Implicitly CLP will turn your SELECT into a cursor.
A cursor which is explicitly defined as READ ONLY will use "blocking".
That is the server will send several rows at once to the client.
Without READ ONLY DB2 will only do this for cursors that are on
principle non updatable (such as joins).

Cheers
Serge

There may be a perceived performance benefit in terms of aggregate
throughput, as you will be taking share locks and thus allowing others
to do the same. Your SELECT won't execute any faster, but more people
will be able to read and thus be productive.

--Jeff