Using Delimited Identifiers Within an Object Name

If you use set quoted_identifier on, you can use double quotes around individual parts of a qualified object name.

Use a separate pair of quotes for each qualifier that requires quotes. For example, use:
database.owner."table_name"."column_name"
Do not use:
database.owner."table_name.column_name"
Parent topic: Identifying Tables or Columns by Their Qualified Object Name