guid

Possible Duplicate: How do you like your primary keys? I'm aware of the benefits of using a GUID, as well as the benefits of using and INT as a PK in a database. Considering that a GUID is in essence a 128 bit INT and a normal INT is 32 bit, the INT is a space saver (though this point is generally moot in most modern systems). In the end, in what circumstances would you see yourself using an INT as a PK versus a GUID? Kimberley Tripp (SQLSkills.com) has an article on using GUID's as primary keys. She advices against it because of the unnecessary overhead. Apart from being a poor choice when

A while ago I worked on a web application where users could buy tickets. Due to the way our client's processes worked, what you effectively got as a result of your purchase was a URL with the ticket number in it. These were tickets to buy property in the Middle East, and each ticket was potentially worth around $3,000,000. Clearly dishing out sequential integers would have been a bad idea. We used GUIDs as they're basically unguessable, but my question is: are they secure enough? As I understand it, the GUIDs .NET produces are totally pseudo-random (except for a few non-varying bits). However,

I just read a blog post about NHibernate's ability to create a GUID from the system time (Guid.Comb), thus avoiding a good amount of database fragmentation. You could call it the client-side equivalent to the SQL Server Sequential ID. Is there a way I could use a similar strategy in my Linq-to-Sql project (by generating the Guid in code)? COMBs are generated the following way: DECLARE @aGuid UNIQUEIDENTIFIER SET @aGuid = CAST(CAST(NEWID() AS BINARY(10)) + CAST(GETDATE() AS BINARY(6)) AS UNIQUEIDENTIFIER) Which transcribed into C# would look like this: public static unsafe Guid CombGuid() {