func (this *builder) visitGroup(group *algebra.Group, aggs map[string]algebra.Aggregate) {
aggn := make(sort.StringSlice, 0, len(aggs))
for n, _ := range aggs {
aggn = append(aggn, n)
}
aggn.Sort()
aggv := make(algebra.Aggregates, len(aggs))
for i, n := range aggn {
aggv[i] = aggs[n]
}
this.subChildren = append(this.subChildren, plan.NewInitialGroup(group.By(), aggv))
this.children = append(this.children, plan.NewParallel(plan.NewSequence(this.subChildren...), this.maxParallelism))
this.children = append(this.children, plan.NewIntermediateGroup(group.By(), aggv))
this.children = append(this.children, plan.NewFinalGroup(group.By(), aggv))
this.subChildren = make([]plan.Operator, 0, 8)
letting := group.Letting()
if letting != nil {
this.subChildren = append(this.subChildren, plan.NewLet(letting))
}
having := group.Having()
if having != nil {
this.subChildren = append(this.subChildren, plan.NewFilter(having))
}
}
func (this *builder) beginMutate(keyspace datastore.Keyspace, ksref *algebra.KeyspaceRef,
keys expression.Expression, indexes algebra.IndexRefs, limit expression.Expression, isDelete bool) error {
ksref.SetDefaultNamespace(this.namespace)
term := algebra.NewKeyspaceTerm(ksref.Namespace(), ksref.Keyspace(), nil, ksref.As(), keys, indexes)
this.children = make([]plan.Operator, 0, 8)
this.subChildren = make([]plan.Operator, 0, 8)
if this.where != nil {
limit = nil
}
scan, err := this.selectScan(keyspace, term, limit)
if err != nil {
return err
}
this.children = append(this.children, scan)
if this.coveringScan != nil {
coverer := expression.NewCoverer(this.coveringScan.Covers())
err = this.cover.MapExpressions(coverer)
if err != nil {
return err
}
if this.where != nil {
this.where, err = coverer.Map(this.where)
if err != nil {
return err
}
}
} else {
var fetch plan.Operator
if isDelete && this.where == nil && isKeyScan(scan) {
fetch = plan.NewDummyFetch(keyspace, term)
} else {
fetch = plan.NewFetch(keyspace, term)
}
this.subChildren = append(this.subChildren, fetch)
}
if this.where != nil {
this.subChildren = append(this.subChildren, plan.NewFilter(this.where))
}
return nil
}
func (this *builder) VisitSubselect(node *algebra.Subselect) (interface{}, error) {
prevCover := this.cover
prevCorrelated := this.correlated
defer func() {
this.cover = prevCover
this.correlated = prevCorrelated
}()
this.correlated = node.IsCorrelated()
if this.cover == nil {
this.cover = node
}
aggs, err := allAggregates(node, this.order)
if err != nil {
return nil, err
}
this.where = node.Where()
group := node.Group()
if group == nil && len(aggs) > 0 {
group = algebra.NewGroup(nil, nil, nil)
this.where = constrainAggregate(this.where, aggs)
}
this.children = make([]plan.Operator, 0, 16) // top-level children, executed sequentially
this.subChildren = make([]plan.Operator, 0, 16) // sub-children, executed across data-parallel streams
err = this.visitFrom(node, group)
if err != nil {
return nil, err
}
if this.coveringScan != nil {
coverer := expression.NewCoverer(this.coveringScan.Covers())
err = this.cover.MapExpressions(coverer)
if err != nil {
return nil, err
}
if this.where != nil {
this.where, err = coverer.Map(this.where)
if err != nil {
return nil, err
}
}
}
if node.Let() != nil {
this.subChildren = append(this.subChildren, plan.NewLet(node.Let()))
}
if node.Where() != nil {
this.subChildren = append(this.subChildren, plan.NewFilter(node.Where()))
}
if group != nil {
this.visitGroup(group, aggs)
}
projection := node.Projection()
this.subChildren = append(this.subChildren, plan.NewInitialProject(projection))
// Initial DISTINCT (parallel)
if projection.Distinct() || this.distinct {
this.subChildren = append(this.subChildren, plan.NewDistinct())
}
if !this.delayProjection {
// Perform the final projection if there is no subsequent ORDER BY
this.subChildren = append(this.subChildren, plan.NewFinalProject())
}
// Parallelize the subChildren
this.children = append(this.children, plan.NewParallel(plan.NewSequence(this.subChildren...), this.maxParallelism))
// Final DISTINCT (serial)
if projection.Distinct() || this.distinct {
this.children = append(this.children, plan.NewDistinct())
}
// Serialize the top-level children
return plan.NewSequence(this.children...), nil
}
func (this *builder) VisitMerge(stmt *algebra.Merge) (interface{}, error) {
children := make([]plan.Operator, 0, 8)
subChildren := make([]plan.Operator, 0, 8)
source := stmt.Source()
if source.Select() != nil {
sel, err := source.Select().Accept(this)
if err != nil {
return nil, err
}
children = append(children, sel.(plan.Operator))
} else {
if source.From() == nil {
return nil, fmt.Errorf("MERGE missing source.")
}
_, err := source.From().Accept(this)
if err != nil {
return nil, err
}
// Update local operator slices with results of building From:
children = append(children, this.children...)
subChildren = append(subChildren, this.subChildren...)
}
if source.As() != "" {
subChildren = append(subChildren, plan.NewAlias(source.As()))
}
ksref := stmt.KeyspaceRef()
ksref.SetDefaultNamespace(this.namespace)
keyspace, err := this.getNameKeyspace(ksref.Namespace(), ksref.Keyspace())
if err != nil {
return nil, err
}
actions := stmt.Actions()
var update, delete, insert plan.Operator
if actions.Update() != nil {
act := actions.Update()
ops := make([]plan.Operator, 0, 5)
if act.Where() != nil {
ops = append(ops, plan.NewFilter(act.Where()))
}
ops = append(ops, plan.NewClone(ksref.Alias()))
if act.Set() != nil {
ops = append(ops, plan.NewSet(act.Set()))
}
if act.Unset() != nil {
ops = append(ops, plan.NewUnset(act.Unset()))
}
ops = append(ops, plan.NewSendUpdate(keyspace, ksref.Alias(), stmt.Limit()))
update = plan.NewSequence(ops...)
}
if actions.Delete() != nil {
act := actions.Delete()
ops := make([]plan.Operator, 0, 4)
if act.Where() != nil {
ops = append(ops, plan.NewFilter(act.Where()))
}
ops = append(ops, plan.NewSendDelete(keyspace, ksref.Alias(), stmt.Limit()))
delete = plan.NewSequence(ops...)
}
if actions.Insert() != nil {
act := actions.Insert()
ops := make([]plan.Operator, 0, 4)
if act.Where() != nil {
ops = append(ops, plan.NewFilter(act.Where()))
}
ops = append(ops, plan.NewSendInsert(keyspace, ksref.Alias(), stmt.Key(), act.Value(), stmt.Limit()))
insert = plan.NewSequence(ops...)
}
merge := plan.NewMerge(keyspace, ksref, stmt.Key(), update, delete, insert)
subChildren = append(subChildren, merge)
if stmt.Returning() != nil {
subChildren = append(subChildren, plan.NewInitialProject(stmt.Returning()), plan.NewFinalProject())
}
parallel := plan.NewParallel(plan.NewSequence(subChildren...), this.maxParallelism)
children = append(children, parallel)
if stmt.Limit() != nil {
children = append(children, plan.NewLimit(stmt.Limit()))
}
if stmt.Returning() == nil {
children = append(children, plan.NewDiscard())
}
return plan.NewSequence(children...), nil
}