September 20, 2011 Leave a comment
Post on UI architectures by Martin Fowler.
random thoughts related to software
September 2, 2011 Leave a comment
A coworker sent this link to me today. It’s an interesting feature for SQL Server 2008 which allows you to save space for nullable columns.
Here’s some of the basic info:
Sparse columns are ordinary columns that have an optimized storage for null values. Sparse columns reduce the space requirements for null values at the cost of more overhead to retrieve nonnull values. Consider using sparse columns when the space saved is at least 20 percent to 40 percent. Sparse columns and column sets are defined by using the CREATE TABLE or ALTER TABLE statements.
Sparse columns can be used with column sets and filtered indexes:
INSERT, UPDATE, and DELETE statements can reference the sparse columns by name. However, you can also view and work with all the sparse columns of a table that are combined into a single XML column. This column is called a column set. For more information about column sets, see Using Column Sets.
Because sparse columns have many null-valued rows, they are especially appropriate for filtered indexes. A filtered index on a sparse column can index only the rows that have populated values. This creates a smaller and more efficient index. For more information, see Filtered Index Design Guidelines.
Sparse columns and filtered indexes enable applications, such as Windows SharePoint Services, to efficiently store and access a large number of user-defined properties by using SQL Server.
Sparse columns have the following characteristics:
For more information about columns sets, see Using Column Sets.