FIX: Query on a secondary replica takes two times as long to run as on a primary replica in SQL Server

Applies to: SQL Server 2016 DeveloperSQL Server 2016 EnterpriseSQL Server 2016 Enterprise Core More

Symptoms


Consider the following scenario:

  • In Microsoft SQL Server, you use Always On Availability Groups.
  • On the secondary replica, you use a query plan that scans many pages to query a large table.
  • No other tasks are running.

In this scenario, it takes about two times as long for the query to run as it does on the primary replica.

Resolution


This problem is fixed in the following update for SQL Server:

Cumulative Update 10 for SQL Server 2016 Service Pack 1

Status


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

References


DBCC TRACEON - Trace Flags (Transact-SQL)

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