RE: [CFCDev] Repost: SQL Concurrency

[Andrew Scott]

The 3 types that I have read are:   Pessimistic concurrency control - a row is unavailable to users from the time the record is fetched until it is updated in the database.   Optimistic concurrency control - a row is unavailable to other users only while the data is actually being updated. The update examines the row in the database and determines whether any changes have been made. Attempting to update a record that has already been changed results in a concurrency violation.   Last in wins - a row is unavailable to other users only while the data is actually being updated. However, no effort is made to compare updates against the original record; the record is simply written out, potentially overwriting any changes made by other users since you last refreshed the records.   With this in mind I was asking what others are doing, and what would be the best approach to this.     Regards Andrew Scott Technical Consultant NuSphere Pty Ltd Level 2/33 Bank Street South Melbourne, Victoria, 3205 Phone: 03 9686 0485  -  Fax: 03 9699 7976 From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Barry Beattie Sent: Friday, 27 May 2005 11:19 AM To: CFCDev@cfczone.org Subject: RE: [CFCDev] Repost: SQL Concurrency   >>  a few articles on MSDN about the 3 types of record locking available   can you elaborate? what are the 3 ways mentioned?   there's many ways to skin this (disconnected client) cat...     -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Andrew Scott Sent: Friday, 27 May 2005 11:17 AM To: CFCDev@cfczone.org Subject: RE: [CFCDev] Repost: SQL Concurrency Ok I am working on an application that is a multi user intranet application, the current system works on the basis that last in wins on the storage of the data placed back to the database.   I was wondering what other people do to prevent this, like record locking. I was reading a few articles on MSDN about the 3 types of record locking available, but wanted to know how others approached or dealt with the subject as well.   Any help or further discussion would be great.     Regards Andrew Scott Technical Consultant NuSphere Pty Ltd Level 2/33 Bank Street South Melbourne, Victoria, 3205 Phone: 03 9686 0485  -  Fax: 03 9699 7976 From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Roland Collins Sent: Friday, 27 May 2005 10:46 AM To: CFCDev@cfczone.org Subject: RE: [CFCDev] Repost: SQL Concurrency   What particular aspects?  SQL concurrency is a pretty large topic, depending on what aspects you’re referring to. ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org