The documentation on SELECT, and SQL Language Expressions refer to column-alias, column-name, table-name and schema-name in the syntax. I can't find documentation however on how names are resolved, for example if table-name is not provided, what table will be used for a given column name in an expression. As an example, if I have I have a subquery that refers to a column that exists in several tables that are in the parent query including itself, which instance will be used? How do I refer to the specific one I want?