Have you ever come across the OLEDB wait type in SQL Server and wondered what it means? In this blog post, we will explore the concept of OLEDB and its significance in SQL Server performance tuning.

OLEDB stands for Object Linking and Embedding Database. It is a wait type that occurs when SQL Server calls the SQL Server Native Client OLE DB Provider. This wait type is not used for synchronization but indicates the duration of calls to the OLE DB provider.

One interesting observation is that the OLEDB wait type is often found in the top 10 wait types in many systems during performance tuning. This raises the question of why it is so prevalent and how it can be reduced.

The OLEDB wait type primarily occurs when a Linked Server or Remote Query is executed. When SQL Server retrieves data from a remote server, it uses the OLEDB API to retrieve the data. If the remote system is not quick enough or the connection between them is not fast enough, SQL Server has to wait for the result’s return from the remote server, leading to the OLEDB wait type.

To reduce the OLEDB wait type, you can start by checking the Link Server configuration. Additionally, monitoring disk-related Perfmon counters can provide insights into potential issues. Some key counters to consider are:

• Average Disk sec/Read (Consistently higher value than 4-8 milliseconds is not good)
• Average Disk sec/Write (Consistently higher value than 4-8 milliseconds is not good)
• Average Disk Read/Write Queue Length (Consistently higher value than the benchmark is not good)

By analyzing these counters and optimizing the Link Server configuration, you can potentially reduce the occurrence of the OLEDB wait type.

It is important to note that the information presented in this blog post is based on the author’s experience and may vary from system to system. It is recommended to consult the official documentation and test any recommendations on a development server before implementing them in a production environment.

Do you have any opinions or insights on the OLEDB wait type? Feel free to share your thoughts in the comments below. Your contribution will be shared with the rest of the community, with due credit given to you.

Thank you for reading this blog post. Stay tuned for more articles in our Wait Types and Queue series.