To force a parallel plan for one query, add the ENABLE_PARALLEL_PLAN_PREFERENCE hint to its OPTION clause. This post shows why a cheap query stays serial, runs a demo query with and without the hint, proves the difference from the last actual plan, and explains why the hint belongs in a test and not in every query.
Rows Read Per Thread: Four Ways to See Them in SQL Server
Rows read per thread show whether a parallel query shares its work evenly. The post shows two plan based methods, a T-SQL query over the last actual plan, and a live DMV for running queries. A 500,000 row demo proves the threads add up to the table.
SQL SERVER – What is Wait Type Parallel Backup Queue?
Only official documentation which I could find was about wait statistics related to Parallel Backup Queue is very little available online.
MAXDOP Guidelines: Audit CPU and Memory Settings in SQL Server
MAXDOP guidelines start from the number of CPUs and NUMA nodes on the server. This post builds three read-only queries that show those facts, the current MAXDOP and cost threshold, and the memory settings. It also shows how to read the answer without changing anything.
Do Queries Always Respect Cost Threshold of Parallelism? – Interview Question of the Week #216
Do queries always respect the Cost Threshold for Parallelism? Not always, and a quick AdventureWorks test with the execution plan shows why.
Update Statistics With FULLSCAN and MAXDOP in SQL Server
To update statistics with FULLSCAN in parallel, add MAXDOP to the statement. This post builds a table of 3 million rows, times the update with MAXDOP 1, the instance default and 8, and shows which statistics speed up and which do not.
SQL SERVER – New Parallel Operation Cannot be Started Due to Too Many Parallel Operations Executing at this Time
A client’s ERRORLOG said: New parallel operation cannot be started due to too many parallel operations executing at this time. Here is what I found behind it.