Maintaining data
partition statistics can improve the performance of many queries.
- In the Administration Console view, select .
- Click the Name field of the table, then click the drop-down arrow and select
Properties.
- In the left pane, click Partitions.
- Click the Name field of the partition, then click the drop-down arrow and select
Update Statistics.
- On the Command Type screen, select the update statistics command to
run.
- On the Hashing screen, select:
- The type of hashing:
- Partial hashing – for columns that have 65536 or fewer unique
values.
- With hashing – for columns that have more than 65536
unique values.
- No hashing.
- A value for max resource granularity (which indicates the
maximum percentage of the systems resources a query can use), if
applicable.
- On the Histogram Tuning screen, set the histogram tuning factor.
The size of the histogram is established by multiplying the number of steps with the
value for histogram tuning factor.
- On the Sampling screen, specify whether to set sampling, and to what
percentage.
- On the Step Number screen, indicate whether to set the number of
histogram steps, and how many.
- On the Summary screen, verify your selections.
- Click Finish.