A commonly used example of bimodality dates back to the late 19th century, when a storm killed a large number of sparrows. An ornithologist measured and plotted the wingspans of the dead birds and found that the birds killed in the storm had either shorter or longer wings than the median.

So what do dead birds have to do with a SQL Server licensing audit?

During a recent staff meeting, a member of my team was sharing insights he had gained from attending a boot camp focused on Microsoft licensing. He noted that it was the lead instructor's supposition that the licensing status of Microsoft Enterprise customers generally exhibited a bimodal distribution. One group [mode] was out of compliance. The other group [mode] had spent or was spending more on software licensing then they needed. Like our birds, this deviation from the median creates an unsustainable situation that wouldn't withstand the "storm" of an audit.

For SQL Server users, the median under our bimodal distribution is pretty easy to characterize. It's the place where you are in compliance and you're not spending one penny more than you need to on your SQL Server software licensing. For our two modes, it's getting to the median that's the tricky part.

Microsoft's licensing rules are very complex. Many tomes have been written on the subject and no single article can cover everything about licensing. But here are three tips that will get you moving to the median of the Microsoft licensing bimodal distribution curve for SQL Server.

1. Be pro-active and understand what you've got

This first step is critically important to getting your company in the optimal spot on the licensing bimodal distribution curve for SQL Server—in compliance and not over spending. Unless you are a very small shop, you're going to need a software asset management tool. There are a lot to choose from. Microsoft offers the Microsoft Assessment and Planning (MAP) Toolkit. It's free and designed to support network-wide automated discovery and assessments for SQL Server. If you think you need outside help, there are also a number of independent consulting firms and resellers, such as Insight, that specialize in helping customers sort out Microsoft licensing. A word to the wise: this should come as no surprise, but Microsoft is investing significant resources in its compliance efforts. The goal is to find additional unrealized revenues in its customer base. Successfully completing this step will help you understand if your company has a compliance issue.

2. Reduce your use of Enterprise edition

One of the key outputs you're looking for from step one is a report that breaks down the number of SQL Server licenses in use by edition. The two numbers you want to pay particular attention to are the mix of Standard and Enterprise editions in use. Why? Because the cost of the enterprise edition is more than 3X the cost of Standard edition. We have two cases (bimodal distribution modes) to consider:

  1. Out of compliance

Under this case, you've done the assessment and have determined that you're using more SQL Server than you've paid for—not a good feeling. The questions that you want to be asking are: Do we need this SQL Server license? Can we consolidate SQL Server instances? Why are we using Enterprise edition? Consolidation of SLQ Server instances and minimizing the use of Enterprise edition is the playbook for success under this case.

  1. Spending too much

For this case, it turns out that your playbook is the same—consolidation to free up licenses for future projects and minimizing the use of Enterprise edition. You just have a different time pressure as a starting condition—unless you have an Enterprise Agreement (EA) coming up for renewal, you've already spent the money.

3. Determine if Software Assurance (SA) is worth the cost

SA is a software maintenance program for Microsoft products. It entitles the user to upgrade rights on an original license. SA is a three-year product and has to be purchased at the time you bought the original license. It generally costs 29% of the full license price per year. Remember you have to buy a different product to get premium support. For SLQ Server users it also provides additional benefits for virtualized environments. A great general discussion on SA can be found in Microsoft software licensing: Seven deadly sins and another discussion in SQL Server 2014 Standard Edition: 3 Misconceptions You Can’t Afford. Bottom line: unless the applications that require SQL Server will definitely need to be upgraded to a new version of SQL Server in three years, avoid the cost.

These are best practices that we have seen work for our customers. You may already be doing them or thinking of doing them. That's ok—as long as you survive the storm.