SQL>
SQL> create table demo
2 ( id int primary key,
3 theBlob blob
4 )
5 /
Table created.
SQL>
SQL> select id, dbms_lob.getlength(theBlob) len, clean(theBlob) piece, dbms_lob.substr(theBlob,40,1) raw_data
2 from demo
3 where id =1
4 /
no rows selected
SQL> drop table demo;
Table dropped.