corrupt Open Hub destinations need to be repaired. To do this you need to check the table RSBOHDEST, for all Open Hub Destination entries where the field DESTYPE is initial/empty or is equal to 'FILE', you must change the DESTYPE for such entries to TAB in the table RSBOHDEST. TAB must be selected because it is not possible to select another valid DESTYPE in the table. When you no longer have the error message 'Destination type is not supported' you can change the destination type to what it should be in the maintenance for the Open Hub Destination in RSA1.

For the users that worked with Open Hub and have the problem that they cannot access RSA1 (not supported (RSBO102) error message), there should be an entry(for each user) in the personalisation table RSAWBN_USR_TREE with the field AWBUSER = to the name of the user ID that has the problem and the field AWBTREE = DEST. You need to delete the entries returned for this selection on the fields AWBUSER and AWBTREE only for the User ID's that have the problem from the table RSAWBN_USR_TREE and the problem should be resolved.

2. Errors when sending data to a 3rd party Open Hub Destination 

Message no. RSBO523 SYSTEM_FAILURE with function RSB_API_OHS_3RDPARTY_NOTIFY and target system x 

Message no. RSBO899 Bean RSB_API_OHS_3RDPARTY_NOTIFY not found on host x, ProgId=x: Object not found in lookup of x 

Message no. RSBK241 Error while updating to target x (type Open Hub Destination)

When you execute the DTP for OHD, the system stores the data in a DB table 

The 3rd party tool is notified with the Function Module RSB_API_OHS_3RDPARTY_NOTIFY, this function has to be implemented by the 3rd party tool, not in the BW system

To resolve this issue;

Check if the function exists on the 3rd party tool using "Extras" --> "function list" after you select the destination in SM59

Implement the necessary function on the 3rd party tool

If you require assistance to implement the function on the 3rd party system, please contact the relevant 3rd party support desk.

Some useful T-Code for BI performance tuning

T-Code	Description
SM66	Global Work Process Overview
ST02	Tune Summary
ST06	System monitor
STAD	SAP workload
ST05	SQL Trace
SE30	ABAP Trace
ST12	Single transaction analysis(including ST05/ST30)
RSMO	BW Load monitor
DB02	DB Load overview
ST04	DB Performance snapshot
RSBATCH	BI Background management
RSODSO_SETTINGS	Maintenance of runtime parameter of DSO
RSRV	Analysis and repair BI Objects
ST03	Workload in system
RSRT	Query Monitor
RSRTRACE	Configure Trace Tool

Disadvantages of AGGREGATES, COMPRESSION, IC PARTIONING, INDEXES, LINE ITEM DIMENSIONS

Disadvantages of 

(1) AGGREGATES

Even though Aggregates are used for performance, but it will decrease the same when you create more aggregates. 

Until Rollup takes place the query won't hit the aggregate Cube

Aggregates - its main disadvantage is that it stores data physically as a redundant, more aggregates will cause waste of memory.

(2) COMPRESSION

Once Cube is compressed, then all the request number will be removed and hence deletion by request id is no more possible.

Compression- compressed request cannot be got back to normal, deletion is difficult

(3) Partition

Partition Handling for several thousand partitions is usually impacting DB performance.

IC partition  - partition cannot be done after data loaded (3.X) but repartition is possible in BI 7.0

(4) INDEXES

If you don't drop the index before loading then the data load will be slow

If you don't create the index before the reporting then the reporting will be slow

Index- for large volume of data create and delete index consume lot of time

(5) LINE ITEM DIMENSIONS

This can be set when you have one only characteristic in the Dim table.

Line item - more number of line item cannot be used as number char used will be reduced.

What is reconciliation?

Reconciliation is nothing but the comparison of the values between BW target data with the Source system data like R/3.

In general this process is taken at 3 places one is comparing the info provider data with R/3 data, Compare the Query display data with R/3 or DSO data and Checking the data available in info provider kefigure with PSA key figure values.