DB2 – Equivalent of Oracle DBMS_LOB.SUBSTR

What could we forget to do?

As documented in the DB2 fixpack readme, after you install on the server, db2schema.bnd needs to be bound to existing databases.

How could we check that bind command executed properly?

If you installed the fix pack on DB2 database products that have existing databases, perform the following commands once for each database:

db2 terminate 
db2 CONNECT TO dbname user USERID using PASSWORD
db2 BIND path\db2schema.bnd BLOCKING ALL GRANT PUBLIC SQLERROR CONTINUE 
db2 BIND path\@db2ubind.lst BLOCKING ALL GRANT PUBLIC ACTION ADD 
db2 BIND path\@db2cli.lst BLOCKING ALL GRANT PUBLIC ACTION ADD 
db2 terminate

where dbname represents the name of a database to which the files should be bound, and where path is the full path name of the directory where the bind files are located, such as INSTHOME\sqllib\bnd where INSTHOME represents the home directory of the DB2 instance. db2ubind.lst and db2cli.lst contain lists of required bind files used by DB2 database products.

How could we try to solve the issue or reveal its root?

may be the installation of the DB2 fixpack was incomplete.

For further your ref:- DB2 SQL Error occurs after DB2 patch install

Inside a stored procedure body you have to use a semi-colon to delimit statements. But semi-colons are also the default for delimiting statements in most clients so you end up needing to change your client's delimiter to something else (I use @). You end up with something like:

create procedure cleanup()
begin
    delete from mytable;
    delete from myothertable;
end @