Cursors WITH HOLD
Informix®
Informix closes opened cursors automatically when a
transaction ends, unless the
WITH HOLD
option is used in the
DECLARE
instruction:DECLARE c1 CURSOR WITH HOLD FOR SELECT ...
OPEN c1
BEGIN WORK
FETCH c1 ...
COMMIT WORK
FETCH c1 ...
CLOSE c1
IBM® DB2®
IBM DB2 can keep
cursors open across transactions, when the transaction is terminated with
COMMIT
.
When a transaction is canceled with a ROLLBACK
, DB2 automatically closes all cursors.
Solution
Normally, BDL cursors declared WITH HOLD
remain open even after terminating a
transaction with a COMMIT WORK
or ROLLBACK WORK
.
Since IBM DB2 closes
cursors when a transaction is rolled back, you must check that your source code does not use
WITH HOLD
cursors after transactions canceled with ROLLBACK
WORK
.
For consistency with other database brands, database cursors that are
not declared WITH HOLD
are automatically closed, when a COMMIT
WORK
or ROLLBACK WORK
is performed.
Important: Opening a
WITH HOLD
cursor declared with a SELECT
FOR UPDATE
results in an SQL error; in the same conditions, this does not normally appear
with Informix. Review the program logic in order to find
another way to set locks.