ODBC Server Installation and Management Manual

Managing NonStop ODBC Server Resources
HP NonStop ODBC Server Installation and Management Manual—429395-002
5-21
Usage Considerations
Effect on SET commands
Setting SQL_MAX_STATEMENT_COST is disallowed. The estimated cost is now
defined in the scheduling policy and cannot be changed by using the SET command.
This attribute can be changed using the utility statement MODIFY GOV; it follows the
dynamic reconfiguration rule.
Setting SQL_MAX_ROWS affects the rows-fetched limit and overrides the limit
specified in the governing policy.
Limitation
The NonStop ODBC Server supports prepare-and-execute operations, and a client can
work on multiple concurrent statements. However, the request for changing priority is
done only once; the new priority persists until the execution of the given statement is
finished. The reason for this restriction is to minimize the swapping of priorities
between multiple statements.
An example of priority changing is shown following:
In the following example, the initial priority is 150:
Prepare s1 from select * from t1 (scheduling action specifies lowering priority by
10 for s1)
Prepare s2 from select * from t2 (scheduling action specifies lowering priority by
30 for s2)
Declare c1 cursor for s1
Declare c2 cursor for s2
Open c1 (
priority lowered to 140 for s1)
Fetch cl
Open c2 (
priority is still 140 for s2)
Fetch cl
Fetch c2
Close c1 (
priority is restored to 150 for s1)
Fetch c2
Close c2