Databases Reference
In-Depth Information
Clicking one of the top SQL statements in the list displays the SQL statement
itself along with various statistics and a greater wealth of other information
about the SQL statement, including execution history and whether this SQL
statement has been tuned.
More information about the Oracle optimizer and how you can tune these
SQL statements is presented later in this chapter.
Explain Plan Graphical Tool
Explain Plan tool
A GUI-based Oracle tool that details the
steps in which a SQL statement is exe-
cuted, as well as what method Oracle
used to access the tables in the query.
Oracle9
i
's
Explain Plan tool
can be launched directly or from the Top SQL tool.
It shows in a step-by-step fashion how a SQL statement is processed and how each
of the tables in the query is accessed—for example, by an index or by reading the
entire table. With the statement in question highlighted in the Top SQL window,
select Drilldown
Explain Plan to bring up the Explain Plan analysis window, as
shown below.
