The compression advisor provides compression estimates and recommendations. Based on
the results of these estimates, you can apply the attributes and compress the selected table.
Prerequisites
If
granular permissions is enabled, you must have
reorg any table privilege
or be the table owner. If granular permissions is not enabled, you must be the table owner
or have sa_role.
Apply compression attributes to the selected tables and apply changes
to its existing data.
Task
Once the compression estimate is initiated, you see the Compression Advisor Results window. The
Results tab shows the compression ratio for the sample table, compared to the selected
table in an uncompressed state.
- (Optional) On the Result screen:
- Click Space usage of sampling table to view the
sampling table's space usage.
- (Optional) Click Space usage of the real table to view
the current table's space usage.
- (Optional) On the Compression Attributes screen:
- (Optional) Click on Current compression attributes to
see a summary of the current table's compression attributes.
- (Optional) You can change attribute values and click
Apply to apply the new values. Any value changes are
applied to new data in the specified table.
- (Optional) To apply changes to existing data or on the entire table, click
Reorganize.
- (Optional) In the left pane, click Messages to show any
server messages related to the compression estimate.
- Click Compress to initiate compression of the selected
table.
You see the Compression Results window, including all messages regarding the
execution of compression.