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planner/core: make join reorder solver stateless (#8680)

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This commit is contained in:
Yiding Cui
2018-12-13 16:31:32 +08:00
committed by GitHub
parent db2127a0dd
commit 2e95ee2804
1 changed files with 19 additions and 12 deletions
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31
planner/core/rule_join_reorder_greedy.go
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@ -49,6 +49,9 @@ func extractJoinGroup(p LogicalPlan) (group []LogicalPlan, eqEdges []*expression
}
type joinReOrderGreedySolver struct {
}
type joinReorderGreedySingleGroupSolver struct {
ctx sessionctx.Context
curJoinGroup []LogicalPlan
eqEdges []*expression.ScalarFunction
@ -67,7 +70,7 @@ type joinReOrderGreedySolver struct {
//
// For the nodes and join trees which don't have a join equal condition to
// connect them, we make a bushy join tree to do the cartesian joins finally.
func (s *joinReOrderGreedySolver) solve() (LogicalPlan, error) {
func (s *joinReorderGreedySingleGroupSolver) solve() (LogicalPlan, error) {
for _, node := range s.curJoinGroup {
_, err := node.deriveStats()
if err != nil {
@ -90,7 +93,7 @@ func (s *joinReOrderGreedySolver) solve() (LogicalPlan, error) {
return s.makeBushyJoin(cartesianGroup), nil
}
func (s *joinReOrderGreedySolver) constructConnectedJoinTree() (LogicalPlan, error) {
func (s *joinReorderGreedySingleGroupSolver) constructConnectedJoinTree() (LogicalPlan, error) {
curJoinTree := s.curJoinGroup[0]
s.curJoinGroup = s.curJoinGroup[1:]
for {
@ -126,7 +129,7 @@ func (s *joinReOrderGreedySolver) constructConnectedJoinTree() (LogicalPlan, err
return curJoinTree, nil
}
func (s *joinReOrderGreedySolver) checkConnectionAndMakeJoin(leftNode, rightNode LogicalPlan) (LogicalPlan, []expression.Expression) {
func (s *joinReorderGreedySingleGroupSolver) checkConnectionAndMakeJoin(leftNode, rightNode LogicalPlan) (LogicalPlan, []expression.Expression) {
var usedEdges []*expression.ScalarFunction
remainOtherConds := make([]expression.Expression, len(s.otherConds))
copy(remainOtherConds, s.otherConds)
@ -159,7 +162,7 @@ func (s *joinReOrderGreedySolver) checkConnectionAndMakeJoin(leftNode, rightNode
return newJoin, remainOtherConds
}
func (s *joinReOrderGreedySolver) makeBushyJoin(cartesianJoinGroup []LogicalPlan) LogicalPlan {
func (s *joinReorderGreedySingleGroupSolver) makeBushyJoin(cartesianJoinGroup []LogicalPlan) LogicalPlan {
resultJoinGroup := make([]LogicalPlan, 0, (len(cartesianJoinGroup)+1)/2)
for len(cartesianJoinGroup) > 1 {
resultJoinGroup = resultJoinGroup[:0]
@ -183,7 +186,7 @@ func (s *joinReOrderGreedySolver) makeBushyJoin(cartesianJoinGroup []LogicalPlan
return cartesianJoinGroup[0]
}
func (s *joinReOrderGreedySolver) newCartesianJoin(lChild, rChild LogicalPlan) *LogicalJoin {
func (s *joinReorderGreedySingleGroupSolver) newCartesianJoin(lChild, rChild LogicalPlan) *LogicalJoin {
join := LogicalJoin{
JoinType: InnerJoin,
reordered: true,
@ -194,22 +197,26 @@ func (s *joinReOrderGreedySolver) newCartesianJoin(lChild, rChild LogicalPlan) *
}
func (s *joinReOrderGreedySolver) optimize(p LogicalPlan) (LogicalPlan, error) {
s.ctx = p.context()
return s.optimizeRecursive(p)
return s.optimizeRecursive(p.context(), p)
}
func (s *joinReOrderGreedySolver) optimizeRecursive(p LogicalPlan) (LogicalPlan, error) {
func (s *joinReOrderGreedySolver) optimizeRecursive(ctx sessionctx.Context, p LogicalPlan) (LogicalPlan, error) {
var err error
curJoinGroup, eqEdges, otherConds := extractJoinGroup(p)
if len(curJoinGroup) > 1 {
for i := range curJoinGroup {
curJoinGroup[i], err = s.optimizeRecursive(curJoinGroup[i])
curJoinGroup[i], err = s.optimizeRecursive(ctx, curJoinGroup[i])
if err != nil {
return nil, err
}
}
s.curJoinGroup, s.eqEdges, s.otherConds = curJoinGroup, eqEdges, otherConds
p, err = s.solve()
groupSolver := &joinReorderGreedySingleGroupSolver{
ctx: ctx,
curJoinGroup: curJoinGroup,
eqEdges: eqEdges,
otherConds: otherConds,
}
p, err = groupSolver.solve()
if err != nil {
return nil, err
}
@ -217,7 +224,7 @@ func (s *joinReOrderGreedySolver) optimizeRecursive(p LogicalPlan) (LogicalPlan,
}
newChildren := make([]LogicalPlan, 0, len(p.Children()))
for _, child := range p.Children() {
newChild, err := s.optimizeRecursive(child)
newChild, err := s.optimizeRecursive(ctx, child)
if err != nil {
return nil, err
}