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// Copyright 2018 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package cascades
import (
"context"
"math"
"testing"
. "github.com/pingcap/check"
"github.com/pingcap/parser"
"github.com/pingcap/parser/model"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/infoschema"
plannercore "github.com/pingcap/tidb/planner/core"
"github.com/pingcap/tidb/planner/memo"
"github.com/pingcap/tidb/planner/property"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/util/testleak"
)
func TestT(t *testing.T) {
CustomVerboseFlag = true
TestingT(t)
}
var _ = Suite(&testCascadesSuite{})
type testCascadesSuite struct {
*parser.Parser
is infoschema.InfoSchema
sctx sessionctx.Context
optimizer *Optimizer
}
func (s *testCascadesSuite) SetUpSuite(c *C) {
testleak.BeforeTest()
s.is = infoschema.MockInfoSchema([]*model.TableInfo{plannercore.MockSignedTable()})
s.sctx = plannercore.MockContext()
s.Parser = parser.New()
s.optimizer = NewOptimizer()
}
func (s *testCascadesSuite) TearDownSuite(c *C) {
testleak.AfterTest(c)()
}
func (s *testCascadesSuite) TestImplGroupZeroCost(c *C) {
stmt, err := s.ParseOneStmt("select t1.a, t2.a from t as t1 left join t as t2 on t1.a = t2.a where t1.a < 1.0", "", "")
c.Assert(err, IsNil)
p, _, err := plannercore.BuildLogicalPlan(context.Background(), s.sctx, stmt, s.is)
c.Assert(err, IsNil)
logic, ok := p.(plannercore.LogicalPlan)
c.Assert(ok, IsTrue)
rootGroup := memo.Convert2Group(logic)
prop := &property.PhysicalProperty{
ExpectedCnt: math.MaxFloat64,
}
impl, err := s.optimizer.implGroup(rootGroup, prop, 0.0)
c.Assert(impl, IsNil)
c.Assert(err, IsNil)
}
func (s *testCascadesSuite) TestInitGroupSchema(c *C) {
stmt, err := s.ParseOneStmt("select a from t", "", "")
c.Assert(err, IsNil)
p, _, err := plannercore.BuildLogicalPlan(context.Background(), s.sctx, stmt, s.is)
c.Assert(err, IsNil)
logic, ok := p.(plannercore.LogicalPlan)
c.Assert(ok, IsTrue)
g := memo.Convert2Group(logic)
c.Assert(g, NotNil)
c.Assert(g.Prop, NotNil)
c.Assert(g.Prop.Schema.Len(), Equals, 1)
c.Assert(g.Prop.Stats, IsNil)
}
func (s *testCascadesSuite) TestFillGroupStats(c *C) {
stmt, err := s.ParseOneStmt("select * from t t1 join t t2 on t1.a = t2.a", "", "")
c.Assert(err, IsNil)
p, _, err := plannercore.BuildLogicalPlan(context.Background(), s.sctx, stmt, s.is)
c.Assert(err, IsNil)
logic, ok := p.(plannercore.LogicalPlan)
c.Assert(ok, IsTrue)
rootGroup := memo.Convert2Group(logic)
err = s.optimizer.fillGroupStats(rootGroup)
c.Assert(err, IsNil)
c.Assert(rootGroup.Prop.Stats, NotNil)
}
func (s *testCascadesSuite) TestPreparePossibleProperties(c *C) {
s.optimizer.ResetTransformationRules(map[memo.Operand][]Transformation{
memo.OperandDataSource: {
NewRuleEnumeratePaths(),
},
})
defer func() {
s.optimizer.ResetTransformationRules(DefaultRuleBatches...)
}()
stmt, err := s.ParseOneStmt("select f, sum(a) from t group by f", "", "")
c.Assert(err, IsNil)
p, _, err := plannercore.BuildLogicalPlan(context.Background(), s.sctx, stmt, s.is)
c.Assert(err, IsNil)
logic, ok := p.(plannercore.LogicalPlan)
c.Assert(ok, IsTrue)
logic, err = s.optimizer.onPhasePreprocessing(s.sctx, logic)
c.Assert(err, IsNil)
// collect the target columns: f, a
ds, ok := logic.Children()[0].Children()[0].(*plannercore.DataSource)
c.Assert(ok, IsTrue)
var columnF, columnA *expression.Column
for i, col := range ds.Columns {
if col.Name.L == "f" {
columnF = ds.Schema().Columns[i]
} else if col.Name.L == "a" {
columnA = ds.Schema().Columns[i]
}
}
c.Assert(columnF, NotNil)
c.Assert(columnA, NotNil)
agg, ok := logic.Children()[0].(*plannercore.LogicalAggregation)
c.Assert(ok, IsTrue)
group := memo.Convert2Group(agg)
err = s.optimizer.onPhaseExploration(s.sctx, group)
c.Assert(err, IsNil)
// The memo looks like this:
// Group#0 Schema:[Column#13,test.t.f]
// Aggregation_2 input:[Group#1], group by:test.t.f, funcs:sum(test.t.a), firstrow(test.t.f)
// Group#1 Schema:[test.t.a,test.t.f]
// TiKVSingleGather_5 input:[Group#2], table:t
// TiKVSingleGather_9 input:[Group#3], table:t, index:f_g
// TiKVSingleGather_7 input:[Group#4], table:t, index:f
// Group#2 Schema:[test.t.a,test.t.f]
// TableScan_4 table:t, pk col:test.t.a
// Group#3 Schema:[test.t.a,test.t.f]
// IndexScan_8 table:t, index:f, g
// Group#4 Schema:[test.t.a,test.t.f]
// IndexScan_6 table:t, index:f
propMap := make(map[*memo.Group][][]*expression.Column)
aggProp := preparePossibleProperties(group, propMap)
// We only have one prop for Group0 : f
c.Assert(len(aggProp), Equals, 1)
c.Assert(aggProp[0][0].Equal(nil, columnF), IsTrue)
gatherGroup := group.Equivalents.Front().Value.(*memo.GroupExpr).Children[0]
gatherProp, ok := propMap[gatherGroup]
c.Assert(ok, IsTrue)
// We have 2 props for Group1: [f], [a]
c.Assert(len(gatherProp), Equals, 2)
for _, prop := range gatherProp {
c.Assert(len(prop), Equals, 1)
c.Assert(prop[0].Equal(nil, columnA) || prop[0].Equal(nil, columnF), IsTrue)
}
}
// fakeTransformation is used for TestAppliedRuleSet.
type fakeTransformation struct {
baseRule
appliedTimes int
}
// OnTransform implements Transformation interface.
func (rule *fakeTransformation) OnTransform(old *memo.ExprIter) (newExprs []*memo.GroupExpr, eraseOld bool, eraseAll bool, err error) {
rule.appliedTimes++
old.GetExpr().AddAppliedRule(rule)
return []*memo.GroupExpr{old.GetExpr()}, true, false, nil
}
func (s *testCascadesSuite) TestAppliedRuleSet(c *C) {
rule := fakeTransformation{}
rule.pattern = memo.NewPattern(memo.OperandProjection, memo.EngineAll)
s.optimizer.ResetTransformationRules(map[memo.Operand][]Transformation{
memo.OperandProjection: {
&rule,
},
})
defer func() {
s.optimizer.ResetTransformationRules(DefaultRuleBatches...)
}()
stmt, err := s.ParseOneStmt("select 1", "", "")
c.Assert(err, IsNil)
p, _, err := plannercore.BuildLogicalPlan(context.Background(), s.sctx, stmt, s.is)
c.Assert(err, IsNil)
logic, ok := p.(plannercore.LogicalPlan)
c.Assert(ok, IsTrue)
group := memo.Convert2Group(logic)
err = s.optimizer.onPhaseExploration(s.sctx, group)
c.Assert(err, IsNil)
c.Assert(rule.appliedTimes, Equals, 1)
}