// simplest possible implementation
// 1. read all plans off plan channel
// 2. return last plan
func (this *SimpleOptimizer) Optimize(planChannel plan.PlanChannel, errChannel query.ErrorChannel) (*plan.Plan, query.Error) {
plans := make([]plan.Plan, 0)
var p plan.Plan
var err query.Error
ok := true
for ok {
select {
case p, ok = <-planChannel:
if ok {
clog.To(optimizer.CHANNEL, "See plan %v", p)
plans = append(plans, p)
}
case err, ok = <-errChannel:
if err != nil {
return nil, err
}
}
}
if len(plans) > 0 {
chosenPlan := plans[len(plans)-1]
clog.To(optimizer.CHANNEL, "Choosing plan %v", chosenPlan)
return &chosenPlan, nil
}
return nil, query.NewError(nil, "No plans produced for optimizer to choose from")
}
func (this *HttpQuery) Process() {
err := this.response.Process()
if err != nil {
clog.To(CHANNEL, "error writing to client, aborting query")
this.StopProcessing()
} else {
clog.To(CHANNEL, "response complete")
}
}
func (this *KeyJoin) Run(stopChannel misc.StopChannel) {
clog.To(CHANNEL, "key join operator starting")
if this.Base.Source != nil {
this.Base.RunOperator(this, stopChannel)
} else {
this.Base.SendError(query.NewError(fmt.Errorf("missing source operator"), ""))
}
clog.To(CHANNEL, "key join operator finished, fetched %d", this.rowsFetched)
}
func (this *StubSource) Run(stopChannel misc.StopChannel) {
clog.To(CHANNEL, "stub source operator starting")
defer close(this.itemChannel)
defer close(this.supportChannel)
for _, item := range this.data {
this.itemChannel <- item
}
clog.To(CHANNEL, "stub source operator finished")
}
func (this *InterpretedExecutor) executeInternal(optimalPlan *plan.Plan, q network.Query, timeoutStopChannel misc.StopChannel) {
clog.To(executor.CHANNEL, "simple executor started")
// first make the plan excutable
executablePipeline, berr := this.xpipelinebuilder.Build(optimalPlan, q)
if berr != nil {
q.Response().SendError(query.NewError(berr, ""))
return
}
root := executablePipeline.Root
// create a stop channel
stopChannel := make(misc.StopChannel)
// set it on the query object, so HTTP layer can
// stop us if the client goes away
q.SetStopChannel(stopChannel)
go root.Run(stopChannel)
// now execute it
var item *dparval.Value
var obj interface{}
sourceItemChannel, supportChannel := root.GetChannels()
ok := true
for ok {
select {
case item, ok = <-sourceItemChannel:
if ok {
ok = this.processItem(q, item)
clog.To(executor.CHANNEL, "simple executor sent client item: %v", item)
}
case obj, ok = <-supportChannel:
if ok {
switch obj := obj.(type) {
case query.Error:
q.Response().SendError(obj)
clog.To(executor.CHANNEL, "simple executor sent client error: %v", obj)
if obj.IsFatal() {
return
}
}
}
case _, ok = <-timeoutStopChannel:
clog.To(executor.CHANNEL, "simple execution aborted, timeout")
return
}
}
q.Response().NoMoreResults()
clog.To(executor.CHANNEL, "simple executor finished")
}
func (this *EliminateDuplicates) afterItems() {
// write the output
for pos, item := range this.buffer {
// we will nil out duplicates and then skip over those entries in the buffer
if item != nil {
if pos < len(this.buffer) {
// look to see if the exact same item appears later in the buffer
for nextpos, nextitem := range this.buffer[pos+1:] {
itemProj, ok := item.GetAttachment("projection").(*dparval.Value)
if ok {
itemVal := itemProj.Value()
if nextitem != nil {
nextItemProj, ok := nextitem.GetAttachment("projection").(*dparval.Value)
if ok {
nextItemVal := nextItemProj.Value()
comp := ast.CollateJSON(itemVal, nextItemVal)
if comp == 0 {
this.buffer[pos+nextpos+1] = nil
}
}
}
}
}
}
clog.To(DEBUG_DUP_CHANNEL, "distinct: %v", item)
this.Base.SendItem(item)
}
}
}
func newPool(s *site, name string) (*pool, query.Error) {
clog.To(catalog.CHANNEL, "Created New Pool %s", name)
cbpool, err := s.client.GetPool(name)
if err != nil {
if name == "default" {
// if default pool is not available, try reconnecting to the server
url := s.URL()
client, err := cb.Connect(url)
if err != nil {
return nil, query.NewError(nil, fmt.Sprintf("Pool %v not found.", name))
}
// check if the default pool exists
cbpool, err = client.GetPool(name)
if err != nil {
return nil, query.NewError(nil, fmt.Sprintf("Pool %v not found.", name))
}
s.client = client
}
}
rv := pool{
site: s,
name: name,
cbpool: cbpool,
bucketCache: make(map[string]catalog.Bucket),
}
go keepPoolFresh(&rv)
return &rv, nil
}
func newBucket(p *pool, name string) (*bucket, query.Error) {
clog.To(catalog.CHANNEL, "Created New Bucket %s", name)
cbbucket, err := p.cbpool.GetBucket(name)
if err != nil {
// go-couchbase caches the buckets
// to be sure no such bucket exists right now
// we trigger a refresh
p.refresh()
// and then check one more time
cbbucket, err = p.cbpool.GetBucket(name)
if err != nil {
// really no such bucket exists
return nil, query.NewError(nil, fmt.Sprintf("Bucket %v not found.", name))
}
}
rv := &bucket{
pool: p,
name: name,
cbbucket: cbbucket,
indexes: make(map[string]catalog.Index),
}
ierr := rv.loadIndexes()
if err != nil {
return nil, ierr
}
return rv, nil
}
func (this *HttpEndpoint) ServeHTTP(w http.ResponseWriter, r *http.Request) {
clog.To(CHANNEL, "request received")
q := NewHttpQuery(w, r)
if q != nil {
this.queryChannel <- q
q.Process()
}
}
func (this *Fetch) Run(stopChannel misc.StopChannel) {
clog.To(CHANNEL, "fetch operator starting")
if this.Base.Source != nil {
this.Base.RunOperator(this, stopChannel)
} else {
defer close(this.Base.itemChannel)
defer close(this.Base.supportChannel)
defer close(this.Base.upstreamStopChannel)
for _, id := range this.ids {
doc := dparval.NewValue(map[string]interface{}{})
doc.SetAttachment("meta", map[string]interface{}{"id": id})
this.processItem(doc)
}
this.afterItems()
}
clog.To(CHANNEL, "fetch operator finished, fetched %d", this.rowsFetched)
}
func (this *KeyScan) Run(stopChannel misc.StopChannel) {
defer close(this.itemChannel)
defer close(this.supportChannel)
// this MUST be here so that it runs before the channels are closed
defer this.RecoverPanic()
clog.To(CHANNEL, "key scan operator starting")
for _, item := range this.keylist {
this.rowsKeyScanned += 1
// rematerialize an object from the data returned by this index entry
doc := dparval.NewValue(map[string]interface{}{})
// attach metadata
doc.SetAttachment("meta", map[string]interface{}{"id": item})
this.SendItem(doc)
}
clog.To(CHANNEL, "key scan operator finished, scanned %d", this.rowsKeyScanned)
}
func (p *pool) refresh() {
// trigger refresh of this pool
clog.To(catalog.CHANNEL, "Refreshing Pool %s", p.name)
newpool, err := p.site.client.GetPool(p.name)
if err != nil {
clog.Warnf("Error updating pool: %v", err)
return
}
p.cbpool = newpool
}
func WalkViewInBatches(result chan cb.ViewRow, errs query.ErrorChannel, bucket *cb.Bucket,
ddoc string, view string, options map[string]interface{}, batchSize int64, limit int64) {
if limit != 0 && limit < batchSize {
batchSize = limit
}
defer close(result)
defer close(errs)
defer func() {
r := recover()
if r != nil {
clog.Error(fmt.Errorf("View Walking Panic: %v\n%s", r, debug.Stack()))
errs <- query.NewError(nil, "Panic In View Walking")
}
}()
options["limit"] = batchSize + 1
numRead := int64(0)
ok := true
for ok {
logURL, err := bucket.ViewURL(ddoc, view, options)
if err == nil {
clog.To(NETWORK_CHANNEL, "Request View: %v", logURL)
}
vres, err := bucket.View(ddoc, view, options)
if err != nil {
errs <- query.NewError(err, "Unable to access view")
return
}
for i, row := range vres.Rows {
if int64(i) < batchSize {
// dont process the last row, its just used to see if we
// need to continue processing
result <- row
numRead += 1
}
}
if (int64(len(vres.Rows)) > batchSize) && (limit == 0 || (limit != 0 && numRead < limit)) {
// prepare for next run
skey := vres.Rows[batchSize].Key
skeydocid := vres.Rows[batchSize].ID
options["startkey"] = skey
options["startkey_docid"] = cb.DocID(skeydocid)
} else {
// stop
ok = false
}
}
}
func (this *DropIndex) Run(stopChannel misc.StopChannel) {
defer close(this.itemChannel)
defer close(this.supportChannel)
// this MUST be here so that it runs before the channels are closed
defer this.RecoverPanic()
this.downstreamStopChannel = stopChannel
clog.To(CHANNEL, "drop_index operator starting")
err := this.index.Drop()
if err != nil {
this.SendError(err)
} else {
item := dparval.NewValue(map[string]interface{}{})
item.SetAttachment("projection", map[string]interface{}{
"dropped": true,
})
this.SendItem(item)
}
clog.To(CHANNEL, "drop_index operator finished")
}
func (this *CreateIndex) Run(stopChannel misc.StopChannel) {
defer close(this.itemChannel)
defer close(this.supportChannel)
// this MUST be here so that it runs before the channels are closed
defer this.RecoverPanic()
indexType := catalog.IndexType(strings.ToLower(this.index_type))
indexOn := make(catalog.IndexKey, len(this.on))
for pos, key := range this.on {
indexOn[pos] = key
}
this.downstreamStopChannel = stopChannel
var index catalog.Index
var err query.Error
if this.primary {
clog.To(CHANNEL, "create_index (primary) operator starting")
index, err = this.bucket.CreatePrimaryIndex()
} else {
clog.To(CHANNEL, "create_index (secondary) operator starting")
index, err = this.bucket.CreateIndex(this.name, indexOn, indexType)
}
if err != nil {
this.SendError(err)
} else {
if index != nil {
item := dparval.NewValue(map[string]interface{}{})
item.SetAttachment("projection", map[string]interface{}{
"id": index.Id(),
"name": index.Name(),
})
this.SendItem(item)
} else {
clog.Warn("Successfully created index, but index was nil")
}
}
clog.To(CHANNEL, "create_index operator finished")
}
func (this *Scan) Run(stopChannel misc.StopChannel) {
defer close(this.itemChannel)
defer close(this.supportChannel)
// this MUST be here so that it runs before the channels are closed
defer this.RecoverPanic()
clog.To(CHANNEL, "scan operator starting")
if this.ranges == nil {
this.scanRange(nil)
} else {
for _, scanRange := range this.ranges {
ok := this.scanRange(scanRange)
if !ok {
break
}
}
}
clog.To(CHANNEL, "scan operator finished, scanned %d", this.rowsScanned)
}
func (this *Explain) Run(stopChannel misc.StopChannel) {
defer close(this.itemChannel)
defer close(this.supportChannel)
// this MUST be here so that it runs before the channels are closed
defer this.RecoverPanic()
this.downstreamStopChannel = stopChannel
clog.To(CHANNEL, "explain operator starting")
item := dparval.NewValue(map[string]interface{}{})
planBytes, err := json.Marshal(this.Plan)
if err != nil {
this.SendError(query.NewError(err, "error serializing plan to JSON"))
} else {
projection := dparval.NewValueFromBytes(planBytes)
item.SetAttachment("projection", projection)
this.SendItem(item)
}
clog.To(CHANNEL, "explain operator finished")
}
func CanIUseThisIndexForThisWhereClause(index catalog.RangeIndex, where ast.Expression, bucket string) (bool, plan.ScanRanges, ast.Expression, error) {
// convert the index key to formal notation
indexKeyFormal, err := IndexKeyInFormalNotation(index.Key(), bucket)
if err != nil {
return false, nil, nil, err
}
// put the where clause into conjunctive normal form
ennf := ast.NewExpressionNNF()
whereNNF, err := where.Accept(ennf)
if err != nil {
return false, nil, nil, err
}
ecnf := ast.NewExpressionCNF()
whereCNF, err := whereNNF.Accept(ecnf)
if err != nil {
return false, nil, nil, err
}
switch whereCNF := whereCNF.(type) {
case *ast.AndOperator:
// this is an and, we can try to satisfy individual operands
found := false
rranges := plan.ScanRanges{}
for _, oper := range whereCNF.Operands {
// see if the where clause expression is sargable with respect to the index key
es := NewExpressionSargable(indexKeyFormal[0])
oper.Accept(es)
if es.IsSargable() {
found = true
for _, ran := range es.ScanRanges() {
rranges = MergeRanges(rranges, ran)
clog.To(planner.CHANNEL, "now ranges are: %v", rranges)
}
}
}
if found {
return true, rranges, nil, nil
}
default:
// not an and, we must satisfy the whole expression
// see if the where clause expression is sargable with respect to the index key
es := NewExpressionSargable(indexKeyFormal[0])
whereCNF.Accept(es)
if es.IsSargable() {
return true, es.ScanRanges(), nil, nil
}
}
// cannot use this index
return false, nil, nil, nil
}
// NewSite creates a new Couchbase site for the given url.
func NewSite(url string) (catalog.Site, query.Error) {
clog.To(catalog.CHANNEL, "Created New Site %s", url)
client, err := cb.Connect(url)
if err != nil {
return nil, query.NewError(err, "")
}
return &site{
client: client,
poolCache: make(map[string]catalog.Pool),
}, nil
}
func (this *InterpretedExecutor) Execute(optimalPlan *plan.Plan, q network.Query, timeout *time.Duration) {
stopChannel := make(misc.StopChannel)
if timeout.Nanoseconds() < 0 {
this.executeInternal(optimalPlan, q, stopChannel)
} else {
c := make(chan error, 1)
go func() {
this.executeInternal(optimalPlan, q, stopChannel)
c <- nil
}()
select {
case <-c:
return
case <-time.After(*timeout):
clog.To(executor.CHANNEL, "simple executor timeout trigger")
close(stopChannel)
clog.To(executor.CHANNEL, "stop channel closed")
}
<-c
q.Response().SendError(query.NewTimeoutError(timeout))
}
}
func ViewTotalRows(bucket *cb.Bucket, ddoc string, view string, options map[string]interface{}) (int64, query.Error) {
options["limit"] = 0
logURL, err := bucket.ViewURL(ddoc, view, options)
if err == nil {
clog.To(NETWORK_CHANNEL, "Request View: %v", logURL)
}
vres, err := bucket.View(ddoc, view, options)
if err != nil {
return 0, query.NewError(err, "Unable to access view")
}
return int64(vres.TotalRows), nil
}
func newPool(s *site, name string) (*pool, query.Error) {
clog.To(catalog.CHANNEL, "Created New Pool %s", name)
cbpool, err := s.client.GetPool(name)
if err != nil {
return nil, query.NewError(nil, fmt.Sprintf("Pool %v not found.", name))
}
rv := pool{
site: s,
name: name,
cbpool: cbpool,
bucketCache: make(map[string]catalog.Bucket),
}
go keepPoolFresh(&rv)
return &rv, nil
}
func (this *FastCount) Run(stopChannel misc.StopChannel) {
defer close(this.itemChannel)
defer close(this.supportChannel)
// this MUST be here so that it runs before the channels are closed
defer this.RecoverPanic()
clog.To(CHANNEL, "fastcount operator starting")
if this.ranges == nil {
if this.index == nil {
count, err := this.bucket.Count()
if err != nil {
this.SendError(query.NewError(err, "Error counting values in bucket"))
} else {
groupDoc := dparval.NewValue(map[string]interface{}{})
aggregates := map[string]interface{}{"COUNT-true-<nil>-false": dparval.NewValue(float64(count))}
groupDoc.SetAttachment("aggregates", aggregates)
this.SendItem(groupDoc)
}
} else {
count, err := this.index.ValueCount()
if err != nil {
this.SendError(query.NewError(err, "Error counting values in index"))
} else {
groupDoc := dparval.NewValue(map[string]interface{}{})
aggkey := fmt.Sprintf("COUNT-false-%v-false", this.expr)
aggregates := map[string]interface{}{aggkey: dparval.NewValue(float64(count))}
groupDoc.SetAttachment("aggregates", aggregates)
this.SendItem(groupDoc)
}
}
}
// FIXME eventually we can support counting ranges
clog.To(CHANNEL, "fastcount operator finished")
}
func (this *Project) processItem(item *dparval.Value) bool {
resultMap := map[string]interface{}{}
for _, resultItem := range this.Result {
val, err := this.Base.projectedValueOfResultExpression(item, resultItem)
if err != nil {
switch err := err.(type) {
case *dparval.Undefined:
// undefined contributes nothing to the result map
continue
default:
return this.Base.SendError(query.NewError(err, "unexpected error projecting expression"))
}
}
if resultItem.Star {
if val != nil {
valval := val.Value()
switch valval := valval.(type) {
case map[string]interface{}:
// then if the result was an object
// add its contents ot the result map
for k, v := range valval {
resultMap[k] = v
}
}
}
} else {
resultMap[resultItem.As] = val
}
}
if !this.projectEmpty && len(resultMap) == 0 {
return true
}
// build a Value from the projection
projection := dparval.NewValue(resultMap)
// store the projection as an attachment on the main item
item.SetAttachment("projection", projection)
clog.To(DEBUG_PROJECT_CHANNEL, "projecting: %v", item)
// write to the output
return this.Base.SendItem(item)
}
func CanFastCountIndex(index catalog.CountIndex, bucket string, resultExprList ast.ResultExpressionList) ast.Expression {
// convert the index key to formal notation
indexKeyFormal, err := IndexKeyInFormalNotation(index.Key(), bucket)
if err != nil {
return nil
}
deps := ast.ExpressionList{indexKeyFormal[0]}
clog.To(planner.CHANNEL, "index deps are: %v", deps)
depChecker := ast.NewExpressionFunctionalDependencyCheckerFull(deps)
// start looking at the projection
for _, resultExpr := range resultExprList {
// cannot be *
if resultExpr.Star {
return nil
}
switch resultExpr := resultExpr.Expr.(type) {
case *ast.FunctionCallCount:
// aggregates all take 1 operand
operands := resultExpr.GetOperands()
if len(operands) < 1 {
return nil
}
aggOperand := operands[0]
// must NOT be *
if aggOperand.Star {
return nil
}
// look at dependencies inside this operand
_, err := depChecker.Visit(aggOperand.Expr)
if err != nil {
return nil
}
default:
return nil
}
}
// if we made it this far, can do fast count on bucket
return indexKeyFormal[0]
}
func NewHttpQuery(w http.ResponseWriter, r *http.Request, info bool) *HttpQuery {
q := HttpQuery{startTime: time.Now(), info: info}
queryString := findQueryStringInRequest(r)
if queryString == "" {
showError(w, "Missing required query string", 500)
return nil
} else {
clog.To(CHANNEL, "query string: %v", queryString)
}
q.request = network.StringQueryRequest{QueryString: queryString}
httpResponse := &HttpResponse{query: &q, w: w, results: make(chan interface{}), returnInfo: info}
q.response = httpResponse
return &q
}
func (p *pool) refresh() {
// trigger refresh of this pool
clog.To(catalog.CHANNEL, "Refreshing Pool %s", p.name)
newpool, err := p.site.client.GetPool(p.name)
if err != nil {
clog.Warnf("Error updating pool name %s: Error %v", p.name, err)
url := p.site.URL()
client, err := cb.Connect(url)
if err != nil {
clog.Warnf("Error connecting to URL %s", url)
}
// check if the default pool exists
newpool, err = client.GetPool(p.name)
if err != nil {
clog.Warnf("Retry Failed Error updating pool name %s: Error %v", p.name, err)
}
p.site.client = client
return
}
p.cbpool = newpool
}
func CanIUseThisIndexForThisProjectionNoWhereNoGroupClause(index catalog.RangeIndex, resultExprList ast.ResultExpressionList, bucket string) (bool, plan.ScanRanges, ast.Expression, error) {
// convert the index key to formal notation
indexKeyFormal, err := IndexKeyInFormalNotation(index.Key(), bucket)
if err != nil {
return false, nil, nil, err
}
// FIXME only looking at first element in key right now
deps := ast.ExpressionList{indexKeyFormal[0]}
clog.To(planner.CHANNEL, "index deps are: %v", deps)
depChecker := ast.NewExpressionFunctionalDependencyCheckerFull(deps)
// start looking at the projection
allAggregateFunctionsMin := true
for _, resultExpr := range resultExprList {
// presence of * means we cannot use index on field, must see all (for this particular optimization)
if resultExpr.Star {
return false, nil, nil, nil
}
switch expr := resultExpr.Expr.(type) {
case ast.AggregateFunctionCallExpression:
_, isMin := expr.(*ast.FunctionCallMin)
if !isMin {
clog.To(planner.CHANNEL, "projection not MIN")
allAggregateFunctionsMin = false
}
// aggregates all take 1 operand
operands := expr.GetOperands()
if len(operands) < 1 {
return false, nil, nil, nil
}
aggOperand := operands[0]
// preence of * means we cannot use this index, must see all (for this particular optimization)
if aggOperand.Star {
return false, nil, nil, nil
}
// look at dependencies inside this operand
_, err := depChecker.Visit(aggOperand.Expr)
if err != nil {
return false, nil, nil, nil
}
default:
// all expressions must be aggregates for this particular optimization
return false, nil, nil, nil
}
}
// if we made it this far, we can in fact use the index
// doing a scan of all non-eliminatable items (non-NULL, non-MISSING)
dummyOp := ast.NewIsNotNullOperator(indexKeyFormal[0])
es := NewExpressionSargable(indexKeyFormal[0])
dummyOp.Accept(es)
if es.IsSargable() {
ranges := es.ScanRanges()
if allAggregateFunctionsMin {
for _, r := range ranges {
r.Limit = 1
}
}
return true, ranges, nil, nil
}
clog.Error(fmt.Errorf("expected this to never happen"))
// cannot use this index
return false, nil, nil, nil
}
func DoesIndexCoverStatement(index catalog.RangeIndex, stmt *ast.SelectStatement) bool {
if stmt.From.Over != nil {
// index cannot cover queries containing OVER right now
return false
}
// convert the index key to formal notation
indexKeyFormal, err := IndexKeyInFormalNotation(index.Key(), stmt.From.As)
if err != nil {
return false
}
deps := ast.ExpressionList{}
for _, indexKey := range indexKeyFormal {
deps = append(deps, indexKey)
}
clog.To(planner.CHANNEL, "index deps are: %v", deps)
depChecker := ast.NewExpressionFunctionalDependencyCheckerFull(deps)
// first check the projection
for _, resultExpr := range stmt.Select {
if resultExpr.Star == true || resultExpr.Expr == nil {
// currently cannot cover *
return false
}
_, err := depChecker.Visit(resultExpr.Expr)
if err != nil {
return false
}
}
if stmt.Where != nil {
_, err = depChecker.Visit(stmt.Where)
if err != nil {
return false
}
}
if stmt.GroupBy != nil {
for _, groupExpr := range stmt.GroupBy {
_, err = depChecker.Visit(groupExpr)
if err != nil {
return false
}
}
if stmt.Having != nil {
_, err = depChecker.Visit(stmt.Having)
if err != nil {
return false
}
}
}
if stmt.OrderBy != nil {
for _, orderExpr := range stmt.OrderBy {
_, err = depChecker.Visit(orderExpr.Expr)
if err != nil {
return false
}
}
}
// if we go this far it is covered
return true
}
func (this *SimplePlanner) buildSelectStatementPlans(stmt *ast.SelectStatement, pc plan.PlanChannel, ec query.ErrorChannel) {
var planHeads []plan.PlanElement
from := stmt.GetFrom()
if from == nil {
// point to :system.dual
from = &ast.From{Pool: system.POOL_NAME, Bucket: system.BUCKET_NAME_DUAL}
}
// get the pool
poolName := from.Pool
if poolName == "" {
poolName = this.defaultPool
}
pool, err := this.site.PoolByName(poolName)
if err != nil {
ec <- query.NewPoolDoesNotExist(poolName)
return
}
bucket, err := pool.BucketByName(from.Bucket)
if err != nil {
ec <- query.NewBucketDoesNotExist(from.Bucket)
return
}
// find all docs index
indexes, err := bucket.Indexes()
if err != nil {
ec <- query.NewError(err, fmt.Sprintf("No indexes found for bucket %v", from.Bucket))
return
}
var keylist []string
if stmt.Keys != nil {
keylist = stmt.Keys.GetKeys()
}
clog.To(planner.CHANNEL, "Indexes in bucket %v", indexes)
if keylist == nil {
for _, index := range indexes {
var lastStep plan.PlanElement
switch index := index.(type) {
case catalog.PrimaryIndex:
clog.To(planner.CHANNEL, "See primary index %v", index.Name())
// if from.Over == nil && stmt.Where == nil && stmt.GroupBy != nil && len(stmt.GroupBy) == 0 && CanFastCountBucket(stmt.Select) {
// lastStep = plan.NewFastCount(pool.Name(), bucket.Name(), "", nil, nil)
// } else {
lastStep = plan.NewScan(pool.Name(), bucket.Name(), index.Name(), nil)
// }
case catalog.RangeIndex:
// see if this index can be used
clog.To(planner.CHANNEL, "See index %v", index.Name())
clog.To(planner.CHANNEL, "with Key %v", index.Key())
if stmt.Where != nil && from.Projection == nil {
possible, ranges, _, err := CanIUseThisIndexForThisWhereClause(index, stmt.Where, stmt.From.As)
if err != nil {
clog.Error(err)
continue
}
clog.To(planner.CHANNEL, "Can I use it1: %v", possible)
if possible {
// great, but lets check for a min optimizatin too
if stmt.GroupBy != nil && len(stmt.GroupBy) == 0 {
possible, minranges, _, _ := CanIUseThisIndexForThisProjectionNoWhereNoGroupClause(index, stmt.Select, stmt.From.As)
if possible {
for _, r := range ranges {
r.Limit = minranges[0].Limit
}
}
}
scan := plan.NewScan(pool.Name(), bucket.Name(), index.Name(), ranges)
// see if this index covers the query
if DoesIndexCoverStatement(index, stmt) {
scan.Cover = true
scan.As = from.As
}
lastStep = scan
} else {
continue
}
} else if from.Projection == nil {
// try to do a fast count if its possible
doingFastCount := false
// countIndex, isCountIndex := index.(catalog.CountIndex)
// if isCountIndex {
// fastCountIndexOnExpr := CanFastCountIndex(countIndex, stmt.From.As, stmt.Select)
// if fastCountIndexOnExpr != nil && from.Over == nil && stmt.Where == nil && stmt.GroupBy != nil && len(stmt.GroupBy) == 0 {
// lastStep = plan.NewFastCount(pool.Name(), bucket.Name(), countIndex.Name(), fastCountIndexOnExpr, nil)
// doingFastCount = true
// }
// }
// this works for aggregates on the whole bucket
if !doingFastCount && stmt.GroupBy != nil && len(stmt.GroupBy) == 0 {
possible, ranges, _, err := CanIUseThisIndexForThisProjectionNoWhereNoGroupClause(index, stmt.Select, stmt.From.As)
if err != nil {
clog.Error(err)
continue
}
clog.To(planner.CHANNEL, "Can I use it2: %v", possible)
if possible {
lastStep = plan.NewScan(pool.Name(), bucket.Name(), index.Name(), ranges)
} else {
continue
}
} else if !doingFastCount {
continue
}
}
default:
clog.To(planner.CHANNEL, "Unsupported type of index %T", index)
continue
}
scanOp, lastStepWasScan := lastStep.(*plan.Scan)
if lastStepWasScan {
if !scanOp.Cover {
lastStep = plan.NewFetch(lastStep, pool.Name(), bucket.Name(), from.Projection, from.As)
nextFrom := from.Over
for nextFrom != nil {
// add document joins
if nextFrom.Keys != nil {
// This is a key-join
lastStep = plan.NewKeyJoin(lastStep, pool.Name(), nextFrom.Bucket, nextFrom.Projection, nextFrom.Type, nextFrom.Oper, *nextFrom.Keys, nextFrom.As)
} else {
lastStep = plan.NewUnnest(lastStep, nextFrom.Projection, nextFrom.Type, nextFrom.As)
}
nextFrom = nextFrom.Over
}
}
}
planHeads = append(planHeads, lastStep)
}
} else if keylist != nil {
// if keylist is present then we avoid a bucket scan
var lastStep plan.PlanElement
lastStep = plan.NewKeyScan(keylist)
lastStep = plan.NewFetch(lastStep, pool.Name(), bucket.Name(), from.Projection, from.As)
nextFrom := from.Over
for nextFrom != nil {
// add in-document joins
if nextFrom.Keys != nil {
lastStep = plan.NewKeyJoin(lastStep, pool.Name(), nextFrom.Bucket, nextFrom.Projection, nextFrom.Type, nextFrom.Oper, *nextFrom.Keys, nextFrom.As)
} else {
lastStep = plan.NewUnnest(lastStep, nextFrom.Projection, nextFrom.Type, nextFrom.As)
}
nextFrom = nextFrom.Over
}
planHeads = append(planHeads, lastStep)
}
if len(planHeads) == 0 {
ec <- query.NewError(nil, fmt.Sprintf("No usable indexes found for bucket %v", from.Bucket))
return
}
// now for all the plan heads, create a full plan
for _, lastStep := range planHeads {
if stmt.GetWhere() != nil {
ids := WhereClauseFindById(stmt.GetWhere())
fetch, ok := lastStep.(*plan.Fetch)
if ids != nil && ok {
fetch.ConvertToIds(ids)
} else {
lastStep = plan.NewFilter(lastStep, stmt.GetWhere())
}
}
if stmt.GetGroupBy() != nil {
_, isFastCount := lastStep.(*plan.FastCount)
if !isFastCount {
lastStep = plan.NewGroup(lastStep, stmt.GetGroupBy(), stmt.GetAggregateReferences())
}
}
if stmt.GetHaving() != nil {
lastStep = plan.NewFilter(lastStep, stmt.GetHaving())
}
lastStep = plan.NewProjector(lastStep, stmt.GetResultExpressionList(), true)
if stmt.IsDistinct() {
lastStep = plan.NewEliminateDuplicates(lastStep)
}
if stmt.GetOrderBy() != nil {
explicitAliases := stmt.GetExplicitProjectionAliases()
lastStep = plan.NewOrder(lastStep, stmt.GetOrderBy(), explicitAliases)
}
if stmt.GetOffset() != 0 {
lastStep = plan.NewOffset(lastStep, stmt.GetOffset())
}
if stmt.GetLimit() >= 0 {
lastStep = plan.NewLimit(lastStep, stmt.GetLimit())
}
if stmt.ExplainOnly {
lastStep = plan.NewExplain(lastStep)
}
pc <- plan.Plan{Root: lastStep}
}
}