func (r *JoinRset) buildSourcePlan(ctx context.Context, t *TableSource) (plan.Plan, []*field.ResultField, error) {
var (
src interface{}
tr *TableRset
err error
)
switch s := t.Source.(type) {
case table.Ident:
fullIdent := s.Full(ctx)
tr, err = newTableRset(fullIdent.Schema.O, fullIdent.Name.O)
if err != nil {
return nil, nil, errors.Trace(err)
}
src = tr
if t.Name == "" {
qualifiedTableName := tr.Schema + "." + tr.Name
if r.tableNames[qualifiedTableName] {
return nil, nil, errors.Errorf("%s: duplicate name %s", r.String(), s)
}
r.tableNames[qualifiedTableName] = true
}
case stmt.Statement:
src = s
default:
return nil, nil, errors.Errorf("invalid table source %T", t.Source)
}
var p plan.Plan
switch x := src.(type) {
case plan.Planner:
if p, err = x.Plan(ctx); err != nil {
return nil, nil, errors.Trace(err)
}
case plan.Plan:
p = x
default:
return nil, nil, errors.Errorf("invalid table source %T, no Plan interface", t.Source)
}
var fields []*field.ResultField
dupNames := make(map[string]struct{}, len(p.GetFields()))
for _, nf := range p.GetFields() {
f := nf.Clone()
if t.Name != "" {
f.TableName = t.Name
}
// duplicate column name in one table is not allowed.
name := strings.ToLower(f.Name)
if _, ok := dupNames[name]; ok {
return nil, nil, errors.Errorf("Duplicate column name '%s'", name)
}
dupNames[name] = struct{}{}
fields = append(fields, f)
}
return p, fields, nil
}
func (r *JoinPlan) filterNode(ctx context.Context, expr expression.Expression, node plan.Plan) (plan.Plan, bool, error) {
if node == nil {
return r, false, nil
}
e2 := expr.Clone()
return node.Filter(ctx, e2)
}
func (r *JoinPlan) findMatchedRows(ctx context.Context, row *plan.Row, p plan.Plan, right bool) (err error) {
r.cursor = 0
r.matchedRows = nil
p.Close()
for {
var cmpRow *plan.Row
cmpRow, err = p.Next(ctx)
if err != nil {
return errors.Trace(err)
}
if cmpRow == nil {
break
}
// Do append(s1, s2) safely. Sometime the s1 capability is larger than its real length, so
// multi append may overwrite last valid data, e.g,
// s1 = make([]interface{}, 0, 1)
// s = append(s1, []interface{}{1})
// ss = append(ss, s)
// s = append(s1, []interface{}{2})
// ss = append(ss, s)
// We will see that ss only contains 2.
joined := make([]interface{}, 0, len(cmpRow.Data)+len(row.Data))
if right {
joined = append(append(joined, cmpRow.Data...), row.Data...)
} else {
joined = append(append(joined, row.Data...), cmpRow.Data...)
}
r.evalArgs[expression.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
return GetIdentValue(name, r.Fields, joined, field.DefaultFieldFlag)
}
var b bool
b, err = expression.EvalBoolExpr(ctx, r.On, r.evalArgs)
if err != nil {
return errors.Trace(err)
}
if b {
cmpRow.Data = joined
keys := make([]*plan.RowKeyEntry, 0, len(row.RowKeys)+len(cmpRow.RowKeys))
cmpRow.RowKeys = append(append(keys, row.RowKeys...), cmpRow.RowKeys...)
r.matchedRows = append(r.matchedRows, cmpRow)
}
}
if len(r.matchedRows) == 0 {
if right {
leftLen := len(r.Fields) - len(r.Right.GetFields())
row.Data = append(make([]interface{}, leftLen), row.Data...)
} else {
rightLen := len(r.Fields) - len(r.Left.GetFields())
row.Data = append(row.Data, make([]interface{}, rightLen)...)
}
r.matchedRows = append(r.matchedRows, row)
}
return nil
}
func (r *JoinPlan) explainNode(w format.Formatter, node plan.Plan) {
sel := !isTableOrIndex(node)
if sel {
w.Format("┌Iterate all rows of virtual table\n")
}
node.Explain(w)
if sel {
w.Format("└Output field names %v\n", field.RFQNames(node.GetFields()))
}
}
func (r *JoinPlan) findMatchedRows(ctx context.Context, row *plan.Row, right bool) (err error) {
var p plan.Plan
if right {
p = r.Left
} else {
p = r.Right
}
r.cursor = 0
r.matchedRows = nil
p.Close()
for {
var cmpRow *plan.Row
cmpRow, err = p.Next(ctx)
if err != nil {
return errors.Trace(err)
}
if cmpRow == nil {
break
}
var joined []interface{}
if right {
joined = append(cmpRow.Data, row.Data...)
} else {
joined = append(row.Data, cmpRow.Data...)
}
r.evalArgs[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
return GetIdentValue(name, r.Fields, joined, field.DefaultFieldFlag)
}
var b bool
b, err = expressions.EvalBoolExpr(ctx, r.On, r.evalArgs)
if err != nil {
return errors.Trace(err)
}
if b {
cmpRow.Data = joined
cmpRow.RowKeys = append(row.RowKeys, cmpRow.RowKeys...)
r.matchedRows = append(r.matchedRows, cmpRow)
}
}
if len(r.matchedRows) == 0 {
if right {
leftLen := len(r.Fields) - len(r.Right.GetFields())
row.Data = append(make([]interface{}, leftLen), row.Data...)
} else {
rightLen := len(r.Fields) - len(r.Left.GetFields())
row.Data = append(row.Data, make([]interface{}, rightLen)...)
}
r.matchedRows = append(r.matchedRows, row)
}
return nil
}
func (v *explainVisitor) explain(p plan.Plan) {
switch x := p.(type) {
case *plan.TableScan:
v.entries = append(v.entries, v.newEntryForTableScan(x))
case *plan.IndexScan:
v.entries = append(v.entries, v.newEntryForIndexScan(x))
case *plan.Sort:
v.sort = true
}
for _, c := range p.GetChildren() {
v.explain(c)
}
}
func (s *UpdateStmt) plan(ctx context.Context) (plan.Plan, error) {
var (
r plan.Plan
err error
)
if s.TableRefs != nil {
r, err = s.TableRefs.Plan(ctx)
if err != nil {
return nil, errors.Trace(err)
}
}
if s.Where != nil {
r, err = (&rsets.WhereRset{Expr: s.Where, Src: r}).Plan(ctx)
if err != nil {
return nil, errors.Trace(err)
}
}
if s.Order != nil {
s.Order.Src = r
r, err = s.Order.Plan(ctx)
if err != nil {
return nil, errors.Trace(err)
}
}
if s.Limit != nil {
s.Limit.Src = r
r, err = s.Limit.Plan(ctx)
if err != nil {
return nil, errors.Trace(err)
}
}
visitor := rsets.NewFromIdentVisitor(r.GetFields(), rsets.UpdateClause)
for i := range s.List {
e, err := s.List[i].Expr.Accept(visitor)
if err != nil {
return nil, errors.Trace(err)
}
s.List[i].Expr = e
}
return r, nil
}
func (e *ExplainExec) prepareExplainInfo(p plan.Plan, parent plan.Plan) error {
for _, child := range p.GetChildren() {
err := e.prepareExplainInfo(child, p)
if err != nil {
return errors.Trace(err)
}
}
explain, err := json.MarshalIndent(p, "", " ")
if err != nil {
return errors.Trace(err)
}
parentStr := ""
if parent != nil {
parentStr = parent.GetID()
}
row := &Row{
Data: types.MakeDatums(p.GetID(), string(explain), parentStr),
}
e.rows = append(e.rows, row)
return nil
}
// Plan implements the plan.Planner interface.
// The whole phase for select is
// `from -> where -> lock -> group by -> having -> select fields -> distinct -> order by -> limit -> final`
func (s *SelectStmt) Plan(ctx context.Context) (plan.Plan, error) {
var (
r plan.Plan
err error
)
if s.From != nil {
r, err = s.From.Plan(ctx)
if err != nil {
return nil, err
}
} else if s.Fields != nil {
// Only evaluate fields values.
fr := &rsets.SelectFromDualRset{Fields: s.Fields}
r, err = fr.Plan(ctx)
if err != nil {
return nil, err
}
}
// Put RowStackFromPlan here so that we can catch the origin from data after above FROM phase.
r = &plans.RowStackFromPlan{Src: r}
if w := s.Where; w != nil {
r, err = (&rsets.WhereRset{Expr: w.Expr, Src: r}).Plan(ctx)
if err != nil {
return nil, err
}
}
lock := s.Lock
if variable.ShouldAutocommit(ctx) {
// Locking of rows for update using SELECT FOR UPDATE only applies when autocommit
// is disabled (either by beginning transaction with START TRANSACTION or by setting
// autocommit to 0. If autocommit is enabled, the rows matching the specification are not locked.
// See: https://dev.mysql.com/doc/refman/5.7/en/innodb-locking-reads.html
lock = coldef.SelectLockNone
}
r = &plans.SelectLockPlan{Src: r, Lock: lock}
if err := s.checkOneColumn(ctx); err != nil {
return nil, errors.Trace(err)
}
// Get select list for futher field values evaluation.
selectList, err := plans.ResolveSelectList(s.Fields, r.GetFields())
if err != nil {
return nil, errors.Trace(err)
}
var groupBy []expression.Expression
if s.GroupBy != nil {
groupBy = s.GroupBy.By
}
if s.Having != nil {
// `having` may contain aggregate functions, and we will add this to hidden fields.
if err = s.Having.CheckAndUpdateSelectList(selectList, groupBy, r.GetFields()); err != nil {
return nil, errors.Trace(err)
}
}
if s.OrderBy != nil {
// `order by` may contain aggregate functions, and we will add this to hidden fields.
if err = s.OrderBy.CheckAndUpdateSelectList(selectList, r.GetFields()); err != nil {
return nil, errors.Trace(err)
}
}
switch {
case !rsets.HasAggFields(selectList.Fields) && s.GroupBy == nil:
// If no group by and no aggregate functions, we will use SelectFieldsPlan.
if r, err = (&rsets.SelectFieldsRset{Src: r,
SelectList: selectList,
}).Plan(ctx); err != nil {
return nil, err
}
default:
if r, err = (&rsets.GroupByRset{By: groupBy,
Src: r,
SelectList: selectList,
}).Plan(ctx); err != nil {
return nil, err
}
}
if s := s.Having; s != nil {
if r, err = (&rsets.HavingRset{
Src: r,
Expr: s.Expr}).Plan(ctx); err != nil {
return nil, err
}
}
if s.Distinct {
r = &plans.DistinctDefaultPlan{Src: r, SelectList: selectList}
}
if s := s.OrderBy; s != nil {
if r, err = (&rsets.OrderByRset{By: s.By,
Src: r,
SelectList: selectList,
}).Plan(ctx); err != nil {
return nil, err
}
}
if s := s.Offset; s != nil {
r = &plans.OffsetDefaultPlan{Count: s.Count, Src: r, Fields: r.GetFields()}
}
if s := s.Limit; s != nil {
r = &plans.LimitDefaultPlan{Count: s.Count, Src: r, Fields: r.GetFields()}
}
r = &plans.SelectFinalPlan{Src: r, SelectList: selectList}
return r, nil
}
// Plan implements the plan.Planner interface.
func (s *UnionStmt) Plan(ctx context.Context) (plan.Plan, error) {
srcs := make([]plan.Plan, 0, len(s.Selects))
columnCount := 0
for _, s := range s.Selects {
p, err := s.Plan(ctx)
if err != nil {
return nil, err
}
if columnCount > 0 && columnCount != len(p.GetFields()) {
return nil, errors.New("The used SELECT statements have a different number of columns")
}
columnCount = len(p.GetFields())
srcs = append(srcs, p)
}
for i := len(s.Distincts) - 1; i >= 0; i-- {
if s.Distincts[i] {
// distinct overwrites all previous all
// e.g, select * from t1 union all select * from t2 union distinct select * from t3.
// The distinct will overwrite all for t1 and t2.
i--
for ; i >= 0; i-- {
s.Distincts[i] = true
}
break
}
}
fields := srcs[0].GetFields()
selectList := &plans.SelectList{}
selectList.ResultFields = make([]*field.ResultField, len(fields))
selectList.HiddenFieldOffset = len(fields)
// Union uses first select return column names and ignores table name.
// We only care result name and type here.
for i, f := range fields {
nf := &field.ResultField{}
nf.Name = f.Name
nf.FieldType = f.FieldType
selectList.ResultFields[i] = nf
}
var (
r plan.Plan
err error
)
r = &plans.UnionPlan{Srcs: srcs, Distincts: s.Distincts, RFields: selectList.ResultFields}
if s := s.OrderBy; s != nil {
if r, err = (&rsets.OrderByRset{By: s.By,
Src: r,
SelectList: selectList,
}).Plan(ctx); err != nil {
return nil, err
}
}
if s := s.Offset; s != nil {
r = &plans.OffsetDefaultPlan{Count: s.Count, Src: r, Fields: r.GetFields()}
}
if s := s.Limit; s != nil {
r = &plans.LimitDefaultPlan{Count: s.Count, Src: r, Fields: r.GetFields()}
}
return r, nil
}