From e3b49f6b43b640126055dda89bea4febbcd45a30 Mon Sep 17 00:00:00 2001
From: tiancaiamao <tiancaiamao@gmail.com>
Date: Sat, 20 Oct 2018 11:40:14 +0800
Subject: [PATCH 1/3] *: move `Statement` and `RecordSet` from ast to sqlexec
 package

Statement use RecordSet and RecordSet use chunk
After moving them out, the ast package do not depends on chunk any more
---
 ast/ast.go                              | 40 -------------------------
 ddl/db_change_test.go                   |  3 +-
 executor/adapter.go                     | 11 +++----
 executor/prepared.go                    |  2 +-
 server/driver_tidb.go                   |  3 +-
 session/bench_test.go                   |  4 +--
 session/session.go                      | 27 +++++++++--------
 session/tidb.go                         | 11 +++----
 session/tidb_test.go                    |  6 ++--
 statistics/ddl.go                       |  3 +-
 statistics/sample.go                    |  3 +-
 statistics/sample_test.go               |  4 +--
 statistics/statistics_test.go           | 15 +++++-----
 store/mockstore/mocktikv/analyze.go     |  4 +--
 util/mock/context.go                    |  3 +-
 util/sqlexec/restricted_sql_executor.go | 40 ++++++++++++++++++++++++-
 util/testkit/testkit.go                 | 10 +++----
 17 files changed, 96 insertions(+), 93 deletions(-)

diff --git a/ast/ast.go b/ast/ast.go
index eef7ac63016fc..a99d806ca9020 100644
--- a/ast/ast.go
+++ b/ast/ast.go
@@ -20,8 +20,6 @@ import (
 
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/types"
-	"github.com/pingcap/tidb/util/chunk"
-	"golang.org/x/net/context"
 )
 
 // Node is the basic element of the AST.
@@ -130,22 +128,6 @@ type ResultField struct {
 	Referenced bool
 }
 
-// RecordSet is an abstract result set interface to help get data from Plan.
-type RecordSet interface {
-	// Fields gets result fields.
-	Fields() []*ResultField
-
-	// Next reads records into chunk.
-	Next(ctx context.Context, chk *chunk.Chunk) error
-
-	// NewChunk creates a new chunk with initial capacity.
-	NewChunk() *chunk.Chunk
-
-	// Close closes the underlying iterator, call Next after Close will
-	// restart the iteration.
-	Close() error
-}
-
 // ResultSetNode interface has a ResultFields property, represents a Node that returns result set.
 // Implementations include SelectStmt, SubqueryExpr, TableSource, TableName and Join.
 type ResultSetNode interface {
@@ -159,28 +141,6 @@ type SensitiveStmtNode interface {
 	SecureText() string
 }
 
-// Statement is an interface for SQL execution.
-// NOTE: all Statement implementations must be safe for
-// concurrent using by multiple goroutines.
-// If the Exec method requires any Execution domain local data,
-// they must be held out of the implementing instance.
-type Statement interface {
-	// OriginText gets the origin SQL text.
-	OriginText() string
-
-	// Exec executes SQL and gets a Recordset.
-	Exec(ctx context.Context) (RecordSet, error)
-
-	// IsPrepared returns whether this statement is prepared statement.
-	IsPrepared() bool
-
-	// IsReadOnly returns if the statement is read only. For example: SelectStmt without lock.
-	IsReadOnly() bool
-
-	// RebuildPlan rebuilds the plan of the statement.
-	RebuildPlan() (schemaVersion int64, err error)
-}
-
 // Visitor visits a Node.
 type Visitor interface {
 	// Enter is called before children nodes are visited.
diff --git a/ddl/db_change_test.go b/ddl/db_change_test.go
index 9cbc5e4818b6d..bac31f693cd78 100644
--- a/ddl/db_change_test.go
+++ b/ddl/db_change_test.go
@@ -34,6 +34,7 @@ import (
 	"github.com/pingcap/tidb/store/mockstore"
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/admin"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pingcap/tidb/util/testkit"
 	"github.com/pingcap/tidb/util/testleak"
 	"github.com/pkg/errors"
@@ -229,7 +230,7 @@ func (s *testStateChangeSuite) test(c *C, tableName, alterTableSQL string, testI
 type stateCase struct {
 	session            session.Session
 	rawStmt            ast.StmtNode
-	stmt               ast.Statement
+	stmt               sqlexec.Statement
 	expectedExecErr    error
 	expectedCompileErr error
 }
diff --git a/executor/adapter.go b/executor/adapter.go
index b5062cf80112c..3c1593769b7b5 100644
--- a/executor/adapter.go
+++ b/executor/adapter.go
@@ -36,6 +36,7 @@ import (
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/logutil"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
@@ -45,7 +46,7 @@ type processinfoSetter interface {
 	SetProcessInfo(string, time.Time, byte)
 }
 
-// recordSet wraps an executor, implements ast.RecordSet interface
+// recordSet wraps an executor, implements sqlexec.RecordSet interface
 type recordSet struct {
 	fields     []*ast.ResultField
 	executor   Executor
@@ -122,7 +123,7 @@ func (a *recordSet) Close() error {
 	return errors.Trace(err)
 }
 
-// ExecStmt implements the ast.Statement interface, it builds a planner.Plan to an ast.Statement.
+// ExecStmt implements the sqlexec.Statement interface, it builds a planner.Plan to an sqlexec.Statement.
 type ExecStmt struct {
 	// InfoSchema stores a reference to the schema information.
 	InfoSchema infoschema.InfoSchema
@@ -183,8 +184,8 @@ func (a *ExecStmt) RebuildPlan() (int64, error) {
 
 // Exec builds an Executor from a plan. If the Executor doesn't return result,
 // like the INSERT, UPDATE statements, it executes in this function, if the Executor returns
-// result, execution is done after this function returns, in the returned ast.RecordSet Next method.
-func (a *ExecStmt) Exec(ctx context.Context) (ast.RecordSet, error) {
+// result, execution is done after this function returns, in the returned sqlexec.RecordSet Next method.
+func (a *ExecStmt) Exec(ctx context.Context) (sqlexec.RecordSet, error) {
 	a.StartTime = time.Now()
 	sctx := a.Ctx
 	if _, ok := a.Plan.(*plannercore.Analyze); ok && sctx.GetSessionVars().InRestrictedSQL {
@@ -247,7 +248,7 @@ func (a *ExecStmt) Exec(ctx context.Context) (ast.RecordSet, error) {
 	}, nil
 }
 
-func (a *ExecStmt) handleNoDelayExecutor(ctx context.Context, sctx sessionctx.Context, e Executor) (ast.RecordSet, error) {
+func (a *ExecStmt) handleNoDelayExecutor(ctx context.Context, sctx sessionctx.Context, e Executor) (sqlexec.RecordSet, error) {
 	// Check if "tidb_snapshot" is set for the write executors.
 	// In history read mode, we can not do write operations.
 	switch e.(type) {
diff --git a/executor/prepared.go b/executor/prepared.go
index 5fded52276104..d857979c4b69a 100644
--- a/executor/prepared.go
+++ b/executor/prepared.go
@@ -240,7 +240,7 @@ func (e *DeallocateExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 }
 
 // CompileExecutePreparedStmt compiles a session Execute command to a stmt.Statement.
-func CompileExecutePreparedStmt(ctx sessionctx.Context, ID uint32, args ...interface{}) (ast.Statement, error) {
+func CompileExecutePreparedStmt(ctx sessionctx.Context, ID uint32, args ...interface{}) (sqlexec.Statement, error) {
 	execStmt := &ast.ExecuteStmt{ExecID: ID}
 	if err := ResetContextOfStmt(ctx, execStmt); err != nil {
 		return nil, err
diff --git a/server/driver_tidb.go b/server/driver_tidb.go
index 0824ac2018b18..a7df39d6f7683 100644
--- a/server/driver_tidb.go
+++ b/server/driver_tidb.go
@@ -28,6 +28,7 @@ import (
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/auth"
 	"github.com/pingcap/tidb/util/chunk"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
@@ -344,7 +345,7 @@ func (tc *TiDBContext) GetSessionVars() *variable.SessionVars {
 }
 
 type tidbResultSet struct {
-	recordSet ast.RecordSet
+	recordSet sqlexec.RecordSet
 	columns   []*ColumnInfo
 	rows      []chunk.Row
 	closed    bool
diff --git a/session/bench_test.go b/session/bench_test.go
index f19dd711e257f..b68a1bdf76823 100644
--- a/session/bench_test.go
+++ b/session/bench_test.go
@@ -19,10 +19,10 @@ import (
 	"testing"
 	"time"
 
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/store/mockstore"
+	"github.com/pingcap/tidb/util/sqlexec"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
 )
@@ -83,7 +83,7 @@ func prepareJoinBenchData(se Session, colType string, valueFormat string, valueC
 	mustExecute(se, "commit")
 }
 
-func readResult(ctx context.Context, rs ast.RecordSet, count int) {
+func readResult(ctx context.Context, rs sqlexec.RecordSet, count int) {
 	chk := rs.NewChunk()
 	for count > 0 {
 		err := rs.Next(ctx, chk)
diff --git a/session/session.go b/session/session.go
index 5b29952d90400..a44b941e60682 100644
--- a/session/session.go
+++ b/session/session.go
@@ -53,6 +53,7 @@ import (
 	"github.com/pingcap/tidb/util/charset"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/kvcache"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pingcap/tidb/util/timeutil"
 	"github.com/pingcap/tipb/go-binlog"
 	"github.com/pkg/errors"
@@ -63,17 +64,17 @@ import (
 // Session context
 type Session interface {
 	sessionctx.Context
-	Status() uint16                                           // Flag of current status, such as autocommit.
-	LastInsertID() uint64                                     // LastInsertID is the last inserted auto_increment ID.
-	AffectedRows() uint64                                     // Affected rows by latest executed stmt.
-	Execute(context.Context, string) ([]ast.RecordSet, error) // Execute a sql statement.
-	String() string                                           // String is used to debug.
+	Status() uint16                                               // Flag of current status, such as autocommit.
+	LastInsertID() uint64                                         // LastInsertID is the last inserted auto_increment ID.
+	AffectedRows() uint64                                         // Affected rows by latest executed stmt.
+	Execute(context.Context, string) ([]sqlexec.RecordSet, error) // Execute a sql statement.
+	String() string                                               // String is used to debug.
 	CommitTxn(context.Context) error
 	RollbackTxn(context.Context) error
 	// PrepareStmt executes prepare statement in binary protocol.
 	PrepareStmt(sql string) (stmtID uint32, paramCount int, fields []*ast.ResultField, err error)
 	// ExecutePreparedStmt executes a prepared statement.
-	ExecutePreparedStmt(ctx context.Context, stmtID uint32, param ...interface{}) (ast.RecordSet, error)
+	ExecutePreparedStmt(ctx context.Context, stmtID uint32, param ...interface{}) (sqlexec.RecordSet, error)
 	DropPreparedStmt(stmtID uint32) error
 	SetClientCapability(uint32) // Set client capability flags.
 	SetConnectionID(uint64)
@@ -97,7 +98,7 @@ var (
 
 type stmtRecord struct {
 	stmtID  uint32
-	st      ast.Statement
+	st      sqlexec.Statement
 	stmtCtx *stmtctx.StatementContext
 	params  []interface{}
 }
@@ -108,7 +109,7 @@ type StmtHistory struct {
 }
 
 // Add appends a stmt to history list.
-func (h *StmtHistory) Add(stmtID uint32, st ast.Statement, stmtCtx *stmtctx.StatementContext, params ...interface{}) {
+func (h *StmtHistory) Add(stmtID uint32, st sqlexec.Statement, stmtCtx *stmtctx.StatementContext, params ...interface{}) {
 	s := &stmtRecord{
 		stmtID:  stmtID,
 		st:      st,
@@ -613,7 +614,7 @@ func createSessionWithDomainFunc(store kv.Storage) func(*domain.Domain) (pools.R
 	}
 }
 
-func drainRecordSet(ctx context.Context, se *session, rs ast.RecordSet) ([]chunk.Row, error) {
+func drainRecordSet(ctx context.Context, se *session, rs sqlexec.RecordSet) ([]chunk.Row, error) {
 	var rows []chunk.Row
 	chk := rs.NewChunk()
 	for {
@@ -728,7 +729,7 @@ func (s *session) SetProcessInfo(sql string, t time.Time, command byte) {
 	s.processInfo.Store(pi)
 }
 
-func (s *session) executeStatement(ctx context.Context, connID uint64, stmtNode ast.StmtNode, stmt ast.Statement, recordSets []ast.RecordSet) ([]ast.RecordSet, error) {
+func (s *session) executeStatement(ctx context.Context, connID uint64, stmtNode ast.StmtNode, stmt sqlexec.Statement, recordSets []sqlexec.RecordSet) ([]sqlexec.RecordSet, error) {
 	s.SetValue(sessionctx.QueryString, stmt.OriginText())
 	if _, ok := stmtNode.(ast.DDLNode); ok {
 		s.SetValue(sessionctx.LastExecuteDDL, true)
@@ -757,7 +758,7 @@ func (s *session) executeStatement(ctx context.Context, connID uint64, stmtNode
 	return recordSets, nil
 }
 
-func (s *session) Execute(ctx context.Context, sql string) (recordSets []ast.RecordSet, err error) {
+func (s *session) Execute(ctx context.Context, sql string) (recordSets []sqlexec.RecordSet, err error) {
 	if recordSets, err = s.execute(ctx, sql); err != nil {
 		err = errors.Trace(err)
 		s.sessionVars.StmtCtx.AppendError(err)
@@ -765,7 +766,7 @@ func (s *session) Execute(ctx context.Context, sql string) (recordSets []ast.Rec
 	return
 }
 
-func (s *session) execute(ctx context.Context, sql string) (recordSets []ast.RecordSet, err error) {
+func (s *session) execute(ctx context.Context, sql string) (recordSets []sqlexec.RecordSet, err error) {
 	s.PrepareTxnCtx(ctx)
 	connID := s.sessionVars.ConnectionID
 	err = s.loadCommonGlobalVariablesIfNeeded()
@@ -908,7 +909,7 @@ func checkArgs(args ...interface{}) error {
 }
 
 // ExecutePreparedStmt executes a prepared statement.
-func (s *session) ExecutePreparedStmt(ctx context.Context, stmtID uint32, args ...interface{}) (ast.RecordSet, error) {
+func (s *session) ExecutePreparedStmt(ctx context.Context, stmtID uint32, args ...interface{}) (sqlexec.RecordSet, error) {
 	err := checkArgs(args...)
 	if err != nil {
 		return nil, errors.Trace(err)
diff --git a/session/tidb.go b/session/tidb.go
index 1357c3e753f01..460620da25b50 100644
--- a/session/tidb.go
+++ b/session/tidb.go
@@ -34,6 +34,7 @@ import (
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/chunk"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
@@ -134,16 +135,16 @@ func Parse(ctx sessionctx.Context, src string) ([]ast.StmtNode, error) {
 }
 
 // Compile is safe for concurrent use by multiple goroutines.
-func Compile(ctx context.Context, sctx sessionctx.Context, stmtNode ast.StmtNode) (ast.Statement, error) {
+func Compile(ctx context.Context, sctx sessionctx.Context, stmtNode ast.StmtNode) (sqlexec.Statement, error) {
 	compiler := executor.Compiler{Ctx: sctx}
 	stmt, err := compiler.Compile(ctx, stmtNode)
 	return stmt, errors.Trace(err)
 }
 
-// runStmt executes the ast.Statement and commit or rollback the current transaction.
-func runStmt(ctx context.Context, sctx sessionctx.Context, s ast.Statement) (ast.RecordSet, error) {
+// runStmt executes the sqlexec.Statement and commit or rollback the current transaction.
+func runStmt(ctx context.Context, sctx sessionctx.Context, s sqlexec.Statement) (sqlexec.RecordSet, error) {
 	var err error
-	var rs ast.RecordSet
+	var rs sqlexec.RecordSet
 	se := sctx.(*session)
 	rs, err = s.Exec(ctx)
 	// All the history should be added here.
@@ -194,7 +195,7 @@ func GetHistory(ctx sessionctx.Context) *StmtHistory {
 }
 
 // GetRows4Test gets all the rows from a RecordSet, only used for test.
-func GetRows4Test(ctx context.Context, sctx sessionctx.Context, rs ast.RecordSet) ([]chunk.Row, error) {
+func GetRows4Test(ctx context.Context, sctx sessionctx.Context, rs sqlexec.RecordSet) ([]chunk.Row, error) {
 	if rs == nil {
 		return nil, nil
 	}
diff --git a/session/tidb_test.go b/session/tidb_test.go
index 1821351008d94..10c0ad259dea8 100644
--- a/session/tidb_test.go
+++ b/session/tidb_test.go
@@ -22,7 +22,6 @@ import (
 	"time"
 
 	. "github.com/pingcap/check"
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/store/mockstore"
@@ -30,6 +29,7 @@ import (
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/auth"
 	"github.com/pingcap/tidb/util/logutil"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pingcap/tidb/util/testleak"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
@@ -195,7 +195,7 @@ func removeStore(c *C, dbPath string) {
 	os.RemoveAll(dbPath)
 }
 
-func exec(se Session, sql string, args ...interface{}) (ast.RecordSet, error) {
+func exec(se Session, sql string, args ...interface{}) (sqlexec.RecordSet, error) {
 	ctx := context.Background()
 	if len(args) == 0 {
 		rs, err := se.Execute(ctx, sql)
@@ -215,7 +215,7 @@ func exec(se Session, sql string, args ...interface{}) (ast.RecordSet, error) {
 	return rs, nil
 }
 
-func mustExecSQL(c *C, se Session, sql string, args ...interface{}) ast.RecordSet {
+func mustExecSQL(c *C, se Session, sql string, args ...interface{}) sqlexec.RecordSet {
 	rs, err := exec(se, sql, args...)
 	c.Assert(err, IsNil)
 	return rs
diff --git a/statistics/ddl.go b/statistics/ddl.go
index da1052249028c..022583ca2198e 100644
--- a/statistics/ddl.go
+++ b/statistics/ddl.go
@@ -16,7 +16,6 @@ package statistics
 import (
 	"fmt"
 
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/ddl/util"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
@@ -119,7 +118,7 @@ func (h *Handle) insertColStats2KV(physicalID int64, colInfo *model.ColumnInfo)
 	// If we didn't update anything by last SQL, it means the stats of this table does not exist.
 	if h.mu.ctx.GetSessionVars().StmtCtx.AffectedRows() > 0 {
 		// By this step we can get the count of this table, then we can sure the count and repeats of bucket.
-		var rs []ast.RecordSet
+		var rs []sqlexec.RecordSet
 		rs, err = exec.Execute(ctx, fmt.Sprintf("select count from mysql.stats_meta where table_id = %d", physicalID))
 		if len(rs) > 0 {
 			defer terror.Call(rs[0].Close)
diff --git a/statistics/sample.go b/statistics/sample.go
index cac1d4229cdaa..9e43f984873a6 100644
--- a/statistics/sample.go
+++ b/statistics/sample.go
@@ -23,6 +23,7 @@ import (
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pingcap/tipb/go-tipb"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
@@ -132,7 +133,7 @@ func (c *SampleCollector) collect(sc *stmtctx.StatementContext, d types.Datum) e
 // Also, if primary key is handle, it will directly build histogram for it.
 type SampleBuilder struct {
 	Sc              *stmtctx.StatementContext
-	RecordSet       ast.RecordSet
+	RecordSet       sqlexec.RecordSet
 	ColLen          int // ColLen is the number of columns need to be sampled.
 	PkBuilder       *SortedBuilder
 	MaxBucketSize   int64
diff --git a/statistics/sample_test.go b/statistics/sample_test.go
index dc3cc3e222303..66d8ceec313fb 100644
--- a/statistics/sample_test.go
+++ b/statistics/sample_test.go
@@ -17,18 +17,18 @@ import (
 	"time"
 
 	. "github.com/pingcap/check"
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/mock"
+	"github.com/pingcap/tidb/util/sqlexec"
 )
 
 var _ = Suite(&testSampleSuite{})
 
 type testSampleSuite struct {
 	count int
-	rs    ast.RecordSet
+	rs    sqlexec.RecordSet
 }
 
 func (s *testSampleSuite) SetUpSuite(c *C) {
diff --git a/statistics/statistics_test.go b/statistics/statistics_test.go
index 02c9da7ae279b..6b71236e76164 100644
--- a/statistics/statistics_test.go
+++ b/statistics/statistics_test.go
@@ -30,6 +30,7 @@ import (
 	"github.com/pingcap/tidb/util/codec"
 	"github.com/pingcap/tidb/util/mock"
 	"github.com/pingcap/tidb/util/ranger"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
@@ -43,8 +44,8 @@ var _ = Suite(&testStatisticsSuite{})
 type testStatisticsSuite struct {
 	count   int
 	samples []types.Datum
-	rc      ast.RecordSet
-	pk      ast.RecordSet
+	rc      sqlexec.RecordSet
+	pk      sqlexec.RecordSet
 }
 
 type recordSet struct {
@@ -169,7 +170,7 @@ func encodeKey(key types.Datum) types.Datum {
 	return types.NewBytesDatum(buf)
 }
 
-func buildPK(sctx sessionctx.Context, numBuckets, id int64, records ast.RecordSet) (int64, *Histogram, error) {
+func buildPK(sctx sessionctx.Context, numBuckets, id int64, records sqlexec.RecordSet) (int64, *Histogram, error) {
 	b := NewSortedBuilder(sctx.GetSessionVars().StmtCtx, numBuckets, id, types.NewFieldType(mysql.TypeLonglong))
 	ctx := context.Background()
 	for {
@@ -193,7 +194,7 @@ func buildPK(sctx sessionctx.Context, numBuckets, id int64, records ast.RecordSe
 	return b.Count, b.hist, nil
 }
 
-func buildIndex(sctx sessionctx.Context, numBuckets, id int64, records ast.RecordSet) (int64, *Histogram, *CMSketch, error) {
+func buildIndex(sctx sessionctx.Context, numBuckets, id int64, records sqlexec.RecordSet) (int64, *Histogram, *CMSketch, error) {
 	b := NewSortedBuilder(sctx.GetSessionVars().StmtCtx, numBuckets, id, types.NewFieldType(mysql.TypeBlob))
 	cms := NewCMSketch(8, 2048)
 	ctx := context.Background()
@@ -282,7 +283,7 @@ func (s *testStatisticsSuite) TestBuild(c *C) {
 	checkRepeats(c, col)
 	c.Assert(col.Len(), Equals, 250)
 
-	tblCount, col, _, err := buildIndex(ctx, bucketCount, 1, ast.RecordSet(s.rc))
+	tblCount, col, _, err := buildIndex(ctx, bucketCount, 1, sqlexec.RecordSet(s.rc))
 	c.Check(err, IsNil)
 	checkRepeats(c, col)
 	col.PreCalculateScalar()
@@ -299,7 +300,7 @@ func (s *testStatisticsSuite) TestBuild(c *C) {
 	c.Check(int(count), Equals, 0)
 
 	s.pk.(*recordSet).cursor = 0
-	tblCount, col, err = buildPK(ctx, bucketCount, 4, ast.RecordSet(s.pk))
+	tblCount, col, err = buildPK(ctx, bucketCount, 4, sqlexec.RecordSet(s.pk))
 	c.Check(err, IsNil)
 	checkRepeats(c, col)
 	col.PreCalculateScalar()
@@ -338,7 +339,7 @@ func (s *testStatisticsSuite) TestBuild(c *C) {
 func (s *testStatisticsSuite) TestHistogramProtoConversion(c *C) {
 	ctx := mock.NewContext()
 	s.rc.Close()
-	tblCount, col, _, err := buildIndex(ctx, 256, 1, ast.RecordSet(s.rc))
+	tblCount, col, _, err := buildIndex(ctx, 256, 1, sqlexec.RecordSet(s.rc))
 	c.Check(err, IsNil)
 	c.Check(int(tblCount), Equals, 100000)
 
diff --git a/store/mockstore/mocktikv/analyze.go b/store/mockstore/mocktikv/analyze.go
index bbda6c3020b00..9b9f799880acb 100644
--- a/store/mockstore/mocktikv/analyze.go
+++ b/store/mockstore/mocktikv/analyze.go
@@ -188,7 +188,7 @@ func (h *rpcHandler) handleAnalyzeColumnsReq(req *coprocessor.Request, analyzeRe
 	return &coprocessor.Response{Data: data}, nil
 }
 
-// Fields implements the ast.RecordSet Fields interface.
+// Fields implements the sqlexec.RecordSet Fields interface.
 func (e *analyzeColumnsExec) Fields() []*ast.ResultField {
 	return e.fields
 }
@@ -232,7 +232,7 @@ func (e *analyzeColumnsExec) NewChunk() *chunk.Chunk {
 	return chunk.NewChunkWithCapacity(fields, 1)
 }
 
-// Close implements the ast.RecordSet Close interface.
+// Close implements the sqlexec.RecordSet Close interface.
 func (e *analyzeColumnsExec) Close() error {
 	return nil
 }
diff --git a/util/mock/context.go b/util/mock/context.go
index 2eb7631e16769..e33879460288b 100644
--- a/util/mock/context.go
+++ b/util/mock/context.go
@@ -19,7 +19,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/owner"
 	"github.com/pingcap/tidb/sessionctx"
@@ -50,7 +49,7 @@ type Context struct {
 }
 
 // Execute implements sqlexec.SQLExecutor Execute interface.
-func (c *Context) Execute(ctx context.Context, sql string) ([]ast.RecordSet, error) {
+func (c *Context) Execute(ctx context.Context, sql string) ([]sqlexec.RecordSet, error) {
 	return nil, errors.Errorf("Not Support.")
 }
 
diff --git a/util/sqlexec/restricted_sql_executor.go b/util/sqlexec/restricted_sql_executor.go
index e95574ea8c354..fd1d5adb846de 100644
--- a/util/sqlexec/restricted_sql_executor.go
+++ b/util/sqlexec/restricted_sql_executor.go
@@ -42,7 +42,7 @@ type RestrictedSQLExecutor interface {
 // For example, privilege/privileges package need execute SQL, if it use
 // session.Session.Execute, then privilege/privileges and tidb would become a circle.
 type SQLExecutor interface {
-	Execute(ctx context.Context, sql string) ([]ast.RecordSet, error)
+	Execute(ctx context.Context, sql string) ([]RecordSet, error)
 }
 
 // SQLParser is an interface provides parsing sql statement.
@@ -52,3 +52,41 @@ type SQLExecutor interface {
 type SQLParser interface {
 	ParseSQL(sql, charset, collation string) ([]ast.StmtNode, error)
 }
+
+// Statement is an interface for SQL execution.
+// NOTE: all Statement implementations must be safe for
+// concurrent using by multiple goroutines.
+// If the Exec method requires any Execution domain local data,
+// they must be held out of the implementing instance.
+type Statement interface {
+	// OriginText gets the origin SQL text.
+	OriginText() string
+
+	// Exec executes SQL and gets a Recordset.
+	Exec(ctx context.Context) (RecordSet, error)
+
+	// IsPrepared returns whether this statement is prepared statement.
+	IsPrepared() bool
+
+	// IsReadOnly returns if the statement is read only. For example: SelectStmt without lock.
+	IsReadOnly() bool
+
+	// RebuildPlan rebuilds the plan of the statement.
+	RebuildPlan() (schemaVersion int64, err error)
+}
+
+// RecordSet is an abstract result set interface to help get data from Plan.
+type RecordSet interface {
+	// Fields gets result fields.
+	Fields() []*ast.ResultField
+
+	// Next reads records into chunk.
+	Next(ctx context.Context, chk *chunk.Chunk) error
+
+	// NewChunk creates a new chunk with initial capacity.
+	NewChunk() *chunk.Chunk
+
+	// Close closes the underlying iterator, call Next after Close will
+	// restart the iteration.
+	Close() error
+}
diff --git a/util/testkit/testkit.go b/util/testkit/testkit.go
index 08cc9a2d87355..cea25aab3ef75 100644
--- a/util/testkit/testkit.go
+++ b/util/testkit/testkit.go
@@ -20,9 +20,9 @@ import (
 	"sync/atomic"
 
 	"github.com/pingcap/check"
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/session"
+	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pingcap/tidb/util/testutil"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
@@ -123,7 +123,7 @@ func NewTestKitWithInit(c *check.C, store kv.Storage) *TestKit {
 var connectionID uint64
 
 // Exec executes a sql statement.
-func (tk *TestKit) Exec(sql string, args ...interface{}) (ast.RecordSet, error) {
+func (tk *TestKit) Exec(sql string, args ...interface{}) (sqlexec.RecordSet, error) {
 	var err error
 	if tk.Se == nil {
 		tk.Se, err = session.CreateSession4Test(tk.store)
@@ -133,7 +133,7 @@ func (tk *TestKit) Exec(sql string, args ...interface{}) (ast.RecordSet, error)
 	}
 	ctx := context.Background()
 	if len(args) == 0 {
-		var rss []ast.RecordSet
+		var rss []sqlexec.RecordSet
 		rss, err = tk.Se.Execute(ctx, sql)
 		if err == nil && len(rss) > 0 {
 			return rss[0], nil
@@ -180,9 +180,9 @@ func (tk *TestKit) MustQuery(sql string, args ...interface{}) *Result {
 	return tk.ResultSetToResult(rs, comment)
 }
 
-// ResultSetToResult converts ast.RecordSet to testkit.Result.
+// ResultSetToResult converts sqlexec.RecordSet to testkit.Result.
 // It is used to check results of execute statement in binary mode.
-func (tk *TestKit) ResultSetToResult(rs ast.RecordSet, comment check.CommentInterface) *Result {
+func (tk *TestKit) ResultSetToResult(rs sqlexec.RecordSet, comment check.CommentInterface) *Result {
 	rows, err := session.GetRows4Test(context.Background(), tk.Se, rs)
 	tk.c.Assert(errors.ErrorStack(err), check.Equals, "", comment)
 	err = rs.Close()

From 04661ba2bbd6e000a97b3815feebdbe03af8593e Mon Sep 17 00:00:00 2001
From: tiancaiamao <tiancaiamao@gmail.com>
Date: Mon, 22 Oct 2018 18:44:09 +0800
Subject: [PATCH 2/3] tiny update

---
 model/model.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/model/model.go b/model/model.go
index 1c050ca73da46..b8a9e1c6e4199 100644
--- a/model/model.go
+++ b/model/model.go
@@ -103,7 +103,7 @@ func (c *ColumnInfo) SetDefaultValue(value interface{}) error {
 			c.DefaultValueBit = []byte(v)
 			return nil
 		}
-		return types.ErrInvalidDefault
+		return types.ErrInvalidDefault.GenWithStackByArgs(c.Name)
 	}
 	return nil
 }

From aeb53f458905576ef4d9466873b383f8a0398fbe Mon Sep 17 00:00:00 2001
From: tiancaiamao <tiancaiamao@gmail.com>
Date: Tue, 23 Oct 2018 15:42:53 +0800
Subject: [PATCH 3/3] address comment

---
 parser/types/etc.go   | 146 ------------------------------------------
 types/convert_test.go |   2 +-
 types/datum.go        |  23 +++++++
 types/etc.go          |  84 ++----------------------
 4 files changed, 28 insertions(+), 227 deletions(-)

diff --git a/parser/types/etc.go b/parser/types/etc.go
index 9b535e89cbad6..983b81503b5d8 100644
--- a/parser/types/etc.go
+++ b/parser/types/etc.go
@@ -21,9 +21,7 @@ import (
 	"strings"
 
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/opcode"
 	"github.com/pingcap/tidb/terror"
-	"github.com/pkg/errors"
 )
 
 // IsTypeBlob returns a boolean indicating whether the tp is a blob type.
@@ -42,57 +40,6 @@ func IsTypeChar(tp byte) bool {
 	return tp == mysql.TypeString || tp == mysql.TypeVarchar
 }
 
-// IsTypeVarchar returns a boolean indicating
-// whether the tp is the varchar type like a varstring type or a varchar type.
-func IsTypeVarchar(tp byte) bool {
-	return tp == mysql.TypeVarString || tp == mysql.TypeVarchar
-}
-
-// IsTypeUnspecified returns a boolean indicating whether the tp is the Unspecified type.
-func IsTypeUnspecified(tp byte) bool {
-	return tp == mysql.TypeUnspecified
-}
-
-// IsTypePrefixable returns a boolean indicating
-// whether an index on a column with the tp can be defined with a prefix.
-func IsTypePrefixable(tp byte) bool {
-	return IsTypeBlob(tp) || IsTypeChar(tp)
-}
-
-// IsTypeFractionable returns a boolean indicating
-// whether the tp can has time fraction.
-func IsTypeFractionable(tp byte) bool {
-	return tp == mysql.TypeDatetime || tp == mysql.TypeDuration || tp == mysql.TypeTimestamp
-}
-
-// IsTypeTime returns a boolean indicating
-// whether the tp is time type like datetime, date or timestamp.
-func IsTypeTime(tp byte) bool {
-	return tp == mysql.TypeDatetime || tp == mysql.TypeDate || tp == mysql.TypeTimestamp
-}
-
-// IsTypeNumeric returns a boolean indicating whether the tp is numeric type.
-func IsTypeNumeric(tp byte) bool {
-	switch tp {
-	case mysql.TypeBit, mysql.TypeTiny, mysql.TypeInt24, mysql.TypeLong, mysql.TypeLonglong, mysql.TypeNewDecimal,
-		mysql.TypeDecimal, mysql.TypeFloat, mysql.TypeDouble, mysql.TypeShort:
-		return true
-	}
-	return false
-}
-
-// IsTemporalWithDate returns a boolean indicating
-// whether the tp is time type with date.
-func IsTemporalWithDate(tp byte) bool {
-	return IsTypeTime(tp)
-}
-
-// IsString returns a boolean indicating
-// whether the field type is a string type.
-func IsString(tp byte) bool {
-	return IsTypeChar(tp) || IsTypeBlob(tp) || IsTypeVarchar(tp) || IsTypeUnspecified(tp)
-}
-
 var type2Str = map[byte]string{
 	mysql.TypeBit:        "bit",
 	mysql.TypeBlob:       "text",
@@ -123,38 +70,11 @@ var type2Str = map[byte]string{
 	mysql.TypeYear:       "year",
 }
 
-var kind2Str = map[byte]string{
-	KindNull:          "null",
-	KindInt64:         "bigint",
-	KindUint64:        "unsigned bigint",
-	KindFloat32:       "float",
-	KindFloat64:       "double",
-	KindString:        "char",
-	KindBytes:         "bytes",
-	KindBinaryLiteral: "bit/hex literal",
-	KindMysqlDecimal:  "decimal",
-	KindMysqlDuration: "time",
-	KindMysqlEnum:     "enum",
-	KindMysqlBit:      "bit",
-	KindMysqlSet:      "set",
-	KindMysqlTime:     "datetime",
-	KindInterface:     "interface",
-	KindMinNotNull:    "min_not_null",
-	KindMaxValue:      "max_value",
-	KindRaw:           "raw",
-	KindMysqlJSON:     "json",
-}
-
 // TypeStr converts tp to a string.
 func TypeStr(tp byte) (r string) {
 	return type2Str[tp]
 }
 
-// KindStr converts kind to a string.
-func KindStr(kind byte) (r string) {
-	return kind2Str[kind]
-}
-
 // TypeToStr converts a field to a string.
 // It is used for converting Text to Blob,
 // or converting Char to Binary.
@@ -174,80 +94,14 @@ func TypeToStr(tp byte, cs string) (r string) {
 	return ts
 }
 
-// InvOp2 returns an invalid operation error.
-func InvOp2(x, y interface{}, o opcode.Op) (interface{}, error) {
-	return nil, errors.Errorf("Invalid operation: %v %v %v (mismatched types %T and %T)", x, o, y, x, y)
-}
-
-// IsTypeTemporal checks if a type is a temporal type.
-func IsTypeTemporal(tp byte) bool {
-	switch tp {
-	case mysql.TypeDuration, mysql.TypeDatetime, mysql.TypeTimestamp,
-		mysql.TypeDate, mysql.TypeNewDate:
-		return true
-	}
-	return false
-}
-
-// Kind constants.
-const (
-	KindNull          byte = 0
-	KindInt64         byte = 1
-	KindUint64        byte = 2
-	KindFloat32       byte = 3
-	KindFloat64       byte = 4
-	KindString        byte = 5
-	KindBytes         byte = 6
-	KindBinaryLiteral byte = 7 // Used for BIT / HEX literals.
-	KindMysqlDecimal  byte = 8
-	KindMysqlDuration byte = 9
-	KindMysqlEnum     byte = 10
-	KindMysqlBit      byte = 11 // Used for BIT table column values.
-	KindMysqlSet      byte = 12
-	KindMysqlTime     byte = 13
-	KindInterface     byte = 14
-	KindMinNotNull    byte = 15
-	KindMaxValue      byte = 16
-	KindRaw           byte = 17
-	KindMysqlJSON     byte = 18
-)
-
 var (
 	dig2bytes = [10]int{0, 1, 1, 2, 2, 3, 3, 4, 4, 4}
 )
 
-// RoundMode is the type for round mode.
-type RoundMode string
-
 // constant values.
 const (
-	ten0 = 1
-	ten1 = 10
-	ten2 = 100
-	ten3 = 1000
-	ten4 = 10000
-	ten5 = 100000
-	ten6 = 1000000
-	ten7 = 10000000
-	ten8 = 100000000
-	ten9 = 1000000000
-
-	maxWordBufLen = 9 // A MyDecimal holds 9 words.
 	digitsPerWord = 9 // A word holds 9 digits.
 	wordSize      = 4 // A word is 4 bytes int32.
-	digMask       = ten8
-	wordBase      = ten9
-	wordMax       = wordBase - 1
-	notFixedDec   = 31
-
-	DivFracIncr = 4
-
-	// ModeHalfEven rounds normally.
-	ModeHalfEven RoundMode = "ModeHalfEven"
-	// Truncate just truncates the decimal.
-	ModeTruncate RoundMode = "Truncate"
-	// Ceiling is not supported now.
-	modeCeiling RoundMode = "Ceiling"
 )
 
 const (
diff --git a/types/convert_test.go b/types/convert_test.go
index f74431f2ef843..35cb6d45df524 100644
--- a/types/convert_test.go
+++ b/types/convert_test.go
@@ -464,7 +464,7 @@ func (s *testTypeConvertSuite) TestStrToNum(c *C) {
 func (s *testTypeConvertSuite) TestFieldTypeToStr(c *C) {
 	defer testleak.AfterTest(c)()
 	v := TypeToStr(mysql.TypeUnspecified, "not binary")
-	c.Assert(v, Equals, type2Str[mysql.TypeUnspecified])
+	c.Assert(v, Equals, TypeStr(mysql.TypeUnspecified))
 	v = TypeToStr(mysql.TypeBlob, charset.CharsetBin)
 	c.Assert(v, Equals, "blob")
 	v = TypeToStr(mysql.TypeString, charset.CharsetBin)
diff --git a/types/datum.go b/types/datum.go
index c683e2e70a88d..959231e633b0f 100644
--- a/types/datum.go
+++ b/types/datum.go
@@ -32,6 +32,29 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+// Kind constants.
+const (
+	KindNull          byte = 0
+	KindInt64         byte = 1
+	KindUint64        byte = 2
+	KindFloat32       byte = 3
+	KindFloat64       byte = 4
+	KindString        byte = 5
+	KindBytes         byte = 6
+	KindBinaryLiteral byte = 7 // Used for BIT / HEX literals.
+	KindMysqlDecimal  byte = 8
+	KindMysqlDuration byte = 9
+	KindMysqlEnum     byte = 10
+	KindMysqlBit      byte = 11 // Used for BIT table column values.
+	KindMysqlSet      byte = 12
+	KindMysqlTime     byte = 13
+	KindInterface     byte = 14
+	KindMinNotNull    byte = 15
+	KindMaxValue      byte = 16
+	KindRaw           byte = 17
+	KindMysqlJSON     byte = 18
+)
+
 // Datum is a data box holds different kind of data.
 // It has better performance and is easier to use than `interface{}`.
 type Datum struct {
diff --git a/types/etc.go b/types/etc.go
index 0629520b4847e..9454b3cb3dcbc 100644
--- a/types/etc.go
+++ b/types/etc.go
@@ -19,7 +19,6 @@ package types
 
 import (
 	"io"
-	"strings"
 
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/parser/opcode"
@@ -29,44 +28,12 @@ import (
 	"github.com/pkg/errors"
 )
 
-// Kind constants.
-const (
-	KindNull          = ast.KindNull
-	KindInt64         = ast.KindInt64
-	KindUint64        = ast.KindUint64
-	KindFloat32       = ast.KindFloat32
-	KindFloat64       = ast.KindFloat64
-	KindString        = ast.KindString
-	KindBytes         = ast.KindBytes
-	KindBinaryLiteral = ast.KindBinaryLiteral
-	KindMysqlDecimal  = ast.KindMysqlDecimal
-	KindMysqlDuration = ast.KindMysqlDuration
-	KindMysqlEnum     = ast.KindMysqlEnum
-	KindMysqlBit      = ast.KindMysqlBit
-	KindMysqlSet      = ast.KindMysqlSet
-	KindMysqlTime     = ast.KindMysqlTime
-	KindInterface     = ast.KindInterface
-	KindMinNotNull    = ast.KindMinNotNull
-	KindMaxValue      = ast.KindMaxValue
-	KindRaw           = ast.KindRaw
-	KindMysqlJSON     = ast.KindMysqlJSON
-)
-
 // IsTypeBlob returns a boolean indicating whether the tp is a blob type.
-func IsTypeBlob(tp byte) bool {
-	switch tp {
-	case mysql.TypeTinyBlob, mysql.TypeMediumBlob, mysql.TypeBlob, mysql.TypeLongBlob:
-		return true
-	default:
-		return false
-	}
-}
+var IsTypeBlob = ast.IsTypeBlob
 
 // IsTypeChar returns a boolean indicating
 // whether the tp is the char type like a string type or a varchar type.
-func IsTypeChar(tp byte) bool {
-	return tp == mysql.TypeString || tp == mysql.TypeVarchar
-}
+var IsTypeChar = ast.IsTypeChar
 
 // IsTypeVarchar returns a boolean indicating
 // whether the tp is the varchar type like a varstring type or a varchar type.
@@ -137,36 +104,6 @@ func IsString(tp byte) bool {
 	return IsTypeChar(tp) || IsTypeBlob(tp) || IsTypeVarchar(tp) || IsTypeUnspecified(tp)
 }
 
-var type2Str = map[byte]string{
-	mysql.TypeBit:        "bit",
-	mysql.TypeBlob:       "text",
-	mysql.TypeDate:       "date",
-	mysql.TypeDatetime:   "datetime",
-	mysql.TypeDecimal:    "unspecified",
-	mysql.TypeNewDecimal: "decimal",
-	mysql.TypeDouble:     "double",
-	mysql.TypeEnum:       "enum",
-	mysql.TypeFloat:      "float",
-	mysql.TypeGeometry:   "geometry",
-	mysql.TypeInt24:      "mediumint",
-	mysql.TypeJSON:       "json",
-	mysql.TypeLong:       "int",
-	mysql.TypeLonglong:   "bigint",
-	mysql.TypeLongBlob:   "longtext",
-	mysql.TypeMediumBlob: "mediumtext",
-	mysql.TypeNull:       "null",
-	mysql.TypeSet:        "set",
-	mysql.TypeShort:      "smallint",
-	mysql.TypeString:     "char",
-	mysql.TypeDuration:   "time",
-	mysql.TypeTimestamp:  "timestamp",
-	mysql.TypeTiny:       "tinyint",
-	mysql.TypeTinyBlob:   "tinytext",
-	mysql.TypeVarchar:    "varchar",
-	mysql.TypeVarString:  "var_string",
-	mysql.TypeYear:       "year",
-}
-
 var kind2Str = map[byte]string{
 	KindNull:          "null",
 	KindInt64:         "bigint",
@@ -190,9 +127,7 @@ var kind2Str = map[byte]string{
 }
 
 // TypeStr converts tp to a string.
-func TypeStr(tp byte) (r string) {
-	return type2Str[tp]
-}
+var TypeStr = ast.TypeStr
 
 // KindStr converts kind to a string.
 func KindStr(kind byte) (r string) {
@@ -205,18 +140,7 @@ func KindStr(kind byte) (r string) {
 // Args:
 //	tp: type enum
 //	cs: charset
-func TypeToStr(tp byte, cs string) (r string) {
-	ts := type2Str[tp]
-	if cs != charset.CharsetBin {
-		return ts
-	}
-	if IsTypeBlob(tp) {
-		ts = strings.Replace(ts, "text", "blob", 1)
-	} else if IsTypeChar(tp) {
-		ts = strings.Replace(ts, "char", "binary", 1)
-	}
-	return ts
-}
+var TypeToStr = ast.TypeToStr
 
 // EOFAsNil filtrates errors,
 // If err is equal to io.EOF returns nil.