Locking problem in INFORMIX ONLINE 7.20. UC2

Dear friends, My problem is as follows : Example --> I have a table tab1 with one field a (char(2)). There are 10 records in it. The value in the field is '1' ,'2','3' .... to '10' for each of the 10 records. Now I am opening one session and locking a particular record as follows : alter table tab1 lock mode (row); begin work; update tab1 set a = 20 where a = 2 ; Now I am opening another session and selecting rows from that table as follows : set isolation to committed read; select * from tab1 where a > = '1' and a <= '9' ; This reads only first record and the second record and will give an SQL error for record lock. This is quiet understandable since there will be an exclusive lock for that row. But does the row level lock prevent all the rows after it also to be locked. I have tried this in different ways but everytime it comes to a locked row it will stop & give error and will not show the remaining rows. What I want to say is that IT LOCKS MORE THAN ONE ROW ( all rows after the locked row). Is this O.K. or an bug or am I doing some mistake in understanding it. Please throw some light if U can. I know about 'set lock mode to wait' but what I am confused is why is it locking more than one row & how to prevent it. Thanks Bharat Shah INFODATA Ltd. P.O.Box 24114, Sharjah, U.A.E. Email: infodsh@emirates.net.ae Tel.: 971 6 599848, Fax: 971 6 592618