The BI Server offers two type of alias:
When you rename in the presentation catalog a table or a column, the admin tool automatically create an alias that you can see in its property (Double click on it). This prevents reports that reference the original element from failing.
With the above example, the below logical SQL
SELECT "Fact".AMOUNT_SALES saw_0 FROM "SH" ORDER BY saw_0
is equivalent to this one.
SELECT "Fact".AMOUNT_SALES saw_0 FROM "SH New Name" ORDER BY saw_0