tree1_optimize.gv

// 优化后 SELECT [ ENAME = 'Mary' & DNAME = 'Research' ] ( EMPLOYEE JOIN DEPARTMENT )
digraph {
	name [label="优化后 SELECT [ ENAME = 'Mary' & DNAME = 'Research' ] ( EMPLOYEE JOIN DEPARTMENT )" shape=rectangle]
	1 [label="⋈"]
	4 [label=" ENAME='Mary'"]
	5 [label=" DNAME='Research'"]
	2 [label=EMPLOYEE]
	3 [label=DEPARTMENT]
		1 -> 4
		1 -> 5
		4 -> 2
		5 -> 3
}