diff --git a/Makefile b/Makefile
index e794990ee..e38ed3860 100644
--- a/Makefile
+++ b/Makefile
@@ -160,12 +160,6 @@ topt-badger:
 	@echo "   log.topt.badger green: \c"; cat log.topt.badger | grep PASS |wc -l
 	@echo "   log.topt.badger   red: \c"; cat log.topt.badger | grep '\-\-\- FAIL' |wc -l
 
-topt-rb:
-	mv log.topt.roaring_badger log.topt.roaring_badger.prev || true
-	PILOSA_TXSRC=roaring_badger go test -v -tags='$(BUILD_TAGS)' $(TESTFLAGS) $(NOCHECKPTR)  2>&1 | tee log.topt.badger
-	@echo "   log.topt.roaring_badger green: \c"; cat log.topt.roaring_badger | grep PASS |wc -l
-	@echo "   log.topt.roaring_badger   red: \c"; cat log.topt.roaring_badger | grep '\-\-\- FAIL' |wc -l
-
 topt-badger-race:
 	mv log.topt.badger-race log.topt.badger-race.prev || true
 	PILOSA_TXSRC=badger go test -race -v -tags='$(BUILD_TAGS)' $(TESTFLAGS) $(NOCHECKPTR)  2>&1 | tee log.topt.badger-race
diff --git a/fragment_internal_test.go b/fragment_internal_test.go
index f30e27ef2..a8851a1bb 100644
--- a/fragment_internal_test.go
+++ b/fragment_internal_test.go
@@ -3902,6 +3902,7 @@ func TestFragment_RoaringImport(t *testing.T) {
 			defer tx.Rollback()
 
 			for num, input := range test {
+				vv("num=%v, input='%#v'", num, input)
 				buf := &bytes.Buffer{}
 				bm := roaring.NewBitmap(input...)
 				_, err := bm.WriteTo(buf)
@@ -3912,6 +3913,8 @@ func TestFragment_RoaringImport(t *testing.T) {
 				if err != nil {
 					t.Fatalf("importing roaring: %v", err)
 				}
+				tx.Dump()
+
 				exp := calcExpected(test[:num+1]...)
 				for row, expCols := range exp {
 					cols := f.mustRow(tx, uint64(row)).Columns()
diff --git a/license.exceptions b/license.exceptions
index e703b7c2a..67767e1e2 100644
--- a/license.exceptions
+++ b/license.exceptions
@@ -10,3 +10,4 @@
 ./logger/filewriter.go
 ./logger/filewriter_test.go
 ./vprint.go
+./rbf/vprint.go
diff --git a/rbf/blake3.go b/rbf/blake3.go
new file mode 100644
index 000000000..3935d2576
--- /dev/null
+++ b/rbf/blake3.go
@@ -0,0 +1,97 @@
+// Copyright 2020 Pilosa Corp.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rbf
+
+import (
+	"encoding/binary"
+	"fmt"
+	"sync"
+
+	cryptorand "crypto/rand"
+	"github.com/zeebo/blake3"
+)
+
+// Blake3Hasher is a thread/goroutine safe way to
+// obtain a blake3 cryptographic hash of input []byte.
+// Reference https://github.com/BLAKE3-team/BLAKE3
+// suggests it is 6x faster than BLAKE2B.
+// The Go github.com/zeebo/blake3 version is
+// AVX2 and SSE4.1 accelerated.
+type Blake3Hasher struct {
+	hasher   *blake3.Hasher
+	hasherMu sync.Mutex
+}
+
+// NewBlake3Hasher returns a new Blake3Hasher.
+func NewBlake3Hasher() *Blake3Hasher {
+	return &Blake3Hasher{
+		hasher: blake3.New(),
+	}
+}
+
+// CryptoHash writes the blake3 cryptographic hash of
+// input into buffer and returns it.
+// Like the standard libary's hash.Hash interface's Sum() method,
+// the buffer is re-used and overwritten
+// to avoid allocation. The caller determines the byte length of
+// the outputCryptohash by the size of the supplied buffer
+// slice, and this will be exactly equal to the supplies bytes.
+// In this way, shorter or longer hashes can be provided as
+// needed.
+func (w *Blake3Hasher) CryptoHash(input []byte, buffer []byte) (outputCryptohash []byte) {
+	w.hasherMu.Lock()
+	w.hasher.Reset()
+
+	// "Write implements part of the hash.Hash interface. It never returns an error."
+	//  -- https://godoc.org/github.com/zeebo/blake3#Hasher.Write
+	_, _ = w.hasher.Write(input)
+
+	// Digest.Read reads data from the hasher into buffer.
+	// "It always fills the entire buffer and never errors."
+	//   -- https://godoc.org/github.com/zeebo/blake3#Digest
+	_, _ = w.hasher.Digest().Read(buffer)
+
+	// no chance of panic, so avoid any defer cost.
+	w.hasherMu.Unlock()
+
+	return buffer
+}
+
+// blake3sum16 might be slower because we allocate a new hasher every time, but
+// it is more conenient for writing debug code. It returns
+// a 16 byte hash as a hexidecimal string.
+func blake3sum16(input []byte) string {
+	hasher := blake3.New()
+
+	_, _ = hasher.Write(input)
+	var buf [16]byte
+	_, _ = hasher.Digest().Read(buf[0:])
+
+	return fmt.Sprintf("%x", buf)
+}
+
+// cryptoRandInt64 uses crypto/rand to get an random int64
+func cryptoRandInt64() int64 {
+	c := 8
+	b := make([]byte, c)
+	_, err := cryptorand.Read(b)
+	if err != nil {
+		panic(err)
+	}
+	r := int64(binary.LittleEndian.Uint64(b))
+	return r
+}
+
+var _ = cryptoRandInt64 // happy linter
diff --git a/rbf/tx.go b/rbf/tx.go
index 83f1ae244..ca208fd1b 100644
--- a/rbf/tx.go
+++ b/rbf/tx.go
@@ -14,10 +14,12 @@
 package rbf
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 	"math"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 
@@ -1152,7 +1154,7 @@ func (itr *containerIterator) Close() {}
 // Next moves the iterator to the next container.
 func (itr *containerIterator) Next() bool {
 	err := itr.cursor.Next()
-	return err != nil
+	return err == nil
 }
 
 // Value returns the current key & container.
@@ -1160,3 +1162,163 @@ func (itr *containerIterator) Value() (uint64, *roaring.Container) {
 	cell := itr.cursor.cell()
 	return cell.Key, toContainer(cell, itr.cursor.tx)
 }
+
+func (tx *Tx) Dump(index string) {
+	fmt.Println(tx.DumpString(index))
+}
+func (tx *Tx) DumpString(index string) (r string) {
+
+	r = "allkeys:[\n"
+
+	// grab root records, for a list of bitmaps.
+	records, err := tx.rootRecords()
+	panicOn(err)
+	n := 0
+	for _, rr := range records {
+		c, err := tx.cursor(rr.Name)
+		panicOn(err)
+		err = c.First()
+		if err == io.EOF {
+			r += "<empty bitmap>"
+			n++
+			continue
+		}
+		panicOn(err)
+		for {
+			err := c.Next() // hung here?
+			if err == io.EOF {
+				break
+			}
+			panicOn(err)
+			cell := c.cell()
+			ckey := cell.Key
+			ct := toContainer(cell, tx)
+
+			s := stringOfCkeyCt(ckey, ct, rr.Name, index)
+			r += s
+			n++
+		}
+	}
+	if n == 0 {
+		return ""
+	}
+	// note that we can have a bitmap present, but it can be empty
+	r += "]\n   all-in-blake3:" + blake3sum16([]byte(r)) + "\n"
+
+	return "rbf-" + r
+}
+
+func containerToBytes(ct *roaring.Container) []byte {
+	ty := roaring.ContainerType(ct)
+	switch ty {
+	case containerNil:
+		panic("nil container")
+	case containerArray:
+		return fromArray16(roaring.AsArray(ct))
+	case containerBitmap:
+		return fromArray64(roaring.AsBitmap(ct))
+	case containerRun:
+		return fromInterval16(roaring.AsRuns(ct))
+	}
+	panic(fmt.Sprintf("unknown container type '%v'", int(ty)))
+}
+
+func badgerKey(index, field, view string, shard uint64, roaringContainerKey uint64) []byte {
+	// The %020d which adds zero padding up to 20 runes is required to
+	// allow the textual sort to accurately
+	// reflect a numeric sort order. This is because, as a string,
+	// math.MaxUint64 is 20 bytes long.
+	// Example of such a badgerKey with a container-key that is math.MaxUint64:
+	// ...........................................12345678901234567890
+	// idx:'i';fld:'f';vw:'standard';shd:'1';ckey@18446744073709551615
+
+	prefix := badgerPrefix(index, field, view, shard)
+	ckey := []byte(fmt.Sprintf("%020d", roaringContainerKey))
+	bkey := append(prefix, ckey...)
+	MustValidateKey(bkey)
+	return bkey
+}
+
+// badgerPrefix returns everything from badgerKey up to and
+// including the '@' fune in a badger key. The prefix excludes the roaring container key itself.
+// NB must be kept in sync with badgerKey() and badgerKeyExtractContainerKey().
+func badgerPrefix(index, field, view string, shard uint64) []byte {
+	return []byte(fmt.Sprintf("idx:'%v';fld:'%v';vw:'%v';shd:'%020v';ckey@", index, field, view, shard))
+}
+
+// MustValidatekey will panic on a bad badgerKey with an informative message.
+func MustValidateKey(bkey []byte) {
+	n := len(bkey)
+	if n < 56 {
+		panic(fmt.Sprintf("bkey too short min size is 56 but we see %v in '%v'", n, string(bkey)))
+	}
+	beforeCkey := bkey[n-26 : n-20]
+	if !bytes.Equal(beforeCkey, ckeyPartExpected) {
+		panic(fmt.Sprintf(`bkey did not have expected ";ckey@" at 26 bytes from the end of the bkey '%v'; instead had '%v'`, string(bkey), string(beforeCkey)))
+	}
+}
+
+func bitmapAsString(rbm *roaring.Bitmap) (r string) {
+	r = "c("
+	slc := rbm.Slice()
+	width := 0
+	s := ""
+	for _, v := range slc {
+		if width == 0 {
+			s = fmt.Sprintf("%v", v)
+		} else {
+			s = fmt.Sprintf(", %v", v)
+		}
+		width += len(s)
+		r += s
+		if width > 70 {
+			r += ",\n"
+			width = 0
+		}
+	}
+	if width == 0 && len(r) > 2 {
+		r = r[:len(r)-2]
+	}
+	return r + ")"
+}
+
+// should really be exported from the pilosa/roaring package so we don't get out of sync...
+const (
+	containerNil    byte = iota // no container
+	containerArray              // slice of bit position values
+	containerBitmap             // slice of 1024 uint64s
+	containerRun                // container of run-encoded bits
+)
+
+var ckeyPartExpected = []byte(";ckey@")
+
+func invName(rbfName string) (field, view string, shard uint64) {
+	s := strings.Split(rbfName, "\x00")
+	if len(s) != 3 {
+		panic("should have 3 parts")
+	}
+	field = s[0]
+	view = s[1]
+	var err error
+	shard, err = strconv.ParseUint(s[2], 10, 64)
+	panicOn(err)
+	return
+}
+
+func stringOfCkeyCt(ckey uint64, ct *roaring.Container, rrName, index string) (s string) {
+
+	by := containerToBytes(ct)
+	hash := blake3sum16(by)
+
+	cts := roaring.NewSliceContainers()
+	cts.Put(ckey, ct)
+	rbm := &roaring.Bitmap{Containers: cts}
+	srbm := bitmapAsString(rbm)
+
+	field, view, shard := invName(rrName)
+	bkey := string(badgerKey(index, field, view, shard, ckey))
+
+	s = fmt.Sprintf("%v -> %v (%v hot)\n", bkey, hash, ct.N())
+	s += "          ......." + srbm + "\n"
+	return
+}
diff --git a/rbf/tx_test.go b/rbf/tx_test.go
index 85195ad1d..e245b73da 100644
--- a/rbf/tx_test.go
+++ b/rbf/tx_test.go
@@ -464,3 +464,29 @@ func BenchmarkTx_Contains(b *testing.B) {
 		})
 	}
 }
+
+func TestTx_Dump(t *testing.T) {
+	db := MustOpenDB(t)
+	defer MustCloseDB(t, db)
+	tx := MustBegin(t, db, true)
+	defer tx.Rollback()
+
+	index, field, view, shard := "i", "f", "v", uint64(15)
+	nm := rbfName(field, view, shard)
+
+	if err := tx.CreateBitmap(nm); err != nil {
+		t.Fatal(err)
+	} else if _, err := tx.Add(nm, 0x00000001, 0x00000002, 0x00010003, 0x00030004); err != nil {
+		t.Fatal(err)
+	}
+
+	// test that we don't crash, and get *something* back
+	s := tx.DumpString(index)
+	if s == "" {
+		panic("should have had 3 containers!")
+	}
+}
+
+func rbfName(field, view string, shard uint64) string {
+	return fmt.Sprintf("%s\x00%s\x00%d", field, view, shard)
+}
diff --git a/rbf/vprint.go b/rbf/vprint.go
new file mode 100644
index 000000000..dfd630c70
--- /dev/null
+++ b/rbf/vprint.go
@@ -0,0 +1,169 @@
+// home: https://github.com/glyerine/vprint
+// Copyright 2019 Jason E. Aten, Ph.D. All rights reserved.
+// License: MIT
+//
+// MIT License
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package rbf
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"runtime"
+	"runtime/debug"
+	"sync"
+	"time"
+)
+
+const RFC3339MsecTz0 = "2006-01-02T15:04:05.000Z07:00"
+const RFC3339UsecTz0 = "2006-01-02T15:04:05.000000Z07:00"
+
+// for tons of debug output
+var VerboseVerbose bool = false
+
+// convience functions for . import
+var pp = PP
+var vv = VV
+
+var panicOn = PanicOn
+
+func init() {
+	// keeper linter happy
+	_ = pp
+	_ = vv
+}
+
+func PanicOn(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+func PP(format string, a ...interface{}) {
+	if VerboseVerbose {
+		TSPrintf(format, a...)
+	}
+}
+
+func VV(format string, a ...interface{}) {
+	TSPrintf(format, a...)
+}
+
+func AlwaysPrintf(format string, a ...interface{}) {
+	TSPrintf(format, a...)
+}
+
+var tsPrintfMut sync.Mutex
+
+// time-stamped printf
+func TSPrintf(format string, a ...interface{}) {
+	tsPrintfMut.Lock()
+	Printf("\n%s %s ", FileLine(3), ts())
+	Printf(format+"\n", a...)
+	tsPrintfMut.Unlock()
+}
+
+// get timestamp for logging purposes
+func ts() string {
+	return time.Now().Format(RFC3339UsecTz0)
+}
+
+// so we can multi write easily, use our own printf
+var OurStdout io.Writer = os.Stdout
+
+// Printf formats according to a format specifier and writes to standard output.
+// It returns the number of bytes written and any write error encountered.
+func Printf(format string, a ...interface{}) (n int, err error) {
+	return fmt.Fprintf(OurStdout, format, a...)
+}
+
+func FileLine(depth int) string {
+	_, fileName, fileLine, ok := runtime.Caller(depth)
+	var s string
+	if ok {
+		s = fmt.Sprintf("%s:%d", path.Base(fileName), fileLine)
+	} else {
+		s = ""
+	}
+	return s
+}
+
+func stack() string {
+	return string(debug.Stack())
+}
+
+func FileExists(name string) bool {
+	fi, err := os.Stat(name)
+	if err != nil {
+		return false
+	}
+	if fi.IsDir() {
+		return false
+	}
+	return true
+}
+
+func DirExists(name string) bool {
+	fi, err := os.Stat(name)
+	if err != nil {
+		return false
+	}
+	if fi.IsDir() {
+		return true
+	}
+	return false
+}
+
+func FileSize(name string) (int64, error) {
+	fi, err := os.Stat(name)
+	if err != nil {
+		return -1, err
+	}
+	return fi.Size(), nil
+}
+
+// Caller returns the name of the calling function.
+func Caller(upStack int) string {
+	// elide ourself and runtime.Callers
+	target := upStack + 2
+
+	pc := make([]uintptr, target+2)
+	n := runtime.Callers(0, pc)
+
+	f := runtime.Frame{Function: "unknown"}
+	if n > 0 {
+		frames := runtime.CallersFrames(pc[:n])
+		for i := 0; i <= target; i++ {
+			contender, more := frames.Next()
+			if i == target {
+				f = contender
+			}
+			if !more {
+				break
+			}
+		}
+	}
+	return f.Function
+}
+
+var _ = stack // happy linter
diff --git a/tx.go b/tx.go
index 051397245..ff544aca7 100644
--- a/tx.go
+++ b/tx.go
@@ -910,7 +910,8 @@ func (tx *RoaringTx) RoaringBitmapReader(index, field, view string, shard uint64
 }
 
 type RBFTx struct {
-	tx *rbf.Tx
+	index string
+	tx    *rbf.Tx
 }
 
 func (tx *RBFTx) Type() string {
@@ -1035,7 +1036,7 @@ func (tx *RBFTx) Pointer() string {
 }
 
 func (tx *RBFTx) Dump() {
-	// todo
+	tx.tx.Dump(tx.index)
 }
 
 // Readonly is true if the transaction is not read-and-write, but only doing reads.