optimizer: fix a bug in optimizeJoinOrder

Fix a bug in optimizeJoinOrder.
chendhui · Mar 16, 2016 · 953c664 · 953c664
1 parent 864c978
commit 953c664
Show file tree

Hide file tree

Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/optimizer/plan/plan_test.go b/optimizer/plan/plan_test.go
@@ -568,6 +568,18 @@ func (s *testPlanSuite) TestJoinPath(c *C) {
 				on t1.i1 = 1 and t1.c1 = t2.i2`,
 			"InnerJoin{Index(t1.i1)->OuterJoin{InnerJoin{Index(t2.i2)->Index(t3.i3)}->Index(t4.i4)}}->Fields",
 		},
+		{
+			`select * from
+				t1 join (
+					t2 left join (
+						t3 join t4
+						on t3.i3 = t4.c4
+					)
+					on t2.i2 = t3.c3
+				)
+				on t1.i1 = t2.c2`,
+			"InnerJoin{OuterJoin{Table(t2)->InnerJoin{Table(t4)->Index(t3.i3)}}->Index(t1.i1)}->Fields",
+		},
 		{
 			`select * from
 				t1 join (

diff --git a/optimizer/plan/planbuilder_join.go b/optimizer/plan/planbuilder_join.go
@@ -444,6 +444,7 @@ func (p *joinPath) optimizeJoinOrder(availablePaths []*joinPath) {
 	}
 	for len(pathMap) > 0 {
 		next := p.nextPath(pathMap, availablePaths)
+		next.optimizeJoinOrder(availablePaths)
 		ordered = append(ordered, next)
 		delete(pathMap, next)
 		availablePaths = append(availablePaths, next)
@@ -456,9 +457,6 @@ func (p *joinPath) optimizeJoinOrder(availablePaths []*joinPath) {
 			}
 		}
 		p.reattach(pathMap, availablePaths)
-		for path := range pathMap {
-			path.optimizeJoinOrder(availablePaths)
-		}
 	}
 	p.inners = ordered
 }