Tesmond's Useful Design

Well made a new interesting discovery today. Combining TOP with ORDER BY can severely slow down a query. I was looking into a slow query which was taking around 10 seconds to return 69 results. It was getting the "TOP 100" from a specific date range and then ordering by ID descending. It was fascinating to me to discover that removing the TOP 100 returned the results in 0.005 seconds. Removing the ORDER BY instead of the TOP 100 also resulted in again producing the results in 0.005 seconds. So the moral of the story is don't use TOP and ORDER BY if you want your results back quickly. I have no idea why this kills performance right now, but it is perhaps even more interesting that even though the query TOP 100 ORDER BY ID ASC results in the same set of results as TOP 100 without an ORDER BY command, it takes 8.8 seconds rather than 0.005 seconds. There are definitely some huge optimisations available in respect to these queries. Update Well after reporting this t...

Photographer :  Cindy J Grady I have been lucky enough to experienced using keyboards on iOS, Android and Windows Phone (8 and 8.1) which has really shown me how important a good input method is in the mobile experience. Each keyboard has unique features which makes choosing the best keyboard a bit of a struggle. Until recently I had completely dismissed iOS keyboard for the following reasons 1. 4" display means that the keys are harder to press accurately 2. Selecting & deleting words is trickier than both Android and Windows Phone not just due to the smaller target area, but also the implementation requires a "long press" to activate the magnifying glass to achieve accurate cursor location. 3. Lack of swype / shape writing style input. While options 1 and 2 were of just minor inconvenience option 3 is a major issue. Swyping / Shape writing There are three great features of shape writing 1. It is a much faster input method on the whole than key p...

Is saving a few seconds really important? Image by  FracFx While practically any change, no matter how sure you are that it is a positive improvement, can be met with anger from the user base performance improvements are not one of them. In an ideal world all webpages would appear the instant we demanded them, however achieving good performance has costs, and those costs need to be offset against the benefits. Features and complexity sells and performance is just one of those features which can be easily ignored and tough to sell, especially if it is say the difference between 10 seconds and 5 seconds. The benefits of speed are often underrated and can be difficult to appreciate. For example a fast application is easier to use, not just because of the reduced frustration of waiting, but because it is easier to explore. If you click in the wrong place as the next piece of information appears instantly you can easily explore the options on the page. If every option takes a...

I always consider the primary constraint in software development to be time. While technically this constraint could be considered a function of money, it is difficult for a developer to assert direct influence over budget. Most organisations require developers to go quite high up the chain of influence in order to try affect the proportion of budget development have access to. Supply and demand factors for the product that development are supplying is difficult for them to directly influence, in most corporate structures sales and marketing are the real influencers of this factor. Yes they rely on the quality of product that development provide, but it is unlikely that and improvement in the product quality will have an equivalent impact on sales. The ability of sales and marketing to reach new customers and alter demand is a much more influential factor. It is one of the great features of software development that you can essentially do anything the customer asks for, but only if y...

In previous blog posts I have mentioned that Cache has good write performance, in fact in certain circumstances it is faster than many other databases. However, it is rarely the case that optimising performance is not desirable. Every one loves a performance boost, it is the most universally loved product change. The closest I have ever experienced to a complaint about a performance boost is "its so fast I didn't believe it had worked". Any way I was working on improving query performance on a server when I noticed some intermittent slow down. I traced the performance issue to a task which performs a huge burst of write operations. The write operations were so heavy that the rest of the server was experiencing slow down. Obviously the code is under review to see if the amount of data being written is necessary, but I was curious about optimising the write operation itself. With read operations I have noticed that dynamic SQL is slower than compiled SQL which is i...

As of today (17th July) CyanogenMod 11 is only available in a semi-functional version. With both GPS and the camera not working it could not be considered a daily driver, and of course there are plenty of other minor niggles. Samsung has introduced lots of great features in its latest version of TouchWiz, and I have always liked the swipe left and right on contacts to send a message or initiate a phone call since it was on the original Galaxy S, but this single likeable feature is does not compare to stock Android. The cleaner look, the instant responsiveness and now with Android L the promise of better battery life we all know that TouchWiz cannot compete. So far I have turned off most of Samsung's proprietary functionality, and found the finger print scanner and heart rate monitor to be next to useless. The Galaxy S5 is still the best phone I have ever owned, but a Google Play edition or CyanogenMod would be a massive step up in usability, speed and enjoyment.

When I first started my current job I was told that the database was an Intersystems database, I had not heard of this before on researching it I found out a number of things. 1. It was ranked number 63 on DB-Engines most popular databases 2. Cache is not a good name for a piece of software if you want to find information in Google 3. There was a distinct lack of examples and people discussing real code This 3rd issue is perhaps the most important. In programming most of what you want to do has been done by thousands of people before you. Want to parse a CSV file, well if your language does not have a built in function someone will have posted a solution on the internet. Not only will you have a working solution it will probably have been commented on by a number of programmers and improved to a level which would have probably taken you several live iterations to achieve. The code examples in the documentation are basic, out of context and ignore even simple advise on field fil...