Tài liệu PL/SQL User’s Guide and Reference phần 7

Dynamic SQL supports all the SQL datatypes. So, for example, define variables and
bind arguments can be collections, LOBs, instances of an object type, and refs. As a
rule, dynamic SQL does not support PL/SQL-specific types. So, for example, define
variables and bind arguments cannot be Booleans or index-by tables. The only
exception is that a PL/SQL record can appear in the INTO clause.
You can execute a dynamic SQL statement repeatedly using new values for the bind
arguments. However, you incur some overhead because EXECUTE IMMEDIATE
re-prepares the dynamic string before every execution.