diff --git a/db/corruption_test.cc b/db/corruption_test.cc
index ecd5b5344f..f835edc68b 100644
--- a/db/corruption_test.cc
+++ b/db/corruption_test.cc
@@ -230,7 +230,7 @@ TEST(CorruptionTest, NewFileErrorDuringWrite) {
 TEST(CorruptionTest, TableFile) {
   Build(100);
   DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
   dbi->TEST_CompactRange(0, nullptr, nullptr);
   dbi->TEST_CompactRange(1, nullptr, nullptr);
 
@@ -241,7 +241,7 @@ TEST(CorruptionTest, TableFile) {
 TEST(CorruptionTest, TableFileIndexData) {
   Build(10000);  // Enough to build multiple Tables
   DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
 
   Corrupt(kTableFile, -2000, 500);
   Reopen();
@@ -279,7 +279,7 @@ TEST(CorruptionTest, SequenceNumberRecovery) {
 TEST(CorruptionTest, CorruptedDescriptor) {
   ASSERT_OK(db_->Put(WriteOptions(), "foo", "hello"));
   DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
   dbi->TEST_CompactRange(0, nullptr, nullptr);
 
   Corrupt(kDescriptorFile, 0, 1000);
@@ -296,7 +296,7 @@ TEST(CorruptionTest, CorruptedDescriptor) {
 TEST(CorruptionTest, CompactionInputError) {
   Build(10);
   DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
   const int last = dbi->MaxMemCompactionLevel();
   ASSERT_EQ(1, Property("rocksdb.num-files-at-level" + NumberToString(last)));
 
@@ -319,11 +319,11 @@ TEST(CorruptionTest, CompactionInputErrorParanoid) {
   for (int level = 1; level < dbi->NumberLevels(); level++) {
     dbi->Put(WriteOptions(), "", "begin");
     dbi->Put(WriteOptions(), "~", "end");
-    dbi->TEST_CompactMemTable();
+    dbi->TEST_FlushMemTable();
   }
 
   Build(10);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
   ASSERT_EQ(1, Property("rocksdb.num-files-at-level0"));
 
   Corrupt(kTableFile, 100, 1);
@@ -341,7 +341,7 @@ TEST(CorruptionTest, CompactionInputErrorParanoid) {
 TEST(CorruptionTest, UnrelatedKeys) {
   Build(10);
   DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
   Corrupt(kTableFile, 100, 1);
 
   std::string tmp1, tmp2;
@@ -349,7 +349,7 @@ TEST(CorruptionTest, UnrelatedKeys) {
   std::string v;
   ASSERT_OK(db_->Get(ReadOptions(), Key(1000, &tmp1), &v));
   ASSERT_EQ(Value(1000, &tmp2).ToString(), v);
-  dbi->TEST_CompactMemTable();
+  dbi->TEST_FlushMemTable();
   ASSERT_OK(db_->Get(ReadOptions(), Key(1000, &tmp1), &v));
   ASSERT_EQ(Value(1000, &tmp2).ToString(), v);
 }
diff --git a/db/db_impl.cc b/db/db_impl.cc
index 57d5916b77..cfb523364b 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -924,13 +924,13 @@ Status DBImpl::WriteLevel0Table(std::vector<MemTable*> &mems, VersionEdit* edit,
   return s;
 }
 
-Status DBImpl::CompactMemTable(bool* madeProgress) {
+Status DBImpl::FlushMemTableToOutputFile(bool* madeProgress) {
   mutex_.AssertHeld();
   assert(imm_.size() != 0);
 
   if (!imm_.IsFlushPending(options_.min_write_buffer_number_to_merge)) {
-    Log(options_.info_log, "Memcompaction already in progress");
-    Status s = Status::IOError("Memcompaction already in progress");
+    Log(options_.info_log, "FlushMemTableToOutputFile already in progress");
+    Status s = Status::IOError("FlushMemTableToOutputFile already in progress");
     return s;
   }
 
@@ -998,7 +998,7 @@ void DBImpl::CompactRange(const Slice* begin, const Slice* end,
       }
     }
   }
-  TEST_CompactMemTable(); // TODO(sanjay): Skip if memtable does not overlap
+  TEST_FlushMemTable(); // TODO(sanjay): Skip if memtable does not overlap
   for (int level = 0; level < max_level_with_files; level++) {
     TEST_CompactRange(level, begin, end);
   }
@@ -1345,7 +1345,7 @@ void DBImpl::TEST_CompactRange(int level, const Slice* begin,const Slice* end) {
     if (bg_compaction_scheduled_ == LargeNumber) {
       bg_compaction_scheduled_ = newvalue;
     }
-    MaybeScheduleCompaction();
+    MaybeScheduleFlushOrCompaction();
     while (manual_compaction_ == &manual) {
       bg_cv_.Wait();
     }
@@ -1366,12 +1366,12 @@ Status DBImpl::FlushMemTable(const FlushOptions& options) {
   Status s = Write(WriteOptions(), nullptr);
   if (s.ok() && options.wait) {
     // Wait until the compaction completes
-    s = WaitForCompactMemTable();
+    s = WaitForFlushMemTable();
   }
   return s;
 }
 
-Status DBImpl::WaitForCompactMemTable() {
+Status DBImpl::WaitForFlushMemTable() {
   Status s;
   // Wait until the compaction completes
   MutexLock l(&mutex_);
@@ -1384,16 +1384,21 @@ Status DBImpl::WaitForCompactMemTable() {
   return s;
 }
 
-Status DBImpl::TEST_CompactMemTable() {
+Status DBImpl::TEST_FlushMemTable() {
   return FlushMemTable(FlushOptions());
 }
 
-Status DBImpl::TEST_WaitForCompactMemTable() {
-  return WaitForCompactMemTable();
+Status DBImpl::TEST_WaitForFlushMemTable() {
+  return WaitForFlushMemTable();
 }
 
 Status DBImpl::TEST_WaitForCompact() {
   // Wait until the compaction completes
+
+  // TODO: a bug here. This function actually does not necessarily
+  // wait for compact. It actually waits for scheduled compaction
+  // OR flush to finish.
+
   MutexLock l(&mutex_);
   while ((bg_compaction_scheduled_ || bg_flush_scheduled_) &&
          bg_error_.ok()) {
@@ -1402,7 +1407,7 @@ Status DBImpl::TEST_WaitForCompact() {
   return bg_error_;
 }
 
-void DBImpl::MaybeScheduleCompaction() {
+void DBImpl::MaybeScheduleFlushOrCompaction() {
   mutex_.AssertHeld();
   if (bg_work_gate_closed_) {
     // gate closed for backgrond work
@@ -1442,9 +1447,9 @@ Status DBImpl::BackgroundFlush() {
   while (stat.ok() &&
          imm_.IsFlushPending(options_.min_write_buffer_number_to_merge)) {
     Log(options_.info_log,
-        "BackgroundCallFlush doing CompactMemTable, flush slots available %d",
+        "BackgroundCallFlush doing FlushMemTableToOutputFile, flush slots available %d",
         options_.max_background_flushes - bg_flush_scheduled_);
-    stat = CompactMemTable();
+    stat = FlushMemTableToOutputFile();
   }
   return stat;
 }
@@ -1521,7 +1526,7 @@ void DBImpl::BackgroundCallCompaction() {
   // So reschedule another compaction if we made progress in the
   // last compaction.
   if (madeProgress) {
-    MaybeScheduleCompaction();
+    MaybeScheduleFlushOrCompaction();
   }
   bg_cv_.SignalAll();
 
@@ -1535,9 +1540,10 @@ Status DBImpl::BackgroundCompaction(bool* madeProgress,
   // TODO: remove memtable flush from formal compaction
   while (imm_.IsFlushPending(options_.min_write_buffer_number_to_merge)) {
     Log(options_.info_log,
-        "BackgroundCompaction doing CompactMemTable, compaction slots available %d",
+        "BackgroundCompaction doing FlushMemTableToOutputFile, compaction slots "
+        "available %d",
         options_.max_background_compactions - bg_compaction_scheduled_);
-    Status stat = CompactMemTable(madeProgress);
+    Status stat = FlushMemTableToOutputFile(madeProgress);
     if (!stat.ok()) {
       return stat;
     }
@@ -1590,7 +1596,7 @@ Status DBImpl::BackgroundCompaction(bool* madeProgress,
     versions_->ReleaseCompactionFiles(c.get(), status);
     *madeProgress = true;
   } else {
-    MaybeScheduleCompaction(); // do more compaction work in parallel.
+    MaybeScheduleFlushOrCompaction(); // do more compaction work in parallel.
     CompactionState* compact = new CompactionState(c.get());
     status = DoCompactionWork(compact);
     CleanupCompaction(compact);
@@ -1914,7 +1920,7 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
       const uint64_t imm_start = env_->NowMicros();
       mutex_.Lock();
       if (imm_.IsFlushPending(options_.min_write_buffer_number_to_merge)) {
-        CompactMemTable();
+        FlushMemTableToOutputFile();
         bg_cv_.SignalAll();  // Wakeup MakeRoomForWrite() if necessary
       }
       mutex_.Unlock();
@@ -2356,7 +2362,7 @@ Status DBImpl::GetImpl(const ReadOptions& options,
 
   if (!options_.disable_seek_compaction &&
       have_stat_update && current->UpdateStats(stats)) {
-    MaybeScheduleCompaction();
+    MaybeScheduleFlushOrCompaction();
   }
   mem->Unref();
   imm.UnrefAll();
@@ -2434,7 +2440,7 @@ std::vector<Status> DBImpl::MultiGet(const ReadOptions& options,
   mutex_.Lock();
   if (!options_.disable_seek_compaction &&
       have_stat_update && current->UpdateStats(stats)) {
-    MaybeScheduleCompaction();
+    MaybeScheduleFlushOrCompaction();
   }
   mem->Unref();
   imm.UnrefAll();
@@ -2853,7 +2859,7 @@ Status DBImpl::MakeRoomForWrite(bool force) {
       mem_->Ref();
       mem_->SetLogNumber(logfile_number_);
       force = false;   // Do not force another compaction if have room
-      MaybeScheduleCompaction();
+      MaybeScheduleFlushOrCompaction();
     }
   }
   return s;
@@ -3229,7 +3235,7 @@ Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
     if (s.ok()) {
       impl->mem_->SetLogNumber(impl->logfile_number_);
       impl->DeleteObsoleteFiles();
-      impl->MaybeScheduleCompaction();
+      impl->MaybeScheduleFlushOrCompaction();
       impl->MaybeScheduleLogDBDeployStats();
     }
   }
diff --git a/db/db_impl.h b/db/db_impl.h
index efc59d2533..ef2ef59449 100644
--- a/db/db_impl.h
+++ b/db/db_impl.h
@@ -82,11 +82,11 @@ class DBImpl : public DB {
   // Compact any files in the named level that overlap [*begin, *end]
   void TEST_CompactRange(int level, const Slice* begin, const Slice* end);
 
-  // Force current memtable contents to be compacted.
-  Status TEST_CompactMemTable();
+  // Force current memtable contents to be flushed.
+  Status TEST_FlushMemTable();
 
   // Wait for memtable compaction
-  Status TEST_WaitForCompactMemTable();
+  Status TEST_WaitForFlushMemTable();
 
   // Wait for any compaction
   Status TEST_WaitForCompact();
@@ -148,9 +148,9 @@ class DBImpl : public DB {
   // Delete any unneeded files and stale in-memory entries.
   void DeleteObsoleteFiles();
 
-  // Compact the in-memory write buffer to disk.  Switches to a new
+  // Flush the in-memory write buffer to storage.  Switches to a new
   // log-file/memtable and writes a new descriptor iff successful.
-  Status CompactMemTable(bool* madeProgress = nullptr);
+  Status FlushMemTableToOutputFile(bool* madeProgress = nullptr);
 
   Status RecoverLogFile(uint64_t log_number,
                         VersionEdit* edit,
@@ -173,14 +173,14 @@ class DBImpl : public DB {
   // Force current memtable contents to be flushed.
   Status FlushMemTable(const FlushOptions& options);
 
-  // Wait for memtable compaction
-  Status WaitForCompactMemTable();
+  // Wait for memtable flushed
+  Status WaitForFlushMemTable();
 
   void MaybeScheduleLogDBDeployStats();
   static void BGLogDBDeployStats(void* db);
   void LogDBDeployStats();
 
-  void MaybeScheduleCompaction();
+  void MaybeScheduleFlushOrCompaction();
   static void BGWorkCompaction(void* db);
   static void BGWorkFlush(void* db);
   void BackgroundCallCompaction();
diff --git a/db/db_test.cc b/db/db_test.cc
index d0dc261469..b59de240b2 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -570,7 +570,7 @@ class DBTest {
     for (int i = 0; i < n; i++) {
       Put(small, "begin");
       Put(large, "end");
-      dbfull()->TEST_CompactMemTable();
+      dbfull()->TEST_FlushMemTable();
     }
   }
 
@@ -739,7 +739,7 @@ TEST(DBTest, GetFromImmutableLayer) {
 TEST(DBTest, GetFromVersions) {
   do {
     ASSERT_OK(Put("foo", "v1"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("v1", Get("foo"));
   } while (ChangeOptions());
 }
@@ -754,7 +754,7 @@ TEST(DBTest, GetSnapshot) {
       ASSERT_OK(Put(key, "v2"));
       ASSERT_EQ("v2", Get(key));
       ASSERT_EQ("v1", Get(key, s1));
-      dbfull()->TEST_CompactMemTable();
+      dbfull()->TEST_FlushMemTable();
       ASSERT_EQ("v2", Get(key));
       ASSERT_EQ("v1", Get(key, s1));
       db_->ReleaseSnapshot(s1);
@@ -770,9 +770,9 @@ TEST(DBTest, GetLevel0Ordering) {
     // one has a smaller "smallest" key.
     ASSERT_OK(Put("bar", "b"));
     ASSERT_OK(Put("foo", "v1"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_OK(Put("foo", "v2"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("v2", Get("foo"));
   } while (ChangeOptions());
 }
@@ -784,7 +784,7 @@ TEST(DBTest, GetOrderedByLevels) {
     ASSERT_EQ("v1", Get("foo"));
     ASSERT_OK(Put("foo", "v2"));
     ASSERT_EQ("v2", Get("foo"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("v2", Get("foo"));
   } while (ChangeOptions());
 }
@@ -822,7 +822,7 @@ TEST(DBTest, GetEncountersEmptyLevel) {
       compaction_count++;
       Put("a", "begin");
       Put("z", "end");
-      dbfull()->TEST_CompactMemTable();
+      dbfull()->TEST_FlushMemTable();
     }
 
     // Step 2: clear level 1 if necessary.
@@ -1668,7 +1668,7 @@ TEST(DBTest, CompactionTrigger) {
       values.push_back(RandomString(&rnd, 10000));
       ASSERT_OK(Put(Key(i), values[i]));
     }
-    dbfull()->TEST_WaitForCompactMemTable();
+    dbfull()->TEST_WaitForFlushMemTable();
     ASSERT_EQ(NumTableFilesAtLevel(0), num + 1);
   }
 
@@ -1706,7 +1706,7 @@ TEST(DBTest, UniversalCompactionTrigger) {
       ASSERT_OK(Put(Key(key_idx), RandomString(&rnd, 10000)));
       key_idx++;
     }
-    dbfull()->TEST_WaitForCompactMemTable();
+    dbfull()->TEST_WaitForFlushMemTable();
     ASSERT_EQ(NumTableFilesAtLevel(0), num + 1);
   }
 
@@ -1741,7 +1741,7 @@ TEST(DBTest, UniversalCompactionTrigger) {
       ASSERT_OK(Put(Key(key_idx), RandomString(&rnd, 10000)));
       key_idx++;
     }
-    dbfull()->TEST_WaitForCompactMemTable();
+    dbfull()->TEST_WaitForFlushMemTable();
     ASSERT_EQ(NumTableFilesAtLevel(0), num + 3);
   }
 
@@ -1770,7 +1770,7 @@ TEST(DBTest, UniversalCompactionTrigger) {
       ASSERT_OK(Put(Key(key_idx), RandomString(&rnd, 10000)));
       key_idx++;
     }
-    dbfull()->TEST_WaitForCompactMemTable();
+    dbfull()->TEST_WaitForFlushMemTable();
     ASSERT_EQ(NumTableFilesAtLevel(0), num + 3);
   }
 
@@ -1840,7 +1840,7 @@ TEST(DBTest, UniversalCompactionSizeAmplification) {
       ASSERT_OK(Put(Key(key_idx), RandomString(&rnd, 10000)));
       key_idx++;
     }
-    dbfull()->TEST_WaitForCompactMemTable();
+    dbfull()->TEST_WaitForFlushMemTable();
     ASSERT_EQ(NumTableFilesAtLevel(0), num + 1);
   }
   ASSERT_EQ(NumTableFilesAtLevel(0), 2);
@@ -1873,7 +1873,7 @@ TEST(DBTest, UniversalCompactionOptions) {
       ASSERT_OK(Put(Key(key_idx), RandomString(&rnd, 10000)));
       key_idx++;
     }
-    dbfull()->TEST_WaitForCompactMemTable();
+    dbfull()->TEST_WaitForFlushMemTable();
 
     if (num < options.level0_file_num_compaction_trigger - 1) {
       ASSERT_EQ(NumTableFilesAtLevel(0), num + 1);
@@ -1994,7 +1994,7 @@ void MinLevelHelper(DBTest* self, Options& options) {
       values.push_back(RandomString(&rnd, 10000));
       ASSERT_OK(self->Put(Key(i), values[i]));
     }
-    self->dbfull()->TEST_WaitForCompactMemTable();
+    self->dbfull()->TEST_WaitForFlushMemTable();
     ASSERT_EQ(self->NumTableFilesAtLevel(0), num + 1);
   }
 
@@ -2219,7 +2219,7 @@ TEST(DBTest, CompactionFilter) {
     snprintf(key, sizeof(key), "B%010d", i);
     Put(key, value);
   }
-  dbfull()->TEST_CompactMemTable();
+  dbfull()->TEST_FlushMemTable();
 
   // Push all files to the highest level L2. Verify that
   // the compaction is each level invokes the filter for
@@ -2267,7 +2267,7 @@ TEST(DBTest, CompactionFilter) {
     snprintf(key, sizeof(key), "B%010d", i);
     Put(key, value);
   }
-  dbfull()->TEST_CompactMemTable();
+  dbfull()->TEST_FlushMemTable();
 
   // push all files to the highest level L2. This
   // means that all keys should pass at least once
@@ -2294,7 +2294,7 @@ TEST(DBTest, CompactionFilter) {
     snprintf(key, sizeof(key), "B%010d", i);
     Put(key, value);
   }
-  dbfull()->TEST_CompactMemTable();
+  dbfull()->TEST_FlushMemTable();
   ASSERT_NE(NumTableFilesAtLevel(0), 0);
   ASSERT_EQ(NumTableFilesAtLevel(1), 0);
   ASSERT_EQ(NumTableFilesAtLevel(2), 0);
@@ -2365,7 +2365,7 @@ TEST(DBTest, CompactionFilterWithValueChange) {
     }
 
     // push all files to  lower levels
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     dbfull()->TEST_CompactRange(0, nullptr, nullptr);
     dbfull()->TEST_CompactRange(1, nullptr, nullptr);
 
@@ -2378,7 +2378,7 @@ TEST(DBTest, CompactionFilterWithValueChange) {
 
     // push all files to  lower levels. This should
     // invoke the compaction filter for all 100000 keys.
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     dbfull()->TEST_CompactRange(0, nullptr, nullptr);
     dbfull()->TEST_CompactRange(1, nullptr, nullptr);
 
@@ -2416,14 +2416,14 @@ TEST(DBTest, SparseMerge) {
       Put(key, value);
     }
     Put("C", "vc");
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     dbfull()->TEST_CompactRange(0, nullptr, nullptr);
 
     // Make sparse update
     Put("A",    "va2");
     Put("B100", "bvalue2");
     Put("C",    "vc2");
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
 
     // Compactions should not cause us to create a situation where
     // a file overlaps too much data at the next level.
@@ -2599,7 +2599,7 @@ TEST(DBTest, HiddenValuesAreRemoved) {
     Put("foo", "tiny");
     Put("pastfoo2", "v2");        // Advance sequence number one more
 
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_GT(NumTableFilesAtLevel(0), 0);
 
     ASSERT_EQ(big, Get("foo", snapshot));
@@ -2634,7 +2634,7 @@ TEST(DBTest, CompactBetweenSnapshots) {
 
     // All entries (including duplicates) exist
     // before any compaction is triggered.
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ("sixth", Get("foo"));
     ASSERT_EQ("fourth", Get("foo", snapshot2));
     ASSERT_EQ("first", Get("foo", snapshot1));
@@ -2673,21 +2673,21 @@ TEST(DBTest, CompactBetweenSnapshots) {
 
 TEST(DBTest, DeletionMarkers1) {
   Put("foo", "v1");
-  ASSERT_OK(dbfull()->TEST_CompactMemTable());
+  ASSERT_OK(dbfull()->TEST_FlushMemTable());
   const int last = dbfull()->MaxMemCompactionLevel();
   ASSERT_EQ(NumTableFilesAtLevel(last), 1);   // foo => v1 is now in last level
 
   // Place a table at level last-1 to prevent merging with preceding mutation
   Put("a", "begin");
   Put("z", "end");
-  dbfull()->TEST_CompactMemTable();
+  dbfull()->TEST_FlushMemTable();
   ASSERT_EQ(NumTableFilesAtLevel(last), 1);
   ASSERT_EQ(NumTableFilesAtLevel(last-1), 1);
 
   Delete("foo");
   Put("foo", "v2");
   ASSERT_EQ(AllEntriesFor("foo"), "[ v2, DEL, v1 ]");
-  ASSERT_OK(dbfull()->TEST_CompactMemTable());  // Moves to level last-2
+  ASSERT_OK(dbfull()->TEST_FlushMemTable());  // Moves to level last-2
   if (CurrentOptions().purge_redundant_kvs_while_flush) {
     ASSERT_EQ(AllEntriesFor("foo"), "[ v2, v1 ]");
   } else {
@@ -2706,20 +2706,20 @@ TEST(DBTest, DeletionMarkers1) {
 
 TEST(DBTest, DeletionMarkers2) {
   Put("foo", "v1");
-  ASSERT_OK(dbfull()->TEST_CompactMemTable());
+  ASSERT_OK(dbfull()->TEST_FlushMemTable());
   const int last = dbfull()->MaxMemCompactionLevel();
   ASSERT_EQ(NumTableFilesAtLevel(last), 1);   // foo => v1 is now in last level
 
   // Place a table at level last-1 to prevent merging with preceding mutation
   Put("a", "begin");
   Put("z", "end");
-  dbfull()->TEST_CompactMemTable();
+  dbfull()->TEST_FlushMemTable();
   ASSERT_EQ(NumTableFilesAtLevel(last), 1);
   ASSERT_EQ(NumTableFilesAtLevel(last-1), 1);
 
   Delete("foo");
   ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v1 ]");
-  ASSERT_OK(dbfull()->TEST_CompactMemTable());  // Moves to level last-2
+  ASSERT_OK(dbfull()->TEST_FlushMemTable());  // Moves to level last-2
   ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v1 ]");
   dbfull()->TEST_CompactRange(last-2, nullptr, nullptr);
   // DEL kept: "last" file overlaps
@@ -2738,10 +2738,10 @@ TEST(DBTest, OverlapInLevel0) {
     //Fill levels 1 and 2 to disable the pushing of new memtables to levels > 0.
     ASSERT_OK(Put("100", "v100"));
     ASSERT_OK(Put("999", "v999"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_OK(Delete("100"));
     ASSERT_OK(Delete("999"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("0,1,1", FilesPerLevel());
 
     // Make files spanning the following ranges in level-0:
@@ -2750,11 +2750,11 @@ TEST(DBTest, OverlapInLevel0) {
     // Note that files are sorted by smallest key.
     ASSERT_OK(Put("300", "v300"));
     ASSERT_OK(Put("500", "v500"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_OK(Put("200", "v200"));
     ASSERT_OK(Put("600", "v600"));
     ASSERT_OK(Put("900", "v900"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("2,1,1", FilesPerLevel());
 
     // Compact away the placeholder files we created initially
@@ -2766,7 +2766,7 @@ TEST(DBTest, OverlapInLevel0) {
     // not detect the overlap with level-0 files and would incorrectly place
     // the deletion in a deeper level.
     ASSERT_OK(Delete("600"));
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("3", FilesPerLevel());
     ASSERT_EQ("NOT_FOUND", Get("600"));
   } while (ChangeOptions(kSkipUniversalCompaction));
@@ -3104,7 +3104,7 @@ TEST(DBTest, ManifestWriteError) {
     ASSERT_EQ("bar", Get("foo"));
 
     // Memtable compaction (will succeed)
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     ASSERT_EQ("bar", Get("foo"));
     const int last = dbfull()->MaxMemCompactionLevel();
     ASSERT_EQ(NumTableFilesAtLevel(last), 1);   // foo=>bar is now in last level
@@ -3152,7 +3152,7 @@ TEST(DBTest, BloomFilter) {
     for (int i = 0; i < N; i += 100) {
       ASSERT_OK(Put(Key(i), Key(i)));
     }
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
 
     // Prevent auto compactions triggered by seeks
     env_->delay_sstable_sync_.Release_Store(env_);
@@ -3322,13 +3322,13 @@ TEST(DBTest, CompactOnFlush) {
     Reopen(&options);
 
     Put("foo", "v1");
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ v1 ]");
 
     // Write two new keys
     Put("a", "begin");
     Put("z", "end");
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
 
     // Case1: Delete followed by a put
     Delete("foo");
@@ -3337,7 +3337,7 @@ TEST(DBTest, CompactOnFlush) {
 
     // After the current memtable is flushed, the DEL should
     // have been removed
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ v2, v1 ]");
 
     dbfull()->CompactRange(nullptr, nullptr);
@@ -3347,7 +3347,7 @@ TEST(DBTest, CompactOnFlush) {
     Delete("foo");
     Delete("foo");
     ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, DEL, v2 ]");
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v2 ]");
     dbfull()->CompactRange(nullptr, nullptr);
     ASSERT_EQ(AllEntriesFor("foo"), "[ ]");
@@ -3356,7 +3356,7 @@ TEST(DBTest, CompactOnFlush) {
     Put("foo", "v3");
     Delete("foo");
     ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v3 ]");
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ DEL ]");
     dbfull()->CompactRange(nullptr, nullptr);
     ASSERT_EQ(AllEntriesFor("foo"), "[ ]");
@@ -3365,7 +3365,7 @@ TEST(DBTest, CompactOnFlush) {
     Put("foo", "v4");
     Put("foo", "v5");
     ASSERT_EQ(AllEntriesFor("foo"), "[ v5, v4 ]");
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ v5 ]");
     dbfull()->CompactRange(nullptr, nullptr);
     ASSERT_EQ(AllEntriesFor("foo"), "[ v5 ]");
@@ -3380,7 +3380,7 @@ TEST(DBTest, CompactOnFlush) {
     Put("foo", "v6");
     const Snapshot* snapshot = db_->GetSnapshot();
     Put("foo", "v7");
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ v7, v6 ]");
     db_->ReleaseSnapshot(snapshot);
 
@@ -3394,7 +3394,7 @@ TEST(DBTest, CompactOnFlush) {
     const Snapshot* snapshot1 = db_->GetSnapshot();
     Put("foo", "v8");
     Put("foo", "v9");
-    ASSERT_OK(dbfull()->TEST_CompactMemTable());
+    ASSERT_OK(dbfull()->TEST_FlushMemTable());
     ASSERT_EQ(AllEntriesFor("foo"), "[ v9 ]");
     db_->ReleaseSnapshot(snapshot1);
   } while (ChangeCompactOptions());
@@ -3662,7 +3662,7 @@ TEST(DBTest, ReadCompaction) {
     }
 
     // clear level 0 and 1 if necessary.
-    dbfull()->TEST_CompactMemTable();
+    dbfull()->TEST_FlushMemTable();
     dbfull()->TEST_CompactRange(0, nullptr, nullptr);
     dbfull()->TEST_CompactRange(1, nullptr, nullptr);
     ASSERT_EQ(NumTableFilesAtLevel(0), 0);
@@ -4186,7 +4186,7 @@ void PrefixScanInit(DBTest *dbtest) {
   snprintf(buf, sizeof(buf), "%02d______:end", 10);
   keystr = std::string(buf);
   ASSERT_OK(dbtest->Put(keystr, keystr));
-  dbtest->dbfull()->TEST_CompactMemTable();
+  dbtest->dbfull()->TEST_FlushMemTable();
   dbtest->dbfull()->CompactRange(nullptr, nullptr); // move to level 1
 
   // GROUP 1
@@ -4197,7 +4197,7 @@ void PrefixScanInit(DBTest *dbtest) {
     snprintf(buf, sizeof(buf), "%02d______:end", i+1);
     keystr = std::string(buf);
     ASSERT_OK(dbtest->Put(keystr, keystr));
-    dbtest->dbfull()->TEST_CompactMemTable();
+    dbtest->dbfull()->TEST_FlushMemTable();
   }
 
   // GROUP 2
@@ -4210,7 +4210,7 @@ void PrefixScanInit(DBTest *dbtest) {
              small_range_sstfiles+i+1);
     keystr = std::string(buf);
     ASSERT_OK(dbtest->Put(keystr, keystr));
-    dbtest->dbfull()->TEST_CompactMemTable();
+    dbtest->dbfull()->TEST_FlushMemTable();
   }
 }
 
diff --git a/db/deletefile_test.cc b/db/deletefile_test.cc
index 3c4c459b46..78a55febb8 100644
--- a/db/deletefile_test.cc
+++ b/db/deletefile_test.cc
@@ -92,12 +92,12 @@ class DeleteFileTest {
   void CreateTwoLevels() {
     AddKeys(50000, 10000);
     DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
-    ASSERT_OK(dbi->TEST_CompactMemTable());
-    ASSERT_OK(dbi->TEST_WaitForCompactMemTable());
+    ASSERT_OK(dbi->TEST_FlushMemTable());
+    ASSERT_OK(dbi->TEST_WaitForFlushMemTable());
 
     AddKeys(50000, 10000);
-    ASSERT_OK(dbi->TEST_CompactMemTable());
-    ASSERT_OK(dbi->TEST_WaitForCompactMemTable());
+    ASSERT_OK(dbi->TEST_FlushMemTable());
+    ASSERT_OK(dbi->TEST_WaitForFlushMemTable());
   }
 
 };
diff --git a/helpers/memenv/memenv_test.cc b/helpers/memenv/memenv_test.cc
index 7cdc2bbeba..19fc8ff2a8 100644
--- a/helpers/memenv/memenv_test.cc
+++ b/helpers/memenv/memenv_test.cc
@@ -215,7 +215,7 @@ TEST(MemEnvTest, DBTest) {
   delete iterator;
 
   DBImpl* dbi = reinterpret_cast<DBImpl*>(db);
-  ASSERT_OK(dbi->TEST_CompactMemTable());
+  ASSERT_OK(dbi->TEST_FlushMemTable());
 
   for (size_t i = 0; i < 3; ++i) {
     std::string res;
diff --git a/tools/reduce_levels_test.cc b/tools/reduce_levels_test.cc
index 154e7929c3..0b504c3ca5 100644
--- a/tools/reduce_levels_test.cc
+++ b/tools/reduce_levels_test.cc
@@ -45,7 +45,7 @@ public:
       return Status::InvalidArgument("DB not opened.");
     }
     DBImpl* db_impl = reinterpret_cast<DBImpl*>(db_);
-    return db_impl->TEST_CompactMemTable();
+    return db_impl->TEST_FlushMemTable();
   }
 
   void CloseDB() {