The function ora-lob-internal-lob-p returns whether it is internal (that is BLOB, CLOB or NCLOB) or not (that is BFILE or CFILE). The function ora-lob-element-type returns the LISP element type that best corresponds to the LOB locator. This will be one of
(unsigned-byte 8)
for BLOB and BFILE, or
base-char
or
simple-char
for CLOB, NCLOB and CFILE, depending on the charset of the LOB object.
It is possible to distinguish between CLOB and NCLOB by looking at the result of ora-lob-char-set-form. It returns 2 for NCLOB and 1 for CLOB.