The workflow assistant for query tuning can display the
access plan for a statement as a diagram. The diagram provides cost
and cardinality estimates for each step in the plan.
About this task
An access plan graph describes both the "operational details"
of query execution and how the data flows. A leaf node of an access
plan graph is either a table node, a workfile node, or an index node
that represents a data source in the query execution plan. Data flows
from the bottom up (as displayed in the graph) and is processed by
operation nodes in the access plan graph.
What to do next
The workflow assistant for query tuning opens to the Review section.
If the Review Access Plan page is not open
because you selected additional options in the Select Activities window,
click Open Access Plan Graph on the left side
of the Review section.
For help on this
page, click the
button at the top of the page. You can also
press F1.
For more information about reading and interpreting
access plan graphs, see Tuning SQL with Optim™ Query
Tuner, Part 1: Understanding access paths.