Trace flags are used to temporarily set specific server characteristics or to switch off a particular behavior. For example, if trace flag 8755 is set when an instance of SQL Server starts, hardware compression for tape drivers is disabled. Trace flags are frequently used to diagnose performance issues or to debug stored procedures or complex computer systems. The following table lists and describes the trace flags that are available in SQL Server. Some trace flags were introduced in specific SQL Server versions. For more information on the applicable version, see the Microsoft Support article associated with a specific trace flag.
Using Queries in SQL Server 2008 R2
Trace flag behavior may not be supported in future releases of SQL Server. In SQL Server, there are three types of trace flags: query, session and global. Query trace flags are active for the context of a specific query. Session trace flags are active for a connection and are visible only to that connection. Global trace flags are set at the server level and are visible to every connection on the server. Some flags can only be enabled as global, and some can be enabled at either global or session scope.
Query hints specify that the indicated hints should be used throughout the query. They affect all operators in the statement. If UNION is involved in the main query, only the last query involving a UNION operation can have the OPTION clause. Query hints are specified as part of the. If one or more query hints cause the query optimizer not to generate a valid plan, error 8677 is raised. Because the SQL Server query optimizer typically selects the best execution plan for a query, we recommend only using hints as a last resort for experienced developers and database administrators. If more than one UNION hint is specified, the query optimizer selects the least expensive strategy from those hints specified.
Data Warehouse Query Performance in SQL Server 2008
If more than one join hint is specified, the optimizer selects the least expensive join strategy from the allowed ones. Try Microsoft Edge A fast and secure browser that's designed for Windows 65 No thanks Get started Stack Exchange network consists of 676 Q A communities including, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. However in our testing environment it takes over 9hrs. SQL7555(+latest patches) is running in production and development. SQL7558R7 is running in testing. I took a look at the Query Plan, and it shows that SQL7558R7 is using TempDB, by way of a Table Spool (lazy spool) to store the returned rows from the linked-server. The next step is showing Nested Loops (left anti semi join) as eating up 96.
Net siteUsing CASE to replace the IIf function that is used in Microsoft Accessand its VB. Net equivalent, assuming you are using an inline SQL statement