What is new in Microsoft SQL Server 2008 July CTP (CTP4)

Microsoft has released the latest Community Technology Preview (CTP) of SQL Server 2008 (code name Katmai) in July.
If you're interested in new and beta products you should have known the Microsoft Connect. You can register and get more detailed information on SQL Server 2008 (Katmai) CTP releases from Microsoft Connect.

New Data Types

Date type and Time type

At first look, we were already expecting the seperation of date and time data types.
This feature, I mean the new Date type and Time type are now introduced with SQL Server 2008 July CTP.

I know you are having a lot of problems in order to fetch specific information from datetime values kept in your SQL databases. You have yo use datetime functions which are sometimes insufficient for your requirements. So you have to develop custom user defined functions. And you have to spare huge sizes in your tables to keep some datetime related data.
Also if you are dealing with applications running world-wide, then you are possibly experiencing problems and difficulties in keeping and displaying datetime values according to the timezones.
Now SQL2K8 has also enhanced datetime data type with support for time-zone awareness.
Also a new data type datetime2 is introduced which is an extended version data type of datetime we are using for years. datetime2 has a larger date range and a larger precision.
Date range now extends with datetime2 from 0001-01-01 to 9999-12-31. And time range now spans from 00:00:00 to 23:59:59.9999999 in more precision.
And it is nice that datetime2 is sharing the same storage size 8 Kb just like datetime data type.

HierarchyID system data type

In the T-SQL side, it has always been difficult to work hierarchies which is most modelled or represented using the tree structures.
Now SQL 2008 has HierarchyID system data type which enables an easier way of modelling and operating on hierarchies in SQL Server databases.
As sql database developers and sql programmers, HierarchyID system data type will make modelling, storing, querying, modelling for us easier and simplier.
HierarchyID system data type is an other new data type as well as Date and Time data types in SQL Server 2008.

Table type variables

SQL Server 2008 is supporting table type variables since June CTP. Now in SQL 2008 July CTP, SQL Server also supports table value parameters which can be used as parameter type to pass a set of rows to a stored procedure or to a function or a user-defined function.
This is very helpful, since we are currently using temporary tables of converting the data rows into character variables by concatenating with a seperator then parsing, or etc. Now we can pass datasets or set of rows as a parameter by the use of table value parameters to stored procedures.

SQL Server Reporting Services improvements

SQL Server Reporting Services also has significant improvements.
Reporting Services has enhancemants in its processing engine and report rendering.
Also dependency for IIS (Internet Information Services) has been removed

Auto Regressive Integrated Moving Average (ARIMA)

In the SQL Server Analysis Services side, a new time series forecasting algorithm has been added to the data mining suite. This new algorithm is the ARIMA, Auto Regressive Integrated Moving Average which provides more stable long term predictions.

You can download Microsoft SQL Server 2008 July CTP for various OS options from Microsoft Connect SQL Server 2008 CTP pages.

If you are thinking to install and try the SQL Server 2008 July CTP, you should know that SQL Server 2008 is not supported side-by-side with SQL Server 2000 installations and with SQL Server 2005 client components.
You can read more about SQL Server 2008 installation problems and solutions at SQL Server "Katmai" installation is not supported side-by-side with SQL Server 2005 Client Components and here Setup has detected one or more instances of SQL Server 2000 on the computer where you are installing SQL Server 2008..
If you have installed the June CTP then in order to install the July CTP, you should first uninstall the Katmai June CTP. After uninstallation of June CTP is comleted then you can install the July CTP. July CTP does not support an upgrade process from previous versions.