Performance Issues with DB Design and Heavy Data - sql-server-2008

Question

I asked the following question regarding DB Design and Performance issue in my application today.
DB Design and Data Retrieval from a heavy table
But, could not get much replies on that. I don't know, I may not have explained the question properly. Now, I have re-defined my question, hoping to get some suggestion from the experts.
I am facing performance issues while selecting data from a particular table. The business logic of the application is as following:
I have a number of import processes which result in creating pivot columns under their parent column names while showing them to the user. As the columns get pivoted, system takes time to convert rows into columns which results in slow performance.
The database tables related to this functionality are as following:
There can be N number of clients. CLT_Clients table stores client information.
There can be N number of projects associated to a client. PRJ_Projects table stores project information and a link to the client.
There can be N number of listings associated to a project. PRJ_Listings table stores listing information and a link to the project.
There can be N number of source entities associated to a listing. ST_Entities table stores source entity information and a link to the listing.
This source entity is the actual import that contains the InvestorID, position values, source date, active and formula status.
The name of the import e.g. L1Entity1 is stored in ST_Entities table alongwith ID field i.e. EntityID
InvestorID, Position, Source Date, Active and Formula values get stored in ST_Positions table
Database Diagram
Data need to be view as following:
With this design I’m able to handle N number of imports because the Position, Source Date, IsActive, Formula columns get Pivoted.
The problem that I’m facing with this design is that the system performs very slow when it has to select data for more than 10-12 source entities, and the requirement is to show about 150 source entities. Because data is not stored row wise and I need to show it column wise, hence dynamic queries are written to pivot these columns which takes long.
Ques 1: Please comment/suggest on my current database design if it’s correct or need to be changed with the new design by taking 150 columns each for Position, Source Date, IsActive, Formula; In this new way data will already be stored in the way I need to retrieve in i.e. I’ll not have to pivot/unpivot it. But the downside is:
a) There are going to be more than 600 columns in this table?
b) There will be limit i.e. 150 on the source entities.
Ques 2: If I need to stick to my current, what can be done to improve the performance?
Please see below the indexing and Pivot method information:
Regarding indexes in Position table, I also have taken ProjectID field with clustered index as the data is selected from Position table either on the basis of ProjectID OR EntityID.
Whenever EntityID is used to select data from Position table, it's always used in JOIN. And Whenever ProjectID is used to select data from this table, it's always used in WHERE.
Point to notice here is that I have a Clustered index on ProjectID but I have not taken any index on Pivoted column OR EntityID. Is there any room for improvement here?
Pivoting Method used:
Example 1:
'Select * From
(
Select DD.InvestorID,Cast(1 As Bit) As IsDSInvestor,DD.Position,
Case DD.ProjectID
When ' + CAST(#ProjectID AS VARCHAR) +' Then DE.SourceName
Else ''' + #PPDeliveryDate + '''+DE.SourceName
End As SourceName
From DE_PositionData DD
Inner Join DE_DataEntities DE ON DE.EntityID=DD.EntityID
Where DD.ProjectID IN (' + CAST(#ProjectID AS VARCHAR) +',' + CAST(#PreviousProjectID AS VARCHAR) +') AND InvestorID IS NOT NULL
) IDD
Pivot
(
max(Position) for SourceName in ('+ #DataColumns+')
) as p1'
Example2:
'Select * From
(
Select DD.InvestorID As DSSOFID,Cast(1 As Bit) As IsActiveInvestor,
Case ST.SourceTypeCode
When ''RSH'' Then Cast(IsNull(DD.IsActive,0) As Int)
Else Cast(IsNull(DD.IsActive,1) As Int)
End As IsActive,
''~''+DE.SourceName As ActiveSourceName
From DE_DataEntities DE
Left Join DE_PositionData DD ON DE.EntityID=DD.EntityID
Left Join
(
Select * From #DataSources
Where ProjectID=' + CAST(#ProjectID AS VARCHAR) +'
) ST ON ST.ESourceID=DE.ESourceID
Where DE.ProjectID=' + CAST(#ProjectID AS VARCHAR) +' AND ST.SourceTypeCode NOT IN (''PBC'',''EBL'',''REG'')
AND InvestorID IS NOT NULL
) IDD
Pivot
(
Max(IsActive) for ActiveSourceName in ('+ #DataColumns+')
) As p1'

Answer 1

I would suggest the following.
You should store your data in the normalized format. You should be able to set up indexes to make the pivoting of the data go faster. If you post the actual query that you are using for pivoting, we might be able to help.
There are many reasons you want to store the data this way:
Flexibility in the number of repeating blocks
Many databases have limits on the number of columns or total width of a table. You don't want your design to approach those limits.
You may want additional information on each block. I always include CreatedBy and CreatedAt columns in my tables, and you would want this per block.
You have additional flexibility in summarization.
Adding/removing intermediate values is cumbersome.
That said, the pivoted table has one key advantage: it is what users want to see. If your data is updated only once per day, then you should create a reporting table with the pivot.
If your data is updated incrementally throughout the day, then you can set up triggers (or stored procedure code) to update the base tables and the reporting summary.
But as I said earlier, you should ask another question is the particular method you are using for pivoting. Perhaps we can improve the performance there.