Database: TempDB

TempDB is a system database in SQL Server that is used to store temporary user objects, temporary tables, and other temporary data. It is recreated every time SQL Server is restarted, and it's used by SQL Server for various operations.

Code Snippets

Here is an example of creating a temporary table in TempDB:

CREATE TABLE #TempTable ( ID int, Name varchar(50) );

Sample Examples

Let's insert some data into the temporary table we created:

INSERT INTO #TempTable (ID, Name) VALUES (1, 'John'), (2, 'Jane');

Now, let's select the data from the temporary table:

SELECT * FROM #TempTable;

The output will be:

ID | Name 1 | John 2 | Jane

Common Use Cases

TempDB is commonly used for storing intermediate results during query processing, storing temporary tables for complex queries, and for managing temporary objects in stored procedures and triggers.

Importance in Interviews

Understanding TempDB is important in SQL Server interviews as it demonstrates knowledge of how SQL Server manages temporary data and the importance of TempDB in query processing.

Conclusion

TempDB is a crucial system database in SQL Server used for storing temporary data and objects. Understanding its usage and importance can help optimize query performance and overall database management.