As the information about how to write software continues to grow on the internet a trend is emerging where software developers are able to write software without really understanding how what they have written works. They are able to copy code snippets from an example, modify it slightly to meet their needs, and plug it into their software without knowing […]

SQL Server Database failover strategies include built in solutions from Microsoft. However, there are some third part failover tools operating outside of SQL Server with different kinds of results. SAN Storage is a popular device for SQL Server data because of performance and high availability built into the SAN itself. It scales to a very large size, and allows for […]

SQL Server Always On was introduced in SQL Server 2012. It combines features of previous failover mechanisms such as database mirroring and database clustering. Always On uses the same concept of database mirroring, expanding the concept from a Primary and a single Mirror to a Primary and multiple Mirrors. Always on replicas work by the primary database transaction log entries […]

SQL Server 2005 introduced a database failover technique new to SQL Server; Database Mirroring. Oracle already supported mirroring. Database mirroring requires two instances of SQL Server, usually on different machines and drives for redundancy, assuring that modifications from the primary database are duplicated to the mirror database. When outage occurs on the primary database the mirror will take over. Clients […]

Windows clustering was introduced in the late 1990s. SQL Server was added to the clustered applications supported I a Windows cluster. SQL Server 2000 made SQL Clustering really popular as a failover strategy. With clustering you have a shared disk subsystem such as a SAN. Other methods can be used, but a SAN is the most common shared method. Only […]

Recently I was talking with a few SQL Server professionals about what failover strategy they employ? The replies were quite different; This conversation emphasized to me why products such as SQL Server have so many failover strategies because each method has different characteristics. The key driving factor behind the failover method you choose is, "how much time can you afford […]

I was watching some of the online training you can access here on SSWUG. Denny Cherry has a series on Windows, SQL Server and SANS with the goal of helping create an installation that is fault tolerant and performant. One of my favorite parts of the training is when Denny reminds us that our Disaster recovery plan is much more […]

Today I had the pleasure of flying across the USA with my family. I hadn’t been to an airport for a while so I had a lot of fun watching how different people interacted. There appears to be a whole new culture in airports where you can see an electric socket with dozens of people surrounding the source, hoping to […]

The un-documented stored procedure sp_msforeachdb found in the Microsoft SQL Server database msdb has been documented on the internet by developers for years, and it has grown in popularity by those who have found it. It is extremely useful in that you can define a query and then have it executed on every database installed on an instance of SQL […]

Developers following Microsoft standard development methods are likely to utilize an Identity column as a primary key in their lookup tables. This method is simple, and guaranteed to be unique. The practice has a number of pitfalls. One pitfall is what happens when you have multiple databases containing the same lookup table, and you want the assigned key value to […]