Category: Administration

Erik Darling warns against messing with the Max Worker Threads setting:

The thing is, all changing that setting does is help you not run out of worker threads. It doesn’t make queries run any better or faster. In fact, under load, performance will most likely be downgraded to Absolute Rubbish© either way.

What’s worse? Running out of worker threads and queries having to wait for them to free up, or having way more queries trying to run on the same CPUs? Six of one, half dozen of punching yourself squarely in the nose.

I think there are a couple good counter-cases brought up in the comments (around mirroring and Service Broker), but it is solid general advice.

Michael Swart has a small console app which searches for INSERT statements missing column specifications:

I’ve got a program here that finds procedures with missing column specifications.

• If for some reason, you don’t care about enforcing this rule for temp tables and table variables, then uncomment the line // visitor.TolerateTempTables = true;

• It uses ScriptDom which you can get from Microsoft as a nuget package.

• The performance is terrible in Visual Studio because ScriptDom uses Antlr which uses exceptions for flow control and this leads to lots of “first chance exceptions” which slows down debugging. Outside of Visual Studio, it’s just fine.

Click through for the code.

Drew Furgiuele explains dynamic DNS and shows how to use Powershell to keep your Google Dynamic DNS record up to date:

Google’s Dynamic DNS API is really little less than a HTTPS POST to a specific URL with some parameters packed into the post. What makes it work, though, is for each dynamic DNS host name you provide, you get an auto-generated user name and password that needs to be part of the POST. PowerShell is really naturally suited for this type of automation, thanks to Invoke-WebRequest (MSDN Link). It’s built for this, and even supports HTTPS. Heck, it even supports the implementation of username:password in the request via a PSCredential object.

All I really needed to do was to wrap the code in a function and add some parameters that can be passed in, invoke the web request, and parse the results.

Click through for more information, including a couple Powershell scripts.

Andrew Peterson has a script to get row counts for each table based on sys.dm_db_partition_stats:

When you need the row count from a table, the most common way is to use count(*). But what if you need the row count for all the tables in your database?  You could use the sp_MSforeachtable stored procedure:

EXEC sys.sp_MSforeachtable ‘select ”?”,count(*) from ?;’;

Nice, but the return format is a bit difficult to manage, since it effectively runs the query for as many times as you have tables in your database.

Click through for Andrew’s script.  One thing to keep in mind is that the number of rows might be off, especially for columnstore tables with ghost records.  It’s an estimate, but one which tends toward the correct answer.

Kevin Hill has a top ten functions list for database administrators:

3. DBCC Opentran – log file filling up?  Processes blocked and timing out? See if some doofus (hopefully not you) left a transaction open and went to lunch.  If you are lucky you can kill it.   Unlucky and you find an undistributed replicated transaction.

4. Getdate() – Not sure why, but this winds up in probably 80% of the scripts I write.  Not surprisingly, it often brings along it’s little brother, DateDiff.

I’d go with GETUTCDATE() or SYSUTCDATETIME() over GETDATE(); that way, everything gets stored as UTC and you spend less time worrying about time zone or Daylight Savings Time issues.

Andrew Peterson has a script to grab space used for each database:

After reviewing the posts, many, perhaps all of the procedures and commands I found provided valuable information. Just not what I wanted. We have:

sp_spaceused, but it returns data in two data sets. Not ideal.  Next we have…

sp_databases, but it just returns a list of databases and the size. Not ideal.  Or use…

DBCC showfilestats,   Ok, but still incomplete. And, since it is not listed on the main DBCC page at MSDN, its most likely deprecated.

And speaking of DBCC, there are other commands to consider. But what I was really hoping to find was a simple way to use the sys.database_files DMV. It is very close, but not quite complete.

Read on for the solution.  One small change I’d prefer is using Aaron Bertrand’s sp_foreachdb for iterating.  Or write a Powershell script if you want to take the looping outside of SQL Server.

Kendra Little explains what the sp_who2 procedure does and how to read its results:

Let’s talk about sp_who2

I started out using sp_who2, also! And I was often confused by sp_who2.

sp_who2 is a built-in stored procedure in SQL Server.

• Shows a lot of sessions, even on an idle instance
• Doesn’t tell you much about what it’s doing

Here’s what an idle SQL Server looks like in sp_who2

This is my dev SQL Server instance. I have a few sessions open, but the only one which was executing anything was the one you see, where I ran sp_who2. I don’t have any agent jobs scheduled on this thing. It’s just waiting for something to happen.

It’s hard to know what to look at, because we see so much. And only 19 of the 49 sessions is on the screen, too.

Kendra then goes on to explain that there are better ways of getting this information and plugs sp_whoisactive.  I’m 100% in agreement.