diff --git a/db/perf_context_test.cc b/db/perf_context_test.cc
index 9d34409c3..6669aaec3 100644
--- a/db/perf_context_test.cc
+++ b/db/perf_context_test.cc
@@ -88,22 +88,27 @@ TEST(PerfContextTest, SeekIntoDeletion) {
     hist_get_time.Add(elapsed_nanos);
   }
 
-  std::cout << "Get uesr key comparison: \n" << hist_get.ToString()
+  std::cout << "Get user key comparison: \n" << hist_get.ToString()
             << "Get time: \n" << hist_get_time.ToString();
 
-  HistogramImpl hist_seek_to_first;
-  std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
+  {
+    HistogramImpl hist_seek_to_first;
+    std::unique_ptr<Iterator> iter(db->NewIterator(read_options));
 
-  perf_context.Reset();
-  StopWatchNano timer(Env::Default(), true);
-  iter->SeekToFirst();
-  hist_seek_to_first.Add(perf_context.user_key_comparison_count);
-  auto elapsed_nanos = timer.ElapsedNanos();
+    perf_context.Reset();
+    StopWatchNano timer(Env::Default(), true);
+    iter->SeekToFirst();
+    hist_seek_to_first.Add(perf_context.user_key_comparison_count);
+    auto elapsed_nanos = timer.ElapsedNanos();
 
-  std::cout << "SeekToFirst uesr key comparison: \n" << hist_seek_to_first.ToString()
-            << "ikey skipped: " << perf_context.internal_key_skipped_count << "\n"
-            << "idelete skipped: " << perf_context.internal_delete_skipped_count << "\n"
-            << "elapsed: " << elapsed_nanos << "\n";
+    std::cout << "SeekToFirst uesr key comparison: \n"
+              << hist_seek_to_first.ToString()
+              << "ikey skipped: " << perf_context.internal_key_skipped_count
+              << "\n"
+              << "idelete skipped: "
+              << perf_context.internal_delete_skipped_count << "\n"
+              << "elapsed: " << elapsed_nanos << "\n";
+  }
 
   HistogramImpl hist_seek;
   for (int i = 0; i < FLAGS_total_keys; ++i) {
@@ -224,7 +229,6 @@ void ProfileQueries(bool enabled_time = false) {
     std::string key = "k" + std::to_string(i);
     std::string value = "v" + std::to_string(i);
 
-    std::vector<Slice> keys = {Slice(key)};
     std::vector<std::string> values;
 
     perf_context.Reset();
@@ -239,7 +243,7 @@ void ProfileQueries(bool enabled_time = false) {
     std::string key = "k" + std::to_string(i);
     std::string value = "v" + std::to_string(i);
 
-    std::vector<Slice> keys = {Slice(key)};
+    std::vector<Slice> multiget_keys = {Slice(key)};
     std::vector<std::string> values;
 
     perf_context.Reset();
@@ -252,7 +256,7 @@ void ProfileQueries(bool enabled_time = false) {
     hist_get.Add(perf_context.user_key_comparison_count);
 
     perf_context.Reset();
-    db->MultiGet(read_options, keys, &values);
+    db->MultiGet(read_options, multiget_keys, &values);
     hist_mget_snapshot.Add(perf_context.get_snapshot_time);
     hist_mget_memtable.Add(perf_context.get_from_memtable_time);
     hist_mget_files.Add(perf_context.get_from_output_files_time);
@@ -329,7 +333,7 @@ void ProfileQueries(bool enabled_time = false) {
     std::string key = "k" + std::to_string(i);
     std::string value = "v" + std::to_string(i);
 
-    std::vector<Slice> keys = {Slice(key)};
+    std::vector<Slice> multiget_keys = {Slice(key)};
     std::vector<std::string> values;
 
     perf_context.Reset();
@@ -342,7 +346,7 @@ void ProfileQueries(bool enabled_time = false) {
     hist_get.Add(perf_context.user_key_comparison_count);
 
     perf_context.Reset();
-    db->MultiGet(read_options, keys, &values);
+    db->MultiGet(read_options, multiget_keys, &values);
     hist_mget_snapshot.Add(perf_context.get_snapshot_time);
     hist_mget_memtable.Add(perf_context.get_from_memtable_time);
     hist_mget_files.Add(perf_context.get_from_output_files_time);
diff --git a/table/table_reader_bench.cc b/table/table_reader_bench.cc
index e6960f751..ea722a8bf 100644
--- a/table/table_reader_bench.cc
+++ b/table/table_reader_bench.cc
@@ -115,7 +115,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
   unique_ptr<TableReader> table_reader;
   unique_ptr<RandomAccessFile> raf;
   if (!through_db) {
-    Status s = env->NewRandomAccessFile(file_name, &raf, env_options);
+    s = env->NewRandomAccessFile(file_name, &raf, env_options);
     uint64_t file_size;
     env->GetFileSize(file_name, &file_size);
     s = opts.table_factory->NewTableReader(
diff --git a/tools/blob_store_bench.cc b/tools/blob_store_bench.cc
index 60a0b84a6..7b820a178 100644
--- a/tools/blob_store_bench.cc
+++ b/tools/blob_store_bench.cc
@@ -59,11 +59,13 @@ struct Result {
     writes = reads = deletes = data_read = data_written = 0;
   }
 
-  Result (uint32_t writes, uint32_t reads, uint32_t deletes,
-          uint64_t data_written, uint64_t data_read) :
-    writes(writes), reads(reads), deletes(deletes),
-    data_written(data_written), data_read(data_read) {}
-
+  Result(uint32_t _writes, uint32_t _reads, uint32_t _deletes,
+         uint64_t _data_written, uint64_t _data_read)
+      : writes(_writes),
+        reads(_reads),
+        deletes(_deletes),
+        data_written(_data_written),
+        data_read(_data_read) {}
 };
 
 namespace {
@@ -81,11 +83,13 @@ struct WorkerThread {
   Result result;
   atomic<bool> stopped;
 
-  WorkerThread(uint64_t data_size_from, uint64_t data_size_to,
-                double read_ratio, uint64_t working_set_size) :
-    data_size_from(data_size_from), data_size_to(data_size_to),
-    read_ratio(read_ratio), working_set_size(working_set_size),
-    stopped(false) {}
+  WorkerThread(uint64_t _data_size_from, uint64_t _data_size_to,
+               double _read_ratio, uint64_t _working_set_size)
+      : data_size_from(_data_size_from),
+        data_size_to(_data_size_to),
+        read_ratio(_read_ratio),
+        working_set_size(_working_set_size),
+        stopped(false) {}
 
   WorkerThread(const WorkerThread& wt) :
     data_size_from(wt.data_size_from), data_size_to(wt.data_size_to),
diff --git a/tools/db_stress.cc b/tools/db_stress.cc
index 42d0fb534..a0d6ea723 100644
--- a/tools/db_stress.cc
+++ b/tools/db_stress.cc
@@ -751,11 +751,8 @@ struct ThreadState {
   SharedState* shared;
   Stats stats;
 
-  ThreadState(uint32_t index, SharedState *shared)
-      : tid(index),
-        rand(1000 + index + shared->GetSeed()),
-        shared(shared) {
-  }
+  ThreadState(uint32_t index, SharedState* _shared)
+      : tid(index), rand(1000 + index + shared->GetSeed()), shared(_shared) {}
 };
 
 }  // namespace
diff --git a/tools/sst_dump.cc b/tools/sst_dump.cc
index 6c496e8dd..03da2b840 100644
--- a/tools/sst_dump.cc
+++ b/tools/sst_dump.cc
@@ -378,7 +378,6 @@ int main(int argc, char** argv) {
     }
     rocksdb::SstFileReader reader(filename, verify_checksum,
                                   output_hex);
-    rocksdb::Status st;
     // scan all files in give file path.
     if (command == "" || command == "scan" || command == "check") {
       st = reader.ReadSequential(command != "check",
diff --git a/util/cache_bench.cc b/util/cache_bench.cc
index 3d006ecf8..92df77267 100644
--- a/util/cache_bench.cc
+++ b/util/cache_bench.cc
@@ -122,10 +122,8 @@ struct ThreadState {
   Random rnd;
   SharedState* shared;
 
-  ThreadState(uint32_t index, SharedState *shared)
-      : tid(index),
-        rnd(1000 + index),
-        shared(shared) {}
+  ThreadState(uint32_t index, SharedState* _shared)
+      : tid(index), rnd(1000 + index), shared(_shared) {}
 };
 }  // namespace