Go to Qlikview help for the same.
Below definition is from QlikView Help.
When data that includes circular references is loaded into QlikView, loosely coupled tables are created automatically, to avoid that the circular references create a loop in the QlikView internal logic.
One or more QlikView internal data tables can be explicitly declared loosely coupled during script execution by using a Loosen Table statement.
The use of one or more Loosen Table statements in the script will make QlikView disregard any setting of tables as loosely coupled made before the script execution.
The syntax is:
Loosen Table[s] tablename [ , tablename2 ...]
Either syntax: Loosen Table and Loosen Tables can be used.
Select * from Trans;
Loosen table Tab1;
Should QlikView find circular references in the data structure which cannot be broken by tables declared loosely coupled interactively or explicitly in the script, one or more additional tables will be forced loosely coupled until no circular references remain. When this happens, the Loop Warning dialog, gives a warning.
Look at the attached QlikView document. By changing the name of the table in the last row of the script you are loosening a different table each time (making this table not propagating the logic through) and you have different results when making selections on the list boxes. You can also do this in the Tables tab of the Document Properties.I hope this helps you to understand the idea behind loosening a table.
loosen table.qvw 146.5 K