Tip of the Day

Tip of the Day #8 (string performance)

Colin Angus Mackay — Mon, 04 Aug 2008 12:00:54 GMT

Concatenating strings in .NET can be very easy. There is the overloaded + operator that makes stringA + stringB + stringC statements very easy to write. But, it isn't very performant. The reason is that strings are immutable, and concatenating strings in this way causes lots of short-lived objects to be created and thrown away, which in turn causes the garbage collector to run frequently.

There are two better ways in .NET to concatenate strings. One is to use the string.Concat() method. The other is to use the StringBuilder class. They both perform better than adding strings together, but you still have to know when to use each.

According to this article on "Performance considerations for strings in C#" string.Concat() is good up to 600 strings. But, only if you have 600 strings to concatenate in a single statement. StringBuilder is better if you have more than 600 strings to concatenate, but you can do so over multiple statements. In reality, I think the benefits of appending strings over multiple statements with StringBuilder will work out better even with much less than 600 strings because to get the performance out of string.Concat() you'll have to perform some form of setup operation to line all those strings up - and that will take time.

So, today's tip is don't use the plus operator to combine strings except in quick / throw-away applications. Use string.Concat() or StringBuilder instead.

Technorati Tags: string,concatenation,concat,stringbuilder

Tip of the Day #7 (SysInternals)

Colin Angus Mackay — Wed, 30 Jul 2008 14:47:33 GMT

I've visited the SysInternals site a few times over the course of my career because of some strange problem that I just couldn't track down. The amount of information about what is actually happening on your system that the SysInternals tools provide is phenomenal. The site was run by Mark Russinovich and Bryce Cogswell until they got hired by Microsoft. However, the tools are still available and being updated, only now they are hosted by Microsoft themselves.

So, today's tip is to visit the SysInternals page on Microsoft's TechNet site and familiarise yourself with what is available. You might find that one day it will save you hours of frustration.

Tip of the Day #6 (Keyboard Shortcuts in IE)

Colin Angus Mackay — Sun, 27 Jul 2008 07:56:57 GMT

If you prefer to use your keyboard more than your mouse then you may be interested in this set of keyboard shortcuts for Internet Explorer 6 and 7.

Technorati Tags: ie,internet explorer,keyboard,keyboard shortcut

Tip of the Day #5 (SQL Server memory usage)

Colin Angus Mackay — Sun, 20 Jul 2008 10:14:29 GMT

You can limit the amount of memory that SQL Server uses by using the sp_configure stored procedure. By limiting the amount of memory that SQL Server is permitted to use it means that more memory is available to other applications or other instances of SQL Server. In fact books on-line recommends setting the minimum and maximum memory used on each instance of SQL Server running on the same machine as SQL Server does not make any attempts to balance memory usage across instances.

In order to use this you must be in an advanced mode. To set this up use:

EXEC sp_configure 'show advanced options', 1
RECONFIGURE WITH OVERRIDE

Next, to make the actual change you need the following:

EXEC sp_configure 'max server memory (MB)', 512
RECONFIGURE WITH OVERRIDE

The above example will set the maximum amount of memory the server will use to 512MB. The RECONFIGURE WITH OVERRIDE is necessary in order for the change to take effect immediately. If it is missed out then the change won't take place until the SQL Server is restarted.

If you want to check that the change has taken place you can use the following:

EXEC sp_configure 'max server memory (MB)'

This will just display the current setting. You will get a result set that looks something like this:

The congif_value is the value that the SQL Server is currently configured with. However, it may not be what is currently in force. The run_value shows you what is currently in force.

If you don't want to type so much SQL yourself, then you can do the same in the SQL Server Management Studio. Right-click the server in the object explorer and select "properties" from the context menu. This will bring you up a dialog with all the server level properties in it. Go to the "memory" page and you can set the values that you want there. There are a couple of radio buttons that will allow you to switch between the currently configured value and the running value. By pressing Okay the updated value is applied to the server immediately.

For more information:

Technorati Tags: sql server,memory

Tip of the Day #4 (Connection Strings in Config files)

Colin Angus Mackay — Sat, 19 Jul 2008 12:51:06 GMT

From .NET 2.0 onwards a new and improved configuration management system has been put in place. You can now add a <connectionString> element to the config file and use it to place the connection strings to the database and then retrieve then in a consistent way in your application. It supports multiple connection strings too if you need to access multiple databases.

The config file looks like this:

<configuration>
... 
  <connectionStrings>
    <add name="Default" connectionString="Server=(local);database=MyDatabase"/>
  </connectionStrings>
...
<configuration>

From the .NET application you can access the connection string like this:

connectionString = 
    ConfigurationManager.ConnectionStrings["Default"].ConnectionString;

Just remember to add a reference to System.Configuration in your project and ensure that the code file is using the System.Configuration namespace as well.

Technorati Tags: .net,connection string,config,configuration

Tip of the Day #3 (Ultimate How To Guide)

Colin Angus Mackay — Mon, 30 Jun 2008 23:01:01 GMT

Today's tip is the ultimate how to guide on being a programmer. It seems to explain almost everything. If, once you've read it and want more it also suggests 4 excellent books to read in chapter 1.

Tip of the Day #2 - (Debugging into the .NET source code)

Colin Angus Mackay — Sat, 28 Jun 2008 17:17:28 GMT

Today's tip is that you can configure Visual Studio to step-into the .NET Framework.

Here's some background: A while ago Scott Guthrie announced that the source code to the .NET Framework was now available. And Shawn Burke detailed how to actually configure Visual Studio 2008 to debug into the .NET Framework.

Tip of the Day #1 (Connection Strings)

Colin Angus Mackay — Sun, 22 Jun 2008 11:11:53 GMT

You can add the Application Name to the connection string for SQL Server so that it becomes easier to debug problems when you use a tool like SQL Profiler as it will be much easier to identify the commands being issued by your application.

For more information see Ben Hall's blog: SQL Connection - Application Name

Technorati Tags: .net,connection string,sql server