Page 277 - DCAP312_WEB_TECHNOLOGIES_II

Unit 14: Debugging and Optimization

2. In the Machine.config file, locate the compilation element. Debugging is enabled when Notes
the debug attribute in the compilation element is set to true.
3. If the debug attribute is true, change the debug attribute to false.
4. The following code sample shows the compilation element with debug set to false:
<compilation
debug= “false”
/ >
Save the Machine.config file.

14.2 Optimizing Using Caching

ASP.NET 3.5 intrinsic cache functionality has long been one of my favourite aspects of ASP.
NET. With a little bit of planning and organization, we can use it to create highly scalable
applications with robust fidelity. Optimization is the act of improving a method or design. In
programming, optimization usually takes the form of increasing the speed of an algorithm, or
reducing the resources it requires.
Best ways are to optimize our use of the ASP.NET cache and what some of the tips are in regards
to how to determine what should and should not go in the cache. Also, are there any rules of
thumb for determining how long something should say in the cache?
14.2.1 ASP.NET Caching Features

The ASP.NET 3.5 Cache API was a revolutionary feature that provided capabilities such as
declarative output caching, programmatic output caching, and invalidation of cached items when
the contents of an XML file or another cached item change. Even though all these increased the
performance of Web applications, ASP.NET 3.5 did not provide a mechanism for invalidating
the data in a cache object when the data in a database changes. This much sought after feature
will finally ship with ASP.NET 3.5 Apart from this, ASP.NET 3.5 will also provide functionalities
to cache the output of a SqlDataSource control, which enable us to take advantage of caching
without writing a single line of code.
In ASP.NET 3.5, caching has improved in a couple of notable ways. Probably the most interesting
improvement is the introduction of database-triggered cache invalidation. In ASP.NET 3.5, we
can invalidate a cached item based on some pre-defined conditions, such as change in an XML
file, change in another cache item, and so on. By using this feature, we can remove or invalidate
an item from the cache when the data or another cached item changes. However, the ASP.NET
3.5 Cache API does not allow us to invalidate an item in the cache when data in a SQL Server
database changes, even though most applications require this capability. ASP.NET 3.5 addresses
this by providing the database-triggered cache invalidation capability that allows us to ensure
that items in the cache are kept up to date with the changes in the database.
Another important caching feature in ASP.NET 3.5 is the ability to enable caching at the
SqlDataSource level. The SqlDataSource control is designed to work with SQL Server, OLE DB,
ODBC, and Oracle databases. As the name suggests, this control enables us to select, update,
delete, and insert data using SQL commands. With the ability to set caching attributes at the
SqlDataSource control level, we now have a finer level of control over the cached data.
The ASP.NET 3.5 also provides a new control named Substitution, which we can use to inject
dynamic content in an otherwise cached Web page. If we have a page with output-caching
but still want to display dynamic content (that needs to be generated every time the page is
requested), consider using the Substitution control.
The following sections provide examples of the above features.

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