diff --git a/trie_by_cid/trie/iterator.go b/trie_by_cid/trie/iterator.go
index 0067bc0..55e7a96 100644
--- a/trie_by_cid/trie/iterator.go
+++ b/trie_by_cid/trie/iterator.go
@@ -21,7 +21,6 @@ import (
 	"errors"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/trie"
 )
 
@@ -83,7 +82,7 @@ type nodeIterator struct {
 	path  []byte               // Path to the current node
 	err   error                // Failure set in case of an internal error in the iterator
 
-	resolver ethdb.KeyValueReader // Optional intermediate resolver above the disk layer
+	resolver trie.NodeResolver // Optional intermediate resolver above the disk layer
 }
 
 // errIteratorEnd is stored in nodeIterator.err when iteration is done.
@@ -111,7 +110,7 @@ func newNodeIterator(trie *Trie, start []byte) NodeIterator {
 	return it
 }
 
-func (it *nodeIterator) AddResolver(resolver ethdb.KeyValueReader) {
+func (it *nodeIterator) AddResolver(resolver trie.NodeResolver) {
 	it.resolver = resolver
 }
 
@@ -315,7 +314,7 @@ func (it *nodeIterator) peekSeek(seekKey []byte) (*nodeIteratorState, *int, []by
 
 func (it *nodeIterator) resolveHash(hash hashNode, path []byte) (node, error) {
 	if it.resolver != nil {
-		if blob, err := it.resolver.Get(hash); err == nil && len(blob) > 0 {
+		if blob := it.resolver(it.trie.owner, path, common.BytesToHash(hash)); len(blob) > 0 {
 			if resolved, err := decodeNode(hash, blob); err == nil {
 				return resolved, nil
 			}
@@ -326,7 +325,7 @@ func (it *nodeIterator) resolveHash(hash hashNode, path []byte) (node, error) {
 
 func (it *nodeIterator) resolveBlob(hash hashNode, path []byte) ([]byte, error) {
 	if it.resolver != nil {
-		if blob, err := it.resolver.Get(hash); err == nil && len(blob) > 0 {
+		if blob := it.resolver(it.trie.owner, path, common.BytesToHash(hash)); len(blob) > 0 {
 			return blob, nil
 		}
 	}
diff --git a/trie_by_cid/trie/iterator_test.go b/trie_by_cid/trie/iterator_test.go
index 2666969..1078b38 100644
--- a/trie_by_cid/trie/iterator_test.go
+++ b/trie_by_cid/trie/iterator_test.go
@@ -114,14 +114,11 @@ func updateTrie(tr *geth_trie.Trie, vals []kvs) (kvMap, error) {
 }
 
 func commitTrie(t *testing.T, db *geth_trie.Database, tr *geth_trie.Trie) common.Hash {
-	root, nodes, err := tr.Commit(false)
-	if err != nil {
-		t.Fatalf("Failed to commit trie %v", err)
-	}
-	if err = db.Update(geth_trie.NewWithNodeSet(nodes)); err != nil {
+	root, nodes := tr.Commit(false)
+	if err := db.Update(geth_trie.NewWithNodeSet(nodes)); err != nil {
 		t.Fatal(err)
 	}
-	if err = db.Commit(root, false, nil); err != nil {
+	if err := db.Commit(root, false); err != nil {
 		t.Fatal(err)
 	}
 	return root
@@ -129,6 +126,7 @@ func commitTrie(t *testing.T, db *geth_trie.Database, tr *geth_trie.Trie) common
 
 // commit a LevelDB state trie, index to IPLD and return new trie
 func indexTrie(t *testing.T, edb ethdb.Database, root common.Hash) *trie.Trie {
+	dbConfig.Driver = postgres.PGX
 	err := helper.IndexChain(dbConfig, geth_state.NewDatabase(edb), common.Hash{}, root)
 	if err != nil {
 		t.Fatal(err)