Although primarily used for converting blobs (long varbinary, long varchar) to string output object, blob_to_string_output may also be used to convert from wide string, persistent XML (XPER) and string_output streams.
string output object contents of blob.
SQL> use Demo; Done. -- 20 msec. SQL> select string_output_string (blob_to_string_output ("Description")) from "Categories"; callret VARCHAR _______________________________________________________________________________ Soft drinks, coffees, teas, beers, and ales Sweet and savory sauces, relishes, spreads, and seasonings Desserts, candies, and sweet breads Cheeses Breads, crackers, pasta, and cereal Prepared meats Dried fruit and bean curd Seaweed and fish 8 Rows. -- 37 msec. SQL>