Microsoft Updates Causing Performance Issues for SQL Server

The Core Issue

Microsoft has officially confirmed that Windows updates released after the October "Patch Tuesday" have caused significant performance disruptions for SQL Server. The issue stems from connections that remain open even after database requests are completed. Consequently, unused connections accumulate within the system, degrading server performance over time and compromising stability.

According to the company, the flaw is particularly prevalent when linked servers in SQL Server utilize OLE DB providers to connect to external databases. This affects both Oracle and PostgreSQL systems. IT administrators report that connections to external databases fail to close even after the corresponding SQL queries have finished. This leads to resource exhaustion and server slowdowns. The bug impacts both client operating systems, such as Windows 10 and Windows 11, and server platforms, including Windows Server 2012 and newer versions.

How to Resolve the Glitch

Microsoft states it is currently working on an out-of-band update, which is expected to be released in the coming days. In the interim, administrators can manually close connections or restart the SQL service, though these remain only temporary measures. Furthermore, restarting the service may interrupt active requests, which is undesirable in critical environments. The company advises business users to contact Microsoft Support to obtain temporary workarounds until the official patch is released.

This is not the first instance recently where Microsoft updates have hindered server systems. In September, the company provided a temporary fix for Windows Server 2025 due to a memory management bug that caused SQL Server to shut down unexpectedly. Additionally, November security updates have faced installation issues on Windows 11 systems that had October preview versions installed. For system administrators managing corporate servers, it is essential to monitor official Microsoft updates and refrain from immediately installing patches on critical systems until their stability is confirmed.