Types of Hierarchies in Data Warehouse:

Hierarchies are logical entities that an end user can use to analyze fact data.  These entities can be made of one or multiple levels.

Hierarchies are classified as three ways:-
1. Balanced
2. Unbalanced
3. Ragged


Have a look at the exhibit given below, hope it will help you to understand about the types of hierarchies in better way


Balanced Hierarchies:-

Each level in a hierarchy has the same number of members above it as any other member at the same level


Un Balanced Hierarchies:-

Each level in a hierarchy may not the same number of members as the member which are at the same level, refer the hierarchy structure shown above.


Ragged Hierarchies:-


It is not like balanced Hierarchy, the logical parent member of at least one member is not in the level immediately above the member. It will skip the immediate parent. 

For Example: In a company, all the divisions will be reporting to the VP thru hierarchical structure, but Finance department will directly reporting to VP without any middle level.

Architecture Changes Between SSRS 2005 Vs. 2008

There are major changes between SSRS architecture 2005 and 2008. Have a look at the following exhibit first then go thru changes listed below: -

SQL Server Architecture 2005:-

 

SQL Server Architecture 2008:-

New Changes in SSRS 2008:-
1. Initially, all the SSRS related applications, services and utilities were running as an individual segment. In 2008, these components are merged as single windows service segment. It makes our jobs simple, easy to manage, deploy, configure the SSRS Objects

2. Report server no longer dependent on IIS. Instead, http.sys is used to handling authentication.  Http.Sys is called as HTTP Server API. In general word, HTTP.sys is just a driver, which allow us to communicate the clients (browser) with Report Server without Microsoft Internet Information Server(IIS). Also SSRS 2008 has all IIS components which require functioning without having any dependency with IIS.
 

3.Moving away from IIS, two major actions to be taken care by SSRS components:
 

 a.    Disabling some of the functionalities IIS handles which there are no equivalent in SSRS 2008, such as anonymous, client certificate and ISAPI.
 

 b. Enabling some of the functionalities that IIS used to handle for SSRS before. Things such as ability to add virtual directory, port, SSL certificate, logging mechanism and so on…
 

4. Report Server uses shared components from SQL Server, such as SQL CLR for ASP.NET management, network interfaces, and memory management capabilities. This implies that any advances in administration and logging in SQL Server can be leveraged in SSRS in future releases.
 

5. CLR Host – All the SSRS components are running under the control of CLR. So CLR is act as host.
 

6. the Report Manager application and the Report Server web service have been combined into a single Windows service