Databases Reference
In-Depth Information
Counter
Occurrence
Value
elapsed time
1
0.009
final cost
1
3.239871842
maximum DOP
1
0
optimizations
1
1
search 0 tasks
1
230
search 0 time
1
0.001
search 1
1
1
search 1 tasks
1
377
search 1 time
1
0.004
gain stage 0 to stage 1
1
0.490795403
tables
1
3
tasks
1
607
Table 5-13:
Optimization information for search 0 and 1 phases.
The output shows that the optimization process went through both the search 0 and
search 1 stages and that a plan was found on the latter. It also shows a cost improvement
of almost 50% by going from the search 0 to the search 1 stage.
Search 2
The last phase, search 2, is called full optimization, and is used for queries ranging from
complex to very complex. A larger set of the potential transformation rules, parallel
operators and other advanced optimization strategies are considered in this phase and,
