INLS 723 Database Systems II, Fall 2006

INLS 723

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Oct 30

Outline

EXPLAIN PLAN
Set up the plan_table to store the plan

start utlxplan    // this is an Oracle script

Generate the plan, but don't run the query

EXPLAIN PLAN 
INTO plan_table
FOR
<select statement goes here>

One query with a standard join

SELECT sname 
FROM sailors s, reserves r
WHERE s.sid = r.sid AND r.bid = 101;

Same results with a nested query

SELECT sname
FROM sailors s
WHERE s.sid IN (SELECT r.sid
		FROM reserves r
		WHERE r.bid = 101);

Look at the plan

SELECT operation, SUBSTR(options,1,30), object_name, position
FROM plan_table;

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