Hi, Kashim
In univese level loops resolved by Chasm Trap and Fan Trap methods.
Chasm Trap: A chasm trap is a type of join path between three tables when two many-to-one joins converge on single table, and there is no context in place that separate the converging join paths.
There is "many-to-one-to-many"relationship beween the three tables in the universe structure.you can define a context for each table at the many end of the joins.
A chasm trap is not dependent on the object types, the query could be made up of only dimensions,only details,or only measures,or any combination of the three types with the "many " tables for chasm to occure.
you can also detect the chasm trap Automatically, tool---->Detect context
To resolve the chasm trap, you need to make two separate Queries and than combine the results Depending on type of objects defined for the fact tables and the type of end user environment,
Fan trap: it is occured when there is a "one-to-many" join to the table that "fans out " into another "one-to-many" join to another table.
Avoid fan trap: The first place by relating all measure objects in the universe to the same table in the universe structure,Avoid placing a measure on anything other than the last table in a in a table path, which is the table with the "many" cardinality attached to it.
This methods is not recomended as it only works for measure objects and may result in inefficienies in processing the query. This resolution works the same for chasm and fan traps.
you can create more alias tables based on your requirement in single universe. and it is true conext, when two or more paths.
Theese methods also apply for resolving loops:
Short cut join also one method for resolving loops
Aggregate aware function used another waty for resolving loops
if you are not resolving the loop result is redusing the number of records.