To list memory-optimized files, join sys.dm_db_xtp_checkpoint_files to sys.database_files. This post builds a small memory-optimized database, shows the container’s logical and physical name and counts its checkpoint files by type and state. It also explains why a container holds far more disk space than its data uses.
AVG of an Integer Column Returns an Integer: Getting Decimals Back
The dashboard says the average is 1 when everyone can see it is 1.5. Here is why AVG does that and the one-line fix.
Drop Multiple Columns in One ALTER TABLE Statement
To drop multiple columns, list them after one DROP COLUMN in one ALTER TABLE statement. This post tests the syntax on a table with a default, a check constraint and an index, shows the error that a dependent object causes and drops the constraints and columns together. It also explains why the disk space doesn’t return until a rebuild.
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.
Columnstore Indexes Without Aggregation: Do They Still Help?
Columnstore indexes without aggregation still help when a query reads many rows but only a few columns. This post builds a rowstore table and a columnstore copy of one million rows and compares reads, size and execution mode. It also shows the case where a plain b-tree index wins.
How to Download the Latest SQL Server Docker Image? – Interview Question of the Week #244
Question: How to Download the Latest SQL Server Docker Image? Answer: The command to download the latest SQL Server Docker Image is here:
Idle CPU Condition in SQL Server Agent: How It Works
The idle CPU condition tells SQL Server Agent when the CPUs are quiet enough to start a job. This post shows where to set it, how the two numbers work and how to create the schedule. It also reads the CPU history of your server in T-SQL, so you can choose values that the server can actually meet.