Know Your Numbers

    By: Jonathan Gennick on Feb 27, 2019

    Know Your Numbers.png

    By Jonathan Gennick

    Every business has numbers that matter. Take the cache-hit ratio as an example. Any DBA in the 1990s worth their salt knew their hit ratio and it was a common topic of discussion. Today that number is somewhat discredited, though a recent article on The Notorious Database Cache Hit Ratio by Guy Harrison shows that the cache-hit ratio can still be a useful metric, just perhaps not quite in the way as was envisioned two decades ago.

    Proper interpretation is everything. Numbers rarely stand alone, but instead must be interpreted in the context of real-world events surrounding them. My conversion rate is one such example that is interesting to share, and provides some insight into the world of book publishing.

    A Real-Life Example

    Readers of my column will remember my October 2018 post on Looking Outside Your Discipline. In it, I describe my journey in drawing inspiration from the field of sales to improve my performance in the world of publishing. Part of my journey has been to diligently track various metrics, and a year has given me enough data to make those metrics interesting.

    My conversion rate is 11%. Put 11 leads into one end of my deal pipeline, and on average I’ll get one signed book contract out the other side. That’s an interesting number to know!

    Furthermore, the rate is consistent. It was 11% in 2018 (Figure 1), and it is 11% so far in 2019 (Figure 2).


    Figure 1. My 2018 conversion rate was 11%


    Figure 2. My 2019 rate through mid-Feb is also 11%

    One way to work the numbers is to think about how many additional books I need to enter my pipeline for each contract signed. The number is 10 … because 1 / 11% = 9.09, and we round up in this case. Every contract signed needs to be replaced with at least 10 new leads, in order to keep the pipe full and deals progressing so I may hit my publishing targets each year.

    Context is Everything: How to Interpret the Numbers

    An 11% conversion rate is neither good nor bad. It simply is. I could reflect on whether to try and influence the rate one direction or the other. Or I can just let it be and work the numbers.

    I’m very much reminded of cache-hit ratios. They simply are, in the same sense that a conversion rate simply is. My conversion rate in isolation is neither good nor bad, but taking note of changes can be interesting. For example, my conversion rate this week suddenly dropped two full points from 11% to just 9%. Why? Am I targeting bad leads? Have I lost my ability to persuade? Is it possible that the drop to just 9% is really an improvement? That latter possibility seems counterintuitive, but keep it in mind.

    The answer to these questions lies in understanding the workload. My management has tasked me with publishing more first-to-market topics. The newness of such topics means that most who blog, Tweet and otherwise come to the surface as author prospects are not qualified to write on these topics. The quality of my leads has fallen due to the sheer newness of the topics I’m chasing. From that perspective, my falling conversion rate is indeed an improvement, because I’m executing the workload that has been assigned.

    The same thinking applies to cache-hit ratios. A higher or lower hit ratio is neither better nor worse in the absence of any surrounding story or business context. A low hit ratio is precisely the correct ratio if the database engine is performing the very work you need the engine to perform. Only when you understand the workload and the business context can you properly interpret whether a change in a ratio is good, bad or indifferent.

    Identifying Value

    Know your numbers. The explosion in business intelligence and data visualization toolsets that we’ve seen in recent years only emphasizes this point. Metrics have value, and often the value is only apparent in the context surrounding the number you’re interpreting.

    Here’s a challenge: Is there a new number this year that you can begin to track that might provide you with valuable insight after a year’s accumulation of data? Consider picking just one new metric – something you’re not currently tracking. Add the habit of tracking that number to your daily routine. See what happens in a year’s time. You might be pleasantly surprised.


    Jonathan Gennick
     is the Apress editor responsible for the IOUG Press, a cooperative publishing arrangement between Apress and IOUG with the aim of providing the very best in content for IOUG members and other Oracle professionals. Learn more at

    Released: February 27, 2019, 11:49 am | Updated: March 5, 2019, 10:46 am
    Keywords: IOUG Press Corner | analytics | IOUG Press | Writing Tips

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