set transaction isolation level 3
Applications that use transaction isolation level 3 should set that isolation level at the beginning of each session. However, setting transaction isolation level 3 causes Adaptive Server to hold any read locks for the duration of the transaction. If you also use the chained transaction mode, that isolation level remains in effect for any data retrieval or modification statement that implicitly begins a transaction. In both cases, this can lead to concurrency problems for some applications, since more locks may be held for longer periods of time.
To return your session to the Adaptive Server default isolation level:
set transaction isolation level 2 or set transaction isolation level repeatable read
To enforce transaction isolation level 2 from a query, use:
select title_id, price, advance from titles at isolation 2
select title_id, price, advance from titles at isolation repeatable read
Transaction isolation level 2 is supported only at the transaction level. You cannot use the at isolation clause in a select or readtext statement to set the isolation level of a query to 2. http://manuals.sybase.com/onlinebooks/group-as/asg1250e/sqlug/@ebt-link;pt=53713?target=%25N%15_54131_START_RESTART_N%25