Database maintenance is very important, a critical part of our database administrators’ daily tasks. However, this aspect is frequently underestimated which could lead to performance problems and respectively angry, unhappy customers. In this article, we will take a look at the different maintenance operations we have in SQL Server and how we can optimize them and take the maximum out of each.
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SQL Server provides you with a good solution to automate a lot of your administrative tasks using the SQL Server Agent jobs. These jobs are handled from the operating system side by a Windows service that is responsible for executing these jobs and feeding the SQL Server systems tables with the metadata about these jobs. The system database that is used by the SQL Server Agent for the job management called the msdb database. All information related to the job steps, schedules and the history can be found in the msdb database tables. The msdb system database is also responsible for the SQL Server Mail, Service Broker, SQL Server Maintenance Plans and the databases backup history.
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More often than not (at least in places I’ve worked at), the job of installing, configuring and subsequent administration of Team Foundation Server (TFS) is performed by different individuals to those administering enterprise applications such as Windows Server, SQL Server, SharePoint etc. This is because TFS, unlike other enterprise applications, often has to be administered from both the server side (i.e. TFS Administration Console) as well as the client side (i.e. using Team Explorer in Visual Studio) – it is thus not surprising that a TFS administrators may once had been a developer. The benefit of having a TFS administrator with a software development experience is that it may be easy to get developer-buy-in into the tool. However, the disadvantage to this is that developers usually get accustomed to doing things in a certain way – like connecting to SQL Server using (local) convenience names.
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One of the more difficult challenges we face when analyzing data is to effectively identify and report on boundaries. Data sets can contain any number of significant starting and stopping points that may indicate significant events, such as missing data, important business events, or actionable changes in usage. Regardless of the use case, knowing how to quickly locate and manage data boundaries is extremely useful. Knowing how to design solutions that can effectively avoid these scenarios can also be helpful in the long run.
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Gaps existence in automatic sequenced columns occurs all the time. Missing identity values (or other sequencing values) occur for a variety of Reasons.
The most common reasons include: roll backed transactions, failed inserts and Deletes, large row deletes after delete commands that occur after many inserts to a sequenced table and so forth.
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The SQL Server backup provides an important solution for protecting critical data that is stored in SQL databases. And in order to minimize the risk of data loss, you need to make sure that you back up your databases regularly taking into consideration the changes applied to your data. It is a best practice to test your backups by restoring random backup files to a test environment and check that the backup files are not corrupted.
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Continuous integration (CI), in the context of databases, refers to the practice of isolated database changes to be integrated, as soon as they are made and pushed to a source control repository. In the early days of CI, daily integration was a rule of thumb to follow. However, today, it is more common, than not, that database changes are integrated several times a day. Each change needs to pass an established testing plan that executes automatically on detected changes committed to the repository and if everything is ok, changes will be automatically merged using the build script. with the remaining code, into a new build that will be pushed to other environments (i.e. production, QA).
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Many times the people focus on the user databases to improve the performance, but sometimes the problem is not the user database itself. Sometimes the problem is the tempdb.
In this article, we will give a brief introduction about the tempdb database, show how to create some temporary objects there and show how to improve and monitor it.
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One of the primary functions in Business Intelligence is to enable business users to understand the nature of data generated by their business systems. For instance in an insurance industry, a business case in a policy claims department would typically involve understanding the number of submitted vs outstanding documents required to successfully process a claim. A denormalized relational representation of such a business case would look as shown in Table 1: Read more »
If you are a DBA and you have one single server with SQL Server to administer, backup the database is a simple task. However, there are several companies with hundreds and some with thousands of Servers with SQL Server. To handle multiple SQL Server backups at the same time is a nightmare.
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When talking about performance and scalability inside SQL Server, I don’t see anyone missing out on the fact to mention how locks get involved. I often see DBA’s complain to developers that their code is not scalable and they are experiencing heavy locks in the system because of the way the code has been written. The more I work with SQL Server, the more I start to understand some of these nuances.
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There are multiple editions of SQL Server 2014 (Enterprise Edition, Enterprise Core Edition, Business Intelligence Edition, Standard Edition, Web Edition, Express and Developer Edition). SQL Server 2014 has a free edition – Express and while the server itself lacks some options that other editions have, SQL Server 2014 Management Studio is the same and can be used with each of these. Read more »
Checking the many SQL Servers health conditions is one of the DBA basic tasks. Monitoring many servers and databases, day after day can be a very tedious job. There are many aspects to look for when checking the server performance figures. Such aspects include among others: CPU, Read and Write Disk counters, Various memory counters and locks performance counters. The DBA needs a tool that checks the most important counters and output a report that states whether the server is considered to be healthy or not. For every aspect, a counter is chosen to represent it to be included in the overall report.
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We have a series of views in our organization’s application database. The views definitions are all static queries that consist of few or many condition clauses.
When the application first started with the initial data, the views operated normally, but after a while, after a period where data volume increased, the application’s performance time, through the views usage, degraded.
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As DBA’s we usually have a lot of utility scripts sitting around that we use in our daily work. Examples might include things like common administrative duties (setting up users for an application for example), installing standardized maintenance routines, or even something as complex as a home grown utility database. Often times these scripts languish on some network share or (worse) our own computers, with previous versions lost for all time when changes are made. For those of us that come from a development background, this approach makes us shiver. Keeping code that is not in some kind of version control system is inexcusable for any level of software professional, and DBA’s should be no exception. Used for quite some time by software developers, version control is a wonderful tool for administrators as well, for reasons we will discuss. But first, I want to talk a little bit about my version control system of choice, Mercurial.
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Working as a DBA, the simplest task requested from you is installing SQL Server. As a start you will check the server’s hardware and software specs to make sure that you can start the installation, checking which services will be installed and the security authentication type required. After this pre-installation plan, you will start the normal installation process.
After completing the installation, you need to apply specific configurations on the server to make sure that the server can host production databases and the users can connect to it successfully.
In this article, I will describe the common configurations that you should apply after the SQL Server installation.
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Filtered indexes are well documented, as they have been around in SQL Server for almost six years now. Despite their longevity and usefulness, discussions of them tend to be very simple overviews using simple queries and not digging too deeply into more precise costs and benefits. This article is inspired by a production problem that cropped up recently involving a filtered index that illustrated that general knowledge of their function was not as complete as it should have been.
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The Problem demonstrated here describes a very common scenario. The IT Security group orders all programmers that all the dynamic input strings that comes from user input to be checked for suspicious SQL injection intentions.
SQL injection is a code injection technique used to attack data-driven applications. During the attack, malicious SQL statements are inserted into data entry fields for execution inside the database engine.
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Because databases aren’t always designed efficiently, data is sometimes stored in ways that make sorting and searching extremely difficult. Requests for meaningful, informative reports from such data, however, still must be fulfilled.
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In a previous chapter, we learned how to use the Tuning Advisor to analyze queries and receive recommendations about indexes, partitions and statistics. In this new chapter, we will learn how to use the command line tool called DTA. The DTA is the command line of the Tuning Advisor.
The DTA is a very powerful tool that can be used to automate some tuning tasks. It can be used combined with the SQL Agent, SSIS, or customized and external tools like programs made in C# or Java.
In this article, we will show how to use this tool.
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