I did a talk yesterday at TechEd Hong Kong on ADO.NET vNext. Most of them just wanted to know what ADO.NET vNext was about. Short and sweet. Here goes...

There are two main new features:
1. Entity data model (EDM) - a mapping of objects over relational database to bring data access to a higher level of abstraction. No longer do you need to code to the DBMS schema, only to the entity schema. Think of it as a new data source.
2. Entity SQL - a new query language, SQL plus extensions to query against the entity data model (EDM). A bit richer than SQL, but SQL-like.

And some integration pieces:
1. An ADO.NET provider over the EDM (the MapProvider). Uses ESQL queries.
2. An ObjectServices layer over EDM. Reminiscent of ObjectSpaces (at least to me). Uses Query<T> and an ObjectContext.
3. An integration piece that allows LINQ over the EDM. "LINQ to Entities".

LINQ for Entities joins:
  LINQ to Objects
  LINQ to SQL (was: DLINQ)
  LINQ to XML (was: XLINQ)
  LINQ to DataSets
  PLINQ (parallel LINQ)

That's all folks.

When installing previous versions of SQL Server, I'd always keep a list of the exact privileges that a SQL Server service account would need. I'd make up a new user and give them exactly these rights. The SQL Server installation program would grant the appropriate permissions during the install, and I'd be set. Principle of least privilege, run SQL Server and associated as the minimum privilege account needed. If I thought about changing the service account, I'd call up knowledge base article Q283811 and sigh at the list of work items. And make sure that I used Enterprise Manager, as the article recommends.

Things are a lot simpler in SQL Server 2005. When you install SQL Server, the process creates Windows groups with exactly the minimum privlege that you need for the appropriate services. The user you specify during the install (which should be a "normal", low privilege user and NOT administrator or LocalSystem, is plunked into the appropriate group. There is a Windows Group for each SQL Server-related service, all nicely decked out with least privileges (file system DACLs, security policies, registry key access, etc). NO more privilege lists to keep around, although they are doc'd in BOL should you need to refer to them.

If you should need to change the service account, things are even better. Just put your new Service Account user in the appropriate Windows groups, and voila, no long list of tasks. Very cool. Or use Configuration Manager.

Twas' not all sweetness and light, however. an FAQ during the early days was "why does SQL Server setup "clutter" my directory with groups?" That's why. First time you need to change service accounts, you'll appreciate the "clutter".

There was a newsgroup discussion recently about the intricacies of Multiple Active Resultsets in SQL Server 2005, and one of the questions that came up was "Who actually needs/uses MARS anyway"? I've been taking a much closer look at ADO.NET vNext lately, one reason being that I'm doing a talk on it at TechEd Hong Kong the week after next. Guess what? Both the supplied ObjectServices and LINQ for Entities samples have "multipleactiveresultsets=true" in their connection strings. Why? Without taking MARS out and seeing where the samples fail (I'll get around to it...), I'd bet they use both the "multiple resultsets on the same connection" and "issue an UPDATE statement while reading a rowset on the same connection" patterns. That's what MARS is supposed to address (the very precise ODBC error message for this is "Statement in Use").

BTW, MARS has some interesting effects on transactions and session settings, too. I'll be doing a talk on this at TechEd Europe in Barcelona in Novemeber. Don't forget to stop by and say hi if you're at either of these excellent events.

Thanks to those who came to my webcast today on SQL Server 2005. Between this webcast and the other upgrading webcasts that are available on the Technet event website and the MSDN event website, you should have a pretty good idea about why you need to upgrade to SQL Server 2005. If you haven't done that already.

As promised, here are the demos and scripts from the session, on the SQLskills website. I'll post a Q&A blog entry and a pointer to the webcast as soon as I have the information.

I've noticed that, as more companies want to run SQL Server applications 24x7x365 interest of clustering has increased dramatically. One of the most asked-for papers about SQL Server 2005 is an update to the clustering whitepaper. Well, its available NOW; an over-100 page treatise by Allan Hirt and Dave Whitney. It covers not only clustering SQL Server 2005 but also Analysis Services 2005. A MUST read. Look for "Failover Clustering for Microsoft SQL Server 2005 and SQL Server 2005 Analysis Services" at Microsoft download site.