what is Difference betwwen sql server 2005 and sql server 2008

Tools Enhancements:

SQL Server Management Studio has the following improvements:

· In the Query Editor window, you can query multiple servers at the same time by opening query windows from registered server groups. The query results can be combined into a single results pane, or can be returned in separate results panes.

· You can access SQL Server Profiler from the Query Editor window, from the Query menu, the Query Editor toolbar, or by pressing CTRL+ALT+P.

· You can now open tables by using a Return Top n rows option.

· On the Tools/Option menu, you can specify the action that results by double-clicking tables in Object Explorer.



Transact-SQL Enhancements:

· Lock Escalation Option - A new LOCK_ESCALATION option of ALTER TABLE allows you to disable lock escalation on a table.

· Query Hints - Table hints can now be specified as query hints to provide advanced query performance tuning options.

· Hierarchyid Data Type - SQL Server 2008 introduces a new system-provided data type to encapsulate hierarchical relationships.

· User-Defined Table Type - The Database Engine introduces a new user-defined table type that supports representing table structures for use as parameters in stored procedures and functions, or in a batch or the body of a stored procedure or function.

· Compatibility Level - ALTER DATABASE SET COMPATIBILITY_LEVEL replaces sp_dbcmptlevel for setting the database compatibility level.

· GROUPING SETS - The GROUPING SETS, ROLLUP, and CUBE operators are added to the GROUP BY clause.

· Table Hints - The FORCESEEK table hint is added to provide advanced query performance tuning options.

· Transact-SQL Row Constructors - Transact-SQL is enhanced to allow multiple value inserts within a single INSERT statement.