Just like its predecessor, SQL Server 2008 is taking its sweet time to actually ship.  However, unlike its predecessor, it won't just be a "worthwhile upgrade".  It will kick ass.

Here are the top 10 reasons why.

10.  Plug-in model for SSMS.   SSMS 2005 also had a plug-in model, but it was not published, so the few developers that braved that environment were flying blind.  Apparently for 2008, the plug-in model will be published and a thousand add-ins will bloom. 

9.  Inline variable assignment.  I often wondered why, as a language, SQL languishes behind the times.  I mean, it has barely any modern syntactic sugar.  Well, in this version, they are at least scratching the the tip of the iceberg. 

Instead of:

DECLARE @myVar int 
SET @myVar = 5


you can do it in one line:

DECLARE @myVar int = 5


Sweet.

8.  C like math syntaxSET @i += 5.  Enough said.  They finally let a C# developer on the SQL team. 

7.  Auditing.  It's a 10 dollar word for storing changes to your data for later review, debugging or in response to regulatory laws.  It's a thankless and a mundane task and no one is ever excited by the prospect of writing triggers to handle it.  SQL Server 2008 introduces automatic auditing, so we can now check one thing off our to do list.

6.  Compression.  You may think that this feature is a waste of time, but it's not what it sounds like.  The release will offer row-level and page-level compression.  The compression mostly takes place on the metadata.  For instance, page compression will store common data for affected rows in a single place. 

The metadata storage for variable length fields is going to be completely crazy: they are pushing things into bits (instead of bytes).  For instance, length of the varchar will be stored in 3 bits. 

Anyway, I don't really care about space savings - storage is cheap.  What I do care about is that the feature promised (key word here "promises") to reduce I/O and RAM utilization, while increasing CPU utilization.  Every single performance problem I ever dealt with had to do with I/O overloading.  Will see how this plays out.  I am skeptical until I see some real world production benchmarks.

5.  Filtered Indexes.  This is another feature that sounds great - will have to see how it plays out.  Anyway, it allows you to create an index while specifying what rows are not to be in the index.  For example, index all rows where Status != null.  Theoretically, it'll get rid of all the dead weight in the index, allowing for faster queries. 

4.  Resource governor.  All I can say is FINALLY.  Sybase has had it since version 12 (that's last millennium, people).  Basically it allows the DBA to specify how much resources (e.g. CPU/RAM) each user is entitled to.  At the very least, it'll prevent people, with sparse SQL knowledge from shooting off a query with a Cartesian product and bringing down the box.

Actually Sybase is still ahead of MS on this feature.  Its ASE server allows you to prioritize one user over another - a feature that I found immensely useful.

3.  Plan freezing.  This is a solution to my personal pet peeve. Sometimes SQL Server decides to change its plan on you (in response to data changes, etc...).  If you've achieved your optimal query plan, now you can stick with it.  Yeah, I know, hints are evil, but there are situations when you want to take a hammer to SQL Server - well, this is the chill pill.

2.  Processing of delimited strings.   This is awesome and I could have used this feature...well, always.  Currently, we pass in delimited strings in the following manner:

exec sp_MySproc 'murphy,35;galen,31;samuels,27;colton,42'


Then the stored proc needs to parse the string into a usable form - a mindless task.

In 2008, Microsoft introduced Table Value Parameters (TVP). 

CREATE TYPE PeepsType AS TABLE (Name varchar(20), Age int) 
DECLARE @myPeeps PeepsType 
INSERT @myPeeps SELECT 'murphy', 35 
INSERT @myPeeps SELECT 'galen', 31 
INSERT @myPeeps SELECT 'samuels', 27 
INSERT @myPeeps SELECT 'colton', 42

exec sp_MySproc2 @myPeeps 


And the sproc would look like this:

CREATE PROCEDURE sp_MySproc2(@myPeeps PeepsType READONLY) ...


The advantage here is that you can treat the Table Type as a regular table, use it in joins, etc.  Say goodbye to all those string parsing routines.

1. Intellisense in the SQL Server Management Studio (SSMS).  This has been previously possible in SQL Server 2000 and 2005 with Intellisense use of 3rd party add-ins like SQL Prompt ($195).  But these tools are a horrible hack at best (e.g. they hook into the editor window and try to interpret what the application is doing). 

Built-in intellisense is huge - it means new people can easily learn the database schema as they go.

There are a ton of other great features - most of them small, but hugely useful.  There is a lot of polishing all over the place, like server resource monitoring right in SSMS, a la Vista. 

I'd love to finish this entry on a happy note, but I can't, because I just finished perusing Editions of SQL Server 2008 page.  In addition to the Standard, Enterprise, Developer and Express editions, there are now Workgroup, Web, Compact (which has nothing to do with SQL Server) and Express Advanced editions.  Here is the comparison matrix.  And you thought picking a version of Vista was complicated.

Buy: Microsoft Sql Server 2008