A column store index organizes the data in individual columns that are joined together to form the index. This new type of index stores data column-wise instead of row-wise. When you add Column Store index the Table becomes “Read only”. So the only solution is to Drop and Recreate the Indexes.
Column vs. Row Index
The data is stored in two pages i.e. “page1” and “page2”. “Page1” has two rows and “page2” also has two rows. Now if you want to fetch only “column1”, you have to pull records from two pages i.e. “Page1” and “Page2”.
If somehow we can store data column wise we can avoid fetching data from multiple pages. That’s what column store indexes do. We now need to fetch “column1” data only from one page rather than querying multiple pages.
So conclusion is that Column Store Indexes stores data in a column manner and are used for Fast Access Data as compared to Row Index.Tags: