large-xml-schema-collections-and-out-of-memory-conditions.md

title	Out-of-memory with large XML schema collections
description	Learn about solutions for handling out-of-memory conditions when loading or dropping a large XML schema collection.
author	MikeRayMSFT
ms.author	mikeray
ms.reviewer	randolphwest
ms.date	05/05/2022
ms.service	sql
ms.subservice	xml
ms.topic	troubleshooting-general
ms.custom	ignite-2025
helpviewer_keywords	out-of-memory conditions XML schema collections [SQL Server], large

Large XML schema collections and out-of-memory conditions

[!INCLUDE SQL Server Azure SQL Database-fabricsqldb]

During a call to the built-in XML_SCHEMA_NAMESPACE() function on a large XML schema collection, or when you try to drop large XML schema collections, an out-of-memory condition may occur. The following are solutions you can use to handle this:

• When the system load is light, use the DROP_XML_SCHEMA_COLLECTION command. If this fails, put the database in single-user mode by using the ALTER DATABASE statement and trying DROP XML SCHEMA COLLECTION again. If the XML schema collection exists in master, model, or tempdb, a server restart is required for single-user mode.

• When you call the XML_SCHEMA_NAMESPACE, you can try to retrieve a single XML schema namespace, you can try the call when the system load is lighter, or you can try the call in single-user mode.

See also

• Requirements and Limitations for XML Schema Collections on the Server