Files
tidb/executor/analyze_test.go

93 lines
2.5 KiB
Go

// Copyright 2017 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 executor_test
import (
"fmt"
"strings"
. "github.com/pingcap/check"
"github.com/pingcap/tidb/ast"
"github.com/pingcap/tidb/executor"
"github.com/pingcap/tidb/util/testkit"
"github.com/pingcap/tidb/util/testleak"
"github.com/pingcap/tidb/util/types"
)
func (s *testSuite) TestAnalyzeTable(c *C) {
defer func() {
testleak.AfterTest(c)()
}()
tk := testkit.NewTestKit(c, s.store)
tk.MustExec("use test")
tk.MustExec("drop table if exists t1")
tk.MustExec("create table t1 (a int)")
tk.MustExec("create index ind_a on t1 (a)")
tk.MustExec("insert into t1 (a) values (1)")
result := tk.MustQuery("explain select * from t1 where t1.a = 1")
rowStr := fmt.Sprintf("%s", result.Rows())
c.Check(strings.Split(rowStr, "{")[0], Equals, "[[IndexScan_5 ")
tk.MustExec("analyze table t1")
result = tk.MustQuery("explain select * from t1 where t1.a = 1")
rowStr = fmt.Sprintf("%s", result.Rows())
c.Check(strings.Split(rowStr, "{")[0], Equals, "[[TableScan_4 ")
}
type recordSet struct {
data []types.Datum
count int
cursor int
}
func (r *recordSet) Fields() ([]*ast.ResultField, error) {
return nil, nil
}
func (r *recordSet) Next() (*ast.Row, error) {
if r.cursor == r.count {
return nil, nil
}
r.cursor++
return &ast.Row{Data: []types.Datum{r.data[r.cursor-1]}}, nil
}
func (r *recordSet) Close() error {
r.cursor = 0
return nil
}
func (s *testSuite) TestCollectSamplesAndEstimateNDVs(c *C) {
count := 10000
rs := &recordSet{
data: make([]types.Datum, count),
count: count,
cursor: 0,
}
start := 1000 // 1000 values is null
for i := start; i < rs.count; i++ {
rs.data[i].SetInt64(int64(i))
}
for i := start; i < rs.count; i += 3 {
rs.data[i].SetInt64(rs.data[i].GetInt64() + 1)
}
for i := start; i < rs.count; i += 5 {
rs.data[i].SetInt64(rs.data[i].GetInt64() + 2)
}
cnt, _, ndvs, err := executor.CollectSamplesAndEstimateNDVs(rs, 1)
c.Assert(err, IsNil)
c.Assert(cnt, Equals, int64(rs.count))
c.Assert(ndvs[0], Equals, int64(6624))
}