Database Reference
In-Depth Information
Figure 35-6.
Delta store and Delete bitmap: Delta store data page
Finally, it is worth noting that a row with Col1=2000000, which we have inserted and deleted after the clustered
columnstore index was created, is not present in the delta store. SQL Server deletes (and updates) rows in the B-Tree
delta store the same way as regular B-Tree tables.
You can use the same approach to examine the content of a deleted bitmap data page. In my case, the page id is 308.
Figure
35-7
shows the partial output of the
DBCC PAGE
command. As you can see, the delete bitmap includes two
columns that uniquely identify a row. The first column is a
row group id
and the second column is the offset of the row
in the segment. Do not be confused by the fact that the column names match table columns.
DBCC PAGE
uses table
metadata to prepare the output.
