FIX: Heavy tempdb contention occurs in SQL Server 2016 or 2017

Applies to: SQL Server 2016 Service Pack 1SQL Server 2016 DeveloperSQL Server 2016 Enterprise

Symptoms


Assume that you are creating or dropping large number of temporary tables in Microsoft SQL Server 2016 or 2017. Certain application workload invalidates the cache of temporary tables. For example, you are creating temporary tables and then creating ALTER TABLE or CREATE INDEX which will invalidate the cache of temporary tables. In this situation, you may experience the following issues:

  • Data Definition Language (DDL) contention in the tempdb on system catalog sysobjvalues and large number of sessions that are waiting on the PAGELATCH_EX, PAGELATCH_SH and PAGELATCH_UP wait type occur.
  • This situation also affects the workload when the entries count is more than 4,000. However, this may vary, depending on the workload. See the following example:

     

    SELECT [name], [type], [entries_count], [entries_in_use_count]

    FROM sys.dm_os_memory_cache_counters

    WHERE [type] = N'CACHESTORE_TEMPTABLES'

    name

    type

    entries_count

    entries_in_use_count

    Temporary Tables & Table Variables

    CACHESTORE_TEMPTABLES

    <count>

    <count>

Resolution


This issue is fixed in the following cumulative updates for SQL Server:

       Cumulative Update 5 for SQL Server 2017

       Cumulative update 8 for SQL Server 2016 SP1

Status


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

References


Learn about the terminology that Microsoft uses to describe software updates.