Skip to main content

70-562 Data Caching


If the data is control by other services, it can be delicate to cache.

Data can be cached and automaticaly updated when sql changes.

It depends on sql 2005 and later Query Notification, previous versions relies on database triggers.

ASP.Net can poll changes to the table, and sql can be configureged with Aspnet_regsql tool.

The the target table has to be configured with the aspnet_regsql tool, a changed id is added to the table.

Polls based caching is very reliable and easy to configure.


Datasource controls have properties to enable caching, this also requires the table to be configured with the aspreg tool.

Table caching caches only tables, not the page.

Can also be based on rows, to change only when specific row changes, for example products of a certain category. It will update only when this row is changed, this is custom caching rules.


QueryNotification caching doesnt require to configure sql. The service broker has to be enabled. Alter database northwind set service broker. Query notification also works in sql express.
A channel has to be created in teh glorbal.asax in the start you start SqlDependency.Start, and the opposite in stop.

QueryNotification can't use aggregates, image columns, cant use non detemrinistic functions like get date, cant use distinct, full name like dbo.tableName, no * in select have to be explicit with culumn names.

To use the datasource, use sqlcommandnotification as an attribute of the datasource, and this can be confugred from code, using SqlCAcheDependency.

Comments

Post a Comment

Popular posts from this blog

React JS Patterns

React JS is always evolving, and evolving quickly. These evolutions can be very significant ones, for example, the addition of hooks. React has a lot of code patterns, often these patterns are motivated by the DRY and/or the open-close principle. These patterns sometimes come in to replace a previous one, yet the previous ones still stays in use, as a consequence, the list of patterns keep growing. The goal of the next few posts will be to list the patterns commonly used in React JS developpement. Some patterns are more specific to JSX and I will start with these, and maybe add patterns specific to Redux.
4 comments
Read more

Rxjs Forkjoin vs Zip

These Rxjs combination operators are handy to make Rest calls in parallel and combine their results. Both take n observables and will return the results, with the difference that forkJoin will complete even if one of the nested observables errors of completes.
Post a Comment
Read more

70-562 ListView

List View is a versatile control that allows to work with a signle control rather than many smaller controls. Provides rich sorting, deleting, editing, it is one of the most flexible grid control. Design view can fill the ListView with fake data to give an overview. In designer, the configure list view link might not show, (currently a bug), to fix configure the datasource but cancel then click configure datasource again and this time click finish and the Cofnoigure ListView link will show up in the smarttag. You can choose templates, LayoutTemplate is crucial, ItemTemplate(a row is part of a table, in a list view they are called items since they don't have to correspond to a table row), AlternatingItemTemplate, ItemSeparatorTemplate, SelectedItem, EmptyItemTemplate, EditItemTemplate, InsertItemTemplate allows to customize what the user will be presented when creating an item, EmptyDataTemplate. The itemPlaceHolder and the groupPlaceHolder are important elements as the will b...
Post a Comment
Read more