Hi Venkatesh,
We have the following types of routines in sap bw.
1.Start Routine
2.End Routine
3.Expert Routine
4.Field Routine.
Start Routine----Using start routine we can perform any type transformation like delete /update.. on package level ,mean package contains group of records so it give better performance.This is mainly work before moving data to target.
Ex: To delete data while moving data from Source(DS/...) to Target(Cube/DSO...)
Delete source_package where fields = values.
Delete source_package where 0 Amount = 0.
End Routine---Using end routine we can perform any type of transformation using Result_Fields .
Both Start and End routines give same performance but the difference is only usage i.e start routine before loading data to target and End routine after loading data to target.
let us consider an example i want to data while loading.
if we use start routine before loading only we are deleting data but if we use end routine 1st move data to target then perform deletion of data this too bad performance because of Double work ,so
based on requirement we to choose which one is better .
Field Routine---This is record by record transformation process like deletion/ updation....this is also bad performance because of record by record process.
Regards
Surendra