Database Reference
In-Depth Information
Figure 10-8.
Query tuning initial recommendations
This is because the Database Engine Tuning Advisor assumes that the load being tested is the full load of the
database. If there are indexes not being used, then they should be removed. This is a best practice and one that
should be implemented on any database. However, in this case, this is a single query, not a full load of the system.
To see whether the advisor can come up with a more meaningful set of recommendations, you must start a
new session.
This time, I'll adjust the options so that the Database Engine Tuning Advisor will not be able to drop any
of the existing structure. This is set on the Tuning Options tab (shown earlier in Figure
10-7
). There I'll change
the Physical Design Structure (PDS) to Keep in Database setting from Do Not Keep Any Existing PDS to Keep
All Existing PDS. I'll keep the running time the same because the evaluation worked well within the time frame.
After running the Database Engine Tuning Advisor again, it finishes in less than a minute and displays the
recommendations shown in Figure
10-9
.
