Recently during the on-demand consultation, I was asked a very interesting question about Stream Aggregate and Hash Aggregate.
Dynamics SQL Server Settings: Five Checks for NAV, AX and CRM
Dynamics SQL Server settings decide most of the speed you get from NAV, AX and CRM, because you rarely control the application code. Five read-only checks cover tempdb, autogrowth, MAXDOP, automatic statistics and statistics age. Each one comes with a short query and a clear rule.
Parallel Plans: Reading Gather Streams and Repartition Streams
Read Gather Streams and other parallel exchanges, inspect rows per thread and spill evidence, and relate exchange waits to actual work.
MAXDOP Query Hint: Override the Server Setting for One Query
The MAXDOP query hint sets how many processors one query can use, whatever the server setting says. This post proves it in both directions on a test table, shows that the hint can’t force a parallel plan and adds the database scoped setting between the two. Every step leaves the server setting alone.
NonParallelPlanReason: Why a Query Refuses to Go Parallel
Read NonParallelPlanReason in actual and cached plans, then check MAXDOP, scalar functions, table variables, and query cost.
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.
Running Several SQL Server Instances on One Machine
Budget several SQL Server instances on one Windows host, inventory services, assign memory and ports, and monitor shared resource pressure.