Category: Back to Basics

Quick Tip: Remove CONVERT\CAST from your WHERE\JOIN clauses

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Quick Tip Remove CONVERT/CAST from your WHERE clauses and JOINS when comparing to variables of different data types. Set their data types to match your table definitions before using them as a filter. Optimizing your queries this way will greatly reduce the amount of CPU time, reads, and I/O generated in your queries and allow your code to take better advantage of indexes. Example We are going to create a very simple stored procedure called ConvertExample. In this procedure we will see two things. One, the first procedure we create will declare two variables as VARCHAR( MAX) data types, then… Continue Reading

Identifying SQL Server Performance Problems Part 2

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Performance Monitoring Tools In this second post we are diving into what tools you can use to capture the important performance metrics you need to gather for baselining your environment. Be sure to read part one first. Performance Monitor First let’s start with what comes native to Windows Server platform, whether you are on an Azure SQL Virtual Machine or your standard SQL Server instance install on premises you have a native tool, called Performance Monitor (affectionately known to most as PerfMon). This reliable tool allows you to easily monitor performance metrics through a Graphical User Interface (GUI), by selecting performance counters for the operating system… Continue Reading

Mastering TempDB: The Basics

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I regularly deliver a presentation called “Mastering TempDB”. I wrote it based on what I wish I knew about TempDB “growing up” in my career as a SQL Server DBA. It really is a breakdown of what TempDB is, how it is used, what problems actually occur within it, and how to best configure it. With advice from my colleagues, I have decided to break that down into this article to educate you. What is TempDB? TempDB is a global resource used by everyone and everything inside SQL Server. Think of it as a dumping ground for anything that doesn’t… Continue Reading

Identifying SQL Server Performance Problems Part 1

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Every server, database, storage appliance and network encounter some sort of performance issues. It is a major part of our job as database administrators to properly monitor and fix those performance issues whether it is in your traditional on premises environment or in the cloud. This article will cover ways monitoring performance and how to establish a baseline. We will go over several important performance metrics every database administrator should know and how to gather and interpret those metrics through several different options within SQL Server and your Windows operating system. Now which tool you use to accumulate these metrics… Continue Reading

Storage Tiers What SQL Server DBAs Need to Know

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“One Gerbil, Two Gerbils or Three Gerbils?” is a common DBA joke about server and storage performance. No matter how many gerbils power your storage, you need to know what type they are and the power that they provide. Storage is not about gerbils it is about IOPs, bandwidth, latency, and tiers. As a DBA it is important for you to understand and know what kind of storage is attached to your servers and how it is handling your data. It is not important to master everything about it, but it is very advantageous to be able to talk to… Continue Reading

Resizing Tempdb (When TEMPDB Wont Shrink)

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Occasionally, we must resize or realign our Tempdb log file (.ldf) or data files (.mdf or .ndf) due to a growth event that forces the file size out of whack. To resize we have three options, restart the SQL Server Service, add additional files, or shrink the current file. We most likely have all been faced with run away log files and in an emergency situation restarting the SQL Services may not be an option but we still need to get our log file size smaller before we run out of disk space for example. The process of shrinking down… Continue Reading

Install ALL Things SQL Server… What?

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Does your server look like this? Many of us have inherited a SQL Server instance that has all SQL Services installed. Someone, maybe even you, went through the SQL Server installation process using GUI and checked every option available to them, then just clicked Next, Next, Next and then Install. If this is your environment, please take a moment to evaluate and decide which of these services that are required. From a performance tuning perspective, it is important to only run the services that you need. Each of these services can consume resources on your server. Sharing resources reduces what… Continue Reading

Quick SSMS Tip

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It is widely known that I am a horrible speller and hate to type code. I tend to use a lot of code snippets and reuse code to avoid writing it. So, when I find little tips that make coding easier for me, I like to share. Did you know that you can surround your code with a click of a button with IF, BEGIN END, WHILE code blocks? SQL Server Management Studio (SSMS) gives us the basic structure of a Transact-SQL statement code block as a starting point. Take Look In SSMS In a query window, Right Click and… Continue Reading

Comparing Execution Plans

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When you run a query twice, and get dramatically different run times, your first step can be to try to identify the differences in execution plans. For many that means running  the two different queries (before & after) and splitting you screen in order to visually compare the plans. Did you know SQL Server Management Studio gives you the option to compare to different execution plans? It makes it easy not only to visualize the differences, but it also shows you detail properties that allow you to dive into the numbers. This functionality was introduced with SQL Server 2016, and… Continue Reading

Filtered Index Basics

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In this post, we continue with another beginner’s blog of database features that may be unknown to many. Let’s take a look at filtered indexes. Many database administrators are fully aware of the power of indexes and know how to create them. However, I find that some have yet to dive into fully optimizing their indexes and taking advantage of what filtered indexes has to offer. What is a filtered index? Simply it’s an index with a where clause. It is an optimized non clustered index that can be narrowed down in scope to better fit a subset of data.… Continue Reading