Dan Waters
dwaters at usinternet.com
Fri May 2 15:17:59 CDT 2003
Arthur, The databases I design typically handle some type of QA process in a manufacturing environment. One of the advantages of using an electronic system over a paper form system is the ability for people to work (almost) in parallel - which leads to the real occurrence of simultaneous updates. So, I always use pessimistic locking, and on the one process where people felt slowed down, I installed a timer on that form so that it closed after 5 minutes with no activity, releasing the locks on the table (that was in A97). I am starting to look at upsizing this db to SQL 2000. From what I understand, I may not be able to use pessimistic locking the same way that I did in AXP. If this is the case, what is the best way to duplicate the pessimistic locking behavior of AXP in SQL 2K? Thanks, Dan Waters -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Arthur Fuller Sent: Friday, May 02, 2003 12:27 PM To: accessd at databaseadvisors.com Subject: RE: [AccessD] Desperately Seeking! <rant> I don't feel like rekindling any bound/unbound wars, so instead I'll try another tack. The problem is disconnected recordsets, which are very cool if the liklihood of simultaneous updates of a row is remote. In fact, it's not so much a database problem as a business practices problem, IMO. What the hell are two people updating the same row for? There's a problem here and it doesn't concern the database; it concerns the workflow, which by definition is outside the specifications. OTOH, excellent arguments from the db folk occasionally persuade management that the problem is indeed outside the db, and should be addressed by someone other than you. </rant> <reality> Given that you must prevent simultaneous updates of a set of rows, and given that you have taken the unbound path, without a massive rewrite I think your quickest option is to revisit all the recordset declarations, setting Pessimism TRUE in your rs.open() arguments. This effectively offloads the problem to the db, which is good, since it won't allow your users to overwrite each other even if your app in theory does. (That's why I always put all the smarts into sprocs and rules and such, rather than coding them in Access. Then, even if your app is buggy, it doesn't matter:-) Lock it all down with pessimistic recordsets and go from there. You can probably visit every occurenece with a project-wide search, and paste the revised string in. </reality> <fantasy> I'm having difficulty coming up with an example where multiple users would want to update the same rows. A wife and husband are both phoning to complain about a VISA charge? Three employees are calling from Client X to revise the purchase quantities in the details of OrderID 2345? Multiple people updating identical rows = a workflow problem, IMO. In a well-designed workflow, this should never occur. Making this point at your next meeting, you are given a 100% salary boost, several opportunities for sex with strangers, and the pleasure of watching the entire organization reconfigure itself to your insights. Suddenly they appreciate how brilliant you are and shape their enterprise around you. Billions at stake, all on your mind. </fantasy> Arthur -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Marcus Tewksbury Sent: May 2, 2003 10:16 AM To: accessd at databaseadvisors.com Subject: [AccessD] Desperately Seeking! Can Anyone Help Me? I have built a client server application using .adp front end and SQL Server back end. Within the application itself I use unbound forms and retrieve records using ADO recordsets at run time. The way I have initially deployed the application is to copy an instance of the .adp to each desktop and run it locally. The problem has been that people keep overwriting each other's updates - and changes are not reflected fast enough. I have a couple of different thoughts on how to tackle this - either ratchet down the ODBC refresh rate, or run a single, centralized copy of the .adp (which throws up some non-updateable warning every time it starts which I don't know how to suppress). Of course, I acknowledge that I am a total newbie, and both of these options may be flawed. Thanks a bunch, - Sherri _________________________________________________________________ The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com