How to Declare Read-Only Cursors in DB2

I am very cool today reading Db2 magazine. I have got an idea why can’t I write a post on DB2 Read-only cursors. So I have written this excellent post. There are so many rules to say a cursors is Read-only. Below are the list of rules, that says if the cursor is Read-only or not.

Read-only cursors: If the result table is read-only, the cursor is read-only.

The first FROM clause identifies or contains any of the following:

• More than one table or view
• A catalog table with no updatable columns
• A read-only view
• A nested table expression
• A table function
• A system-maintained materialized query table
• A single table that is a system-period temporal table, and a period specification for SYSTEM_TIME is used
• A single view that directly or indirectly references a system-period temporal table in the FROM clause of the outer fullselect of the view definition, and a period specification for SYSTEM_TIME is used
• The first SELECT clause specifies the keyword DISTINCT, contains an aggregate function, or uses both
  It contains an SQL data change statement
• The outer subselect contains a GROUP BY clause, a HAVING clause, or both clauses
• It contains a subquery such that the base object of the outer subselect, and of the subquery, is the same table
• Any of the following operators or clauses are specified:
  – A set operator
  –  An ORDER BY clause (except when the cursor is declared as SENSITIVE STATIC scrollable)
  –  A FOR READ ONLY clause
  –  It is executed with isolation level UR and a FOR UPDATE clause is not specified.
  –  It is a VALUES clause.

So, in cursor declaration, if we mention the above clauses, then that cursor will become Read-only cursor.