Tuesday, July 28, 2009

SSRS 2008...

I have been working with SSRS 2008 for a while now and have come across a couple of things. The first one seems like a bug in SSRS 2008, it has to do with the ReportItems collection. When you have columns placed on the report, the actual values are displayed in textboxes in the report. These textboxes are part of the ReportItems Collection, when one is in the ExpressionBox and you type ReportItems!, you can see a list of textbox item ID's. In the situation i ran into I typed in ReportItems!textbox40 in the expression, at preview time of the report i kept getting an error saying item not found or cannot be part part of the expression. After a few tries ,it kept getting frustrating and it was not listed in the collection, finally I put the exact name like ReportItems!Textbox40 and it worked. The issue was the case sensitivity of the name, also noticed in the ReportItems collection there are some with lowercase names and other with the first Character capitalised. I hope in the future releases these are made consistent.
One of the neat features available in SSRS 2008 is the adjacent Group feature in the tablix control.

This provides a great of flexibility in grouping, it allows grouping of the data in 2 different ways in the same control. One of the things I had to do was represent 2 parent child relationships in the same report, for this the adjacent group feature was very handy.

Friday, July 17, 2009

Data Mining...

Yesterday i had been to a Data Mining Conference in Cary,NC. The topic of presentation was about the usefulness of Data Mining and utilising the JMP Software for Data Mining. The JMP software came out of SAS, this is more aimed for the Desktop users who want to perform Data Mining tasks, there are 2 versions available 32-bit and 64-bit. One of the Key factors mentioned about Data Mining was that around 60-90% of the time is spent in the Preparation of data. The key aspect in Data mining projects is to define the Business goal/problem statement clearly. The lecture was delived by Dick De Veaux, is a Professor in the Department of Mathematics and Statistics at Williams College in Williamstown, MA. Once can google on his name to find out about his talks on Data Mining. There were Data Mining Methods Discussed which are part of the SQL Server 2008 Analysis Services Suite. The talk also bought about the differences between methods used for Descriptive and Predictive Data. For any one intesrested in the Jmp software, here is the web site: www.jmp.com.

Friday, July 10, 2009

Data Compression-SQL Server 2008

We have a sizeable data mart with around 50 tables. Initially they did not have any compression methods applied on them. In SQL Server 2008 there are two kinds of compression which are exposed at the table level: They are Page and Row compression. These techniques enable great space savings and also better query performances. One of things which i noticed was it takes lesser time to load the pages of the table into the memory when it is compressed, this has give me better query performances. In SQL Server 2008 there is a Data Compression Wizard available through SSMS. This feature allows the developers to test out the compression space savings. The Data compression option is set at the table level, this can be done at the CREATE TABLE or ALTER TABLE statements. The wizard is launched by right clicking on a table.

When you choose the Manage Compression Option, the Data Compression wizard comes up.

In this under the Compression Type dropdown there are the Page and Row Compression. When any one of these is chosen one can choose the calculate option and figure out the space savings as listed under the Current Space and Requested Compressed Space. In my Scenario i achieved more savings using Page Compression.

Tuesday, July 7, 2009

Enterprise Database Management Report...

The report which evaluates the different RDBMS vendors is available. In the report all the vendors providing relational database management systems have been evaluated, it is exhauastive in terms of the various factors which went to examining the different RDBMS offerings. In particular emphasis related to Microsoft SQL Server, here is a Quote from the report:

Microsoft: The most aggressive DBMS vendor with a strong road map. Microsoft has done reasonably well in the database business but over the past three years has shown increasing focus and commitment to going after the enterprise market. SQL Server 2005 and, more recently, SQL Server 2008 have enabled Microsoft to take market share in moderately sized to large enterprises, delivering good performance, scalability, security, and availability functionality. Five years ago, hardly any enterprises ran multiterabyte databases with SQL Server to support critical applications. Today, hundreds of enterprises are running 10-terabyte and larger transactional SQL Server databases.

For a complete read on the report: Use the link mentioned below