Declare variables of built-in data types
A variable that you declare as a built-in SQL data type
can hold a value retrieved from a column of that built-in type. You
can declare an SPL variable as most built-in types, except BIGSERIAL,
SERIAL, and SERIAL8, as the following figure illustrates.
You can declare SPL variables of appropriate integer data types (such as BIGINT, INT, or INT8) to store the values of serial columns or of sequence objects.