How can you minimize Cxpacket waits?
The Real Way to Reduce CXPACKET Waits Set MAXDOP per Microsoft’s recommendations in KB 2806535. Set Cost Threshold for Parallelism in a way that lets your small queries stay single-threaded, but still gets more students involved when there’s a really big project.
What is a Cxconsumer wait type?
The simplest explanation of this wait type is that there are parallel plans running. This wait type was added in 2016 SP2 and 2017 RTM CU3 (as a result of a Connect item I submitted in 2016) to reduce the number of actionable CXPACKET waits that occur.
Why are cxpacket wait types so high in SQL?
A closer look at CXPACKET wait type in SQL Server. Problem. If you have a server that has more than one CPU core, you may experience high values of CXPACKET wait types. This is typically due to queries that run in parallel and the real issue is to understand how different versions of a query can impact CXPACKET waits.
What does cxpacket and cxconsumer mean in SQL Server?
CXPACKET and CXCONSUMER are wait types that indicate that work isn’t equally balanced. When you see these wait stats on your server, you’ll know that SQL Server is running queries in parallel, but not doing a great job of distributing them across available processors.
How much of the cxpacket Wait is cxconsumer?
CXCONSUMER isn’t a huge portion of the wait profile, but at a little over 10% of the CXPACKET waits, you can see how it’s already separating the good parallelism from the bad parallelism. This is of course a contrived test, and SQL Server is employing parallelism poorly because it still incorrectly thinks the table is huge.
How many cores does SQL Server cxpacket use?
Include the actual execution plan, clear the wait stats and make sure the system you are using is idle otherwise, the CXPACKET will not reflect our query waits alone. The server I tested on has 2 quad core CPUs for a total of 8 cores.