forked from pingcap/tidb
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
plan, executor: give special treat for index columns when analyze tab…
…le (pingcap#2436) * plan/statistics: statistics support add index info
- Loading branch information
Showing
16 changed files
with
519 additions
and
144 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,170 @@ | ||
| // 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 | ||
|
|
||
| import ( | ||
| "math/rand" | ||
|
|
||
| "github.com/juju/errors" | ||
| "github.com/pingcap/tidb/ast" | ||
| "github.com/pingcap/tidb/context" | ||
| "github.com/pingcap/tidb/expression" | ||
| "github.com/pingcap/tidb/meta" | ||
| "github.com/pingcap/tidb/model" | ||
| "github.com/pingcap/tidb/plan/statistics" | ||
| "github.com/pingcap/tidb/plan/statscache" | ||
| "github.com/pingcap/tidb/util/types" | ||
| ) | ||
|
|
||
| var _ Executor = &AnalyzeExec{} | ||
|
|
||
| // AnalyzeExec represents Analyze executor. | ||
| type AnalyzeExec struct { | ||
| schema *expression.Schema | ||
| tblInfo *model.TableInfo | ||
| ctx context.Context | ||
| idxOffsets []int | ||
| colOffsets []int | ||
| pkOffset int | ||
| Srcs []Executor | ||
| } | ||
|
|
||
| const ( | ||
| maxSampleCount = 10000 | ||
| defaultBucketCount = 256 | ||
| ) | ||
|
|
||
| // Schema implements the Executor Schema interface. | ||
| func (e *AnalyzeExec) Schema() *expression.Schema { | ||
| return e.schema | ||
| } | ||
|
|
||
| // Close implements the Executor Close interface. | ||
| func (e *AnalyzeExec) Close() error { | ||
| for _, src := range e.Srcs { | ||
| err := src.Close() | ||
| if err != nil { | ||
| return errors.Trace(err) | ||
| } | ||
| } | ||
| return nil | ||
| } | ||
|
|
||
| // Next implements the Executor Next interface. | ||
| func (e *AnalyzeExec) Next() (*Row, error) { | ||
| for _, src := range e.Srcs { | ||
| ae := src.(*AnalyzeExec) | ||
| var count int64 = -1 | ||
| var sampleRows []*ast.Row | ||
| if ae.colOffsets != nil { | ||
| rs := &recordSet{executor: ae.Srcs[len(ae.Srcs)-1]} | ||
| var err error | ||
| count, sampleRows, err = collectSamples(rs) | ||
| if err != nil { | ||
| return nil, errors.Trace(err) | ||
| } | ||
| } | ||
| columnSamples := rowsToColumnSamples(sampleRows) | ||
| var pkRS ast.RecordSet | ||
| if ae.pkOffset != -1 { | ||
| offset := len(ae.Srcs) - 1 | ||
| if ae.colOffsets != nil { | ||
| offset-- | ||
| } | ||
| pkRS = &recordSet{executor: ae.Srcs[offset]} | ||
| } | ||
| idxRS := make([]ast.RecordSet, 0, len(ae.idxOffsets)) | ||
| for i := range ae.idxOffsets { | ||
| idxRS = append(idxRS, &recordSet{executor: ae.Srcs[i]}) | ||
| } | ||
| err := ae.buildStatisticsAndSaveToKV(count, columnSamples, idxRS, pkRS) | ||
| if err != nil { | ||
| return nil, errors.Trace(err) | ||
| } | ||
| } | ||
| return nil, nil | ||
| } | ||
|
|
||
| func (e *AnalyzeExec) buildStatisticsAndSaveToKV(count int64, columnSamples [][]types.Datum, idxRS []ast.RecordSet, pkRS ast.RecordSet) error { | ||
| txn := e.ctx.Txn() | ||
| statBuilder := &statistics.Builder{ | ||
| Sc: e.ctx.GetSessionVars().StmtCtx, | ||
| TblInfo: e.tblInfo, | ||
| StartTS: int64(txn.StartTS()), | ||
| Count: count, | ||
| NumBuckets: defaultBucketCount, | ||
| ColumnSamples: columnSamples, | ||
| ColOffsets: e.colOffsets, | ||
| IdxRecords: idxRS, | ||
| IdxOffsets: e.idxOffsets, | ||
| PkRecords: pkRS, | ||
| PkOffset: e.pkOffset, | ||
| } | ||
| t, err := statBuilder.NewTable() | ||
| if err != nil { | ||
| return errors.Trace(err) | ||
| } | ||
| statscache.SetStatisticsTableCache(e.tblInfo.ID, t) | ||
| tpb, err := t.ToPB() | ||
| if err != nil { | ||
| return errors.Trace(err) | ||
| } | ||
| m := meta.NewMeta(txn) | ||
| err = m.SetTableStats(e.tblInfo.ID, tpb) | ||
| if err != nil { | ||
| return errors.Trace(err) | ||
| } | ||
| return nil | ||
| } | ||
|
|
||
| // collectSamples collects sample from the result set, using Reservoir Sampling algorithm. | ||
| // See https://en.wikipedia.org/wiki/Reservoir_sampling | ||
| func collectSamples(e ast.RecordSet) (count int64, samples []*ast.Row, err error) { | ||
| for { | ||
| row, err := e.Next() | ||
| if err != nil { | ||
| return count, samples, errors.Trace(err) | ||
| } | ||
| if row == nil { | ||
| break | ||
| } | ||
| if len(samples) < maxSampleCount { | ||
| samples = append(samples, row) | ||
| } else { | ||
| shouldAdd := rand.Int63n(count) < maxSampleCount | ||
| if shouldAdd { | ||
| idx := rand.Intn(maxSampleCount) | ||
| samples[idx] = row | ||
| } | ||
| } | ||
| count++ | ||
| } | ||
| return count, samples, nil | ||
| } | ||
|
|
||
| func rowsToColumnSamples(rows []*ast.Row) [][]types.Datum { | ||
| if len(rows) == 0 { | ||
| return nil | ||
| } | ||
| columnSamples := make([][]types.Datum, len(rows[0].Data)) | ||
| for i := range columnSamples { | ||
| columnSamples[i] = make([]types.Datum, len(rows)) | ||
| } | ||
| for j, row := range rows { | ||
| for i, val := range row.Data { | ||
| columnSamples[i][j] = val | ||
| } | ||
| } | ||
| return columnSamples | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,40 @@ | ||
| // 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/util/testkit" | ||
| "github.com/pingcap/tidb/util/testleak" | ||
| ) | ||
|
|
||
| func (s *testSuite) TestAnalyzeTable(c *C) { | ||
| defer 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 ") | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.