influxdb/storage/flux/table.gen.go

// Generated by tmpl
// https://github.com/benbjohnson/tmpl
//
// DO NOT EDIT!
// Source: table.gen.go.tmpl

package storageflux

import (
	"math"
	"sync"

	"github.com/apache/arrow/go/arrow/array"
	"github.com/influxdata/flux"
	"github.com/influxdata/flux/arrow"
	"github.com/influxdata/flux/execute"
	"github.com/influxdata/flux/memory"
	"github.com/influxdata/influxdb/v2"
	"github.com/influxdata/influxdb/v2/models"
	storage "github.com/influxdata/influxdb/v2/storage/reads"
	"github.com/influxdata/influxdb/v2/tsdb/cursors"
)

//
// *********** Float ***********
//

type floatTable struct {
	table
	mu    sync.Mutex
	cur   cursors.FloatArrayCursor
	alloc *memory.Allocator
}

func newFloatTable(
	done chan struct{},
	cur cursors.FloatArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *floatTable {
	t := &floatTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *floatTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	t.mu.Unlock()
}

func (t *floatTable) Statistics() cursors.CursorStats {
	t.mu.Lock()
	defer t.mu.Unlock()
	cur := t.cur
	if cur == nil {
		return cursors.CursorStats{}
	}
	cs := cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

func (t *floatTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *floatTable) advance() bool {
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

// window table
type floatWindowTable struct {
	floatTable
	windowEvery int64
	offset      int64
	arr         *cursors.FloatArray
	nextTS      int64
	idxInArr    int
	createEmpty bool
	timeColumn  string
}

func newFloatWindowTable(
	done chan struct{},
	cur cursors.FloatArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	createEmpty bool,
	timeColumn string,

	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *floatWindowTable {
	t := &floatWindowTable{
		floatTable: floatTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		createEmpty: createEmpty,
		timeColumn:  timeColumn,
	}
	if t.createEmpty {
		start := int64(bounds.Start)
		t.nextTS = storage.WindowStop(start, every, offset)
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *floatWindowTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

// createNextBufferTimes will read the timestamps from the array
// cursor and construct the values for the next buffer.
func (t *floatWindowTable) createNextBufferTimes() (start, stop *array.Int64, ok bool) {
	startB := arrow.NewIntBuilder(t.alloc)
	stopB := arrow.NewIntBuilder(t.alloc)

	if t.createEmpty {
		// There are no more windows when the start time is greater
		// than or equal to the stop time.
		if startT := t.nextTS - t.windowEvery; startT >= int64(t.bounds.Stop) {
			return nil, nil, false
		}

		// Create a buffer with the buffer size.
		// TODO(jsternberg): Calculate the exact size with max points as the maximum.
		startB.Resize(storage.MaxPointsPerBlock)
		stopB.Resize(storage.MaxPointsPerBlock)
		for ; ; t.nextTS += t.windowEvery {
			startT, stopT := t.getWindowBoundsFor(t.nextTS)
			if startT >= int64(t.bounds.Stop) {
				break
			}
			startB.Append(startT)
			stopB.Append(stopT)
		}
		start = startB.NewInt64Array()
		stop = stopB.NewInt64Array()
		return start, stop, true
	}

	// Retrieve the next buffer so we can copy the timestamps.
	if !t.nextBuffer() {
		return nil, nil, false
	}

	// Copy over the timestamps from the next buffer and adjust
	// times for the boundaries.
	startB.Resize(len(t.arr.Timestamps))
	stopB.Resize(len(t.arr.Timestamps))
	for _, stopT := range t.arr.Timestamps {
		startT, stopT := t.getWindowBoundsFor(stopT)
		startB.Append(startT)
		stopB.Append(stopT)
	}
	start = startB.NewInt64Array()
	stop = stopB.NewInt64Array()
	return start, stop, true
}

func (t *floatWindowTable) getWindowBoundsFor(ts int64) (startT, stopT int64) {
	startT, stopT = ts-t.windowEvery, ts
	if startT < int64(t.bounds.Start) {
		startT = int64(t.bounds.Start)
	}
	if stopT > int64(t.bounds.Stop) {
		stopT = int64(t.bounds.Stop)
	}
	return startT, stopT
}

// nextAt will retrieve the next value that can be used with
// the given stop timestamp. If no values can be used with the timestamp,
// it will return the default value and false.
func (t *floatWindowTable) nextAt(ts int64) (v float64, ok bool) {
	if !t.nextBuffer() {
		return
	} else if !t.isInWindow(ts, t.arr.Timestamps[t.idxInArr]) {
		return
	}
	v, ok = t.arr.Values[t.idxInArr], true
	t.idxInArr++
	return v, ok
}

// isInWindow will check if the given time at stop can be used within
// the window stop time for ts. The ts may be a truncated stop time
// because of a restricted boundary while stop will be the true
// stop time returned by storage.
func (t *floatWindowTable) isInWindow(ts int64, stop int64) bool {
	// This method checks if the stop time is a valid stop time for
	// that interval. This calculation is different from the calculation
	// of the window itself. For example, for a 10 second window that
	// starts at 20 seconds, we would include points between [20, 30).
	// The stop time for this interval would be 30, but because the stop
	// time can be truncated, valid stop times range from anywhere between
	// (20, 30]. The storage engine will always produce 30 as the end time
	// but we may have truncated the stop time because of the boundary
	// and this is why we are checking for this range instead of checking
	// if the two values are equal.
	start := stop - t.windowEvery
	return start < ts && ts <= stop
}

// nextBuffer will ensure the array cursor is filled
// and will return true if there is at least one value
// that can be read from it.
func (t *floatWindowTable) nextBuffer() bool {
	// Discard the current array cursor if we have
	// exceeded it.
	if t.arr != nil && t.idxInArr >= t.arr.Len() {
		t.arr = nil
	}

	// Retrieve the next array cursor if needed.
	if t.arr == nil {
		arr := t.cur.Next()
		if arr.Len() == 0 {
			return false
		}
		t.arr, t.idxInArr = arr, 0
	}
	return true
}

// appendValues will scan the timestamps and append values
// that match those timestamps from the buffer.
func (t *floatWindowTable) appendValues(intervals []int64, appendValue func(v float64), appendNull func()) {
	for i := 0; i < len(intervals); i++ {
		if v, ok := t.nextAt(intervals[i]); ok {
			appendValue(v)
			continue
		}
		appendNull()
	}
}

func (t *floatWindowTable) advance() bool {
	if !t.nextBuffer() {
		return false
	}
	// Create the timestamps for the next window.
	start, stop, ok := t.createNextBufferTimes()
	if !ok {
		return false
	}
	values := t.mergeValues(stop.Int64Values())

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(stop.Len())
	if t.timeColumn != "" {
		switch t.timeColumn {
		case execute.DefaultStopColLabel:
			cr.cols[timeColIdx] = stop
			start.Release()
		case execute.DefaultStartColLabel:
			cr.cols[timeColIdx] = start
			stop.Release()
		}
		cr.cols[valueColIdx] = values
		t.appendBounds(cr)
	} else {
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[windowedValueColIdx] = values
	}
	t.appendTags(cr)
	return true
}

// This table implementation will not have any empty windows.
type floatWindowSelectorTable struct {
	floatTable
	windowEvery int64
	offset      int64
	timeColumn  string
}

func newFloatWindowSelectorTable(
	done chan struct{},
	cur cursors.FloatArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *floatWindowSelectorTable {
	t := &floatWindowSelectorTable{
		floatTable: floatTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *floatWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *floatWindowSelectorTable) advance() bool {
	arr := t.cur.Next()
	if arr.Len() == 0 {
		return false
	}

	cr := t.allocateBuffer(arr.Len())

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		cr.cols[timeColIdx] = t.startTimes(arr)
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		cr.cols[timeColIdx] = t.stopTimes(arr)
		t.appendBounds(cr)
	default:
		cr.cols[startColIdx] = t.startTimes(arr)
		cr.cols[stopColIdx] = t.stopTimes(arr)
		cr.cols[timeColIdx] = arrow.NewInt(arr.Timestamps, t.alloc)
	}

	cr.cols[valueColIdx] = t.toArrowBuffer(arr.Values)
	t.appendTags(cr)
	return true
}

func (t *floatWindowSelectorTable) startTimes(arr *cursors.FloatArray) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(arr.Len())

	rangeStart := int64(t.bounds.Start)

	for _, v := range arr.Timestamps {
		if windowStart := storage.WindowStart(v, t.windowEvery, t.offset); windowStart < rangeStart {
			start.Append(rangeStart)
		} else {
			start.Append(windowStart)
		}
	}
	return start.NewInt64Array()
}

func (t *floatWindowSelectorTable) stopTimes(arr *cursors.FloatArray) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(arr.Len())

	rangeStop := int64(t.bounds.Stop)

	for _, v := range arr.Timestamps {
		if windowStop := storage.WindowStop(v, t.windowEvery, t.offset); windowStop > rangeStop {
			stop.Append(rangeStop)
		} else {
			stop.Append(windowStop)
		}
	}
	return stop.NewInt64Array()
}

// This table implementation may contain empty windows
// in addition to non-empty windows.
type floatEmptyWindowSelectorTable struct {
	floatTable
	arr         *cursors.FloatArray
	idx         int
	rangeStart  int64
	rangeStop   int64
	windowStart int64
	windowStop  int64
	windowEvery int64
	timeColumn  string
}

func newFloatEmptyWindowSelectorTable(
	done chan struct{},
	cur cursors.FloatArrayCursor,
	bounds execute.Bounds,
	windowEvery int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *floatEmptyWindowSelectorTable {
	rangeStart := int64(bounds.Start)
	rangeStop := int64(bounds.Stop)
	t := &floatEmptyWindowSelectorTable{
		floatTable: floatTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		arr:         cur.Next(),
		rangeStart:  rangeStart,
		rangeStop:   rangeStop,
		windowStart: storage.WindowStart(rangeStart, windowEvery, offset),
		windowStop:  storage.WindowStop(rangeStart, windowEvery, offset),
		windowEvery: windowEvery,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *floatEmptyWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *floatEmptyWindowSelectorTable) advance() bool {
	if t.arr.Len() == 0 {
		return false
	}

	values := t.arrowBuilder()
	values.Resize(storage.MaxPointsPerBlock)

	var cr *colReader

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		start := t.startTimes(values)
		cr = t.allocateBuffer(start.Len())
		cr.cols[timeColIdx] = start
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		stop := t.stopTimes(values)
		cr = t.allocateBuffer(stop.Len())
		cr.cols[timeColIdx] = stop
		t.appendBounds(cr)
	default:
		start, stop, time := t.startStopTimes(values)
		cr = t.allocateBuffer(time.Len())
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[timeColIdx] = time
	}

	cr.cols[valueColIdx] = values.NewFloat64Array()
	t.appendTags(cr)
	return true
}

func (t *floatEmptyWindowSelectorTable) startTimes(builder *array.Float64Builder) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if start.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array()
}

func (t *floatEmptyWindowSelectorTable) stopTimes(builder *array.Float64Builder) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if stop.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return stop.NewInt64Array()
}

func (t *floatEmptyWindowSelectorTable) startStopTimes(builder *array.Float64Builder) (*array.Int64, *array.Int64, *array.Int64) {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	time := arrow.NewIntBuilder(t.alloc)
	time.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			time.Append(v)
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			time.AppendNull()
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if time.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array(), stop.NewInt64Array(), time.NewInt64Array()
}

// group table

type floatGroupTable struct {
	table
	mu  sync.Mutex
	gc  storage.GroupCursor
	cur cursors.FloatArrayCursor
}

func newFloatGroupTable(
	done chan struct{},
	gc storage.GroupCursor,
	cur cursors.FloatArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *floatGroupTable {
	t := &floatGroupTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		gc:    gc,
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *floatGroupTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	if t.gc != nil {
		t.gc.Close()
		t.gc = nil
	}
	t.mu.Unlock()
}

func (t *floatGroupTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *floatGroupTable) advance() bool {
RETRY:
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		if t.advanceCursor() {
			goto RETRY
		}

		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

func (t *floatGroupTable) advanceCursor() bool {
	t.cur.Close()
	t.cur = nil
	for t.gc.Next() {
		cur := t.gc.Cursor()
		if cur == nil {
			continue
		}

		if typedCur, ok := cur.(cursors.FloatArrayCursor); !ok {
			// TODO(sgc): error or skip?
			cur.Close()
			t.err = &influxdb.Error{
				Code: influxdb.EInvalid,
				Err: &GroupCursorError{
					typ:    "float",
					cursor: cur,
				},
			}
			return false
		} else {
			t.readTags(t.gc.Tags())
			t.cur = typedCur
			return true
		}
	}
	return false
}

func (t *floatGroupTable) Statistics() cursors.CursorStats {
	if t.cur == nil {
		return cursors.CursorStats{}
	}
	cs := t.cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

//
// *********** Integer ***********
//

type integerTable struct {
	table
	mu    sync.Mutex
	cur   cursors.IntegerArrayCursor
	alloc *memory.Allocator
}

func newIntegerTable(
	done chan struct{},
	cur cursors.IntegerArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *integerTable {
	t := &integerTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *integerTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	t.mu.Unlock()
}

func (t *integerTable) Statistics() cursors.CursorStats {
	t.mu.Lock()
	defer t.mu.Unlock()
	cur := t.cur
	if cur == nil {
		return cursors.CursorStats{}
	}
	cs := cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

func (t *integerTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *integerTable) advance() bool {
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

// window table
type integerWindowTable struct {
	integerTable
	windowEvery int64
	offset      int64
	arr         *cursors.IntegerArray
	nextTS      int64
	idxInArr    int
	createEmpty bool
	timeColumn  string
	fillValue   *int64
}

func newIntegerWindowTable(
	done chan struct{},
	cur cursors.IntegerArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	createEmpty bool,
	timeColumn string,
	fillValue *int64,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *integerWindowTable {
	t := &integerWindowTable{
		integerTable: integerTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		createEmpty: createEmpty,
		timeColumn:  timeColumn,
		fillValue:   fillValue,
	}
	if t.createEmpty {
		start := int64(bounds.Start)
		t.nextTS = storage.WindowStop(start, every, offset)
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *integerWindowTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

// createNextBufferTimes will read the timestamps from the array
// cursor and construct the values for the next buffer.
func (t *integerWindowTable) createNextBufferTimes() (start, stop *array.Int64, ok bool) {
	startB := arrow.NewIntBuilder(t.alloc)
	stopB := arrow.NewIntBuilder(t.alloc)

	if t.createEmpty {
		// There are no more windows when the start time is greater
		// than or equal to the stop time.
		if startT := t.nextTS - t.windowEvery; startT >= int64(t.bounds.Stop) {
			return nil, nil, false
		}

		// Create a buffer with the buffer size.
		// TODO(jsternberg): Calculate the exact size with max points as the maximum.
		startB.Resize(storage.MaxPointsPerBlock)
		stopB.Resize(storage.MaxPointsPerBlock)
		for ; ; t.nextTS += t.windowEvery {
			startT, stopT := t.getWindowBoundsFor(t.nextTS)
			if startT >= int64(t.bounds.Stop) {
				break
			}
			startB.Append(startT)
			stopB.Append(stopT)
		}
		start = startB.NewInt64Array()
		stop = stopB.NewInt64Array()
		return start, stop, true
	}

	// Retrieve the next buffer so we can copy the timestamps.
	if !t.nextBuffer() {
		return nil, nil, false
	}

	// Copy over the timestamps from the next buffer and adjust
	// times for the boundaries.
	startB.Resize(len(t.arr.Timestamps))
	stopB.Resize(len(t.arr.Timestamps))
	for _, stopT := range t.arr.Timestamps {
		startT, stopT := t.getWindowBoundsFor(stopT)
		startB.Append(startT)
		stopB.Append(stopT)
	}
	start = startB.NewInt64Array()
	stop = stopB.NewInt64Array()
	return start, stop, true
}

func (t *integerWindowTable) getWindowBoundsFor(ts int64) (startT, stopT int64) {
	startT, stopT = ts-t.windowEvery, ts
	if startT < int64(t.bounds.Start) {
		startT = int64(t.bounds.Start)
	}
	if stopT > int64(t.bounds.Stop) {
		stopT = int64(t.bounds.Stop)
	}
	return startT, stopT
}

// nextAt will retrieve the next value that can be used with
// the given stop timestamp. If no values can be used with the timestamp,
// it will return the default value and false.
func (t *integerWindowTable) nextAt(ts int64) (v int64, ok bool) {
	if !t.nextBuffer() {
		return
	} else if !t.isInWindow(ts, t.arr.Timestamps[t.idxInArr]) {
		return
	}
	v, ok = t.arr.Values[t.idxInArr], true
	t.idxInArr++
	return v, ok
}

// isInWindow will check if the given time at stop can be used within
// the window stop time for ts. The ts may be a truncated stop time
// because of a restricted boundary while stop will be the true
// stop time returned by storage.
func (t *integerWindowTable) isInWindow(ts int64, stop int64) bool {
	// This method checks if the stop time is a valid stop time for
	// that interval. This calculation is different from the calculation
	// of the window itself. For example, for a 10 second window that
	// starts at 20 seconds, we would include points between [20, 30).
	// The stop time for this interval would be 30, but because the stop
	// time can be truncated, valid stop times range from anywhere between
	// (20, 30]. The storage engine will always produce 30 as the end time
	// but we may have truncated the stop time because of the boundary
	// and this is why we are checking for this range instead of checking
	// if the two values are equal.
	start := stop - t.windowEvery
	return start < ts && ts <= stop
}

// nextBuffer will ensure the array cursor is filled
// and will return true if there is at least one value
// that can be read from it.
func (t *integerWindowTable) nextBuffer() bool {
	// Discard the current array cursor if we have
	// exceeded it.
	if t.arr != nil && t.idxInArr >= t.arr.Len() {
		t.arr = nil
	}

	// Retrieve the next array cursor if needed.
	if t.arr == nil {
		arr := t.cur.Next()
		if arr.Len() == 0 {
			return false
		}
		t.arr, t.idxInArr = arr, 0
	}
	return true
}

// appendValues will scan the timestamps and append values
// that match those timestamps from the buffer.
func (t *integerWindowTable) appendValues(intervals []int64, appendValue func(v int64), appendNull func()) {
	for i := 0; i < len(intervals); i++ {
		if v, ok := t.nextAt(intervals[i]); ok {
			appendValue(v)
			continue
		}
		appendNull()
	}
}

func (t *integerWindowTable) advance() bool {
	if !t.nextBuffer() {
		return false
	}
	// Create the timestamps for the next window.
	start, stop, ok := t.createNextBufferTimes()
	if !ok {
		return false
	}
	values := t.mergeValues(stop.Int64Values())

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(stop.Len())
	if t.timeColumn != "" {
		switch t.timeColumn {
		case execute.DefaultStopColLabel:
			cr.cols[timeColIdx] = stop
			start.Release()
		case execute.DefaultStartColLabel:
			cr.cols[timeColIdx] = start
			stop.Release()
		}
		cr.cols[valueColIdx] = values
		t.appendBounds(cr)
	} else {
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[windowedValueColIdx] = values
	}
	t.appendTags(cr)
	return true
}

// This table implementation will not have any empty windows.
type integerWindowSelectorTable struct {
	integerTable
	windowEvery int64
	offset      int64
	timeColumn  string
}

func newIntegerWindowSelectorTable(
	done chan struct{},
	cur cursors.IntegerArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *integerWindowSelectorTable {
	t := &integerWindowSelectorTable{
		integerTable: integerTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *integerWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *integerWindowSelectorTable) advance() bool {
	arr := t.cur.Next()
	if arr.Len() == 0 {
		return false
	}

	cr := t.allocateBuffer(arr.Len())

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		cr.cols[timeColIdx] = t.startTimes(arr)
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		cr.cols[timeColIdx] = t.stopTimes(arr)
		t.appendBounds(cr)
	default:
		cr.cols[startColIdx] = t.startTimes(arr)
		cr.cols[stopColIdx] = t.stopTimes(arr)
		cr.cols[timeColIdx] = arrow.NewInt(arr.Timestamps, t.alloc)
	}

	cr.cols[valueColIdx] = t.toArrowBuffer(arr.Values)
	t.appendTags(cr)
	return true
}

func (t *integerWindowSelectorTable) startTimes(arr *cursors.IntegerArray) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(arr.Len())

	rangeStart := int64(t.bounds.Start)

	for _, v := range arr.Timestamps {
		if windowStart := storage.WindowStart(v, t.windowEvery, t.offset); windowStart < rangeStart {
			start.Append(rangeStart)
		} else {
			start.Append(windowStart)
		}
	}
	return start.NewInt64Array()
}

func (t *integerWindowSelectorTable) stopTimes(arr *cursors.IntegerArray) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(arr.Len())

	rangeStop := int64(t.bounds.Stop)

	for _, v := range arr.Timestamps {
		if windowStop := storage.WindowStop(v, t.windowEvery, t.offset); windowStop > rangeStop {
			stop.Append(rangeStop)
		} else {
			stop.Append(windowStop)
		}
	}
	return stop.NewInt64Array()
}

// This table implementation may contain empty windows
// in addition to non-empty windows.
type integerEmptyWindowSelectorTable struct {
	integerTable
	arr         *cursors.IntegerArray
	idx         int
	rangeStart  int64
	rangeStop   int64
	windowStart int64
	windowStop  int64
	windowEvery int64
	timeColumn  string
}

func newIntegerEmptyWindowSelectorTable(
	done chan struct{},
	cur cursors.IntegerArrayCursor,
	bounds execute.Bounds,
	windowEvery int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *integerEmptyWindowSelectorTable {
	rangeStart := int64(bounds.Start)
	rangeStop := int64(bounds.Stop)
	t := &integerEmptyWindowSelectorTable{
		integerTable: integerTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		arr:         cur.Next(),
		rangeStart:  rangeStart,
		rangeStop:   rangeStop,
		windowStart: storage.WindowStart(rangeStart, windowEvery, offset),
		windowStop:  storage.WindowStop(rangeStart, windowEvery, offset),
		windowEvery: windowEvery,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *integerEmptyWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *integerEmptyWindowSelectorTable) advance() bool {
	if t.arr.Len() == 0 {
		return false
	}

	values := t.arrowBuilder()
	values.Resize(storage.MaxPointsPerBlock)

	var cr *colReader

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		start := t.startTimes(values)
		cr = t.allocateBuffer(start.Len())
		cr.cols[timeColIdx] = start
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		stop := t.stopTimes(values)
		cr = t.allocateBuffer(stop.Len())
		cr.cols[timeColIdx] = stop
		t.appendBounds(cr)
	default:
		start, stop, time := t.startStopTimes(values)
		cr = t.allocateBuffer(time.Len())
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[timeColIdx] = time
	}

	cr.cols[valueColIdx] = values.NewInt64Array()
	t.appendTags(cr)
	return true
}

func (t *integerEmptyWindowSelectorTable) startTimes(builder *array.Int64Builder) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if start.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array()
}

func (t *integerEmptyWindowSelectorTable) stopTimes(builder *array.Int64Builder) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if stop.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return stop.NewInt64Array()
}

func (t *integerEmptyWindowSelectorTable) startStopTimes(builder *array.Int64Builder) (*array.Int64, *array.Int64, *array.Int64) {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	time := arrow.NewIntBuilder(t.alloc)
	time.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			time.Append(v)
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			time.AppendNull()
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if time.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array(), stop.NewInt64Array(), time.NewInt64Array()
}

// group table

type integerGroupTable struct {
	table
	mu  sync.Mutex
	gc  storage.GroupCursor
	cur cursors.IntegerArrayCursor
}

func newIntegerGroupTable(
	done chan struct{},
	gc storage.GroupCursor,
	cur cursors.IntegerArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *integerGroupTable {
	t := &integerGroupTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		gc:    gc,
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *integerGroupTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	if t.gc != nil {
		t.gc.Close()
		t.gc = nil
	}
	t.mu.Unlock()
}

func (t *integerGroupTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *integerGroupTable) advance() bool {
RETRY:
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		if t.advanceCursor() {
			goto RETRY
		}

		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

func (t *integerGroupTable) advanceCursor() bool {
	t.cur.Close()
	t.cur = nil
	for t.gc.Next() {
		cur := t.gc.Cursor()
		if cur == nil {
			continue
		}

		if typedCur, ok := cur.(cursors.IntegerArrayCursor); !ok {
			// TODO(sgc): error or skip?
			cur.Close()
			t.err = &influxdb.Error{
				Code: influxdb.EInvalid,
				Err: &GroupCursorError{
					typ:    "integer",
					cursor: cur,
				},
			}
			return false
		} else {
			t.readTags(t.gc.Tags())
			t.cur = typedCur
			return true
		}
	}
	return false
}

func (t *integerGroupTable) Statistics() cursors.CursorStats {
	if t.cur == nil {
		return cursors.CursorStats{}
	}
	cs := t.cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

//
// *********** Unsigned ***********
//

type unsignedTable struct {
	table
	mu    sync.Mutex
	cur   cursors.UnsignedArrayCursor
	alloc *memory.Allocator
}

func newUnsignedTable(
	done chan struct{},
	cur cursors.UnsignedArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *unsignedTable {
	t := &unsignedTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *unsignedTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	t.mu.Unlock()
}

func (t *unsignedTable) Statistics() cursors.CursorStats {
	t.mu.Lock()
	defer t.mu.Unlock()
	cur := t.cur
	if cur == nil {
		return cursors.CursorStats{}
	}
	cs := cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

func (t *unsignedTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *unsignedTable) advance() bool {
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

// window table
type unsignedWindowTable struct {
	unsignedTable
	windowEvery int64
	offset      int64
	arr         *cursors.UnsignedArray
	nextTS      int64
	idxInArr    int
	createEmpty bool
	timeColumn  string
}

func newUnsignedWindowTable(
	done chan struct{},
	cur cursors.UnsignedArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	createEmpty bool,
	timeColumn string,

	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *unsignedWindowTable {
	t := &unsignedWindowTable{
		unsignedTable: unsignedTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		createEmpty: createEmpty,
		timeColumn:  timeColumn,
	}
	if t.createEmpty {
		start := int64(bounds.Start)
		t.nextTS = storage.WindowStop(start, every, offset)
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *unsignedWindowTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

// createNextBufferTimes will read the timestamps from the array
// cursor and construct the values for the next buffer.
func (t *unsignedWindowTable) createNextBufferTimes() (start, stop *array.Int64, ok bool) {
	startB := arrow.NewIntBuilder(t.alloc)
	stopB := arrow.NewIntBuilder(t.alloc)

	if t.createEmpty {
		// There are no more windows when the start time is greater
		// than or equal to the stop time.
		if startT := t.nextTS - t.windowEvery; startT >= int64(t.bounds.Stop) {
			return nil, nil, false
		}

		// Create a buffer with the buffer size.
		// TODO(jsternberg): Calculate the exact size with max points as the maximum.
		startB.Resize(storage.MaxPointsPerBlock)
		stopB.Resize(storage.MaxPointsPerBlock)
		for ; ; t.nextTS += t.windowEvery {
			startT, stopT := t.getWindowBoundsFor(t.nextTS)
			if startT >= int64(t.bounds.Stop) {
				break
			}
			startB.Append(startT)
			stopB.Append(stopT)
		}
		start = startB.NewInt64Array()
		stop = stopB.NewInt64Array()
		return start, stop, true
	}

	// Retrieve the next buffer so we can copy the timestamps.
	if !t.nextBuffer() {
		return nil, nil, false
	}

	// Copy over the timestamps from the next buffer and adjust
	// times for the boundaries.
	startB.Resize(len(t.arr.Timestamps))
	stopB.Resize(len(t.arr.Timestamps))
	for _, stopT := range t.arr.Timestamps {
		startT, stopT := t.getWindowBoundsFor(stopT)
		startB.Append(startT)
		stopB.Append(stopT)
	}
	start = startB.NewInt64Array()
	stop = stopB.NewInt64Array()
	return start, stop, true
}

func (t *unsignedWindowTable) getWindowBoundsFor(ts int64) (startT, stopT int64) {
	startT, stopT = ts-t.windowEvery, ts
	if startT < int64(t.bounds.Start) {
		startT = int64(t.bounds.Start)
	}
	if stopT > int64(t.bounds.Stop) {
		stopT = int64(t.bounds.Stop)
	}
	return startT, stopT
}

// nextAt will retrieve the next value that can be used with
// the given stop timestamp. If no values can be used with the timestamp,
// it will return the default value and false.
func (t *unsignedWindowTable) nextAt(ts int64) (v uint64, ok bool) {
	if !t.nextBuffer() {
		return
	} else if !t.isInWindow(ts, t.arr.Timestamps[t.idxInArr]) {
		return
	}
	v, ok = t.arr.Values[t.idxInArr], true
	t.idxInArr++
	return v, ok
}

// isInWindow will check if the given time at stop can be used within
// the window stop time for ts. The ts may be a truncated stop time
// because of a restricted boundary while stop will be the true
// stop time returned by storage.
func (t *unsignedWindowTable) isInWindow(ts int64, stop int64) bool {
	// This method checks if the stop time is a valid stop time for
	// that interval. This calculation is different from the calculation
	// of the window itself. For example, for a 10 second window that
	// starts at 20 seconds, we would include points between [20, 30).
	// The stop time for this interval would be 30, but because the stop
	// time can be truncated, valid stop times range from anywhere between
	// (20, 30]. The storage engine will always produce 30 as the end time
	// but we may have truncated the stop time because of the boundary
	// and this is why we are checking for this range instead of checking
	// if the two values are equal.
	start := stop - t.windowEvery
	return start < ts && ts <= stop
}

// nextBuffer will ensure the array cursor is filled
// and will return true if there is at least one value
// that can be read from it.
func (t *unsignedWindowTable) nextBuffer() bool {
	// Discard the current array cursor if we have
	// exceeded it.
	if t.arr != nil && t.idxInArr >= t.arr.Len() {
		t.arr = nil
	}

	// Retrieve the next array cursor if needed.
	if t.arr == nil {
		arr := t.cur.Next()
		if arr.Len() == 0 {
			return false
		}
		t.arr, t.idxInArr = arr, 0
	}
	return true
}

// appendValues will scan the timestamps and append values
// that match those timestamps from the buffer.
func (t *unsignedWindowTable) appendValues(intervals []int64, appendValue func(v uint64), appendNull func()) {
	for i := 0; i < len(intervals); i++ {
		if v, ok := t.nextAt(intervals[i]); ok {
			appendValue(v)
			continue
		}
		appendNull()
	}
}

func (t *unsignedWindowTable) advance() bool {
	if !t.nextBuffer() {
		return false
	}
	// Create the timestamps for the next window.
	start, stop, ok := t.createNextBufferTimes()
	if !ok {
		return false
	}
	values := t.mergeValues(stop.Int64Values())

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(stop.Len())
	if t.timeColumn != "" {
		switch t.timeColumn {
		case execute.DefaultStopColLabel:
			cr.cols[timeColIdx] = stop
			start.Release()
		case execute.DefaultStartColLabel:
			cr.cols[timeColIdx] = start
			stop.Release()
		}
		cr.cols[valueColIdx] = values
		t.appendBounds(cr)
	} else {
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[windowedValueColIdx] = values
	}
	t.appendTags(cr)
	return true
}

// This table implementation will not have any empty windows.
type unsignedWindowSelectorTable struct {
	unsignedTable
	windowEvery int64
	offset      int64
	timeColumn  string
}

func newUnsignedWindowSelectorTable(
	done chan struct{},
	cur cursors.UnsignedArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *unsignedWindowSelectorTable {
	t := &unsignedWindowSelectorTable{
		unsignedTable: unsignedTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *unsignedWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *unsignedWindowSelectorTable) advance() bool {
	arr := t.cur.Next()
	if arr.Len() == 0 {
		return false
	}

	cr := t.allocateBuffer(arr.Len())

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		cr.cols[timeColIdx] = t.startTimes(arr)
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		cr.cols[timeColIdx] = t.stopTimes(arr)
		t.appendBounds(cr)
	default:
		cr.cols[startColIdx] = t.startTimes(arr)
		cr.cols[stopColIdx] = t.stopTimes(arr)
		cr.cols[timeColIdx] = arrow.NewInt(arr.Timestamps, t.alloc)
	}

	cr.cols[valueColIdx] = t.toArrowBuffer(arr.Values)
	t.appendTags(cr)
	return true
}

func (t *unsignedWindowSelectorTable) startTimes(arr *cursors.UnsignedArray) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(arr.Len())

	rangeStart := int64(t.bounds.Start)

	for _, v := range arr.Timestamps {
		if windowStart := storage.WindowStart(v, t.windowEvery, t.offset); windowStart < rangeStart {
			start.Append(rangeStart)
		} else {
			start.Append(windowStart)
		}
	}
	return start.NewInt64Array()
}

func (t *unsignedWindowSelectorTable) stopTimes(arr *cursors.UnsignedArray) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(arr.Len())

	rangeStop := int64(t.bounds.Stop)

	for _, v := range arr.Timestamps {
		if windowStop := storage.WindowStop(v, t.windowEvery, t.offset); windowStop > rangeStop {
			stop.Append(rangeStop)
		} else {
			stop.Append(windowStop)
		}
	}
	return stop.NewInt64Array()
}

// This table implementation may contain empty windows
// in addition to non-empty windows.
type unsignedEmptyWindowSelectorTable struct {
	unsignedTable
	arr         *cursors.UnsignedArray
	idx         int
	rangeStart  int64
	rangeStop   int64
	windowStart int64
	windowStop  int64
	windowEvery int64
	timeColumn  string
}

func newUnsignedEmptyWindowSelectorTable(
	done chan struct{},
	cur cursors.UnsignedArrayCursor,
	bounds execute.Bounds,
	windowEvery int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *unsignedEmptyWindowSelectorTable {
	rangeStart := int64(bounds.Start)
	rangeStop := int64(bounds.Stop)
	t := &unsignedEmptyWindowSelectorTable{
		unsignedTable: unsignedTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		arr:         cur.Next(),
		rangeStart:  rangeStart,
		rangeStop:   rangeStop,
		windowStart: storage.WindowStart(rangeStart, windowEvery, offset),
		windowStop:  storage.WindowStop(rangeStart, windowEvery, offset),
		windowEvery: windowEvery,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *unsignedEmptyWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *unsignedEmptyWindowSelectorTable) advance() bool {
	if t.arr.Len() == 0 {
		return false
	}

	values := t.arrowBuilder()
	values.Resize(storage.MaxPointsPerBlock)

	var cr *colReader

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		start := t.startTimes(values)
		cr = t.allocateBuffer(start.Len())
		cr.cols[timeColIdx] = start
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		stop := t.stopTimes(values)
		cr = t.allocateBuffer(stop.Len())
		cr.cols[timeColIdx] = stop
		t.appendBounds(cr)
	default:
		start, stop, time := t.startStopTimes(values)
		cr = t.allocateBuffer(time.Len())
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[timeColIdx] = time
	}

	cr.cols[valueColIdx] = values.NewUint64Array()
	t.appendTags(cr)
	return true
}

func (t *unsignedEmptyWindowSelectorTable) startTimes(builder *array.Uint64Builder) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if start.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array()
}

func (t *unsignedEmptyWindowSelectorTable) stopTimes(builder *array.Uint64Builder) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if stop.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return stop.NewInt64Array()
}

func (t *unsignedEmptyWindowSelectorTable) startStopTimes(builder *array.Uint64Builder) (*array.Int64, *array.Int64, *array.Int64) {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	time := arrow.NewIntBuilder(t.alloc)
	time.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			time.Append(v)
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			time.AppendNull()
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if time.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array(), stop.NewInt64Array(), time.NewInt64Array()
}

// group table

type unsignedGroupTable struct {
	table
	mu  sync.Mutex
	gc  storage.GroupCursor
	cur cursors.UnsignedArrayCursor
}

func newUnsignedGroupTable(
	done chan struct{},
	gc storage.GroupCursor,
	cur cursors.UnsignedArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *unsignedGroupTable {
	t := &unsignedGroupTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		gc:    gc,
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *unsignedGroupTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	if t.gc != nil {
		t.gc.Close()
		t.gc = nil
	}
	t.mu.Unlock()
}

func (t *unsignedGroupTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *unsignedGroupTable) advance() bool {
RETRY:
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		if t.advanceCursor() {
			goto RETRY
		}

		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

func (t *unsignedGroupTable) advanceCursor() bool {
	t.cur.Close()
	t.cur = nil
	for t.gc.Next() {
		cur := t.gc.Cursor()
		if cur == nil {
			continue
		}

		if typedCur, ok := cur.(cursors.UnsignedArrayCursor); !ok {
			// TODO(sgc): error or skip?
			cur.Close()
			t.err = &influxdb.Error{
				Code: influxdb.EInvalid,
				Err: &GroupCursorError{
					typ:    "unsigned",
					cursor: cur,
				},
			}
			return false
		} else {
			t.readTags(t.gc.Tags())
			t.cur = typedCur
			return true
		}
	}
	return false
}

func (t *unsignedGroupTable) Statistics() cursors.CursorStats {
	if t.cur == nil {
		return cursors.CursorStats{}
	}
	cs := t.cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

//
// *********** String ***********
//

type stringTable struct {
	table
	mu    sync.Mutex
	cur   cursors.StringArrayCursor
	alloc *memory.Allocator
}

func newStringTable(
	done chan struct{},
	cur cursors.StringArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *stringTable {
	t := &stringTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *stringTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	t.mu.Unlock()
}

func (t *stringTable) Statistics() cursors.CursorStats {
	t.mu.Lock()
	defer t.mu.Unlock()
	cur := t.cur
	if cur == nil {
		return cursors.CursorStats{}
	}
	cs := cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

func (t *stringTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *stringTable) advance() bool {
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

// window table
type stringWindowTable struct {
	stringTable
	windowEvery int64
	offset      int64
	arr         *cursors.StringArray
	nextTS      int64
	idxInArr    int
	createEmpty bool
	timeColumn  string
}

func newStringWindowTable(
	done chan struct{},
	cur cursors.StringArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	createEmpty bool,
	timeColumn string,

	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *stringWindowTable {
	t := &stringWindowTable{
		stringTable: stringTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		createEmpty: createEmpty,
		timeColumn:  timeColumn,
	}
	if t.createEmpty {
		start := int64(bounds.Start)
		t.nextTS = storage.WindowStop(start, every, offset)
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *stringWindowTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

// createNextBufferTimes will read the timestamps from the array
// cursor and construct the values for the next buffer.
func (t *stringWindowTable) createNextBufferTimes() (start, stop *array.Int64, ok bool) {
	startB := arrow.NewIntBuilder(t.alloc)
	stopB := arrow.NewIntBuilder(t.alloc)

	if t.createEmpty {
		// There are no more windows when the start time is greater
		// than or equal to the stop time.
		if startT := t.nextTS - t.windowEvery; startT >= int64(t.bounds.Stop) {
			return nil, nil, false
		}

		// Create a buffer with the buffer size.
		// TODO(jsternberg): Calculate the exact size with max points as the maximum.
		startB.Resize(storage.MaxPointsPerBlock)
		stopB.Resize(storage.MaxPointsPerBlock)
		for ; ; t.nextTS += t.windowEvery {
			startT, stopT := t.getWindowBoundsFor(t.nextTS)
			if startT >= int64(t.bounds.Stop) {
				break
			}
			startB.Append(startT)
			stopB.Append(stopT)
		}
		start = startB.NewInt64Array()
		stop = stopB.NewInt64Array()
		return start, stop, true
	}

	// Retrieve the next buffer so we can copy the timestamps.
	if !t.nextBuffer() {
		return nil, nil, false
	}

	// Copy over the timestamps from the next buffer and adjust
	// times for the boundaries.
	startB.Resize(len(t.arr.Timestamps))
	stopB.Resize(len(t.arr.Timestamps))
	for _, stopT := range t.arr.Timestamps {
		startT, stopT := t.getWindowBoundsFor(stopT)
		startB.Append(startT)
		stopB.Append(stopT)
	}
	start = startB.NewInt64Array()
	stop = stopB.NewInt64Array()
	return start, stop, true
}

func (t *stringWindowTable) getWindowBoundsFor(ts int64) (startT, stopT int64) {
	startT, stopT = ts-t.windowEvery, ts
	if startT < int64(t.bounds.Start) {
		startT = int64(t.bounds.Start)
	}
	if stopT > int64(t.bounds.Stop) {
		stopT = int64(t.bounds.Stop)
	}
	return startT, stopT
}

// nextAt will retrieve the next value that can be used with
// the given stop timestamp. If no values can be used with the timestamp,
// it will return the default value and false.
func (t *stringWindowTable) nextAt(ts int64) (v string, ok bool) {
	if !t.nextBuffer() {
		return
	} else if !t.isInWindow(ts, t.arr.Timestamps[t.idxInArr]) {
		return
	}
	v, ok = t.arr.Values[t.idxInArr], true
	t.idxInArr++
	return v, ok
}

// isInWindow will check if the given time at stop can be used within
// the window stop time for ts. The ts may be a truncated stop time
// because of a restricted boundary while stop will be the true
// stop time returned by storage.
func (t *stringWindowTable) isInWindow(ts int64, stop int64) bool {
	// This method checks if the stop time is a valid stop time for
	// that interval. This calculation is different from the calculation
	// of the window itself. For example, for a 10 second window that
	// starts at 20 seconds, we would include points between [20, 30).
	// The stop time for this interval would be 30, but because the stop
	// time can be truncated, valid stop times range from anywhere between
	// (20, 30]. The storage engine will always produce 30 as the end time
	// but we may have truncated the stop time because of the boundary
	// and this is why we are checking for this range instead of checking
	// if the two values are equal.
	start := stop - t.windowEvery
	return start < ts && ts <= stop
}

// nextBuffer will ensure the array cursor is filled
// and will return true if there is at least one value
// that can be read from it.
func (t *stringWindowTable) nextBuffer() bool {
	// Discard the current array cursor if we have
	// exceeded it.
	if t.arr != nil && t.idxInArr >= t.arr.Len() {
		t.arr = nil
	}

	// Retrieve the next array cursor if needed.
	if t.arr == nil {
		arr := t.cur.Next()
		if arr.Len() == 0 {
			return false
		}
		t.arr, t.idxInArr = arr, 0
	}
	return true
}

// appendValues will scan the timestamps and append values
// that match those timestamps from the buffer.
func (t *stringWindowTable) appendValues(intervals []int64, appendValue func(v string), appendNull func()) {
	for i := 0; i < len(intervals); i++ {
		if v, ok := t.nextAt(intervals[i]); ok {
			appendValue(v)
			continue
		}
		appendNull()
	}
}

func (t *stringWindowTable) advance() bool {
	if !t.nextBuffer() {
		return false
	}
	// Create the timestamps for the next window.
	start, stop, ok := t.createNextBufferTimes()
	if !ok {
		return false
	}
	values := t.mergeValues(stop.Int64Values())

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(stop.Len())
	if t.timeColumn != "" {
		switch t.timeColumn {
		case execute.DefaultStopColLabel:
			cr.cols[timeColIdx] = stop
			start.Release()
		case execute.DefaultStartColLabel:
			cr.cols[timeColIdx] = start
			stop.Release()
		}
		cr.cols[valueColIdx] = values
		t.appendBounds(cr)
	} else {
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[windowedValueColIdx] = values
	}
	t.appendTags(cr)
	return true
}

// This table implementation will not have any empty windows.
type stringWindowSelectorTable struct {
	stringTable
	windowEvery int64
	offset      int64
	timeColumn  string
}

func newStringWindowSelectorTable(
	done chan struct{},
	cur cursors.StringArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *stringWindowSelectorTable {
	t := &stringWindowSelectorTable{
		stringTable: stringTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *stringWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *stringWindowSelectorTable) advance() bool {
	arr := t.cur.Next()
	if arr.Len() == 0 {
		return false
	}

	cr := t.allocateBuffer(arr.Len())

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		cr.cols[timeColIdx] = t.startTimes(arr)
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		cr.cols[timeColIdx] = t.stopTimes(arr)
		t.appendBounds(cr)
	default:
		cr.cols[startColIdx] = t.startTimes(arr)
		cr.cols[stopColIdx] = t.stopTimes(arr)
		cr.cols[timeColIdx] = arrow.NewInt(arr.Timestamps, t.alloc)
	}

	cr.cols[valueColIdx] = t.toArrowBuffer(arr.Values)
	t.appendTags(cr)
	return true
}

func (t *stringWindowSelectorTable) startTimes(arr *cursors.StringArray) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(arr.Len())

	rangeStart := int64(t.bounds.Start)

	for _, v := range arr.Timestamps {
		if windowStart := storage.WindowStart(v, t.windowEvery, t.offset); windowStart < rangeStart {
			start.Append(rangeStart)
		} else {
			start.Append(windowStart)
		}
	}
	return start.NewInt64Array()
}

func (t *stringWindowSelectorTable) stopTimes(arr *cursors.StringArray) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(arr.Len())

	rangeStop := int64(t.bounds.Stop)

	for _, v := range arr.Timestamps {
		if windowStop := storage.WindowStop(v, t.windowEvery, t.offset); windowStop > rangeStop {
			stop.Append(rangeStop)
		} else {
			stop.Append(windowStop)
		}
	}
	return stop.NewInt64Array()
}

// This table implementation may contain empty windows
// in addition to non-empty windows.
type stringEmptyWindowSelectorTable struct {
	stringTable
	arr         *cursors.StringArray
	idx         int
	rangeStart  int64
	rangeStop   int64
	windowStart int64
	windowStop  int64
	windowEvery int64
	timeColumn  string
}

func newStringEmptyWindowSelectorTable(
	done chan struct{},
	cur cursors.StringArrayCursor,
	bounds execute.Bounds,
	windowEvery int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *stringEmptyWindowSelectorTable {
	rangeStart := int64(bounds.Start)
	rangeStop := int64(bounds.Stop)
	t := &stringEmptyWindowSelectorTable{
		stringTable: stringTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		arr:         cur.Next(),
		rangeStart:  rangeStart,
		rangeStop:   rangeStop,
		windowStart: storage.WindowStart(rangeStart, windowEvery, offset),
		windowStop:  storage.WindowStop(rangeStart, windowEvery, offset),
		windowEvery: windowEvery,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *stringEmptyWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *stringEmptyWindowSelectorTable) advance() bool {
	if t.arr.Len() == 0 {
		return false
	}

	values := t.arrowBuilder()
	values.Resize(storage.MaxPointsPerBlock)

	var cr *colReader

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		start := t.startTimes(values)
		cr = t.allocateBuffer(start.Len())
		cr.cols[timeColIdx] = start
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		stop := t.stopTimes(values)
		cr = t.allocateBuffer(stop.Len())
		cr.cols[timeColIdx] = stop
		t.appendBounds(cr)
	default:
		start, stop, time := t.startStopTimes(values)
		cr = t.allocateBuffer(time.Len())
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[timeColIdx] = time
	}

	cr.cols[valueColIdx] = values.NewBinaryArray()
	t.appendTags(cr)
	return true
}

func (t *stringEmptyWindowSelectorTable) startTimes(builder *array.BinaryBuilder) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if start.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array()
}

func (t *stringEmptyWindowSelectorTable) stopTimes(builder *array.BinaryBuilder) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if stop.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return stop.NewInt64Array()
}

func (t *stringEmptyWindowSelectorTable) startStopTimes(builder *array.BinaryBuilder) (*array.Int64, *array.Int64, *array.Int64) {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	time := arrow.NewIntBuilder(t.alloc)
	time.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			time.Append(v)
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			time.AppendNull()
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if time.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array(), stop.NewInt64Array(), time.NewInt64Array()
}

// group table

type stringGroupTable struct {
	table
	mu  sync.Mutex
	gc  storage.GroupCursor
	cur cursors.StringArrayCursor
}

func newStringGroupTable(
	done chan struct{},
	gc storage.GroupCursor,
	cur cursors.StringArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *stringGroupTable {
	t := &stringGroupTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		gc:    gc,
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *stringGroupTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	if t.gc != nil {
		t.gc.Close()
		t.gc = nil
	}
	t.mu.Unlock()
}

func (t *stringGroupTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *stringGroupTable) advance() bool {
RETRY:
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		if t.advanceCursor() {
			goto RETRY
		}

		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

func (t *stringGroupTable) advanceCursor() bool {
	t.cur.Close()
	t.cur = nil
	for t.gc.Next() {
		cur := t.gc.Cursor()
		if cur == nil {
			continue
		}

		if typedCur, ok := cur.(cursors.StringArrayCursor); !ok {
			// TODO(sgc): error or skip?
			cur.Close()
			t.err = &influxdb.Error{
				Code: influxdb.EInvalid,
				Err: &GroupCursorError{
					typ:    "string",
					cursor: cur,
				},
			}
			return false
		} else {
			t.readTags(t.gc.Tags())
			t.cur = typedCur
			return true
		}
	}
	return false
}

func (t *stringGroupTable) Statistics() cursors.CursorStats {
	if t.cur == nil {
		return cursors.CursorStats{}
	}
	cs := t.cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

//
// *********** Boolean ***********
//

type booleanTable struct {
	table
	mu    sync.Mutex
	cur   cursors.BooleanArrayCursor
	alloc *memory.Allocator
}

func newBooleanTable(
	done chan struct{},
	cur cursors.BooleanArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *booleanTable {
	t := &booleanTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *booleanTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	t.mu.Unlock()
}

func (t *booleanTable) Statistics() cursors.CursorStats {
	t.mu.Lock()
	defer t.mu.Unlock()
	cur := t.cur
	if cur == nil {
		return cursors.CursorStats{}
	}
	cs := cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}

func (t *booleanTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *booleanTable) advance() bool {
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

// window table
type booleanWindowTable struct {
	booleanTable
	windowEvery int64
	offset      int64
	arr         *cursors.BooleanArray
	nextTS      int64
	idxInArr    int
	createEmpty bool
	timeColumn  string
}

func newBooleanWindowTable(
	done chan struct{},
	cur cursors.BooleanArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	createEmpty bool,
	timeColumn string,

	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *booleanWindowTable {
	t := &booleanWindowTable{
		booleanTable: booleanTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		createEmpty: createEmpty,
		timeColumn:  timeColumn,
	}
	if t.createEmpty {
		start := int64(bounds.Start)
		t.nextTS = storage.WindowStop(start, every, offset)
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *booleanWindowTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

// createNextBufferTimes will read the timestamps from the array
// cursor and construct the values for the next buffer.
func (t *booleanWindowTable) createNextBufferTimes() (start, stop *array.Int64, ok bool) {
	startB := arrow.NewIntBuilder(t.alloc)
	stopB := arrow.NewIntBuilder(t.alloc)

	if t.createEmpty {
		// There are no more windows when the start time is greater
		// than or equal to the stop time.
		if startT := t.nextTS - t.windowEvery; startT >= int64(t.bounds.Stop) {
			return nil, nil, false
		}

		// Create a buffer with the buffer size.
		// TODO(jsternberg): Calculate the exact size with max points as the maximum.
		startB.Resize(storage.MaxPointsPerBlock)
		stopB.Resize(storage.MaxPointsPerBlock)
		for ; ; t.nextTS += t.windowEvery {
			startT, stopT := t.getWindowBoundsFor(t.nextTS)
			if startT >= int64(t.bounds.Stop) {
				break
			}
			startB.Append(startT)
			stopB.Append(stopT)
		}
		start = startB.NewInt64Array()
		stop = stopB.NewInt64Array()
		return start, stop, true
	}

	// Retrieve the next buffer so we can copy the timestamps.
	if !t.nextBuffer() {
		return nil, nil, false
	}

	// Copy over the timestamps from the next buffer and adjust
	// times for the boundaries.
	startB.Resize(len(t.arr.Timestamps))
	stopB.Resize(len(t.arr.Timestamps))
	for _, stopT := range t.arr.Timestamps {
		startT, stopT := t.getWindowBoundsFor(stopT)
		startB.Append(startT)
		stopB.Append(stopT)
	}
	start = startB.NewInt64Array()
	stop = stopB.NewInt64Array()
	return start, stop, true
}

func (t *booleanWindowTable) getWindowBoundsFor(ts int64) (startT, stopT int64) {
	startT, stopT = ts-t.windowEvery, ts
	if startT < int64(t.bounds.Start) {
		startT = int64(t.bounds.Start)
	}
	if stopT > int64(t.bounds.Stop) {
		stopT = int64(t.bounds.Stop)
	}
	return startT, stopT
}

// nextAt will retrieve the next value that can be used with
// the given stop timestamp. If no values can be used with the timestamp,
// it will return the default value and false.
func (t *booleanWindowTable) nextAt(ts int64) (v bool, ok bool) {
	if !t.nextBuffer() {
		return
	} else if !t.isInWindow(ts, t.arr.Timestamps[t.idxInArr]) {
		return
	}
	v, ok = t.arr.Values[t.idxInArr], true
	t.idxInArr++
	return v, ok
}

// isInWindow will check if the given time at stop can be used within
// the window stop time for ts. The ts may be a truncated stop time
// because of a restricted boundary while stop will be the true
// stop time returned by storage.
func (t *booleanWindowTable) isInWindow(ts int64, stop int64) bool {
	// This method checks if the stop time is a valid stop time for
	// that interval. This calculation is different from the calculation
	// of the window itself. For example, for a 10 second window that
	// starts at 20 seconds, we would include points between [20, 30).
	// The stop time for this interval would be 30, but because the stop
	// time can be truncated, valid stop times range from anywhere between
	// (20, 30]. The storage engine will always produce 30 as the end time
	// but we may have truncated the stop time because of the boundary
	// and this is why we are checking for this range instead of checking
	// if the two values are equal.
	start := stop - t.windowEvery
	return start < ts && ts <= stop
}

// nextBuffer will ensure the array cursor is filled
// and will return true if there is at least one value
// that can be read from it.
func (t *booleanWindowTable) nextBuffer() bool {
	// Discard the current array cursor if we have
	// exceeded it.
	if t.arr != nil && t.idxInArr >= t.arr.Len() {
		t.arr = nil
	}

	// Retrieve the next array cursor if needed.
	if t.arr == nil {
		arr := t.cur.Next()
		if arr.Len() == 0 {
			return false
		}
		t.arr, t.idxInArr = arr, 0
	}
	return true
}

// appendValues will scan the timestamps and append values
// that match those timestamps from the buffer.
func (t *booleanWindowTable) appendValues(intervals []int64, appendValue func(v bool), appendNull func()) {
	for i := 0; i < len(intervals); i++ {
		if v, ok := t.nextAt(intervals[i]); ok {
			appendValue(v)
			continue
		}
		appendNull()
	}
}

func (t *booleanWindowTable) advance() bool {
	if !t.nextBuffer() {
		return false
	}
	// Create the timestamps for the next window.
	start, stop, ok := t.createNextBufferTimes()
	if !ok {
		return false
	}
	values := t.mergeValues(stop.Int64Values())

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(stop.Len())
	if t.timeColumn != "" {
		switch t.timeColumn {
		case execute.DefaultStopColLabel:
			cr.cols[timeColIdx] = stop
			start.Release()
		case execute.DefaultStartColLabel:
			cr.cols[timeColIdx] = start
			stop.Release()
		}
		cr.cols[valueColIdx] = values
		t.appendBounds(cr)
	} else {
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[windowedValueColIdx] = values
	}
	t.appendTags(cr)
	return true
}

// This table implementation will not have any empty windows.
type booleanWindowSelectorTable struct {
	booleanTable
	windowEvery int64
	offset      int64
	timeColumn  string
}

func newBooleanWindowSelectorTable(
	done chan struct{},
	cur cursors.BooleanArrayCursor,
	bounds execute.Bounds,
	every int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *booleanWindowSelectorTable {
	t := &booleanWindowSelectorTable{
		booleanTable: booleanTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		windowEvery: every,
		offset:      offset,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *booleanWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *booleanWindowSelectorTable) advance() bool {
	arr := t.cur.Next()
	if arr.Len() == 0 {
		return false
	}

	cr := t.allocateBuffer(arr.Len())

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		cr.cols[timeColIdx] = t.startTimes(arr)
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		cr.cols[timeColIdx] = t.stopTimes(arr)
		t.appendBounds(cr)
	default:
		cr.cols[startColIdx] = t.startTimes(arr)
		cr.cols[stopColIdx] = t.stopTimes(arr)
		cr.cols[timeColIdx] = arrow.NewInt(arr.Timestamps, t.alloc)
	}

	cr.cols[valueColIdx] = t.toArrowBuffer(arr.Values)
	t.appendTags(cr)
	return true
}

func (t *booleanWindowSelectorTable) startTimes(arr *cursors.BooleanArray) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(arr.Len())

	rangeStart := int64(t.bounds.Start)

	for _, v := range arr.Timestamps {
		if windowStart := storage.WindowStart(v, t.windowEvery, t.offset); windowStart < rangeStart {
			start.Append(rangeStart)
		} else {
			start.Append(windowStart)
		}
	}
	return start.NewInt64Array()
}

func (t *booleanWindowSelectorTable) stopTimes(arr *cursors.BooleanArray) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(arr.Len())

	rangeStop := int64(t.bounds.Stop)

	for _, v := range arr.Timestamps {
		if windowStop := storage.WindowStop(v, t.windowEvery, t.offset); windowStop > rangeStop {
			stop.Append(rangeStop)
		} else {
			stop.Append(windowStop)
		}
	}
	return stop.NewInt64Array()
}

// This table implementation may contain empty windows
// in addition to non-empty windows.
type booleanEmptyWindowSelectorTable struct {
	booleanTable
	arr         *cursors.BooleanArray
	idx         int
	rangeStart  int64
	rangeStop   int64
	windowStart int64
	windowStop  int64
	windowEvery int64
	timeColumn  string
}

func newBooleanEmptyWindowSelectorTable(
	done chan struct{},
	cur cursors.BooleanArrayCursor,
	bounds execute.Bounds,
	windowEvery int64,
	offset int64,
	timeColumn string,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *booleanEmptyWindowSelectorTable {
	rangeStart := int64(bounds.Start)
	rangeStop := int64(bounds.Stop)
	t := &booleanEmptyWindowSelectorTable{
		booleanTable: booleanTable{
			table: newTable(done, bounds, key, cols, defs, cache, alloc),
			cur:   cur,
		},
		arr:         cur.Next(),
		rangeStart:  rangeStart,
		rangeStop:   rangeStop,
		windowStart: storage.WindowStart(rangeStart, windowEvery, offset),
		windowStop:  storage.WindowStop(rangeStart, windowEvery, offset),
		windowEvery: windowEvery,
		timeColumn:  timeColumn,
	}
	t.readTags(tags)
	t.init(t.advance)
	return t
}

func (t *booleanEmptyWindowSelectorTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *booleanEmptyWindowSelectorTable) advance() bool {
	if t.arr.Len() == 0 {
		return false
	}

	values := t.arrowBuilder()
	values.Resize(storage.MaxPointsPerBlock)

	var cr *colReader

	switch t.timeColumn {
	case execute.DefaultStartColLabel:
		start := t.startTimes(values)
		cr = t.allocateBuffer(start.Len())
		cr.cols[timeColIdx] = start
		t.appendBounds(cr)
	case execute.DefaultStopColLabel:
		stop := t.stopTimes(values)
		cr = t.allocateBuffer(stop.Len())
		cr.cols[timeColIdx] = stop
		t.appendBounds(cr)
	default:
		start, stop, time := t.startStopTimes(values)
		cr = t.allocateBuffer(time.Len())
		cr.cols[startColIdx] = start
		cr.cols[stopColIdx] = stop
		cr.cols[timeColIdx] = time
	}

	cr.cols[valueColIdx] = values.NewBooleanArray()
	t.appendTags(cr)
	return true
}

func (t *booleanEmptyWindowSelectorTable) startTimes(builder *array.BooleanBuilder) *array.Int64 {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if start.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array()
}

func (t *booleanEmptyWindowSelectorTable) stopTimes(builder *array.BooleanBuilder) *array.Int64 {
	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if stop.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return stop.NewInt64Array()
}

func (t *booleanEmptyWindowSelectorTable) startStopTimes(builder *array.BooleanBuilder) (*array.Int64, *array.Int64, *array.Int64) {
	start := arrow.NewIntBuilder(t.alloc)
	start.Resize(storage.MaxPointsPerBlock)

	stop := arrow.NewIntBuilder(t.alloc)
	stop.Resize(storage.MaxPointsPerBlock)

	time := arrow.NewIntBuilder(t.alloc)
	time.Resize(storage.MaxPointsPerBlock)

	for t.windowStart < t.rangeStop {

		// The first window should start at the
		// beginning of the time range.
		if t.windowStart < t.rangeStart {
			start.Append(t.rangeStart)
		} else {
			start.Append(t.windowStart)
		}

		// The last window should stop at the end of
		// the time range.
		if t.windowStop > t.rangeStop {
			stop.Append(t.rangeStop)
		} else {
			stop.Append(t.windowStop)
		}

		var v int64

		if t.arr.Len() == 0 {
			v = math.MaxInt64
		} else {
			v = t.arr.Timestamps[t.idx]
		}

		// If the current timestamp falls within the
		// current window, append the value to the
		// builder, otherwise append a null value.
		if t.windowStart <= v && v < t.windowStop {
			time.Append(v)
			t.append(builder, t.arr.Values[t.idx])
			t.idx++
		} else {
			time.AppendNull()
			builder.AppendNull()
		}

		t.windowStart += t.windowEvery
		t.windowStop += t.windowEvery

		// If the current array is non-empty and has
		// been read in its entirety, call Next().
		if t.arr.Len() > 0 && t.idx == t.arr.Len() {
			t.arr = t.cur.Next()
			t.idx = 0
		}

		if time.Len() == storage.MaxPointsPerBlock {
			break
		}
	}
	return start.NewInt64Array(), stop.NewInt64Array(), time.NewInt64Array()
}

// group table

type booleanGroupTable struct {
	table
	mu  sync.Mutex
	gc  storage.GroupCursor
	cur cursors.BooleanArrayCursor
}

func newBooleanGroupTable(
	done chan struct{},
	gc storage.GroupCursor,
	cur cursors.BooleanArrayCursor,
	bounds execute.Bounds,
	key flux.GroupKey,
	cols []flux.ColMeta,
	tags models.Tags,
	defs [][]byte,
	cache *tagsCache,
	alloc *memory.Allocator,
) *booleanGroupTable {
	t := &booleanGroupTable{
		table: newTable(done, bounds, key, cols, defs, cache, alloc),
		gc:    gc,
		cur:   cur,
	}
	t.readTags(tags)
	t.init(t.advance)

	return t
}

func (t *booleanGroupTable) Close() {
	t.mu.Lock()
	if t.cur != nil {
		t.cur.Close()
		t.cur = nil
	}
	if t.gc != nil {
		t.gc.Close()
		t.gc = nil
	}
	t.mu.Unlock()
}

func (t *booleanGroupTable) Do(f func(flux.ColReader) error) error {
	return t.do(f, t.advance)
}

func (t *booleanGroupTable) advance() bool {
RETRY:
	a := t.cur.Next()
	l := a.Len()
	if l == 0 {
		if t.advanceCursor() {
			goto RETRY
		}

		return false
	}

	// Retrieve the buffer for the data to avoid allocating
	// additional slices. If the buffer is still being used
	// because the references were retained, then we will
	// allocate a new buffer.
	cr := t.allocateBuffer(l)
	cr.cols[timeColIdx] = arrow.NewInt(a.Timestamps, t.alloc)
	cr.cols[valueColIdx] = t.toArrowBuffer(a.Values)
	t.appendTags(cr)
	t.appendBounds(cr)
	return true
}

func (t *booleanGroupTable) advanceCursor() bool {
	t.cur.Close()
	t.cur = nil
	for t.gc.Next() {
		cur := t.gc.Cursor()
		if cur == nil {
			continue
		}

		if typedCur, ok := cur.(cursors.BooleanArrayCursor); !ok {
			// TODO(sgc): error or skip?
			cur.Close()
			t.err = &influxdb.Error{
				Code: influxdb.EInvalid,
				Err: &GroupCursorError{
					typ:    "boolean",
					cursor: cur,
				},
			}
			return false
		} else {
			t.readTags(t.gc.Tags())
			t.cur = typedCur
			return true
		}
	}
	return false
}

func (t *booleanGroupTable) Statistics() cursors.CursorStats {
	if t.cur == nil {
		return cursors.CursorStats{}
	}
	cs := t.cur.Stats()
	return cursors.CursorStats{
		ScannedValues: cs.ScannedValues,
		ScannedBytes:  cs.ScannedBytes,
	}
}