i don't think using a date field to determine concurrency issues is a good practice.
Hello, Thanks for your comments.
Yes, some people don't like using DateTimes to identify the "Lost Update" problem. This is a concern when a higher level of precision is required than what is offered by the DateTime (i.e. you have very high concurrency with lots of updates within milliseconds
of each other). An alternative that many find acceptable is to use the TimeStamp data type.
In any event, the primary concept here was really meant to be more about the neat things we can do with XQuery, and I do hope you found something useful there.
Concerning XQuery, a member of the SQL Server Engine team recently contacted me about a few issues which I either did not address (e.g. performance of Value() vs. Exist(), using XML or VarBinary data types for input parameters rather than TEXT, code page
and encoding issues ), or was unaware of (e.g. potential data corruption attributable to code page and XML encoding). He graciously offered to write a post on these subjects for
www.DesignPatternsFor.Net in the next month or two.