Re: CDR and timestamps
At 03:33 PM 2/25/97 GMT, Juan R. Guzman wrote: }Joel Vannorsdel wrote: } }> Usually the manner that this is controlled is by having a GMT offset on }> each machine that is participating in replication. This way each }> machine can provide the time corrected to GMT on an individual. Also }> the time of an update usually does not affect other data. In the case }> of an update to an existing row, how often would you have two different }> users updating the same row at the same time. } }yes, }rarely do users update the same row at the same time. But it is }possible and if Informix hasn't resolved the issue then we're looking at }two outcomes. 1) Informix Online didn't know what to do with the }updates so it brought down CDR (best case scenario) or 2) It didn't know }what to do with the updates but didn't bring down CDR so your data is }now invalid and you don't know it (I've lived thru a similar bug in HDR }with 7.11UC1). Either way I'm not happy. To address this, Informix allows you to define conflict resolution rules. You can, therefore define conflict resolution as a combination of timestamp and stored procedures. This way, if in the event you end up with a timestamp conflict, the defined sproc will be executed. This sproc would/could determine which row is right, and apply the correct/ or winning row. }And the issue about daylight saving time is still open. What happens }when you have two servers in different time zones and one switches to }daylight savings time and the other doesn't. When server A changes }it'ss time to one hour back does Serverr B think it's receiving }transactions from an hour ago when they actually aren't. It doesn't }matter if you use GMT or not. If you do, the transactions are now GMT-6 }instead of GMT-5. Maybe this is where your 'timestamp and sproc' conflict resultion rules come into play. However this is an interesting problem. Even if all timezones do change to DST, they don't all at the same time! Jon ---------------------------------------------------------------------------- --- Jon C. Vemo "Life is like a dogsled team, if you ain't the jvemo@cyberspace.com lead dog the scenery never changes." ---------------------------------------------------------------------------- ---