July 1, 2005 at 1:04 am
Hi all,
I understand that 1.Indexed Views 2. summary tables
helps in faster response of the view.
The "Indexed Views" - by creating indexes on views , it will be faster.
The "summary tables", talks about aggregation ,analysis service,etc.
Can any one explain with an example.
Thanks in advance.
July 1, 2005 at 1:35 am
For indexed views, take for example your classic Product hierarchy. In a normalised OLTP system the tables might look like this,
Product
ProductID, ProductName
ProductCategory
CategoryID, CategoryName
ProductSubCategory
SubCategoryID, SubCategoryName
Normal datawarehousing technique would have you bring all these fields together in a single de-normalised table. However, doing this you lose the ability to apply referential integrity constraints. With an indexed view, you can keep your base tables in their OTLP structure, maintaining all the business rules and then build your cubes on the de-normalised indexed view.
For summary tables, in your OLTP system sales information is kept for each individual sale. When it comes to show the sales for a particular region, or employee, you have to add up all the sales everytime you want a report. Providing summary tables means that there is no further calculations to perform and your report shows the information from the summary table.
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Colt 45 - the original point and click interface
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