Monthly Archives: July 2009

It’s Just Too Noisy In Here

Posted on by
2

Until last night, I was following over 1100 people on Twitter. I love Twitter, but lately, I am feeling increasingly like every-time I open Twirl, I am being screamed at by 100 people at once.  It was becoming all nigh to follow what the people I really care about (@MrsAngell, @ChrisSaad, @michaelmcneill,  @DallasClark and @StephenKelly to name a few) where talking about.

Basically, as much as I’ve loved talking to you all, I just can’t keep it up.  In a society which is approaching economies of scarcity, I have reached a saturation point where my Twitter value is dropping because I can’t hold meaningful, deep, 140 character conversations with people anymore.  My Social Graph has become so wide that it barely holds definition anymore.  Too many trivial relationships, talking too loudly.

So starting last night, I’ve started a mass excommunication of my followers.   I have already culled over 300 people (thanks to Twitters recently improved interface tweaks).

Twitter _ People AshleyAngell is following

I am trying to be selective.  If you have *something* in common with me, professionally, personally, intellectually or geographically; then you’re probably safe.  I will an try to ensure that I follow people I converse with (so any @ replies count).

So, I am sorry if your one of the exiled, It’s not personal – It’s Just Too Noisy In Here!

Update

Twitter _ People AshleyAngell is following-1

Extracting Specific Date-time Components in Postgres

Posted on by
Reply

When programming, sometimes it’s useful to extract various time components from a Date-time field in SQL queries.  For example, you might want to filter the date field by, hour, or year (or both).  Fortunately, Postgres has a easy way to pull this data out within the query itself:

SELECT EXTRACT(hour FROM a_datetime_field) FROM a_table;

If the field was the value ‘4/5/2009 13:09:00’ then that above query would return “13” in the select.

In a stranger, practical example, I was moving a database from one server to another and for some unknown reason, all the dates in a table were fudged so that instead of being the year 2009, it was 142009, and the seconds were also stuffed up – the result being that any queries I ran against the table threw ADO.NET exceptions because the dates couldn’t be parsed properly.  I needed to run a query like this one to set things right again:

update atable
  set datetimeadded = cast( '2009-' || EXTRACT(month FROM datetimeadded) || '-' ||
    EXTRACT(day FROM datetimeadded) || ' ' || EXTRACT(hour FROM datetimeadded) || ':' ||
    EXTRACT(minute FROM datetimeadded) as timestamp),
  datetimeupdated =  cast('2009-' || EXTRACT(month FROM datetimeupdated) || '-' ||
    EXTRACT(day FROM datetimeupdated) || ' ' || EXTRACT(hour FROM datetimeupdated) || ':' ||
    EXTRACT(minute FROM datetimeupdated) as timestamp);

The casts are needed to get the update to cooperate, but basically this recreates the date time piece-by-piece based on the original date-time value.

Better way to get the Scheme, Host and Port from Uri Object in .Net

Posted on by
Reply

Recently I was working on a project where I needed to strip the scheme, host and port (if it wasn’t 80) from a Uri object. Obviously I could have used string concatenation to get the value I needed, but it just seemed so ghastly and inelegant. In frustration and annoyance that it wasn’t part of the standard Uri object definition, I asked a friend who gave me this little gem:

side effect of clomid

Uri uri = new Uri("http://localhost:6767/h/ello.php");
string url = new Uri(uri.AbsoluteUri).GetComponents(UriComponents.SchemeAndServer, UriFormat.Unescaped);

The string, ‘url’, will (in this example) hold the value “http://localhost:6767”. This works in .Net 2.0 and up, and with .Net 3.0, you could even create a static method extension to make it even easier.

Sometimes, Microsoft Gets it Right (The .NET Framework 4)

Posted on by
2

Parallel Programming are two words which are not nearly used enough by programmers today. I think this is partially due to the fact that most developers are answerable to management types who simply “want to get the job done”. It’s also highly susceptible to deadlocks, race conditions and other problems, which are somewhat more avoidable in traditional single-threaded-apartment model applications. The problem is, that we’ve reached a precipice in CPU architecture where CPUs are scaling out instead of up. In other words, instead of simply working harder and faster, they’re working smarter – executing many simultaneous operations.

The only problem with this is that applications need to be programmed to capitalize on this architecture – and making Multi-threaded applications easier is obviously on Microsoft’s mind with the announcements of features in the upcoming The .NET Framework 4.0.

One of the main the main features I am looking forward to is the Parallel class to easily thread simple loops. This Parallel class represents a significant advancement in simplistically managing loops.  The .Net 4.0 team assures us that “for many common scenarios, it just works, resulting in terrific speedups”.  A similar technique can be used to write parallel loops over iteration spaces of non-integral objects.

Parallel.For(0, N, i=>
  {
    DoWork(i);
  });

There are also overhauls to the ThreadPool class (which was in dire need of serious attention) and the inclusion of “Tasks” – simple generic types which assist developers in creating native IAsyncResult objects: this means that Task can be used as the core of a Begin/End implementation.  They’ve also really thought about these improvments, with easy and clear ways to cancel parallel operations, as well as a number of great ways to handle Exceptions within parallel blocks.

There are of course other advantages to the 4.0 Framework, but it’s the big emphasis on easing MTA (Multi-Threaded Apartment) model application development that’s got me excited.

Enjoy!