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Category: T-SQL Tuesday

Checking File Sizes In SQL Server

Published 2018-07-12 by Kevin Feasel

Andy Mallon looks back at a contribution by Junior DBA Andy, this one on checking file sizes:

This is every DBA’s favorite game. Figuring out what DMV contains the data you want. It turns out there are two places that database file size info is maintained. Each database has sys.database_files which has information for that database. The master database also has sys.master_files, which contains information for every database.

Using sys.master_files seems like it would be the obvious choice: everything in one view in master is going to be easier to query than hitting a view in a bunch of different databases. Alas, there’s a minor snag. For tempdb, sys.master_files has the initial file size, but not the current file size. This is valuable information, but doesn’t answer the use cases we set out above. I want to know the current file sizes. Thankfully, sys.database_files has the correct current file sizes for tempdb, so we can use that.

Using sys.database_files seems like it’s going to be the right move for us then. Alas, this isn’t quite perfect either. With Log Shipping, and Availability Group secondaries, if you’ve moved data files to a different location, sys.database_files will contain the location of the files on the primary database. Thankfully, sys.master_files has the correct local file locations for user databases, so we can use that.

Ugh, so it looks like the answer is “both”… we’ll need to use sys.database_files for tempdb, and sys.master_files for everything else.

Click through for the script, including Andy’s critical reflection on how Past Andy has failed him.

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Adding IN Search Functionality To .NET

Published 2018-07-12 by Kevin Feasel

Jay Robinson shows off a few extension methods he creates to make dealing with C# easier:

Then I could use the extension like this:

if (mySeries.In(Enum.Series.ProMazda, Enum.Series.Usf2000)) myChassis = "Tatuus";

As for the other two methods, well… When is a null not a null? When it’s a System.DBNull.Value, of course! SQL Server pros who have spent any time in the .NET Framework will recognize this awkwardness:

var p = new System.Data.SqlClient.SqlParameter("@myParam", System.Data.SqlDbType.Int);
p.Value = (object)myVar ?? System.DBNull.Value;

With the extension, the second line becomes:

p.Value = mVar.ToDbNull();

I like it that Jay ended up going with a different language than T-SQL.  It’s no F#, but it’ll do.

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Finding Low-Hanging Fruit When Tuning SQL Server

Published 2018-07-12 by Kevin Feasel

Kevin Hill has a couple scripts which help him find easy performance gains:

Recently, I’ve been getting a lot of performance tuning work, much of which is basically “things are slow…can you fix them?” type of requests.  Most experienced DBAs know that there a few gazillion factors that can lead to this request, and I won’t re-hash them here.

Lets assume, that we’ve optimzed or eliminated the server, disks, network, etc. and were now looking at SQL code and everyone’s favorite – indexes.

I have two scripts I use that give me a quick overview of the type of work SQL Server is doing.   These complement each other, and are used AS A STARTING POINT to locate the low-hanging fruit that can be causing excessive work for the disks and memory of the server.

Click through for those scripts.

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Generating Index Drop And Create Statements

Published 2018-07-11 by Kevin Feasel

Drew Furgiuele says “Game over, man, game over!” to indexes:

The premise is simple: it will generate a series of DROP and then CREATE INDEX commands for every index. The process is a little more complex in practice, but at a high level it:

  1. Creates a special schema to house a temporary object,
  2. Creates a special stored procedure to run the code,
  3. Calls said stored procedure,
  4. Generates a bunch of PRINT statements that serve as the output (along with new line support for readability),
  5. Cleans up the stored procedure it generated,
  6. And finally deletes the schema it created.

Nifty.

Click through for the script, as well as a bonus Powershell script.  Because hey, it’s only six lines of code.

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Instance-To-Instance Migrations With Start-DbaMigration

Published 2018-07-11 by Kevin Feasel

Chrissy LeMaire touts one of the best parts of dbatools:

dbatools is such a fun toolset to work on, but specifically, I can no longer live without Start-DbaMigration. Even in smaller shops, migrations are often required and they are always a lot of work.

At least they used to be, before I built the command that started it all: Start-DbaMigration. Start-DbaMigration is an instance to instance migration command that migrates just about everything. It’s really a wrapper that simplifies nearly 30 other copy commands, including Copy-DbaDatabase, Copy-DbaLogin, and Copy-DbaSqlServerAgent.

Also a bonus shout out to dbachecks.

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Gathering Info On Tables

Published 2018-07-11 by Kevin Feasel

Raul Gonzales has a script which provides useful information for tables and columns:

Useful information it provides at table level:

  • tableType, to identify HEAP tables
  • row_count, to identify tables with plenty of rows or now rows at all
  • TotalSpaceMB, to identify big tables in size
  • LastUserAccess, to identify tables that are not used
  • TotalUserAccess, to identify tables that are heavily used
  • TableTriggers, to identify tables that have triggers

Useful information it provides at column level:

  • DataType-Size, to identify supersized, incorrect or deprecated data types

  • Identity, to identify identity columns

  • Mandatory-DefaultValue, to identify NULL/NOT NULL columns or with default constraints

  • PrimaryKey, to identify primary key columns

  • Collation, to identify columns that might have different collation from the database

  • ForeignKey-ReferencedColumn, to identify foreign keys and the table.column they reference

Click through for the script.

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The Best Of The Underground Toolbox

Published 2018-07-10 by Kevin Feasel

Adrian Buckman shares some of his favorite creations:

sp_AGreconfigure

This is a great goto proc for an alternative to the Always on availability group GUI for changing Failover mode, Synchronous mode or even Readable options.

When you manage multiple servers with multiple Availability groups this stored procedure can save you alot of time, sometimes I find the GUI can take a long time to open but equally it can take some time to execute the command.

sp_AGreconfigure can speed this process up for you, we tend to use this as our goto for switching synchronous settings when patching/rebooting replicas but also I tend to use it in @Checkonly = 1 mode for giving the Availability group settings a once over.

Click through for this and several other useful tools.

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sp_ctrl3 — Getting Information On Database Objects

Published 2018-07-10 by Kevin Feasel

Daniel Hutmacher shows off his sp_ctrl3 solution:

My absolute number one favorite homebrew tool is without a doubt sp_ctrl3. I started building it a long time ago to replace the built-in sp_help procedure in SQL Server, which is accessible using the Alt+F1 shortcut in Management Studio.

sp_help shows you object information on database objects, such as column definitions, parameters, indexes, etc, but it’s old (I remember it in SQL Server 2000, but it’s probably way older than that) and it hasn’t really aged that well since then. What’s more, sp_help won’t show you the more technical details and features from newer versions (like filters and included columns on indexes) , so you can’t really just copy and paste information from it very reliably or effortlessly.

Like the name implies, cp_ctrl3 aims to address some of those issues, and years later, I find myself adding features to it whenever there’s something I miss.

Check it out as a worthy replacement to sp_help.

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Essential SQL Server Tools

Published 2018-04-30 by Kevin Feasel

Jens Vestergaard shares the most recent T-SQL Tuesday round-up:

Tuesday 3rd of this Month I invited people in the SQL Server community to share which tools are essential to their daily work. I was really overwhelmed by the number of stories that the topic triggered. 22 in total took the time to write down and share which tools they use for their work chores.
Going through 22 posts and aggregating them has been taking more time than I had hoped for, since my trusted laptop broke down – blinking codes are well and alive I tell you!

Click through for the 22 submissions as well as Jens’s set of links to the tools people mentioned.

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Retrieving Server And Database Permissions

Published 2018-04-12 by Kevin Feasel

Kenneth Fisher wants you to know about your SQL Server’s permission setup:

Our host for T-SQL Tuesday this month is Jens Vestergaard (b/t) and he has asked about our favorite SSMS tool. My initial thought was to talk about using solutions in SSMSbut I’d already written about that. My next thought was to write about sp_DBPermissions and sp_SrvPermissionswhich of course I’ve written about several times. No big surprise, I wrote them after all.

So what tool am I going to write about? Well, sp_DBPermissions and sp_SrvPermissions of course. I mean I did write them after all, and Jens did say we could brag about something we wrote :).

Read on for more information about these useful tools.

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