Iteratively Perfecting

Database DEnormalization and Violating Simplicity Principles

2010-03-16T14:52:00.000-07:00

Timothy Claason, at SQL Server Central, writes:

"Denormalization is not a design strategy. It is a design work-around. Well
normalized databases represent a good design strategy, but can often lead to a
great deal of complexity when it comes to support, maintenance, and new
development. A well designed database can mean that, in order to get specific
data you need, you need to go through 5, 10, or even more tables which represent
the data you're looking for. Though there are many solutions to this dilemma,
such as virtual tables (views), programmatic solutions, temporary tables, and
more, I think it's important to not discount the value of well-placed
denormalization in the database. The intent of this article is to consider some
use cases for denormalization, and from those use cases, assert some
generalizations about when and why to use denormalization."

Continued

File Hash Checker

2010-03-10T11:22:00.000-08:00

Download here

This is a simple utility I wrote that displays the hash code of one or two files, and then compares them to see if they are the same. I used this to find duplicate image files (where the names of the files could be different).

Conditional Compilation

2010-03-05T12:47:00.000-08:00

#define test = true
class TestClass {
void test() {
#if test
// do something
#else
// do something else
#endif
}}

Here's the equivalent code in VB.NET:

#Const test = True
Class TestClass
Sub test()
#If test
'do something
#Else
'do something else
#End If
End Sub
End Class

Here's the same but using the DEBUG constant which is automatically set by Visual Studio based on whether you are in debug mode:

Class TestClass
Sub test()
#If DEBUG
'do something
#Else
'do something else
#End If
End Sub
End Class

Software Testing

2010-03-05T12:38:00.000-08:00

Unit Tests
The major benefits to be had from unit testing are

1. It allows the developer test parts of an application without waiting for the other parts to be available.

2. Exceptional conditions can be tested for the unit

3. The debugging process is simplified by limiting the search for bugs to a small unit rather than the complete application.

4. It helps avoid lengthy compile-build-debug cycles when debugging difficult problems.

5. Detection and removal of defects can be done at a much lower cost.

Integration Testing
The purpose of this kind of testing is to verify whether the major subsystems of the application are integrated. It helps in uncovering the errors that may arise due to conflicts between different units of an application. Integration testing is performed in different ways.

Bottom Up Approach: The testing is commenced from the smallest subsystem and progresses up the hierarchy to cover the whole system. This methodology requires the developer to write a number of test driver programs that test the integration between the subsystems.

Top down Approach: This begins at the top. The top level interfaces are first tested and then the smaller sub systems are examined. Stubs are written for modules that are not ready for testing.

Umbrella Approach: The focus in this methodology is on testing the modules that have a high degree of user interaction. Stubs are used in place of process intensive modules. This enables the developer test the graphical user interface and improves the functionality of the interface.

Regression Testing
Regression testing is performed whenever the program is modified. The process involves the rerun of all the tests mentioned in the preceding sections. It has two main goals:

Verification of known bugs that were corrected
Verification of new bugs.

Testing International Applications
Applications created for international usage are to be tested by checking for the language, the country and dependencies. The following factors are to be considered when testing such applications:

Whether the application’s data and user interface conform to the locale’s standards for date, time, numeric values, currency, list separators and measurements.
Whether the application runs on different languages and culture variants.
If Unicode has not been used in the application the culture/locale code of the operating system will have to be set to the localized version of the application.
The Input data in the language should be supported by the localized version.
In this section of the lesson we have focused upon the testing of Windows applications. In the sections that follow we shall briefly look at tracing windows applications.

Javascript Error trapping

2009-02-05T13:58:00.000-08:00


onerror=handleErr;
var noErrors = true;

function handleErr(msg,url,l)
{
 if(noErrors){
  txt="There was an error detected.\n\n";
  txt+="Error: " + msg + "\n";
  txt+="URL: " + url + "\n";
  txt+="Line: " + l + "\n\n";
  txt+="Click OK to continue.\n\n";
  alert(txt);
  noErrors = false;
  return true;
 }
 else{
  return true;
 }
}

Attaching SQL Server .mdb without .ldf file

2008-10-13T10:31:00.000-07:00

If you're using SQL Server 2005:
create a database of equal size to the one you're trying to attach
shutdown the server
swap in the old mdf file
bring up the server and let the database attempt to be recovered and then go into suspect mode
put the database into emergency mode with ALTER DATABASE
run DBCC CHECKDB (dbname, REPAIR_ALLOW_DATA_LOSS) which will rebuild the log and run full repair
Your database will be available again but you'll have lost data and the data won't be transactionally consistent - see the following blog posts:
https://blogs.msdn.com/sqlserverstorageengine/archive/2006/06/15/632398.aspx
https://blogs.msdn.com/sqlserverstorageengine/archive/2006/06/16/633645.aspx
https://blogs.msdn.com/sqlserverstorageengine/archive/2006/06/18/636105.aspx
If you're on SQL Server 2000, you can still do this but you'll need to use the undocumented DBCC REBUILD_LOG at your own risk.

original post on MSDN

Flash Frame by Frame Animation

2008-08-13T12:30:00.000-07:00

Found out two great shortcuts for creating flash frame by frame animation:

1. When you begin, in the timeline, select a whole range of frames and right click, and select "Convert to Blank Keyframes"
2. Turn on Onion Skinning, of course.
3. As you draw each frame, just use the period key to move forward (and the comma key to go back to previous frame).

So much faster and easier!

Flash after 7 years...

2008-08-13T11:46:00.001-07:00

I'm getting back into Flash after about 7 years. I find it inscrutable why, after all that time, the designers still don't want to show the keyboard shortcuts on the menu for inserting a KEYFRAME and a BLANK KEYFRAME.

F5 - Insert Frame
F6 - Insert Keyframe
F7 - Insert Blank Keyframe

Unicode

2008-06-02T12:06:00.001-07:00

Succinctly puts in context:

[edit] Variable-Width Characters
Before UNICODE, there was an internationalization attempt that introduced character strings with variable-width characters. Some characters, such as the standard ASCII characters would be 1 byte long. Other characters, such as extended character sets, were two characters long. These types of character formats fell out of favor with the advent of UNICODE because they are harder to write and much harder to read. Windows does still maintain some functionality to deal with variable-width strings, but we won't discuss those here.

Unfortunately all advantages of using wide characters were lost because the number of characters needed quickly exceeded the 65,536 possible 16-bit values. Windows actually uses what is called UTF-16 to store characters, where a large number of characters actually take //two// words, these are called "surrogate pairs". This development is after much of the Windows API documentation was written and much of it is now obsolete. You should never treat string data as an "array of characters", instead always treat it as a null-terminated block. For instance always send the entire string to a function to draw it on the screen, do not attempt to draw each character. Any code that puts a square bracket after a LPSTR is wrong.

At the same time, variable-width character-based strings made a big comeback in the multi-platform standard called UTF-8, which is pretty much the same idea as UTF-16 except with 8-bit units. It's primary advantage is that there is no need for two api's, the 'a' and 'w' apis would have been the same if this was used, and since both are variable-sized, it has no disadvantage. Although most Windows programmers are unfamiliar with it, you may see increased references to using the non-UNICODE api.

-- from Windows Programming

SearchPlugins for Firefox

2008-05-19T14:03:00.000-07:00

Trying to figure out this baby. In this arena, IE has Firefox beat.

In Firefox, look at the xml files in the following folder:
C:\program files\Mozilla Firefox\searchplugins

So far, to search Amazon MP3's, I've winnowed the search url down to:

http://www.amazon.com/s?url=search-alias%3Ddigital-music&field-keywords=TEST

SQL for Running Totals: The Power of Cross Join

2008-04-01T15:46:00.000-07:00


SELECT 
t.transaction_date, t.amount, t.[description], sum (t2.amount) as RunningTotal
FROM 
cash_transaction_table t 
CROSS JOIN cash_transaction_table t2
WHERE
(t2.transaction_date <= t.transaction_date)
GROUP BY
t.transaction_date,
t.amount,
t.[description]
ORDER BY
t.transaction_date

IE7 and Mathematical Characters

2008-01-09T14:28:00.000-08:00

Certain mathematical characters no longer display in the default font of IE7 unless the operating system is Vista, including the "union" and "element of" characters. To get around this, in CSS you have to specify a different font, and the most common Windows font that works is 'Lucida Sans Unicode'.

Example:

∈

will display fine in both XP and Vista, but
∈
will not display correctly on XP.

Amazon Goes Ajax - New Interface Today

2007-11-15T15:39:00.000-08:00

Well, mark today down in UI design for websites and e-commerce. Amazon.com unveiled their new interface and it is Ajax (particular the Dynamic HTML aspect).

Certified E-Mail

2007-11-15T08:45:00.000-08:00

Let it be known throughout the land, I received my first ever CERTIFIED e-mail today in Yahoo Mail. Will this be a turning point in web history?

The e-mail was from Build-a-Bear Workshop, so parents of young children are probably going to be the first to notice the trend.

Also see:
http://help.yahoo.com/l/us/yahoo/mail/yahoomail/context/context-08.html

Apache losing market share to Microsoft IIS?

2007-11-08T11:21:00.000-08:00

Wow, I was startled to see this graph!

Apache has around a 10% market share advantage over IIS now, which is the smallest gap between the two since IIS was launched in 1996.

src: Netcraft

Idiot's Guide to Implementing Microsoft.Practices.EnterpriseLibrary.ExceptionHandling

2007-11-06T12:59:00.000-08:00

A simple tutorial for VB.NET folks.

Get Enterprise Library 3.0

Install.

In your app, add reference to C:\Program Files\Microsoft Enterprise Library 3.1—May 2007\Bin

Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.dll
Microsoft.Practices.EnterpriseLibrary.Common.dll

If you con't have an app.config file, add one now (you could have this done for you later, but let's keep it simple).

Now open up "Enterprise Library Configuration", a utility installed along with the Enterprise Library that can be found off the Start menu....

Do File/Open... and point to the app.config file in your app.

Right-click the name of your app, select New... and then "Exception Handling Application Block".

Right-click the newly created tree node (it will have a red stop sign with a white X in it) and select New..Exception Policy. Name this "Global Policy".

Save it.

Now, back in Visual Studio 2005, your Try Catch blocks should be changed to the following pattern:


Try
            'for testing: Throw New Exception("This is a sample exception.")
            'put your real code here


Catch ex As Exception
            Dim rethrow As Boolean = Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.HandleException(ex, "Global Policy")
            If rethrow Then
                Throw
            End If
End Try

You should now be able to compile and start playing with the advanced features of the Enterprise Library 3.0 version of the old ApplicationBlocks.

Also see: C# Tutorial.

I Hate Overloads

2007-11-01T11:04:00.000-07:00

I just started working the the replacement for Microsoft's Application Blocks. ExceptionManagement, called Microsoft.Practices.EnterpriseLibrary. Specifically, I'm using the Logging class. Guess how many overloads there are for the Write method? NINETEEN!!! 19 overloads, that's right. Imagine if you did not have Intellisense. In my opinion, overloads undermine the whole organization of Object Oriented Programming (OOP), and are to be used SPARINGLY.

Speech Synthesis with .NET 3.0

2007-10-22T14:17:00.000-07:00

Very simple:
Reference System.Speech.dll


        Dim synth As New Speech.Synthesis.SpeechSynthesizer
        synth.SpeakAsync("Hello world.")

Visual Studio 2005 Code Generation Settings

2007-09-24T10:07:00.000-07:00

Microsoft does not acknowledge the existence of an Option Setting in Visual Studio 2005.

I could not find any mention of the Windows Forms Designer, General, Code Generation Settings, Optimized Code Generation setting on MSDN, nor, surpisingly, on Google. It remains a mystery.

Flash quick notes

2007-09-18T17:07:00.001-07:00

Put this in the Action window (F9) for a movie clip's instance.

onClipEvent(enterFrame){
_x = _root._xmouse;
_y = _root._ymouse;
_alpha = _root._xmouse/10;
_rotation = _root._ymouse/10;

}

Adoption of Widescreen Monitors

2007-09-07T13:42:00.001-07:00

I had a good discussion today with colleagues about the impact of widescreen monitors on application and web design. I am skeptical about the usability of widescreen monitors for readability (due to the well known design principle of narrow text columns increasing readability). I've also noticed that generally stores are discounting widescreens below the cost of standard aspect ration monitors. For all I know, this is because they are having trouble getting rid of them.

Then, seemingly explaining all this, I came across this tidbit:

Philips: Widescreen adoption in LCD monitors not as quick as expected

By: Calvin Shao, Taipei; Carrie Yu, DIGITIMES [Friday 20 January 2006]
Friday, January 20, 2006 15:23

Although panel makers have aggressively pushed widescreen LCD monitor panels, the adoption rate is not expected to proceed as fast as expected, with the penetration rate of the segment now set to increase from 2% in 2005 to 9.8% in 2008, according to Sara Liu, assistant manager of market intelligence, Philips CEBLC-MMFD, Royal Philips Electronics.

Panel makers have rolled out various widescreen monitor panels, as it is more cost-efficient to cut glass substrates from later generation panel plants into widescreen models, rather than into standard (4:3 ratio) panels, sources said.

For example, a sixth-generation (6G) LCD substrate can output four more widescreen 20.1-inch panels than standard 20.1-inch panels. In addition, the utilization rate of the substrate would increase by 15 percentage points to over 90%, the sources indicated.

However, when purchasing monitors, consumers tend to judge the size of a monitor by the height of the model. As a result, widescreen models, which look smaller, may not end up being as attractive to customers, Liu said. In fact, a 16:9 20-inch LCD monitor has a 182 square-inch viewing area, compared with 194 square-inches for a 4:3 20.1-inch model, she added.

Chi Mei Optoelectronics (CMO) was the main producer of 19-inch widescreen LCD monitor panels as of the end of last year. ViewSonic, Acer and CMV all use CMO panels in their 19-inch widescreen LCD monitors.

And I thought it had to do with pushing users to view movies on their computers. Instead, it looks like the marketplace is trying to push users to want to view movies on their computers so that they can sell them the less expensive widescreens.
Or something like that.

Notes from Peepcode tutorial on Prototype.js

2007-08-10T23:11:00.000-07:00

Notes from Peepcode tutorial on Prototype.js
ver 1.5.1

$H()
$A()

for Hash Object and Array Objects

var smedly = {ape:'brown',frog:'green'}
smedly.ape

var smedly = $H({ape:'brown',frog:'green'})
smedly.keys()

$A isn't really needed...
var asmedly = ['ape','frog','toad']
asmedly.first()

Element.hide('smedly')

$('smedly').hide()

$('smedly').show()

$$('boldTextCSSclass').invoke('hide')

$$('a').invoke('hide')

Anonymous Functions:

$$('a').each(takesAFunction)

$$('a').each(function(element){element.hide()})

Other selector syntaxes (generally uses CSS):
$$('a,p') selects both a's and p's
$$('div p') selects all p's in a div
$$('img') selects all images
$$('img[alt=mephisto-badge]') selects all images with 'mephisto-badge' as alt parm
--------------------------------------------------------

Modules
This is pure JavaScript. Create modules using Hashes.

var myHash = {mykey:myvalue, mykey2:myvalue2}

Now just put function in for the key:value pairs:

var HandyFunctions = {hideLinks: function(){}, showLinks: function(){}}
var HandyFunctions = {
hideLinks: function(){
$$('a').invoke('hide');
},
showLinks: function(){
$$('a').invoke('show')
}
};

Note: when you call these functions, even though they are Hash keys, make sure to put parentheses at end:
HandyFunction.hideLinks()

Classes
Note: see Yahoo video for painfully in-depth exploration of JavaScript classes.
Prototype makes it simpler. Just use Class.create() !!
They are similar to the Module concept above, but with some added functionality:
initialize,
parameters that can be passed to functions,
and you can use "this" keyword.

var Butter = Class.create()
Butter.prototype = {mykey:myvalue}

Butter.prototype = {
initialize: function(brand) {
this.brand = brand;
this.melted = false;
},
melt: function(){
this.melted = true;
}
}

var parkay = new Butter('Parkay');

Extend

addMethods

See Quirksmode for list of cross-browser behaviors (onmousever, onclick, etc)

JavaScript Hash

2007-08-10T12:22:00.000-07:00

var animalColors = {'ape':'black', 'pig':'pink', 'frog':'green'}

alert(animalColors['ape'])

alert(animalColors.ape)

Too Many Stored Procedures

2007-08-06T11:05:00.001-07:00

Is there such a thing as Too Many Stored Procedures?
Jeff Atwood at Coding Horror makes some great points that reflect my own thoughts over at:
http://www.codinghorror.com/blog/archives/000117.html

I think SQL Server's Object Explorer needs to have a built-in mechanism for managing the thousands of stored procedures that occupy a database, instead of trusting that a sensible naming convention will be used. In my experience, eventually any naming convention breaks down after time, as new developers and technologies arrive.

Linked to in Atwood's post is this by Frans Bouma, who seems to be the main promoter of cautionary use of Stored Procedures: http://weblogs.asp.net/fbouma/archive/2003/11/18/38178.aspx

Quick ASP Log

2007-08-02T11:00:00.000-07:00

Handy for debugging errors:

function writeLog(msg)

Dim fso
Dim logfile
Dim logFileName
Dim strLog
logFileName = Server.MapPath("logfile.txt")
Set fso = Server.CreateObject("Scripting.FileSystemObject")
Set logfile = FSO.OpenTextFile(logFileName, 8, True)
logfile.writeline now() & ":" & msg
set fso = nothing
set logfile = nothing

end function