When it comes to optimizing performance in SQL Server, there are various strategies that can be employed. One such strategy is using a separate hard drive for several database objects. This simple yet effective technique can have a significant impact on the overall performance of your SQL Server.

A non-clustered index and tempdb can be created on a separate disk to improve performance. By doing so, you can reduce disk contention and improve I/O performance. This is particularly beneficial in scenarios where you have heavy read and write operations on your database.

Creating a non-clustered index on a separate disk allows for faster read operations as the index data is stored on a different disk, reducing the I/O load on the primary disk. Similarly, moving tempdb to a separate disk can improve performance by reducing contention with other database objects.

By distributing the workload across multiple disks, you can achieve better parallelism and utilize the available resources more efficiently. This can result in faster query execution times and improved overall system performance.

It is important to note that while using a separate hard drive for database objects can improve performance, it is not a one-size-fits-all solution. The effectiveness of this technique depends on various factors such as the workload, hardware configuration, and database design.

To find the list of fixed hard drives and free space on your server, you can use the following stored procedure:

EXEC master..xp_fixeddrives

This will provide you with information about the number of fixed drives (hard drives) on your system and the free space on each of those drives.

It is worth mentioning that SQL Server allows only one clustered index per table. This is because a clustered index physically stores data or arranges data in one order, depending on the column(s) you have defined the clustered index on and the order specified. Since a set of data can only be stored in one order, only one clustered index is possible.

Understanding the difference between line feed (\n) and carriage return (\r) is essential when working with SQL Server. Line feed (LF) is represented by \n and has a decimal value of 10, while carriage return (CR) is represented by \r and has a decimal value of 13.

To use line feed and carriage return in SQL Server, you can declare a variable and concatenate it with the desired text:

DECLARE @NewLineChar AS CHAR(2) = CHAR(13) + CHAR(10)
PRINT('SELECT FirstLine AS FL ' + @NewLineChar + 'SELECT SecondLine AS SL')

Having a clustered index on a separate drive from the original table location is not possible in SQL Server. The clustered index is tightly integrated with the table data and cannot be separated.

When it comes to optimizing query performance, hints can be a powerful tool. Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. They override the execution plan selected by the query optimizer.

There are three types of hints in SQL Server:

• Join Hint: Used when multiple tables are involved in a query. It forces the type of join algorithm to be used.
• Query Hint: Applied to the entire query and used to apply specific logic to the query as a whole.
• Table Hint: Used to control the locking mechanism of tables in specific scenarios where the default behavior needs to be overridden.

To delete duplicate rows in SQL Server, you can use the CTE (Common Table Expression) and ROW_NUMBER() feature. Here’s an example:

WITH CTE (Col1, Col2, DuplicateCount) AS (
  SELECT Col1, Col2, ROW_NUMBER() OVER (PARTITION BY Col1, Col2 ORDER BY Col1) AS DuplicateCount
  FROM DuplicateRecordTable
)
DELETE FROM CTE WHERE DuplicateCount > 1

Finally, if you notice that a trigger is firing multiple times in a single login, it could be due to multiple SQL Server services running or the IntelliSense feature being turned on. It is important to ensure that only the necessary services are running and to disable IntelliSense if it is causing issues.

By implementing these strategies and understanding the concepts discussed, you can optimize the performance of your SQL Server and ensure smooth and efficient operations.