A referential integrity constraint cannot reference a column on a local temporary database except from a table on the same local temporary database. alter table fails when it attempts to create a reference to a column on a local temporary database from a table in another database.
You cannot encrypt a column with an encryption key stored in a local temporary database unless the column’s table resides on the same local temporary database. alter table fails if it attempts to encrypt a column with an encryption key on the local temporary database and the table is in another database.