Hi,
1.While using "for all entries", check internal table is initial or not. In your case check SOURCE_PACKAGE is initial or not
2.pass SOURCE_PACKAGE to a temporary internal table, delete adjacent duplicates based on the fields in where condition and use temporary internal table in select statement
3.Check whether the fields in where condition are primary key, if not check the feasibility of secondary index on whether it is required. Please go through the same if required. What to Keep in Mind for Secondary Indexes (SAP Library - Tables)
3.Try to remove "into corresponding" in select statement
4.remove "move-corresponding"
5.Use field symbols in loop
Regards
Anand