Developers and DBA’s

October 20th, 2009 § 0

How well do you know your database server?  And no!, I’m not talking about favourite colours, favourite things to do, or other first date questions here… I mean how well do you know the technology behind your database server and what makes it tick?  Many developers out there focus on the web and application layers and only look to the database layer as a persistence medium.  At least until they need to get a LOT of data in or out in a hurry that is…

More often than not, small companies can’t afford to have a dedicated database administrator (DBA). So it often falls to the technical operations guy/gal and the developers to manage the company database(s).  I’ve been in the position of one of those developers, where looking after databases was more of an add-on task than any official duty, and that experience has taught me that a good DBA is worth their weight in gold.

Every developer should get to know at least one database technology intimately because your database can do a lot more for you than just persist data.  Get to know the engine of your database server: how it works; how it makes decisions on query plans; different algorithms for joining and grouping data and how it all evolved.

As an example, have you ever written a program that processes data on-the-fly and batching bulk-inserts?  Assuming all that bulk-inserted data goes into a set of tables that will later be processed for rollups, you’ll have some indexes on those tables, so that the rollups run faster… right?  Well those indexes will have a dramatic performance impact on your bulk-insert operation… I’ve learned that when processing large amounts of data for crunching rollups later on… only create the indexes just before you need them and then drop the indexes again afterwards.  The reason is that the bulk-insert is probably going to be the long-running operation and writing to a table with 3 indexes across columns can take 2-3 times longer than writing to a table with no indexes.

My database of preference is SQL Server because I’ve worked with Microsoft technologies all my working life and found the tool-sets generally hit the mark on best compromise between functionality and easy learning curve.  SQL Server 2000 was the top dog around the time I was finding my feet and an invaluable resource was Kalen Delaney’s book Inside Microsoft SQL Server 2000.  I have *huge* respect for the team that created one of the first databases that was capable of running on desktop computer hardware, whilst having a .dll/.exe footprint in the order of 10’s of Megabytes and, to this day, is capable of managing databases in the order of Terabytes!

A standard PC more expensive than a high-spec PC?

August 11th, 2009 § 2

A couple of weeks ago, I wrote about how developer’s need faster hard disks.  Now I’ll try to expand on that and build a case for how much it might be costing you to continue using that standard build corporate development PC.  You’re probably like many other developers out there and using a standard-build office PC, possibly with a little boost of RAM to allow you to run some local databases along with your development environment.  Of course, this is all assuming that you are like most developers out there that use a PC purchased and supplied by your company.

If you’re like me and work with .NET for most of your day and spend time developing with Visual Studio, you should start paying attention to how much time you end up waiting for your PC to complete any operation that makes you wait.  (This also applies to PHP or Java developers, using Eclipse or any other Java-driven development environment.)  For example, switching between Code and Design view can cause long waits on complex projects.  What about cleaning, compiling and debugging your code?  Starting up your browser? Hitting an exception and switching to debug in Visual Studio?  All these little waits add up and 10-15 cumulative minutes of your day spent waiting is not an unrealistic figure.

So what is a Developer’s time worth? 

Here are some assumptions, based on the UK market average salary for a “.NET developer” (avg. salary taken from itjobswatch.co.uk) UK average .NET developer salary is £34,000

If we take our worst case estimate of 15 minutes spent “waiting” each day, then we can extrapolate the following based on a 37.5 hour week: 15 minutes per day equates to £1,133.29 per year

The best case estimate of “waiting” 10 minutes each day:10 minutes per day equates to £755.53 per year

Now looking at the Dell website (I’m not biased towards Dell in any way and I’m only using them to provide a quick comparative cost), an Optiplex 960 with the following specification:

  • Intel Core 2 Duo E8400 (3GHz, 1333MHz, 6MB)
  • 4GB 800Mhz Non-ECC DDRII Memory
  • Drive 1: 74GB 2.5 inch Serial ATA (10,000rpm)
  • Drive 2: 160GB 2.5 inch Serial ATA (7,200rpm)
  • Intel Graphics Media Accelerator 3100 with a maximum 256MB of shared video memory
  • 16x DVD-ROM
  • Vista Ultimate SP1 32-bit (free upgrade to Windows 7, or add £5 to downgrade to XP pro SP3)
  • 3yr warranty next business day

This costs £873.00 excl. VAT (and businesses would claim back VAT anyway) at today’s prices – 11 August 2009.  This desktop spec is targeted at a typical web-developer.  If you’re going to be doing any serious graphics or .NET WPF, consider adding the “ATI Radeon HD 3470 256MB DDR2 full height DVI/VGA Output” for an extra £97.00.  I’ve left out the monitor, keyboard and mouse because you should have those on your current machine.  We’re pricing an upgrade here, with the aim of passing your standard-build back into the office pc-pool.

No matter how high-spec the new PC, its never going to perform operations instantly, so we’re never going to save ALL of that 15 minutes per day.  Even if we could reduce it to half the time, or less, then this exercise is probably worthwhile.  Most IT business cases that I have seen, want to pay themselves back within 3 years, and as long as we can shave at least a third off that “waiting” time, then we’re in business!

There’s also an additional benefit that is harder to attach a price to.  When typical developers end up waiting for a long-running task to complete, they probably context-switch themselves onto another task to try and keep up efficiency.  I firmly believe that any serious development should be done without distractions (I’ll save the detail for another post), and this “context-switching” could be considered a distraction.  What if you forget to go back and finish some task after switching over to reading an email, for example?  Maybe you’ve just inadvertently introduced a bug…?  How much time and money does that cost, since it might affect you, as well as anyone else involved in checking or using your software.

So development team managers:

Take another look at the equipment your team is using and ask yourself “how much are those standard-build PC’s really saving me by being cheaper than a higher-spec version?”

Developers! Search engine optimise your CV

August 5th, 2009 § 0

Avoid employing unlucky people – throw half of the pile of CVs in the bin without reading them. (David Brent)

The UK recruitment industry turns over approximately 27 billion pounds a year in the UK (most likely pre credit-crunch times though).  That would tend to suggest that most employment or contract vacancies are filled through agencies.  That’s an incredible number of posts filled by recruitment agents.  The industry is extremely competitive and agencies want to be the first to find the ideal candidate and get their CV introduced to a potential client before any other agency beats them to it.  IT recruitment in particular is a very busy segment of the market and the content of this article probably applies more to technical professions because they’re filled with jargon and technical keywords.

So how do the agencies find the ideal candidate as efficiently as possible?

prove_myselfWell for starters, most agencies will keep a database of CV’s that have been submitted by candidates recently or in the past.  There are also job boards, such as Jobsite, Jobserve and Monster (in the UK) where candidates are able to upload a copy of their CV and apply for positions directly from the job board website.  Candidates may also make their CV available to be searched by recruiters via the job board.

The key concept here is that agencies search a database for your CV.  Whether its their own in-house database that has been built up over time or a job board database, the agency is forming a query and executing a search to retrieve a list of candidates.  That might be an obvious point to make, but if its so obvious then why don’t we make use of it.

Keywords

In my case, I am an ASP.NET programmer, so as a minimum, I would ensure that my CV is focused on the core .NET keywords and closely related technologies: ASP.NET, .NET 3.5, C#, VB.NET, SQL Server, LINQ.

Don’t forget little things like version numbers. The “3.5” in there might just make the difference… I’m a practical, common sense driven programmer and I might know that a hiring senior-developer worth their salt could figure out that LINQ would imply that I am familiar with .NET Framework 3.5. However, most recruitment agents are not technical and you can probably bet that if they have a brief from their client that mentions ASP.NET 3.5, they will be searching for “ASP.NET 3.5”.  If your CV mentions “3.5” and another one in their database doesn’t, then you can probably also bet that if they were displayed in a list on the recruiters screen, the CV with “3.5” in it is going to be higher up in the list…

Most candidates are probably going to mention their core competencies in their CV and one focused solely on “.NET”, “ASP.NET”, “3.5”, “HTML”, “CSS”, “XML” is probably going to be pretty common among the thousands of others that mention the same general skill-set.  This is where its worth dropping in names of more specific products that you’ve worked with where you applied your core skills.  For example, you may have worked with object-relational mapping technologies like NHibernate and SubSonic, or web content management systems like Sitecore, Interwoven or Umbraco – mention them!  Most companies will have some preferred product(s) and will mention it in a brief to agencies as an ideal requirement.  Your recruitment agent will be adding these keywords to his search query.

Common sense

I’ve focused quite a lot on the concept of keyword-targeting in this article to get my point across, but don’t take that advice to the exclusion of all other factors.  You need those focused keywords to help get your CV found by an agency but ultimately your CV must still read well because it is going to be sent to your potential new employer.  A comma-delimited list of acronyms is just not going to cut it!  A CV still needs to be a well structured document and read well, with succinct summaries of your recent work in reverse chronological order, ideally.

Self-correction

Keyword-targeting is SEO for your CV’s.  In an ideal world, I would prefer that things didn’t work this way. “Don’t hate the player, hate the game” comes to mind.  Again, this sort of thing probably applies more in IT-related fields and I’m placing my hopes on the self-correcting nature of an open market.  By pointing this out, possibly more people will start to employ the strategy and force recruitment search algorithms to adapt and improve, so that one day the quality and content of a technical CV will count more than name dropping to get your foot in the door for an interview.

« Older Entries

Newer Entries »