SERIALLY_REUSABLE pragma specifies that the package state is needed for only one call to the server (for example, an OCI call to the database or a stored procedure invocation through a database link).
After this call, the storage for the package variables can be reused, reducing the memory overhead for long-running sessions.
This pragma is appropriate for packages that declare large temporary work areas that are used once in the same session.
SERIALLY_REUSABLE pragma can appear in the
declare_section of the specification of a bodiless package, or in both the specification and body of a package, but not in only the body of a package.