Symptoms. In Microsoft SQL Server 2016 and 2017, the temporary table cachestore memory object contention causes the CMEMTHREAD waits, which lead to slow performance. Cause. A major point of contention in highly concurrent Tempdb workloads which create temp tables in stored procs is the contention on the Temp Table cachestore memory object.

When you execute many ad hoc queries to retrieve data from those tables concurrently, you may experience CMEMTHREAD waits during the execution. Resolution. Cumulative Update information. The issue was first fixed in the following cumulative update of SQL Server. Cumulative Update 2 for SQL Server 2014 SP1. Cumulative Update 9 for SQL Server 2014.

KB2492381 - FIX: SQL Server 2008 R2 performs poorly when most threads wait for the CMEMTHREAD wait type if the threads use table variables or temp tables to load or update rowsets - Microsoft Support.

A CMEMTHREAD wait type indicates the wait on the internal, thread-safe memory objects. Higher levels of query parallelism may trigger the wait that leads to decreased performance of the spatial activity. This fix partitions the CMEMTHREAD that associates with the "Spatial Memory Object" by using NUMA node partitioning.

KB4013128 - FIX: Decreased performance and long waits for CLR_AUTO_EVENT and CMEMTHREAD when SQLCLR UDT is used as a stored procedure parameter for a SQL RPC call - Microsoft Support.

Symptoms. In SQL Server 2012, you may notice that high CMEMTHREAD waits on memory object MEMOBJ_SESCHEMAMGR. Resolution. Update information. This issue is fixed in Cumulative Update 5 for SQL Server 2012 Service Pack 3. Recommendation: Install the latest cumulative update for SQL Server. Status.

When you are at the stage where the available virtual address space is very low, queries that try to perform memory allocation may also encounter a wait type of CMEMTHREAD. The following data points will continue to increase over time: DMV: sys.dm_os_process_memory and sys.dm_os_memory_nodes - column virtual_address_space_reserved_kb

In this situation, the log write waits counter for the log buffer on the SQL Server instance has a high value. You will also notice high values for CMEMTHREAD and WRITELOG wait types in dynamic management views (DMVs). Additionally, mini dump files are generated. Note The log pool is an in-memory cache of the transaction log.

Symptoms. In Microsoft SQL Server 2016 and 2017, the temporary table cachestore memory object contention causes the CMEMTHREAD waits, which lead to slow performance. Cause. A major point of contention in highly concurrent Tempdb workloads which create temp tables in stored procs is the contention on the Temp Table cachestore memory object.

Note: If you're monitoring wait statistics, you may also notice an increase in the CMEMTHREAD wait type during the affected timeframe. Note This issue doesn't occur if the login (s) belongs to the sysadmin role. To protect the instance of SQL Server and the data that's stored on it, we suggest you to have logins with minimal required privileges.