diff --git a/leveldb/external_test.go b/leveldb/external_test.go
index 53d6038..669d77f 100644
--- a/leveldb/external_test.go
+++ b/leveldb/external_test.go
@@ -32,7 +32,7 @@
 				db := newTestingDB(o, nil, nil)
 				t := testutil.DBTesting{
 					DB:      db,
-					Deleted: testutil.KeyValue_Generate(nil, 500, 1, 50, 5, 5).Clone(),
+					Deleted: testutil.KeyValue_Generate(nil, 500, 1, 1, 50, 5, 5).Clone(),
 				}
 				testutil.DoDBTesting(&t)
 				db.TestClose()
@@ -66,7 +66,7 @@
 				Expect(err).NotTo(HaveOccurred())
 				t0 := &testutil.DBTesting{
 					DB:      tr,
-					Deleted: testutil.KeyValue_Generate(nil, 200, 1, 50, 5, 5).Clone(),
+					Deleted: testutil.KeyValue_Generate(nil, 200, 1, 1, 50, 5, 5).Clone(),
 				}
 				testutil.DoDBTesting(t0)
 				testutil.TestGet(tr, t0.Present)
diff --git a/leveldb/iterator/array_iter_test.go b/leveldb/iterator/array_iter_test.go
index 1ed6d07..f16d014 100644
--- a/leveldb/iterator/array_iter_test.go
+++ b/leveldb/iterator/array_iter_test.go
@@ -17,7 +17,7 @@
 	Describe("Array iterator", func() {
 		It("Should iterates and seeks correctly", func() {
 			// Build key/value.
-			kv := testutil.KeyValue_Generate(nil, 70, 1, 5, 3, 3)
+			kv := testutil.KeyValue_Generate(nil, 70, 1, 1, 5, 3, 3)
 
 			// Test the iterator.
 			t := testutil.IteratorTesting{
diff --git a/leveldb/iterator/indexed_iter_test.go b/leveldb/iterator/indexed_iter_test.go
index f37e34e..fde8016 100644
--- a/leveldb/iterator/indexed_iter_test.go
+++ b/leveldb/iterator/indexed_iter_test.go
@@ -52,7 +52,7 @@
 					for _, x := range n {
 						sum += x
 					}
-					kv := testutil.KeyValue_Generate(nil, sum, 1, 10, 4, 4)
+					kv := testutil.KeyValue_Generate(nil, sum, 1, 1, 10, 4, 4)
 					for i, j := 0, 0; i < len(n); i++ {
 						for x := n[i]; x > 0; x-- {
 							key, value := kv.Index(j)
diff --git a/leveldb/iterator/merged_iter_test.go b/leveldb/iterator/merged_iter_test.go
index a992f79..ee40881 100644
--- a/leveldb/iterator/merged_iter_test.go
+++ b/leveldb/iterator/merged_iter_test.go
@@ -24,7 +24,7 @@
 
 					// Build key/value.
 					filledKV := make([]testutil.KeyValue, filled)
-					kv := testutil.KeyValue_Generate(nil, 100, 1, 10, 4, 4)
+					kv := testutil.KeyValue_Generate(nil, 100, 1, 1, 10, 4, 4)
 					kv.Iterate(func(i int, key, value []byte) {
 						filledKV[rnd.Intn(filled)].Put(key, value)
 					})
diff --git a/leveldb/memdb/memdb_test.go b/leveldb/memdb/memdb_test.go
index 5dd6dbc..3f0a31e 100644
--- a/leveldb/memdb/memdb_test.go
+++ b/leveldb/memdb/memdb_test.go
@@ -73,7 +73,7 @@
 				db := New(comparer.DefaultComparer, 0)
 				t := testutil.DBTesting{
 					DB:      db,
-					Deleted: testutil.KeyValue_Generate(nil, 1000, 1, 30, 5, 5).Clone(),
+					Deleted: testutil.KeyValue_Generate(nil, 1000, 1, 1, 30, 5, 5).Clone(),
 					PostFn: func(t *testutil.DBTesting) {
 						Expect(db.Len()).Should(Equal(t.Present.Len()))
 						Expect(db.Size()).Should(Equal(t.Present.Size()))
diff --git a/leveldb/table/reader.go b/leveldb/table/reader.go
index 1edf4e2..67de650 100644
--- a/leveldb/table/reader.go
+++ b/leveldb/table/reader.go
@@ -61,7 +61,7 @@
 func (b *block) seek(cmp comparer.Comparer, rstart, rlimit int, key []byte) (index, offset int, err error) {
 	index = sort.Search(b.restartsLen-rstart-(b.restartsLen-rlimit), func(i int) bool {
 		offset := int(binary.LittleEndian.Uint32(b.data[b.restartsOffset+4*(rstart+i):]))
-		offset += 1                                 // shared always zero, since this is a restart point
+		offset++                                    // shared always zero, since this is a restart point
 		v1, n1 := binary.Uvarint(b.data[offset:])   // key length
 		_, n2 := binary.Uvarint(b.data[offset+n1:]) // value length
 		m := offset + n1 + n2
@@ -356,7 +356,7 @@
 	i.value = nil
 	offset := i.block.restartOffset(ri)
 	if offset == i.offset {
-		ri -= 1
+		ri--
 		if ri < 0 {
 			i.dir = dirSOI
 			return false
@@ -826,18 +826,21 @@
 
 	index := r.newBlockIter(indexBlock, nil, nil, true)
 	defer index.Release()
+
 	if !index.Seek(key) {
-		err = index.Error()
-		if err == nil {
+		if err = index.Error(); err == nil {
 			err = ErrNotFound
 		}
 		return
 	}
+
 	dataBH, n := decodeBlockHandle(index.Value())
 	if n == 0 {
 		r.err = r.newErrCorruptedBH(r.indexBH, "bad data block handle")
-		return
+		return nil, nil, r.err
 	}
+
+	// The filter should only used for exact match.
 	if filtered && r.filter != nil {
 		filterBlock, frel, ferr := r.getFilterBlock(true)
 		if ferr == nil {
@@ -847,30 +850,53 @@
 			}
 			frel.Release()
 		} else if !errors.IsCorrupted(ferr) {
-			err = ferr
+			return nil, nil, ferr
+		}
+	}
+
+	data := r.getDataIter(dataBH, nil, r.verifyChecksum, !ro.GetDontFillCache())
+	if !data.Seek(key) {
+		data.Release()
+		if err = data.Error(); err != nil {
+			return
+		}
+
+		// The nearest greater-than key is the first key of the next block.
+		if !index.Next() {
+			if err = index.Error(); err == nil {
+				err = ErrNotFound
+			}
+			return
+		}
+
+		dataBH, n = decodeBlockHandle(index.Value())
+		if n == 0 {
+			r.err = r.newErrCorruptedBH(r.indexBH, "bad data block handle")
+			return nil, nil, r.err
+		}
+
+		data = r.getDataIter(dataBH, nil, r.verifyChecksum, !ro.GetDontFillCache())
+		if !data.Next() {
+			data.Release()
+			if err = data.Error(); err == nil {
+				err = ErrNotFound
+			}
 			return
 		}
 	}
-	data := r.getDataIter(dataBH, nil, r.verifyChecksum, !ro.GetDontFillCache())
-	defer data.Release()
-	if !data.Seek(key) {
-		err = data.Error()
-		if err == nil {
-			err = ErrNotFound
-		}
-		return
-	}
-	// Don't use block buffer, no need to copy the buffer.
+
+	// Key doesn't use block buffer, no need to copy the buffer.
 	rkey = data.Key()
 	if !noValue {
 		if r.bpool == nil {
 			value = data.Value()
 		} else {
-			// Use block buffer, and since the buffer will be recycled, the buffer
-			// need to be copied.
+			// Value does use block buffer, and since the buffer will be
+			// recycled, it need to be copied.
 			value = append([]byte{}, data.Value()...)
 		}
 	}
+	data.Release()
 	return
 }
 
@@ -1039,9 +1065,8 @@
 		if errors.IsCorrupted(err) {
 			r.err = err
 			return r, nil
-		} else {
-			return nil, err
 		}
+		return nil, err
 	}
 
 	// Set data end.
@@ -1086,9 +1111,8 @@
 			if errors.IsCorrupted(err) {
 				r.err = err
 				return r, nil
-			} else {
-				return nil, err
 			}
+			return nil, err
 		}
 		if r.filter != nil {
 			r.filterBlock, err = r.readFilterBlock(r.filterBH)
diff --git a/leveldb/table/table_test.go b/leveldb/table/table_test.go
index 1bc73ed..232efcd 100644
--- a/leveldb/table/table_test.go
+++ b/leveldb/table/table_test.go
@@ -111,7 +111,7 @@
 			}
 
 			testutil.AllKeyValueTesting(nil, Build, nil, nil)
-			Describe("with one key per block", Test(testutil.KeyValue_Generate(nil, 9, 1, 10, 512, 512), func(r *Reader) {
+			Describe("with one key per block", Test(testutil.KeyValue_Generate(nil, 9, 1, 1, 10, 512, 512), func(r *Reader) {
 				It("should have correct blocks number", func() {
 					indexBlock, err := r.readBlock(r.indexBH, true)
 					Expect(err).To(BeNil())
diff --git a/leveldb/testutil/kv.go b/leveldb/testutil/kv.go
index 471d570..608cbf3 100644
--- a/leveldb/testutil/kv.go
+++ b/leveldb/testutil/kv.go
@@ -292,7 +292,7 @@
 
 var keymap = []byte("012345678ABCDEFGHIJKLMNOPQRSTUVWXYabcdefghijklmnopqrstuvwxy")
 
-func KeyValue_Generate(rnd *rand.Rand, n, minlen, maxlen, vminlen, vmaxlen int) *KeyValue {
+func KeyValue_Generate(rnd *rand.Rand, n, incr, minlen, maxlen, vminlen, vmaxlen int) *KeyValue {
 	if rnd == nil {
 		rnd = NewRand()
 	}
@@ -308,7 +308,7 @@
 	}
 
 	kv := &KeyValue{}
-	endC := byte(len(keymap) - 1)
+	endC := byte(len(keymap) - incr)
 	gen := make([]byte, 0, maxlen)
 	for i := 0; i < n; i++ {
 		m := rrand(minlen, maxlen)
@@ -325,8 +325,8 @@
 				if c == endC {
 					continue
 				}
-				gen[j] = c + 1
-				for j += 1; j < m; j++ {
+				gen[j] = c + byte(incr)
+				for j++; j < m; j++ {
 					gen[j] = 0
 				}
 				goto ok
diff --git a/leveldb/testutil/kvtest.go b/leveldb/testutil/kvtest.go
index e6687d6..f7563dc 100644
--- a/leveldb/testutil/kvtest.go
+++ b/leveldb/testutil/kvtest.go
@@ -23,15 +23,15 @@
 
 		// Using exact key.
 		rkey, rvalue, err := db.TestFind(key)
-		Expect(err).ShouldNot(HaveOccurred(), "Error for key %q", key)
+		Expect(err).ShouldNot(HaveOccurred(), "Error for exact key %q", key)
 		Expect(rkey).Should(Equal(key), "Key")
-		Expect(rvalue).Should(Equal(value), "Value for key %q", key)
+		Expect(rvalue).Should(Equal(value), "Value for exact key %q", key)
 
 		// Using inexact key.
 		rkey, rvalue, err = db.TestFind(key_)
-		Expect(err).ShouldNot(HaveOccurred(), "Error for key %q (%q)", key_, key)
-		Expect(rkey).Should(Equal(key))
-		Expect(rvalue).Should(Equal(value), "Value for key %q (%q)", key_, key)
+		Expect(err).ShouldNot(HaveOccurred(), "Error for inexact key %q (%q)", key_, key)
+		Expect(rkey).Should(Equal(key), "Key for inexact key %q (%q)", key_, key)
+		Expect(rvalue).Should(Equal(value), "Value for inexact key %q (%q)", key_, key)
 	})
 }
 
@@ -207,5 +207,6 @@
 	Describe("with big value", Test(KeyValue_BigValue()))
 	Describe("with special key", Test(KeyValue_SpecialKey()))
 	Describe("with multiple key/value", Test(KeyValue_MultipleKeyValue()))
-	Describe("with generated key/value", Test(KeyValue_Generate(nil, 120, 1, 50, 10, 120)))
+	Describe("with generated key/value 2-incr", Test(KeyValue_Generate(nil, 120, 2, 1, 50, 10, 120)))
+	Describe("with generated key/value 3-incr", Test(KeyValue_Generate(nil, 120, 3, 1, 50, 10, 120)))
 }