[Fwd: Re: Locking problem in INFORMIX ONLINE 7.20. UC2]

This is a multi-part message in MIME format. --------------1E7310831924 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit -- \\\\|// Vijay R. Anisetti |6 6| -------------------oooO--U--Oooo---------------------------- oooO Oooo ( ) ( ) Just hangin on to this profession ---------------\\( -- )/------------------------------------- \\) (/ --------------1E7310831924 Content-Type: message/rfc822 Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-ID: <33C29615.FAB@sprynet.com> Date: Tue, 08 Jul 1997 15:33:41 -0400 From: "Vijay R. Anisetti" <rambabu@sprynet.com> Organization: personal X-Mailer: Mozilla 3.0 (Win95; I) MIME-Version: 1.0 To: "Infodata Ltd. (Sharjah) U.A.E." <infodsh@emirates.net.ae> Subject: Re: Locking problem in INFORMIX ONLINE 7.20. UC2 References: <199707081321.RAA26141@ns2.emirates.net.ae> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Yes, if it encounters an error while reading rows, it stops the execution. You check the following SQL to exclude the locked row: select * from tab1 where a = '1' or ( a > '2' and a < '9') ; hope this is not one of the 'different ways' you tried. -- \\\\|// Vijay R. Anisetti |6 6| -------------------oooO--U--Oooo---------------------------- oooO Oooo ( ) ( ) Just hangin on to this profession ---------------\\( -- )/------------------------------------- \\) (/ Infodata Ltd. (Sharjah) U.A.E. wrote: > > 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 --------------1E7310831924--