Question

What are the best mapping development practices?

Answer 1

Best mapping development practices are as follows -  

1. Source Qualifier - This includes extracting the necessary data-keeping aside the unnecessary ones. It also includes limiting columns and rows. Shortcuts are mainly used in the source qualifier. The default query options like for example User Defined Join and Filter etc, are suitable to use other than using source qualifier query override. The latter doesn't allow the use of partitioning possible all the time. 
2. Expressions - It includes the use of local variables in order to limit the number of huge calculations. Avoiding data type conversions and reducing invoking external coding is also part of an expression. Using operators are way better than using functions as numeric operations are better and faster than string operation.
3. Aggregator - Filtering the data is a necessity before the Aggregation process. It is also important to use sorted input. 
4. Filter - The data needs a filter transformation and it is a necessity to be close to the source. Sometimes, multiple filters are also needed to be used which can also be later replied by a router.  
5. Joiner - The data is required to be joined in the Source Qualifier as it is important to do so. It is also important to avoid the outer joins. A fewer row is much more efficient to be used as a Master Source.  
6. Lookup - Here, joins replace the large lookup tables and the database is reviewed. Also, database indexes are added to columns. Lookups should only return those ports that meet a particular condition.