Vidas Matelis Analysis Services Blog

While writing SSIS package to load one of my data warehouse tables, I encountered SSIS problem that took me some time to figure out. I noticed that in the dataflow task one of the OLE DB source components was not returning any data even I know that records were there. So I did some investigation and found what was causing this issue.

I found that when following conditions are met, OLE DB Source component will not return any data:

• “OLE DB Source” component is based on the SQL Query
• SQL Query contains parameters
• SQL Query contains line that starts with comments symbol “–” 

 Example, this query (database “Adventure Works DW”) works:

SELECT CurrencyKey
  FROM dbo.DimCurrency
WHERE CurrencyKey BETWEEN ? AND ?

But this query always returns empty result set:

SELECT CurrencyKey
FROM dbo.DimCurrency
— my comments
WHERE CurrencyKey BETWEEN ? AND ?

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This weekend I had some time to play with SQL Server 2008 (Katmai) June CTP, and I am posting here my first impressions (focus on Analysis Services).

Installation

As a first attempt I tried to setup SQL Server 2008 on the computer that already had SQL Server 2005 default instance installed. I wanted to install SQL 2008 as a named instance and compare SQL 2005 and 2008 side by side. After answering few standard questions I got message that because SQL Server 2005 was found on the machine, SQL Server 2008 cannot install client tools. I proceed with installation without client tools. After installation I tried to use SQL Server 2005 BIDS environment and connect to Katmai instance, but somehow that did not work. Then finally I decided that maybe I should read readmesqlkatmai.htm file. Found that side by side installation is not supported. From readme file: Read the rest of this entry »

With SQL Server 2005 Service Pack 2 Microsoft introduced storage format vardecimal. As I work a lot with big fact tables, I decided to test how this new format affects storage. If you want to get estimated impact on using vardecimal storage format, you can run stored procedure sp_estimated_rowsize_reduction_for_vardecimal. This SP expects table name as parameter and returns row count, average row length for fixed format and average row length for vardecimal format.

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