core: remove redundant storage of transactions and receipts (#14801)

* core: remove redundant storage of transactions and receipts

* core, eth, internal: new transaction schema usage polishes

* eth: implement upgrade mechanism for db deduplication

* core, eth: drop old sequential key db upgrader

* eth: close last iterator on successful db upgrage

* core: prefix the lookup entries to make their purpose clearer

12 files changed, 274 insertions, 628 deletions

diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
index 7ac8b5820..14bf7bd75 100644
--- a/accounts/abi/bind/backends/simulated.go
+++ b/accounts/abi/bind/backends/simulated.go
@@ -144,7 +144,8 @@ func (b *SimulatedBackend) StorageAt(ctx context.Context, contract common.Addres
 
 // TransactionReceipt returns the receipt of a transaction.
 func (b *SimulatedBackend) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
-	return core.GetReceipt(b.database, txHash), nil
+	receipt, _, _, _ := core.GetReceipt(b.database, txHash)
+	return receipt, nil
 }
 
 // PendingCodeAt returns the code associated with an account in the pending state.
diff --git a/core/blockchain.go b/core/blockchain.go
index 6772ea284..bb1c14f43 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -759,16 +759,10 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 				log.Crit("Failed to write log blooms", "err", err)
 				return
 			}
-			if err := WriteTransactions(bc.chainDb, block); err != nil {
-				errs[index] = fmt.Errorf("failed to write individual transactions: %v", err)
+			if err := WriteTxLookupEntries(bc.chainDb, block); err != nil {
+				errs[index] = fmt.Errorf("failed to write lookup metadata: %v", err)
 				atomic.AddInt32(&failed, 1)
-				log.Crit("Failed to write individual transactions", "err", err)
-				return
-			}
-			if err := WriteReceipts(bc.chainDb, receipts); err != nil {
-				errs[index] = fmt.Errorf("failed to write individual receipts: %v", err)
-				atomic.AddInt32(&failed, 1)
-				log.Crit("Failed to write individual receipts", "err", err)
+				log.Crit("Failed to write lookup metadata", "err", err)
 				return
 			}
 			atomic.AddInt32(&stats.processed, 1)
@@ -1002,12 +996,8 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 			blockInsertTimer.UpdateSince(bstart)
 			events = append(events, ChainEvent{block, block.Hash(), logs})
 
-			// This puts transactions in a extra db for rpc
-			if err := WriteTransactions(bc.chainDb, block); err != nil {
-				return i, err
-			}
-			// store the receipts
-			if err := WriteReceipts(bc.chainDb, receipts); err != nil {
+			// Write the positional metadata for transaction and receipt lookups
+			if err := WriteTxLookupEntries(bc.chainDb, block); err != nil {
 				return i, err
 			}
 			// Write map map bloom filters
@@ -1167,16 +1157,12 @@ func (bc *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	for _, block := range newChain {
 		// insert the block in the canonical way, re-writing history
 		bc.insert(block)
-		// write canonical receipts and transactions
-		if err := WriteTransactions(bc.chainDb, block); err != nil {
-			return err
-		}
-		receipts := GetBlockReceipts(bc.chainDb, block.Hash(), block.NumberU64())
-		// write receipts
-		if err := WriteReceipts(bc.chainDb, receipts); err != nil {
+		// write lookup entries for hash based transaction/receipt searches
+		if err := WriteTxLookupEntries(bc.chainDb, block); err != nil {
 			return err
 		}
 		// Write map map bloom filters
+		receipts := GetBlockReceipts(bc.chainDb, block.Hash(), block.NumberU64())
 		if err := WriteMipmapBloom(bc.chainDb, block.NumberU64(), receipts); err != nil {
 			return err
 		}
@@ -1188,8 +1174,7 @@ func (bc *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
 	// When transactions get deleted from the database that means the
 	// receipts that were created in the fork must also be deleted
 	for _, tx := range diff {
-		DeleteReceipt(bc.chainDb, tx.Hash())
-		DeleteTransaction(bc.chainDb, tx.Hash())
+		DeleteTxLookupEntry(bc.chainDb, tx.Hash())
 	}
 	// Must be posted in a goroutine because of the transaction pool trying
 	// to acquire the chain manager lock
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index 371522ab7..5fa671e2b 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -806,8 +806,8 @@ func TestChainTxReorgs(t *testing.T) {
 		if txn, _, _, _ := GetTransaction(db, tx.Hash()); txn != nil {
 			t.Errorf("drop %d: tx %v found while shouldn't have been", i, txn)
 		}
-		if GetReceipt(db, tx.Hash()) != nil {
-			t.Errorf("drop %d: receipt found while shouldn't have been", i)
+		if rcpt, _, _, _ := GetReceipt(db, tx.Hash()); rcpt != nil {
+			t.Errorf("drop %d: receipt %v found while shouldn't have been", i, rcpt)
 		}
 	}
 	// added tx
@@ -815,7 +815,7 @@ func TestChainTxReorgs(t *testing.T) {
 		if txn, _, _, _ := GetTransaction(db, tx.Hash()); txn == nil {
 			t.Errorf("add %d: expected tx to be found", i)
 		}
-		if GetReceipt(db, tx.Hash()) == nil {
+		if rcpt, _, _, _ := GetReceipt(db, tx.Hash()); rcpt == nil {
 			t.Errorf("add %d: expected receipt to be found", i)
 		}
 	}
@@ -824,7 +824,7 @@ func TestChainTxReorgs(t *testing.T) {
 		if txn, _, _, _ := GetTransaction(db, tx.Hash()); txn == nil {
 			t.Errorf("share %d: expected tx to be found", i)
 		}
-		if GetReceipt(db, tx.Hash()) == nil {
+		if rcpt, _, _, _ := GetReceipt(db, tx.Hash()); rcpt == nil {
 			t.Errorf("share %d: expected receipt to be found", i)
 		}
 	}
diff --git a/core/database_util.go b/core/database_util.go
index b4a230c9c..697111394 100644
--- a/core/database_util.go
+++ b/core/database_util.go
@@ -45,24 +45,17 @@ var (
 	blockHashPrefix     = []byte("H")   // blockHashPrefix + hash -> num (uint64 big endian)
 	bodyPrefix          = []byte("b")   // bodyPrefix + num (uint64 big endian) + hash -> block body
 	blockReceiptsPrefix = []byte("r")   // blockReceiptsPrefix + num (uint64 big endian) + hash -> block receipts
+	lookupPrefix        = []byte("l")   // lookupPrefix + hash -> transaction/receipt lookup metadata
 	preimagePrefix      = "secure-key-" // preimagePrefix + hash -> preimage
 
-	txMetaSuffix   = []byte{0x01}
-	receiptsPrefix = []byte("receipts-")
-
 	mipmapPre    = []byte("mipmap-log-bloom-")
 	MIPMapLevels = []uint64{1000000, 500000, 100000, 50000, 1000}
 
 	configPrefix = []byte("ethereum-config-") // config prefix for the db
 
-	// used by old (non-sequential keys) db, now only used for conversion
-	oldBlockPrefix         = []byte("block-")
-	oldHeaderSuffix        = []byte("-header")
-	oldTdSuffix            = []byte("-td") // headerPrefix + num (uint64 big endian) + hash + tdSuffix -> td
-	oldBodySuffix          = []byte("-body")
-	oldBlockNumPrefix      = []byte("block-num-")
-	oldBlockReceiptsPrefix = []byte("receipts-block-")
-	oldBlockHashPrefix     = []byte("block-hash-") // [deprecated by the header/block split, remove eventually]
+	// used by old db, now only used for conversion
+	oldReceiptsPrefix = []byte("receipts-")
+	oldTxMetaSuffix   = []byte{0x01}
 
 	ErrChainConfigNotFound = errors.New("ChainConfig not found") // general config not found error
 
@@ -72,6 +65,14 @@ var (
 	preimageHitCounter = metrics.NewCounter("db/preimage/hits")
 )
 
+// txLookupEntry is a positional metadata to help looking up the data content of
+// a transaction or receipt given only its hash.
+type txLookupEntry struct {
+	BlockHash  common.Hash
+	BlockIndex uint64
+	Index      uint64
+}
+
 // encodeBlockNumber encodes a block number as big endian uint64
 func encodeBlockNumber(number uint64) []byte {
 	enc := make([]byte, 8)
@@ -83,10 +84,7 @@ func encodeBlockNumber(number uint64) []byte {
 func GetCanonicalHash(db ethdb.Database, number uint64) common.Hash {
 	data, _ := db.Get(append(append(headerPrefix, encodeBlockNumber(number)...), numSuffix...))
 	if len(data) == 0 {
-		data, _ = db.Get(append(oldBlockNumPrefix, big.NewInt(int64(number)).Bytes()...))
-		if len(data) == 0 {
-			return common.Hash{}
-		}
+		return common.Hash{}
 	}
 	return common.BytesToHash(data)
 }
@@ -100,15 +98,7 @@ const missingNumber = uint64(0xffffffffffffffff)
 func GetBlockNumber(db ethdb.Database, hash common.Hash) uint64 {
 	data, _ := db.Get(append(blockHashPrefix, hash.Bytes()...))
 	if len(data) != 8 {
-		data, _ := db.Get(append(append(oldBlockPrefix, hash.Bytes()...), oldHeaderSuffix...))
-		if len(data) == 0 {
-			return missingNumber
-		}
-		header := new(types.Header)
-		if err := rlp.Decode(bytes.NewReader(data), header); err != nil {
-			log.Crit("Failed to decode block header", "err", err)
-		}
-		return header.Number.Uint64()
+		return missingNumber
 	}
 	return binary.BigEndian.Uint64(data)
 }
@@ -151,9 +141,6 @@ func GetHeadFastBlockHash(db ethdb.Database) common.Hash {
 // if the header's not found.
 func GetHeaderRLP(db ethdb.Database, hash common.Hash, number uint64) rlp.RawValue {
 	data, _ := db.Get(append(append(headerPrefix, encodeBlockNumber(number)...), hash.Bytes()...))
-	if len(data) == 0 {
-		data, _ = db.Get(append(append(oldBlockPrefix, hash.Bytes()...), oldHeaderSuffix...))
-	}
 	return data
 }
 
@@ -175,9 +162,6 @@ func GetHeader(db ethdb.Database, hash common.Hash, number uint64) *types.Header
 // GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
 func GetBodyRLP(db ethdb.Database, hash common.Hash, number uint64) rlp.RawValue {
 	data, _ := db.Get(append(append(bodyPrefix, encodeBlockNumber(number)...), hash.Bytes()...))
-	if len(data) == 0 {
-		data, _ = db.Get(append(append(oldBlockPrefix, hash.Bytes()...), oldBodySuffix...))
-	}
 	return data
 }
 
@@ -201,10 +185,7 @@ func GetBody(db ethdb.Database, hash common.Hash, number uint64) *types.Body {
 func GetTd(db ethdb.Database, hash common.Hash, number uint64) *big.Int {
 	data, _ := db.Get(append(append(append(headerPrefix, encodeBlockNumber(number)...), hash[:]...), tdSuffix...))
 	if len(data) == 0 {
-		data, _ = db.Get(append(append(oldBlockPrefix, hash.Bytes()...), oldTdSuffix...))
-		if len(data) == 0 {
-			return nil
-		}
+		return nil
 	}
 	td := new(big.Int)
 	if err := rlp.Decode(bytes.NewReader(data), td); err != nil {
@@ -239,10 +220,7 @@ func GetBlock(db ethdb.Database, hash common.Hash, number uint64) *types.Block {
 func GetBlockReceipts(db ethdb.Database, hash common.Hash, number uint64) types.Receipts {
 	data, _ := db.Get(append(append(blockReceiptsPrefix, encodeBlockNumber(number)...), hash[:]...))
 	if len(data) == 0 {
-		data, _ = db.Get(append(oldBlockReceiptsPrefix, hash.Bytes()...))
-		if len(data) == 0 {
-			return nil
-		}
+		return nil
 	}
 	storageReceipts := []*types.ReceiptForStorage{}
 	if err := rlp.DecodeBytes(data, &storageReceipts); err != nil {
@@ -256,10 +234,38 @@ func GetBlockReceipts(db ethdb.Database, hash common.Hash, number uint64) types.
 	return receipts
 }
 
+// GetTxLookupEntry retrieves the positional metadata associated with a transaction
+// hash to allow retrieving the transaction or receipt by hash.
+func GetTxLookupEntry(db ethdb.Database, hash common.Hash) (common.Hash, uint64, uint64) {
+	// Load the positional metadata from disk and bail if it fails
+	data, _ := db.Get(append(lookupPrefix, hash.Bytes()...))
+	if len(data) == 0 {
+		return common.Hash{}, 0, 0
+	}
+	// Parse and return the contents of the lookup entry
+	var entry txLookupEntry
+	if err := rlp.DecodeBytes(data, &entry); err != nil {
+		log.Error("Invalid lookup entry RLP", "hash", hash, "err", err)
+		return common.Hash{}, 0, 0
+	}
+	return entry.BlockHash, entry.BlockIndex, entry.Index
+}
+
 // GetTransaction retrieves a specific transaction from the database, along with
 // its added positional metadata.
 func GetTransaction(db ethdb.Database, hash common.Hash) (*types.Transaction, common.Hash, uint64, uint64) {
-	// Retrieve the transaction itself from the database
+	// Retrieve the lookup metadata and resolve the transaction from the body
+	blockHash, blockNumber, txIndex := GetTxLookupEntry(db, hash)
+
+	if blockHash != (common.Hash{}) {
+		body := GetBody(db, blockHash, blockNumber)
+		if body == nil || len(body.Transactions) <= int(txIndex) {
+			log.Error("Transaction referenced missing", "number", blockNumber, "hash", blockHash, "index", txIndex)
+			return nil, common.Hash{}, 0, 0
+		}
+		return body.Transactions[txIndex], blockHash, blockNumber, txIndex
+	}
+	// Old transaction representation, load the transaction and it's metadata separately
 	data, _ := db.Get(hash.Bytes())
 	if len(data) == 0 {
 		return nil, common.Hash{}, 0, 0
@@ -269,33 +275,42 @@ func GetTransaction(db ethdb.Database, hash common.Hash) (*types.Transaction, co
 		return nil, common.Hash{}, 0, 0
 	}
 	// Retrieve the blockchain positional metadata
-	data, _ = db.Get(append(hash.Bytes(), txMetaSuffix...))
+	data, _ = db.Get(append(hash.Bytes(), oldTxMetaSuffix...))
 	if len(data) == 0 {
 		return nil, common.Hash{}, 0, 0
 	}
-	var meta struct {
-		BlockHash  common.Hash
-		BlockIndex uint64
-		Index      uint64
-	}
-	if err := rlp.DecodeBytes(data, &meta); err != nil {
+	var entry txLookupEntry
+	if err := rlp.DecodeBytes(data, &entry); err != nil {
 		return nil, common.Hash{}, 0, 0
 	}
-	return &tx, meta.BlockHash, meta.BlockIndex, meta.Index
+	return &tx, entry.BlockHash, entry.BlockIndex, entry.Index
 }
 
-// GetReceipt returns a receipt by hash
-func GetReceipt(db ethdb.Database, hash common.Hash) *types.Receipt {
-	data, _ := db.Get(append(receiptsPrefix, hash[:]...))
+// GetReceipt retrieves a specific transaction receipt from the database, along with
+// its added positional metadata.
+func GetReceipt(db ethdb.Database, hash common.Hash) (*types.Receipt, common.Hash, uint64, uint64) {
+	// Retrieve the lookup metadata and resolve the receipt from the receipts
+	blockHash, blockNumber, receiptIndex := GetTxLookupEntry(db, hash)
+
+	if blockHash != (common.Hash{}) {
+		receipts := GetBlockReceipts(db, blockHash, blockNumber)
+		if len(receipts) <= int(receiptIndex) {
+			log.Error("Receipt refereced missing", "number", blockNumber, "hash", blockHash, "index", receiptIndex)
+			return nil, common.Hash{}, 0, 0
+		}
+		return receipts[receiptIndex], blockHash, blockNumber, receiptIndex
+	}
+	// Old receipt representation, load the receipt and set an unknown metadata
+	data, _ := db.Get(append(oldReceiptsPrefix, hash[:]...))
 	if len(data) == 0 {
-		return nil
+		return nil, common.Hash{}, 0, 0
 	}
 	var receipt types.ReceiptForStorage
 	err := rlp.DecodeBytes(data, &receipt)
 	if err != nil {
 		log.Error("Invalid receipt RLP", "hash", hash, "err", err)
 	}
-	return (*types.Receipt)(&receipt)
+	return (*types.Receipt)(&receipt), common.Hash{}, 0, 0
 }
 
 // WriteCanonicalHash stores the canonical hash for the given block number.
@@ -416,76 +431,29 @@ func WriteBlockReceipts(db ethdb.Database, hash common.Hash, number uint64, rece
 	return nil
 }
 
-// WriteTransactions stores the transactions associated with a specific block
-// into the given database. Beside writing the transaction, the function also
-// stores a metadata entry along with the transaction, detailing the position
-// of this within the blockchain.
-func WriteTransactions(db ethdb.Database, block *types.Block) error {
+// WriteTxLookupEntries stores a positional metadata for every transaction from
+// a block, enabling hash based transaction and receipt lookups.
+func WriteTxLookupEntries(db ethdb.Database, block *types.Block) error {
 	batch := db.NewBatch()
 
-	// Iterate over each transaction and encode it with its metadata
+	// Iterate over each transaction and encode its metadata
 	for i, tx := range block.Transactions() {
-		// Encode and queue up the transaction for storage
-		data, err := rlp.EncodeToBytes(tx)
-		if err != nil {
-			return err
-		}
-		if err = batch.Put(tx.Hash().Bytes(), data); err != nil {
-			return err
-		}
-		// Encode and queue up the transaction metadata for storage
-		meta := struct {
-			BlockHash  common.Hash
-			BlockIndex uint64
-			Index      uint64
-		}{
+		entry := txLookupEntry{
 			BlockHash:  block.Hash(),
 			BlockIndex: block.NumberU64(),
 			Index:      uint64(i),
 		}
-		data, err = rlp.EncodeToBytes(meta)
-		if err != nil {
-			return err
-		}
-		if err := batch.Put(append(tx.Hash().Bytes(), txMetaSuffix...), data); err != nil {
-			return err
-		}
-	}
-	// Write the scheduled data into the database
-	if err := batch.Write(); err != nil {
-		log.Crit("Failed to store transactions", "err", err)
-	}
-	return nil
-}
-
-// WriteReceipt stores a single transaction receipt into the database.
-func WriteReceipt(db ethdb.Database, receipt *types.Receipt) error {
-	storageReceipt := (*types.ReceiptForStorage)(receipt)
-	data, err := rlp.EncodeToBytes(storageReceipt)
-	if err != nil {
-		return err
-	}
-	return db.Put(append(receiptsPrefix, receipt.TxHash.Bytes()...), data)
-}
-
-// WriteReceipts stores a batch of transaction receipts into the database.
-func WriteReceipts(db ethdb.Database, receipts types.Receipts) error {
-	batch := db.NewBatch()
-
-	// Iterate over all the receipts and queue them for database injection
-	for _, receipt := range receipts {
-		storageReceipt := (*types.ReceiptForStorage)(receipt)
-		data, err := rlp.EncodeToBytes(storageReceipt)
+		data, err := rlp.EncodeToBytes(entry)
 		if err != nil {
 			return err
 		}
-		if err := batch.Put(append(receiptsPrefix, receipt.TxHash.Bytes()...), data); err != nil {
+		if err := batch.Put(append(lookupPrefix, tx.Hash().Bytes()...), data); err != nil {
 			return err
 		}
 	}
 	// Write the scheduled data into the database
 	if err := batch.Write(); err != nil {
-		log.Crit("Failed to store receipts", "err", err)
+		log.Crit("Failed to store lookup entries", "err", err)
 	}
 	return nil
 }
@@ -524,15 +492,9 @@ func DeleteBlockReceipts(db ethdb.Database, hash common.Hash, number uint64) {
 	db.Delete(append(append(blockReceiptsPrefix, encodeBlockNumber(number)...), hash.Bytes()...))
 }
 
-// DeleteTransaction removes all transaction data associated with a hash.
-func DeleteTransaction(db ethdb.Database, hash common.Hash) {
-	db.Delete(hash.Bytes())
-	db.Delete(append(hash.Bytes(), txMetaSuffix...))
-}
-
-// DeleteReceipt removes all receipt data associated with a transaction hash.
-func DeleteReceipt(db ethdb.Database, hash common.Hash) {
-	db.Delete(append(receiptsPrefix, hash.Bytes()...))
+// DeleteTxLookupEntry removes all transaction data associated with a hash.
+func DeleteTxLookupEntry(db ethdb.Database, hash common.Hash) {
+	db.Delete(append(lookupPrefix, hash.Bytes()...))
 }
 
 // returns a formatted MIP mapped key by adding prefix, canonical number and level
diff --git a/core/database_util_test.go b/core/database_util_test.go
index 9f16b660a..e9a6df97b 100644
--- a/core/database_util_test.go
+++ b/core/database_util_test.go
@@ -290,8 +290,8 @@ func TestHeadStorage(t *testing.T) {
 	}
 }
 
-// Tests that transactions and associated metadata can be stored and retrieved.
-func TestTransactionStorage(t *testing.T) {
+// Tests that positional lookup metadata can be stored and retrieved.
+func TestLookupStorage(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 
 	tx1 := types.NewTransaction(1, common.BytesToAddress([]byte{0x11}), big.NewInt(111), big.NewInt(1111), big.NewInt(11111), []byte{0x11, 0x11, 0x11})
@@ -308,7 +308,10 @@ func TestTransactionStorage(t *testing.T) {
 		}
 	}
 	// Insert all the transactions into the database, and verify contents
-	if err := WriteTransactions(db, block); err != nil {
+	if err := WriteBlock(db, block); err != nil {
+		t.Fatalf("failed to write block contents: %v", err)
+	}
+	if err := WriteTxLookupEntries(db, block); err != nil {
 		t.Fatalf("failed to write transactions: %v", err)
 	}
 	for i, tx := range txs {
@@ -325,72 +328,13 @@ func TestTransactionStorage(t *testing.T) {
 	}
 	// Delete the transactions and check purge
 	for i, tx := range txs {
-		DeleteTransaction(db, tx.Hash())
+		DeleteTxLookupEntry(db, tx.Hash())
 		if txn, _, _, _ := GetTransaction(db, tx.Hash()); txn != nil {
 			t.Fatalf("tx #%d [%x]: deleted transaction returned: %v", i, tx.Hash(), txn)
 		}
 	}
 }
 
-// Tests that receipts can be stored and retrieved.
-func TestReceiptStorage(t *testing.T) {
-	db, _ := ethdb.NewMemDatabase()
-
-	receipt1 := &types.Receipt{
-		PostState:         []byte{0x01},
-		CumulativeGasUsed: big.NewInt(1),
-		Logs: []*types.Log{
-			{Address: common.BytesToAddress([]byte{0x11})},
-			{Address: common.BytesToAddress([]byte{0x01, 0x11})},
-		},
-		TxHash:          common.BytesToHash([]byte{0x11, 0x11}),
-		ContractAddress: common.BytesToAddress([]byte{0x01, 0x11, 0x11}),
-		GasUsed:         big.NewInt(111111),
-	}
-	receipt2 := &types.Receipt{
-		PostState:         []byte{0x02},
-		CumulativeGasUsed: big.NewInt(2),
-		Logs: []*types.Log{
-			{Address: common.BytesToAddress([]byte{0x22})},
-			{Address: common.BytesToAddress([]byte{0x02, 0x22})},
-		},
-		TxHash:          common.BytesToHash([]byte{0x22, 0x22}),
-		ContractAddress: common.BytesToAddress([]byte{0x02, 0x22, 0x22}),
-		GasUsed:         big.NewInt(222222),
-	}
-	receipts := []*types.Receipt{receipt1, receipt2}
-
-	// Check that no receipt entries are in a pristine database
-	for i, receipt := range receipts {
-		if r := GetReceipt(db, receipt.TxHash); r != nil {
-			t.Fatalf("receipt #%d [%x]: non existent receipt returned: %v", i, receipt.TxHash, r)
-		}
-	}
-	// Insert all the receipts into the database, and verify contents
-	if err := WriteReceipts(db, receipts); err != nil {
-		t.Fatalf("failed to write receipts: %v", err)
-	}
-	for i, receipt := range receipts {
-		if r := GetReceipt(db, receipt.TxHash); r == nil {
-			t.Fatalf("receipt #%d [%x]: receipt not found", i, receipt.TxHash)
-		} else {
-			rlpHave, _ := rlp.EncodeToBytes(r)
-			rlpWant, _ := rlp.EncodeToBytes(receipt)
-
-			if !bytes.Equal(rlpHave, rlpWant) {
-				t.Fatalf("receipt #%d [%x]: receipt mismatch: have %v, want %v", i, receipt.TxHash, r, receipt)
-			}
-		}
-	}
-	// Delete the receipts and check purge
-	for i, receipt := range receipts {
-		DeleteReceipt(db, receipt.TxHash)
-		if r := GetReceipt(db, receipt.TxHash); r != nil {
-			t.Fatalf("receipt #%d [%x]: deleted receipt returned: %v", i, receipt.TxHash, r)
-		}
-	}
-}
-
 // Tests that receipts associated with a single block can be stored and retrieved.
 func TestBlockReceiptStorage(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
@@ -530,10 +474,6 @@ func TestMipmapChain(t *testing.T) {
 		}
 
 		// store the receipts
-		err := WriteReceipts(db, receipts)
-		if err != nil {
-			t.Fatal(err)
-		}
 		WriteMipmapBloom(db, uint64(i+1), receipts)
 	})
 	for i, block := range chain {
diff --git a/eth/backend.go b/eth/backend.go
index 78478e86e..c7df517c0 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -59,8 +59,8 @@ type LesServer interface {
 type Ethereum struct {
 	chainConfig *params.ChainConfig
 	// Channel for shutting down the service
-	shutdownChan  chan bool // Channel for shutting down the ethereum
-	stopDbUpgrade func()    // stop chain db sequential key upgrade
+	shutdownChan  chan bool    // Channel for shutting down the ethereum
+	stopDbUpgrade func() error // stop chain db sequential key upgrade
 	// Handlers
 	txPool          *core.TxPool
 	blockchain      *core.BlockChain
@@ -103,7 +103,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 	if err != nil {
 		return nil, err
 	}
-	stopDbUpgrade := upgradeSequentialKeys(chainDb)
+	stopDbUpgrade := upgradeDeduplicateData(chainDb)
 	chainConfig, genesisHash, genesisErr := core.SetupGenesisBlock(chainDb, config.Genesis)
 	if _, ok := genesisErr.(*params.ConfigCompatError); genesisErr != nil && !ok {
 		return nil, genesisErr
diff --git a/eth/backend_test.go b/eth/backend_test.go
index f60e3214c..4351b24cf 100644
--- a/eth/backend_test.go
+++ b/eth/backend_test.go
@@ -33,24 +33,15 @@ func TestMipmapUpgrade(t *testing.T) {
 	genesis := new(core.Genesis).MustCommit(db)
 
 	chain, receipts := core.GenerateChain(params.TestChainConfig, genesis, db, 10, func(i int, gen *core.BlockGen) {
-		var receipts types.Receipts
 		switch i {
 		case 1:
 			receipt := types.NewReceipt(nil, new(big.Int))
 			receipt.Logs = []*types.Log{{Address: addr}}
 			gen.AddUncheckedReceipt(receipt)
-			receipts = types.Receipts{receipt}
 		case 2:
 			receipt := types.NewReceipt(nil, new(big.Int))
 			receipt.Logs = []*types.Log{{Address: addr}}
 			gen.AddUncheckedReceipt(receipt)
-			receipts = types.Receipts{receipt}
-		}
-
-		// store the receipts
-		err := core.WriteReceipts(db, receipts)
-		if err != nil {
-			t.Fatal(err)
 		}
 	})
 	for i, block := range chain {
diff --git a/eth/db_upgrade.go b/eth/db_upgrade.go
index 82cdd7e55..90111b2b3 100644
--- a/eth/db_upgrade.go
+++ b/eth/db_upgrade.go
@@ -19,237 +19,120 @@ package eth
 
 import (
 	"bytes"
-	"encoding/binary"
 	"fmt"
-	"math/big"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
-var useSequentialKeys = []byte("dbUpgrade_20160530sequentialKeys")
+var deduplicateData = []byte("dbUpgrade_20170714deduplicateData")
 
-// upgradeSequentialKeys checks the chain database version and
+// upgradeDeduplicateData checks the chain database version and
 // starts a background process to make upgrades if necessary.
 // Returns a stop function that blocks until the process has
 // been safely stopped.
-func upgradeSequentialKeys(db ethdb.Database) (stopFn func()) {
-	data, _ := db.Get(useSequentialKeys)
+func upgradeDeduplicateData(db ethdb.Database) func() error {
+	// If the database is already converted or empty, bail out
+	data, _ := db.Get(deduplicateData)
 	if len(data) > 0 && data[0] == 42 {
-		return nil // already converted
+		return nil
 	}
-
 	if data, _ := db.Get([]byte("LastHeader")); len(data) == 0 {
-		db.Put(useSequentialKeys, []byte{42})
-		return nil // empty database, nothing to do
+		db.Put(deduplicateData, []byte{42})
+		return nil
 	}
-
-	log.Warn("Upgrading chain database to use sequential keys")
-
-	stopChn := make(chan struct{})
-	stoppedChn := make(chan struct{})
+	// Start the deduplication upgrade on a new goroutine
+	log.Warn("Upgrading database to use lookup entries")
+	stop := make(chan chan error)
 
 	go func() {
-		stopFn := func() bool {
-			select {
-			case <-time.After(time.Microsecond * 100): // make sure other processes don't get starved
-			case <-stopChn:
-				return true
-			}
-			return false
-		}
-
-		err, stopped := upgradeSequentialCanonicalNumbers(db, stopFn)
-		if err == nil && !stopped {
-			err, stopped = upgradeSequentialBlocks(db, stopFn)
-		}
-		if err == nil && !stopped {
-			err, stopped = upgradeSequentialOrphanedReceipts(db, stopFn)
-		}
-		if err == nil && !stopped {
-			log.Info("Database conversion successful")
-			db.Put(useSequentialKeys, []byte{42})
-		}
-		if err != nil {
-			log.Error("Database conversion failed", "err", err)
-		}
-		close(stoppedChn)
-	}()
-
-	return func() {
-		close(stopChn)
-		<-stoppedChn
-	}
-}
-
-// upgradeSequentialCanonicalNumbers reads all old format canonical numbers from
-// the database, writes them in new format and deletes the old ones if successful.
-func upgradeSequentialCanonicalNumbers(db ethdb.Database, stopFn func() bool) (error, bool) {
-	prefix := []byte("block-num-")
-	it := db.(*ethdb.LDBDatabase).NewIterator()
-	defer func() {
-		it.Release()
-	}()
-	it.Seek(prefix)
-	cnt := 0
-	for bytes.HasPrefix(it.Key(), prefix) {
-		keyPtr := it.Key()
-		if len(keyPtr) < 20 {
-			cnt++
-			if cnt%100000 == 0 {
+		// Create an iterator to read the entire database and covert old lookup entires
+		it := db.(*ethdb.LDBDatabase).NewIterator()
+		defer func() {
+			if it != nil {
 				it.Release()
-				it = db.(*ethdb.LDBDatabase).NewIterator()
-				it.Seek(keyPtr)
-				log.Info("Converting canonical numbers", "count", cnt)
 			}
-			number := big.NewInt(0).SetBytes(keyPtr[10:]).Uint64()
-			newKey := []byte("h12345678n")
-			binary.BigEndian.PutUint64(newKey[1:9], number)
-			if err := db.Put(newKey, it.Value()); err != nil {
-				return err, false
+		}()
+
+		var (
+			converted uint64
+			failed    error
+		)
+		for failed == nil && it.Next() {
+			// Skip any entries that don't look like old transaction meta entires (<hash>0x01)
+			key := it.Key()
+			if len(key) != common.HashLength+1 || key[common.HashLength] != 0x01 {
+				continue
 			}
-			if err := db.Delete(keyPtr); err != nil {
-				return err, false
+			// Skip any entries that don't contain metadata (name clash between <hash>0x01 and <some-prefix><hash>)
+			var meta struct {
+				BlockHash  common.Hash
+				BlockIndex uint64
+				Index      uint64
 			}
-		}
-
-		if stopFn() {
-			return nil, true
-		}
-		it.Next()
-	}
-	if cnt > 0 {
-		log.Info("converted canonical numbers", "count", cnt)
-	}
-	return nil, false
-}
-
-// upgradeSequentialBlocks reads all old format block headers, bodies, TDs and block
-// receipts from the database, writes them in new format and deletes the old ones
-// if successful.
-func upgradeSequentialBlocks(db ethdb.Database, stopFn func() bool) (error, bool) {
-	prefix := []byte("block-")
-	it := db.(*ethdb.LDBDatabase).NewIterator()
-	defer func() {
-		it.Release()
-	}()
-	it.Seek(prefix)
-	cnt := 0
-	for bytes.HasPrefix(it.Key(), prefix) {
-		keyPtr := it.Key()
-		if len(keyPtr) >= 38 {
-			cnt++
-			if cnt%10000 == 0 {
-				it.Release()
-				it = db.(*ethdb.LDBDatabase).NewIterator()
-				it.Seek(keyPtr)
-				log.Info("Converting blocks", "count", cnt)
+			if err := rlp.DecodeBytes(it.Value(), &meta); err != nil {
+				continue
 			}
-			// convert header, body, td and block receipts
-			var keyPrefix [38]byte
-			copy(keyPrefix[:], keyPtr[0:38])
-			hash := keyPrefix[6:38]
-			if err := upgradeSequentialBlockData(db, hash); err != nil {
-				return err, false
-			}
-			// delete old db entries belonging to this hash
-			for bytes.HasPrefix(it.Key(), keyPrefix[:]) {
-				if err := db.Delete(it.Key()); err != nil {
-					return err, false
+			// Skip any already upgraded entries (clash due to <hash> ending with 0x01 (old suffix))
+			hash := key[:common.HashLength]
+
+			if hash[0] == byte('l') {
+				// Potential clash, the "old" `hash` must point to a live transaction.
+				if tx, _, _, _ := core.GetTransaction(db, common.BytesToHash(hash)); tx == nil || !bytes.Equal(tx.Hash().Bytes(), hash) {
+					continue
 				}
-				it.Next()
 			}
-			if err := db.Delete(append([]byte("receipts-block-"), hash...)); err != nil {
-				return err, false
+			// Convert the old metadata to a new lookup entry, delete duplicate data
+			if failed = db.Put(append([]byte("l"), hash...), it.Value()); failed == nil { // Write the new looku entry
+				if failed = db.Delete(hash); failed == nil { // Delete the duplicate transaction data
+					if failed = db.Delete(append([]byte("receipts-"), hash...)); failed == nil { // Delete the duplicate receipt data
+						if failed = db.Delete(key); failed != nil { // Delete the old transaction metadata
+							break
+						}
+					}
+				}
 			}
-		} else {
-			it.Next()
-		}
-
-		if stopFn() {
-			return nil, true
-		}
-	}
-	if cnt > 0 {
-		log.Info("Converted blocks", "count", cnt)
-	}
-	return nil, false
-}
+			// Bump the conversion counter, and recreate the iterator occasionally to
+			// avoid too high memory consumption.
+			converted++
+			if converted%100000 == 0 {
+				it.Release()
+				it = db.(*ethdb.LDBDatabase).NewIterator()
+				it.Seek(key)
 
-// upgradeSequentialOrphanedReceipts removes any old format block receipts from the
-// database that did not have a corresponding block
-func upgradeSequentialOrphanedReceipts(db ethdb.Database, stopFn func() bool) (error, bool) {
-	prefix := []byte("receipts-block-")
-	it := db.(*ethdb.LDBDatabase).NewIterator()
-	defer it.Release()
-	it.Seek(prefix)
-	cnt := 0
-	for bytes.HasPrefix(it.Key(), prefix) {
-		// phase 2 already converted receipts belonging to existing
-		// blocks, just remove if there's anything left
-		cnt++
-		if err := db.Delete(it.Key()); err != nil {
-			return err, false
+				log.Info("Deduplicating database entries", "deduped", converted)
+			}
+			// Check for termination, or continue after a bit of a timeout
+			select {
+			case errc := <-stop:
+				errc <- nil
+				return
+			case <-time.After(time.Microsecond * 100):
+			}
 		}
-
-		if stopFn() {
-			return nil, true
+		// Upgrade finished, mark a such and terminate
+		if failed == nil {
+			log.Info("Database deduplication successful", "deduped", converted)
+			db.Put(deduplicateData, []byte{42})
+		} else {
+			log.Error("Database deduplication failed", "deduped", converted, "err", failed)
 		}
-		it.Next()
-	}
-	if cnt > 0 {
-		log.Info("Removed orphaned block receipts", "count", cnt)
-	}
-	return nil, false
-}
+		it.Release()
+		it = nil
 
-// upgradeSequentialBlockData upgrades the header, body, td and block receipts
-// database entries belonging to a single hash (doesn't delete old data).
-func upgradeSequentialBlockData(db ethdb.Database, hash []byte) error {
-	// get old chain data and block number
-	headerRLP, _ := db.Get(append(append([]byte("block-"), hash...), []byte("-header")...))
-	if len(headerRLP) == 0 {
-		return nil
-	}
-	header := new(types.Header)
-	if err := rlp.Decode(bytes.NewReader(headerRLP), header); err != nil {
-		return err
-	}
-	number := header.Number.Uint64()
-	bodyRLP, _ := db.Get(append(append([]byte("block-"), hash...), []byte("-body")...))
-	tdRLP, _ := db.Get(append(append([]byte("block-"), hash...), []byte("-td")...))
-	receiptsRLP, _ := db.Get(append([]byte("receipts-block-"), hash...))
-	// store new hash -> number association
-	encNum := make([]byte, 8)
-	binary.BigEndian.PutUint64(encNum, number)
-	if err := db.Put(append([]byte("H"), hash...), encNum); err != nil {
-		return err
-	}
-	// store new chain data
-	if err := db.Put(append(append([]byte("h"), encNum...), hash...), headerRLP); err != nil {
-		return err
-	}
-	if len(tdRLP) != 0 {
-		if err := db.Put(append(append(append([]byte("h"), encNum...), hash...), []byte("t")...), tdRLP); err != nil {
-			return err
-		}
-	}
-	if len(bodyRLP) != 0 {
-		if err := db.Put(append(append([]byte("b"), encNum...), hash...), bodyRLP); err != nil {
-			return err
-		}
-	}
-	if len(receiptsRLP) != 0 {
-		if err := db.Put(append(append([]byte("r"), encNum...), hash...), receiptsRLP); err != nil {
-			return err
-		}
+		errc := <-stop
+		errc <- failed
+	}()
+	// Assembly the cancellation callback
+	return func() error {
+		errc := make(chan error)
+		stop <- errc
+		return <-errc
 	}
-	return nil
 }
 
 func addMipmapBloomBins(db ethdb.Database) (err error) {
diff --git a/eth/filters/filter_test.go b/eth/filters/filter_test.go
index cd5e7cafd..b6cfd4bbc 100644
--- a/eth/filters/filter_test.go
+++ b/eth/filters/filter_test.go
@@ -82,12 +82,6 @@ func BenchmarkMipmaps(b *testing.B) {
 			gen.AddUncheckedReceipt(receipt)
 
 		}
-
-		// store the receipts
-		err := core.WriteReceipts(db, receipts)
-		if err != nil {
-			b.Fatal(err)
-		}
 		core.WriteMipmapBloom(db, uint64(i+1), receipts)
 	})
 	for i, block := range chain {
@@ -183,12 +177,6 @@ func TestFilters(t *testing.T) {
 			gen.AddUncheckedReceipt(receipt)
 			receipts = types.Receipts{receipt}
 		}
-
-		// store the receipts
-		err := core.WriteReceipts(db, receipts)
-		if err != nil {
-			t.Fatal(err)
-		}
 		// i is used as block number for the writes but since the i
 		// starts at 0 and block 0 (genesis) is already present increment
 		// by one
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index c22c56dfb..1b23ac559 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -17,7 +17,6 @@
 package ethapi
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -35,7 +34,6 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/params"
@@ -769,7 +767,7 @@ func (s *PublicBlockChainAPI) rpcOutputBlock(b *types.Block, inclTx bool, fullTx
 
 		if fullTx {
 			formatTx = func(tx *types.Transaction) (interface{}, error) {
-				return newRPCTransaction(b, tx.Hash())
+				return newRPCTransactionFromBlockHash(b, tx.Hash()), nil
 			}
 		}
 
@@ -812,15 +810,17 @@ type RPCTransaction struct {
 	S                *hexutil.Big    `json:"s"`
 }
 
-// newRPCPendingTransaction returns a pending transaction that will serialize to the RPC representation
-func newRPCPendingTransaction(tx *types.Transaction) *RPCTransaction {
+// newRPCTransaction returns a transaction that will serialize to the RPC
+// representation, with the given location metadata set (if available).
+func newRPCTransaction(tx *types.Transaction, blockHash common.Hash, blockNumber uint64, index uint64) *RPCTransaction {
 	var signer types.Signer = types.FrontierSigner{}
 	if tx.Protected() {
 		signer = types.NewEIP155Signer(tx.ChainId())
 	}
 	from, _ := types.Sender(signer, tx)
 	v, r, s := tx.RawSignatureValues()
-	return &RPCTransaction{
+
+	result := &RPCTransaction{
 		From:     from,
 		Gas:      (*hexutil.Big)(tx.Gas()),
 		GasPrice: (*hexutil.Big)(tx.GasPrice()),
@@ -833,58 +833,46 @@ func newRPCPendingTransaction(tx *types.Transaction) *RPCTransaction {
 		R:        (*hexutil.Big)(r),
 		S:        (*hexutil.Big)(s),
 	}
+	if blockHash != (common.Hash{}) {
+		result.BlockHash = blockHash
+		result.BlockNumber = (*hexutil.Big)(new(big.Int).SetUint64(blockNumber))
+		result.TransactionIndex = hexutil.Uint(index)
+	}
+	return result
 }
 
-// newRPCTransaction returns a transaction that will serialize to the RPC representation.
-func newRPCTransactionFromBlockIndex(b *types.Block, txIndex uint) (*RPCTransaction, error) {
-	if txIndex < uint(len(b.Transactions())) {
-		tx := b.Transactions()[txIndex]
-		var signer types.Signer = types.FrontierSigner{}
-		if tx.Protected() {
-			signer = types.NewEIP155Signer(tx.ChainId())
-		}
-		from, _ := types.Sender(signer, tx)
-		v, r, s := tx.RawSignatureValues()
-		return &RPCTransaction{
-			BlockHash:        b.Hash(),
-			BlockNumber:      (*hexutil.Big)(b.Number()),
-			From:             from,
-			Gas:              (*hexutil.Big)(tx.Gas()),
-			GasPrice:         (*hexutil.Big)(tx.GasPrice()),
-			Hash:             tx.Hash(),
-			Input:            hexutil.Bytes(tx.Data()),
-			Nonce:            hexutil.Uint64(tx.Nonce()),
-			To:               tx.To(),
-			TransactionIndex: hexutil.Uint(txIndex),
-			Value:            (*hexutil.Big)(tx.Value()),
-			V:                (*hexutil.Big)(v),
-			R:                (*hexutil.Big)(r),
-			S:                (*hexutil.Big)(s),
-		}, nil
-	}
-
-	return nil, nil
+// newRPCPendingTransaction returns a pending transaction that will serialize to the RPC representation
+func newRPCPendingTransaction(tx *types.Transaction) *RPCTransaction {
+	return newRPCTransaction(tx, common.Hash{}, 0, 0)
 }
 
-// newRPCRawTransactionFromBlockIndex returns the bytes of a transaction given a block and a transaction index.
-func newRPCRawTransactionFromBlockIndex(b *types.Block, txIndex uint) (hexutil.Bytes, error) {
-	if txIndex < uint(len(b.Transactions())) {
-		tx := b.Transactions()[txIndex]
-		return rlp.EncodeToBytes(tx)
+// newRPCTransactionFromBlockIndex returns a transaction that will serialize to the RPC representation.
+func newRPCTransactionFromBlockIndex(b *types.Block, index uint64) *RPCTransaction {
+	txs := b.Transactions()
+	if index >= uint64(len(txs)) {
+		return nil
 	}
+	return newRPCTransaction(txs[index], b.Hash(), b.NumberU64(), index)
+}
 
-	return nil, nil
+// newRPCRawTransactionFromBlockIndex returns the bytes of a transaction given a block and a transaction index.
+func newRPCRawTransactionFromBlockIndex(b *types.Block, index uint64) hexutil.Bytes {
+	txs := b.Transactions()
+	if index >= uint64(len(txs)) {
+		return nil
+	}
+	blob, _ := rlp.EncodeToBytes(txs[index])
+	return blob
 }
 
-// newRPCTransaction returns a transaction that will serialize to the RPC representation.
-func newRPCTransaction(b *types.Block, txHash common.Hash) (*RPCTransaction, error) {
+// newRPCTransactionFromBlockHash returns a transaction that will serialize to the RPC representation.
+func newRPCTransactionFromBlockHash(b *types.Block, hash common.Hash) *RPCTransaction {
 	for idx, tx := range b.Transactions() {
-		if tx.Hash() == txHash {
-			return newRPCTransactionFromBlockIndex(b, uint(idx))
+		if tx.Hash() == hash {
+			return newRPCTransactionFromBlockIndex(b, uint64(idx))
 		}
 	}
-
-	return nil, nil
+	return nil
 }
 
 // PublicTransactionPoolAPI exposes methods for the RPC interface
@@ -898,24 +886,6 @@ func NewPublicTransactionPoolAPI(b Backend, nonceLock *AddrLocker) *PublicTransa
 	return &PublicTransactionPoolAPI{b, nonceLock}
 }
 
-func getTransaction(chainDb ethdb.Database, b Backend, txHash common.Hash) (*types.Transaction, bool, error) {
-	txData, err := chainDb.Get(txHash.Bytes())
-	isPending := false
-	tx := new(types.Transaction)
-
-	if err == nil && len(txData) > 0 {
-		if err := rlp.DecodeBytes(txData, tx); err != nil {
-			return nil, isPending, err
-		}
-	} else {
-		// pending transaction?
-		tx = b.GetPoolTransaction(txHash)
-		isPending = true
-	}
-
-	return tx, isPending, nil
-}
-
 // GetBlockTransactionCountByNumber returns the number of transactions in the block with the given block number.
 func (s *PublicTransactionPoolAPI) GetBlockTransactionCountByNumber(ctx context.Context, blockNr rpc.BlockNumber) *hexutil.Uint {
 	if block, _ := s.b.BlockByNumber(ctx, blockNr); block != nil {
@@ -935,35 +905,35 @@ func (s *PublicTransactionPoolAPI) GetBlockTransactionCountByHash(ctx context.Co
 }
 
 // GetTransactionByBlockNumberAndIndex returns the transaction for the given block number and index.
-func (s *PublicTransactionPoolAPI) GetTransactionByBlockNumberAndIndex(ctx context.Context, blockNr rpc.BlockNumber, index hexutil.Uint) (*RPCTransaction, error) {
+func (s *PublicTransactionPoolAPI) GetTransactionByBlockNumberAndIndex(ctx context.Context, blockNr rpc.BlockNumber, index hexutil.Uint) *RPCTransaction {
 	if block, _ := s.b.BlockByNumber(ctx, blockNr); block != nil {
-		return newRPCTransactionFromBlockIndex(block, uint(index))
+		return newRPCTransactionFromBlockIndex(block, uint64(index))
 	}
-	return nil, nil
+	return nil
 }
 
 // GetTransactionByBlockHashAndIndex returns the transaction for the given block hash and index.
-func (s *PublicTransactionPoolAPI) GetTransactionByBlockHashAndIndex(ctx context.Context, blockHash common.Hash, index hexutil.Uint) (*RPCTransaction, error) {
+func (s *PublicTransactionPoolAPI) GetTransactionByBlockHashAndIndex(ctx context.Context, blockHash common.Hash, index hexutil.Uint) *RPCTransaction {
 	if block, _ := s.b.GetBlock(ctx, blockHash); block != nil {
-		return newRPCTransactionFromBlockIndex(block, uint(index))
+		return newRPCTransactionFromBlockIndex(block, uint64(index))
 	}
-	return nil, nil
+	return nil
 }
 
 // GetRawTransactionByBlockNumberAndIndex returns the bytes of the transaction for the given block number and index.
-func (s *PublicTransactionPoolAPI) GetRawTransactionByBlockNumberAndIndex(ctx context.Context, blockNr rpc.BlockNumber, index hexutil.Uint) (hexutil.Bytes, error) {
+func (s *PublicTransactionPoolAPI) GetRawTransactionByBlockNumberAndIndex(ctx context.Context, blockNr rpc.BlockNumber, index hexutil.Uint) hexutil.Bytes {
 	if block, _ := s.b.BlockByNumber(ctx, blockNr); block != nil {
-		return newRPCRawTransactionFromBlockIndex(block, uint(index))
+		return newRPCRawTransactionFromBlockIndex(block, uint64(index))
 	}
-	return nil, nil
+	return nil
 }
 
 // GetRawTransactionByBlockHashAndIndex returns the bytes of the transaction for the given block hash and index.
-func (s *PublicTransactionPoolAPI) GetRawTransactionByBlockHashAndIndex(ctx context.Context, blockHash common.Hash, index hexutil.Uint) (hexutil.Bytes, error) {
+func (s *PublicTransactionPoolAPI) GetRawTransactionByBlockHashAndIndex(ctx context.Context, blockHash common.Hash, index hexutil.Uint) hexutil.Bytes {
 	if block, _ := s.b.GetBlock(ctx, blockHash); block != nil {
-		return newRPCRawTransactionFromBlockIndex(block, uint(index))
+		return newRPCRawTransactionFromBlockIndex(block, uint64(index))
 	}
-	return nil, nil
+	return nil
 }
 
 // GetTransactionCount returns the number of transactions the given address has sent for the given block number
@@ -976,90 +946,42 @@ func (s *PublicTransactionPoolAPI) GetTransactionCount(ctx context.Context, addr
 	return (*hexutil.Uint64)(&nonce), state.Error()
 }
 
-// getTransactionBlockData fetches the meta data for the given transaction from the chain database. This is useful to
-// retrieve block information for a hash. It returns the block hash, block index and transaction index.
-func getTransactionBlockData(chainDb ethdb.Database, txHash common.Hash) (common.Hash, uint64, uint64, error) {
-	var txBlock struct {
-		BlockHash  common.Hash
-		BlockIndex uint64
-		Index      uint64
-	}
-
-	blockData, err := chainDb.Get(append(txHash.Bytes(), 0x0001))
-	if err != nil {
-		return common.Hash{}, uint64(0), uint64(0), err
-	}
-
-	reader := bytes.NewReader(blockData)
-	if err = rlp.Decode(reader, &txBlock); err != nil {
-		return common.Hash{}, uint64(0), uint64(0), err
-	}
-
-	return txBlock.BlockHash, txBlock.BlockIndex, txBlock.Index, nil
-}
-
 // GetTransactionByHash returns the transaction for the given hash
-func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, hash common.Hash) (*RPCTransaction, error) {
-	var tx *types.Transaction
-	var isPending bool
-	var err error
-
-	if tx, isPending, err = getTransaction(s.b.ChainDb(), s.b, hash); err != nil {
-		log.Debug("Failed to retrieve transaction", "hash", hash, "err", err)
-		return nil, nil
-	} else if tx == nil {
-		return nil, nil
+func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, hash common.Hash) *RPCTransaction {
+	// Try to return an already finalized transaction
+	if tx, blockHash, blockNumber, index := core.GetTransaction(s.b.ChainDb(), hash); tx != nil {
+		return newRPCTransaction(tx, blockHash, blockNumber, index)
 	}
-	if isPending {
-		return newRPCPendingTransaction(tx), nil
-	}
-
-	blockHash, _, _, err := getTransactionBlockData(s.b.ChainDb(), hash)
-	if err != nil {
-		log.Debug("Failed to retrieve transaction block", "hash", hash, "err", err)
-		return nil, nil
+	// No finalized transaction, try to retrieve it from the pool
+	if tx := s.b.GetPoolTransaction(hash); tx != nil {
+		return newRPCPendingTransaction(tx)
 	}
-
-	if block, _ := s.b.GetBlock(ctx, blockHash); block != nil {
-		return newRPCTransaction(block, hash)
-	}
-	return nil, nil
+	// Transaction unknown, return as such
+	return nil
 }
 
 // GetRawTransactionByHash returns the bytes of the transaction for the given hash.
 func (s *PublicTransactionPoolAPI) GetRawTransactionByHash(ctx context.Context, hash common.Hash) (hexutil.Bytes, error) {
 	var tx *types.Transaction
-	var err error
 
-	if tx, _, err = getTransaction(s.b.ChainDb(), s.b, hash); err != nil {
-		log.Debug("Failed to retrieve transaction", "hash", hash, "err", err)
-		return nil, nil
-	} else if tx == nil {
-		return nil, nil
+	// Retrieve a finalized transaction, or a pooled otherwise
+	if tx, _, _, _ = core.GetTransaction(s.b.ChainDb(), hash); tx == nil {
+		if tx = s.b.GetPoolTransaction(hash); tx == nil {
+			// Transaction not found anywhere, abort
+			return nil, nil
+		}
 	}
-
+	// Serialize to RLP and return
 	return rlp.EncodeToBytes(tx)
 }
 
 // GetTransactionReceipt returns the transaction receipt for the given transaction hash.
 func (s *PublicTransactionPoolAPI) GetTransactionReceipt(hash common.Hash) (map[string]interface{}, error) {
-	receipt := core.GetReceipt(s.b.ChainDb(), hash)
-	if receipt == nil {
-		log.Debug("Receipt not found for transaction", "hash", hash)
-		return nil, nil
-	}
-
-	tx, _, err := getTransaction(s.b.ChainDb(), s.b, hash)
-	if err != nil {
-		log.Debug("Failed to retrieve transaction", "hash", hash, "err", err)
-		return nil, nil
-	}
-
-	txBlock, blockIndex, index, err := getTransactionBlockData(s.b.ChainDb(), hash)
-	if err != nil {
-		log.Debug("Failed to retrieve transaction block", "hash", hash, "err", err)
+	tx, blockHash, blockNumber, index := core.GetTransaction(s.b.ChainDb(), hash)
+	if tx == nil {
 		return nil, nil
 	}
+	receipt, _, _, _ := core.GetReceipt(s.b.ChainDb(), hash) // Old receipts don't have the lookup data available
 
 	var signer types.Signer = types.FrontierSigner{}
 	if tx.Protected() {
@@ -1069,8 +991,8 @@ func (s *PublicTransactionPoolAPI) GetTransactionReceipt(hash common.Hash) (map[
 
 	fields := map[string]interface{}{
 		"root":              hexutil.Bytes(receipt.PostState),
-		"blockHash":         txBlock,
-		"blockNumber":       hexutil.Uint64(blockIndex),
+		"blockHash":         blockHash,
+		"blockNumber":       hexutil.Uint64(blockNumber),
 		"transactionHash":   hash,
 		"transactionIndex":  hexutil.Uint64(index),
 		"from":              from,
diff --git a/light/txpool.go b/light/txpool.go
index 0430b280f..416148b7e 100644
--- a/light/txpool.go
+++ b/light/txpool.go
@@ -130,19 +130,6 @@ type txBlockData struct {
 	Index      uint64
 }
 
-// storeTxBlockData stores the block position of a mined tx in the local db
-func (pool *TxPool) storeTxBlockData(txh common.Hash, tbd txBlockData) {
-	//fmt.Println("storeTxBlockData", txh, tbd)
-	data, _ := rlp.EncodeToBytes(tbd)
-	pool.chainDb.Put(append(txh[:], byte(1)), data)
-}
-
-// removeTxBlockData removes the stored block position of a rolled back tx
-func (pool *TxPool) removeTxBlockData(txh common.Hash) {
-	//fmt.Println("removeTxBlockData", txh)
-	pool.chainDb.Delete(append(txh[:], byte(1)))
-}
-
 // txStateChanges stores the recent changes between pending/mined states of
 // transactions. True means mined, false means rolled back, no entry means no change
 type txStateChanges map[common.Hash]bool
@@ -172,59 +159,48 @@ func (txc txStateChanges) getLists() (mined []common.Hash, rollback []common.Has
 // checkMinedTxs checks newly added blocks for the currently pending transactions
 // and marks them as mined if necessary. It also stores block position in the db
 // and adds them to the received txStateChanges map.
-func (pool *TxPool) checkMinedTxs(ctx context.Context, hash common.Hash, idx uint64, txc txStateChanges) error {
-	//fmt.Println("checkMinedTxs")
+func (pool *TxPool) checkMinedTxs(ctx context.Context, hash common.Hash, number uint64, txc txStateChanges) error {
+	// If no transactions are pending, we don't care about anything
 	if len(pool.pending) == 0 {
 		return nil
 	}
-	//fmt.Println("len(pool) =", len(pool.pending))
-
-	block, err := GetBlock(ctx, pool.odr, hash, idx)
-	var receipts types.Receipts
+	block, err := GetBlock(ctx, pool.odr, hash, number)
 	if err != nil {
-		//fmt.Println(err)
 		return err
 	}
-	//fmt.Println("len(block.Transactions()) =", len(block.Transactions()))
-
+	// Gather all the local transaction mined in this block
 	list := pool.mined[hash]
-	for i, tx := range block.Transactions() {
-		txHash := tx.Hash()
-		//fmt.Println(" txHash:", txHash)
-		if tx, ok := pool.pending[txHash]; ok {
-			//fmt.Println("TX FOUND")
-			if receipts == nil {
-				receipts, err = GetBlockReceipts(ctx, pool.odr, hash, idx)
-				if err != nil {
-					return err
-				}
-				if len(receipts) != len(block.Transactions()) {
-					panic(nil) // should never happen if hashes did match
-				}
-				core.SetReceiptsData(pool.config, block, receipts)
-			}
-			//fmt.Println("WriteReceipt", receipts[i].TxHash)
-			core.WriteReceipt(pool.chainDb, receipts[i])
-			pool.storeTxBlockData(txHash, txBlockData{hash, idx, uint64(i)})
-			delete(pool.pending, txHash)
+	for _, tx := range block.Transactions() {
+		if _, ok := pool.pending[tx.Hash()]; ok {
 			list = append(list, tx)
-			txc.setState(txHash, true)
 		}
 	}
+	// If some transactions have been mined, write the needed data to disk and update
 	if list != nil {
+		// Retrieve all the receipts belonging to this block and write the loopup table
+		if _, err := GetBlockReceipts(ctx, pool.odr, hash, number); err != nil { // ODR caches, ignore results
+			return err
+		}
+		if err := core.WriteTxLookupEntries(pool.chainDb, block); err != nil {
+			return err
+		}
+		// Update the transaction pool's state
+		for _, tx := range list {
+			delete(pool.pending, tx.Hash())
+			txc.setState(tx.Hash(), true)
+		}
 		pool.mined[hash] = list
 	}
 	return nil
 }
 
 // rollbackTxs marks the transactions contained in recently rolled back blocks
-// as rolled back. It also removes block position info from the db and adds them
-// to the received txStateChanges map.
+// as rolled back. It also removes any positional lookup entries.
 func (pool *TxPool) rollbackTxs(hash common.Hash, txc txStateChanges) {
 	if list, ok := pool.mined[hash]; ok {
 		for _, tx := range list {
 			txHash := tx.Hash()
-			pool.removeTxBlockData(txHash)
+			core.DeleteTxLookupEntry(pool.chainDb, txHash)
 			pool.pending[txHash] = tx
 			txc.setState(txHash, false)
 		}
diff --git a/miner/worker.go b/miner/worker.go
index e44514755..411bc4e1b 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -293,9 +293,7 @@ func (self *worker) wait() {
 				// check if canon block and write transactions
 				if stat == core.CanonStatTy {
 					// This puts transactions in a extra db for rpc
-					core.WriteTransactions(self.chainDb, block)
-					// store the receipts
-					core.WriteReceipts(self.chainDb, work.receipts)
+					core.WriteTxLookupEntries(self.chainDb, block)
 					// Write map map bloom filters
 					core.WriteMipmapBloom(self.chainDb, block.NumberU64(), work.receipts)
 					// implicit by posting ChainHeadEvent