diff --git a/db/builder.cc b/db/builder.cc
index bd695f1dd..065bbaf47 100644
--- a/db/builder.cc
+++ b/db/builder.cc
@@ -43,11 +43,12 @@ TableBuilder* NewTableBuilder(
         int_tbl_prop_collector_factories,
     uint32_t column_family_id, WritableFileWriter* file,
     const CompressionType compression_type,
-    const CompressionOptions& compression_opts, const bool skip_filters) {
+    const CompressionOptions& compression_opts, 
+    const bool skip_filters, const bool skip_flush) {
   return ioptions.table_factory->NewTableBuilder(
       TableBuilderOptions(ioptions, internal_comparator,
                           int_tbl_prop_collector_factories, compression_type,
-                          compression_opts, skip_filters),
+                          compression_opts, skip_filters, skip_flush),
       column_family_id, file);
 }
 
@@ -86,7 +87,8 @@ Status BuildTable(
 
       builder = NewTableBuilder(
           ioptions, internal_comparator, int_tbl_prop_collector_factories,
-          column_family_id, file_writer.get(), compression, compression_opts);
+          column_family_id, file_writer.get(), compression, compression_opts,
+          false, env_options.skip_table_builder_flush);
     }
 
     MergeHelper merge(env, internal_comparator.user_comparator(),
diff --git a/db/builder.h b/db/builder.h
index cdafa4ab3..cf32f4b62 100644
--- a/db/builder.h
+++ b/db/builder.h
@@ -41,7 +41,8 @@ TableBuilder* NewTableBuilder(
     uint32_t column_family_id, WritableFileWriter* file,
     const CompressionType compression_type,
     const CompressionOptions& compression_opts,
-    const bool skip_filters = false);
+    const bool skip_filters = false,
+    const bool skip_flush = false);
 
 // Build a Table file from the contents of *iter.  The generated file
 // will be named according to number specified in meta. On success, the rest of
diff --git a/db/compaction_job.cc b/db/compaction_job.cc
index ea052b84f..0028acacb 100644
--- a/db/compaction_job.cc
+++ b/db/compaction_job.cc
@@ -939,11 +939,12 @@ Status CompactionJob::OpenCompactionOutputFile(
   // data is going to be found
   bool skip_filters =
       cfd->ioptions()->optimize_filters_for_hits && bottommost_level_;
+  bool skip_flush = db_options_.skip_table_builder_flush;
   sub_compact->builder.reset(NewTableBuilder(
       *cfd->ioptions(), cfd->internal_comparator(),
       cfd->int_tbl_prop_collector_factories(), cfd->GetID(),
       sub_compact->outfile.get(), sub_compact->compaction->output_compression(),
-      cfd->ioptions()->compression_opts, skip_filters));
+      cfd->ioptions()->compression_opts, skip_filters, skip_flush));
   LogFlush(db_options_.info_log);
   return s;
 }
diff --git a/db/db_bench.cc b/db/db_bench.cc
index e3edc8396..0074056e3 100644
--- a/db/db_bench.cc
+++ b/db/db_bench.cc
@@ -376,6 +376,12 @@ DEFINE_int32(compaction_readahead_size, 0, "Compaction readahead size");
 DEFINE_int32(random_access_max_buffer_size, 1024 * 1024,
              "Maximum windows randomaccess buffer size");
 
+DEFINE_int32(writable_file_max_buffer_size, 1024 * 1024, 
+             "Maximum write buffer for Writeable File");
+
+DEFINE_int32(skip_table_builder_flush, false, "Skip flushing block in "
+             "table builder ");
+
 DEFINE_int32(bloom_bits, -1, "Bloom filter bits per key. Negative means"
              " use default settings.");
 DEFINE_int32(memtable_bloom_bits, 0, "Bloom filter bits per key for memtable. "
@@ -2299,6 +2305,8 @@ class Benchmark {
         FLAGS_new_table_reader_for_compaction_inputs;
     options.compaction_readahead_size = FLAGS_compaction_readahead_size;
     options.random_access_max_buffer_size = FLAGS_random_access_max_buffer_size;
+    options.writable_file_max_buffer_size = FLAGS_writable_file_max_buffer_size;
+    options.skip_table_builder_flush = FLAGS_skip_table_builder_flush;
     options.statistics = dbstats;
     if (FLAGS_enable_io_prio) {
       FLAGS_env->LowerThreadPoolIOPriority(Env::LOW);
diff --git a/include/rocksdb/env.h b/include/rocksdb/env.h
index 9e20a15aa..5f8e8c79c 100644
--- a/include/rocksdb/env.h
+++ b/include/rocksdb/env.h
@@ -94,6 +94,12 @@ struct EnvOptions {
   // See DBOPtions doc
   size_t random_access_max_buffer_size;
 
+  // See DBOptions doc
+  size_t writable_file_max_buffer_size = 1024 * 1024;
+
+  // See DBOptions doc
+  bool skip_table_builder_flush = false;
+
   // If not nullptr, write rate limiting is enabled for flush and compaction
   RateLimiter* rate_limiter = nullptr;
 };
diff --git a/include/rocksdb/options.h b/include/rocksdb/options.h
index acd0016ac..036e08cb7 100644
--- a/include/rocksdb/options.h
+++ b/include/rocksdb/options.h
@@ -1089,6 +1089,27 @@ struct DBOptions {
   // Default: 1 Mb
   size_t random_access_max_buffer_size;
 
+  // This is the maximum buffer size that is used by WritableFileWriter.
+  // On Windows, we need to maintain an aligned buffer for writes. 
+  // We allow the buffer to grow until it's size hits the limit. 
+  //
+  // Default: 1024 * 1024 (1 MB)
+  size_t writable_file_max_buffer_size;
+
+  // If true, block will not be explictly flushed to disk during building
+  // a SstTable. Instead, buffer in WritableFileWriter will take 
+  // care of the flushing when it is full. 
+  //
+  // On Windows, this option helps a lot when unbuffered I/O 
+  // (allow_os_buffer = false) is used, since it avoids small 
+  // unbuffered disk write. 
+  //
+  // User may also adjust writable_file_max_buffer_size to optimize disk I/O 
+  // size. 
+  //
+  // Default: false
+  bool skip_table_builder_flush;
+
   // Use adaptive mutex, which spins in the user space before resorting
   // to kernel. This could reduce context switch when the mutex is not
   // heavily contended. However, if the mutex is hot, we could end up
diff --git a/table/block_based_table_builder.cc b/table/block_based_table_builder.cc
index 402528a52..addbe1c94 100644
--- a/table/block_based_table_builder.cc
+++ b/table/block_based_table_builder.cc
@@ -465,6 +465,7 @@ struct BlockBasedTableBuilder::Rep {
   BlockHandle pending_handle;  // Handle to add to index block
 
   std::string compressed_output;
+  bool skip_flush;
   std::unique_ptr<FlushBlockPolicy> flush_block_policy;
 
   std::vector<std::unique_ptr<IntTblPropCollector>> table_properties_collectors;
@@ -476,7 +477,8 @@ struct BlockBasedTableBuilder::Rep {
           int_tbl_prop_collector_factories,
       uint32_t column_family_id, WritableFileWriter* f,
       const CompressionType _compression_type,
-      const CompressionOptions& _compression_opts, const bool skip_filters)
+      const CompressionOptions& _compression_opts, 
+      const bool skip_filters, const bool skip_flush)
       : ioptions(_ioptions),
         table_options(table_opt),
         internal_comparator(icomparator),
@@ -490,6 +492,7 @@ struct BlockBasedTableBuilder::Rep {
         compression_opts(_compression_opts),
         filter_block(skip_filters ? nullptr : CreateFilterBlockBuilder(
                                                   _ioptions, table_options)),
+        skip_flush(skip_flush),
         flush_block_policy(
             table_options.flush_block_policy_factory->NewFlushBlockPolicy(
                 table_options, data_block)) {
@@ -512,7 +515,8 @@ BlockBasedTableBuilder::BlockBasedTableBuilder(
         int_tbl_prop_collector_factories,
     uint32_t column_family_id, WritableFileWriter* file,
     const CompressionType compression_type,
-    const CompressionOptions& compression_opts, const bool skip_filters) {
+    const CompressionOptions& compression_opts,
+    const bool skip_filters, const bool skip_flush) {
   BlockBasedTableOptions sanitized_table_options(table_options);
   if (sanitized_table_options.format_version == 0 &&
       sanitized_table_options.checksum != kCRC32c) {
@@ -526,7 +530,7 @@ BlockBasedTableBuilder::BlockBasedTableBuilder(
 
   rep_ = new Rep(ioptions, sanitized_table_options, internal_comparator,
                  int_tbl_prop_collector_factories, column_family_id, file,
-                 compression_type, compression_opts, skip_filters);
+                 compression_type, compression_opts, skip_filters, skip_flush);
 
   if (rep_->filter_block != nullptr) {
     rep_->filter_block->StartBlock(0);
@@ -552,11 +556,12 @@ void BlockBasedTableBuilder::Add(const Slice& key, const Slice& value) {
     assert(r->internal_comparator.Compare(key, Slice(r->last_key)) > 0);
   }
 
-  auto should_flush = r->flush_block_policy->Update(key, value);
-  if (should_flush) {
+  auto should_seal = r->flush_block_policy->Update(key, value);
+  if (should_seal) {
     assert(!r->data_block.empty());
+    SealDataBlock();
     Flush();
-
+    
     // Add item to index block.
     // We do not emit the index entry for a block until we have seen the
     // first key for the next data block.  This allows us to use shorter
@@ -587,19 +592,23 @@ void BlockBasedTableBuilder::Add(const Slice& key, const Slice& value) {
 }
 
 void BlockBasedTableBuilder::Flush() {
+  Rep* r = rep_;
+  if (ok() && !r->skip_flush) {
+    r->status = r->file->Flush();
+  }
+}
+
+void BlockBasedTableBuilder::SealDataBlock() {
   Rep* r = rep_;
   assert(!r->closed);
   if (!ok()) return;
   if (r->data_block.empty()) return;
   WriteBlock(&r->data_block, &r->pending_handle);
-  if (ok()) {
-    r->status = r->file->Flush();
-  }
   if (r->filter_block != nullptr) {
     r->filter_block->StartBlock(r->offset);
   }
   r->props.data_size = r->offset;
-  ++r->props.num_data_blocks;
+  ++r->props.num_data_blocks; 
 }
 
 void BlockBasedTableBuilder::WriteBlock(BlockBuilder* block,
@@ -728,6 +737,7 @@ Status BlockBasedTableBuilder::InsertBlockInCache(const Slice& block_contents,
 Status BlockBasedTableBuilder::Finish() {
   Rep* r = rep_;
   bool empty_data_block = r->data_block.empty();
+  SealDataBlock();
   Flush();
   assert(!r->closed);
   r->closed = true;
diff --git a/table/block_based_table_builder.h b/table/block_based_table_builder.h
index 7dc93b754..2a40c4984 100644
--- a/table/block_based_table_builder.h
+++ b/table/block_based_table_builder.h
@@ -42,7 +42,8 @@ class BlockBasedTableBuilder : public TableBuilder {
           int_tbl_prop_collector_factories,
       uint32_t column_family_id, WritableFileWriter* file,
       const CompressionType compression_type,
-      const CompressionOptions& compression_opts, const bool skip_filters);
+      const CompressionOptions& compression_opts, 
+      const bool skip_filters, const bool skip_flush);
 
   // REQUIRES: Either Finish() or Abandon() has been called.
   ~BlockBasedTableBuilder();
@@ -101,6 +102,8 @@ class BlockBasedTableBuilder : public TableBuilder {
   // REQUIRES: Finish(), Abandon() have not been called
   void Flush();
 
+  void SealDataBlock();
+
   // Some compression libraries fail when the raw size is bigger than int. If
   // uncompressed size is bigger than kCompressionSizeLimit, don't compress it
   const uint64_t kCompressionSizeLimit = std::numeric_limits<int>::max();
diff --git a/table/block_based_table_factory.cc b/table/block_based_table_factory.cc
index 1631652dd..f95aa8f66 100644
--- a/table/block_based_table_factory.cc
+++ b/table/block_based_table_factory.cc
@@ -69,7 +69,8 @@ TableBuilder* BlockBasedTableFactory::NewTableBuilder(
       table_builder_options.int_tbl_prop_collector_factories, column_family_id,
       file, table_builder_options.compression_type,
       table_builder_options.compression_opts,
-      table_builder_options.skip_filters);
+      table_builder_options.skip_filters,
+      table_builder_options.skip_flush);
 
   return table_builder;
 }
diff --git a/table/sst_file_writer.cc b/table/sst_file_writer.cc
index 1c21a25f7..3dca61474 100644
--- a/table/sst_file_writer.cc
+++ b/table/sst_file_writer.cc
@@ -114,7 +114,8 @@ Status SstFileWriter::Open(const std::string& file_path) {
 
   TableBuilderOptions table_builder_options(
       r->ioptions, r->internal_comparator, &int_tbl_prop_collector_factories,
-      compression_type, r->ioptions.compression_opts, false);
+      compression_type, r->ioptions.compression_opts, false, 
+      r->env_options.skip_table_builder_flush);
   r->file_writer.reset(
       new WritableFileWriter(std::move(sst_file), r->env_options));
   r->builder.reset(r->ioptions.table_factory->NewTableBuilder(
diff --git a/table/table_builder.h b/table/table_builder.h
index 55a1077fa..32d0b0718 100644
--- a/table/table_builder.h
+++ b/table/table_builder.h
@@ -44,13 +44,15 @@ struct TableBuilderOptions {
       const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
           _int_tbl_prop_collector_factories,
       CompressionType _compression_type,
-      const CompressionOptions& _compression_opts, bool _skip_filters)
+      const CompressionOptions& _compression_opts, 
+      bool _skip_filters, bool _skip_flush)
       : ioptions(_ioptions),
         internal_comparator(_internal_comparator),
         int_tbl_prop_collector_factories(_int_tbl_prop_collector_factories),
         compression_type(_compression_type),
         compression_opts(_compression_opts),
-        skip_filters(_skip_filters) {}
+        skip_filters(_skip_filters),
+        skip_flush(_skip_flush) {}
   const ImmutableCFOptions& ioptions;
   const InternalKeyComparator& internal_comparator;
   const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
@@ -58,6 +60,7 @@ struct TableBuilderOptions {
   CompressionType compression_type;
   const CompressionOptions& compression_opts;
   bool skip_filters = false;
+  bool skip_flush = false;
 };
 
 // TableBuilder provides the interface used to build a Table
diff --git a/table/table_reader_bench.cc b/table/table_reader_bench.cc
index c4106e4b3..378dd410e 100644
--- a/table/table_reader_bench.cc
+++ b/table/table_reader_bench.cc
@@ -98,7 +98,8 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
     tb = opts.table_factory->NewTableBuilder(
         TableBuilderOptions(ioptions, ikc, &int_tbl_prop_collector_factories,
                             CompressionType::kNoCompression,
-                            CompressionOptions(), false),
+                            CompressionOptions(), false, 
+                            env_options.skip_table_builder_flush),
         0, file_writer.get());
   } else {
     s = DB::Open(opts, dbname, &db);
diff --git a/table/table_test.cc b/table/table_test.cc
index 58607bbb2..d19554b65 100644
--- a/table/table_test.cc
+++ b/table/table_test.cc
@@ -273,7 +273,8 @@ class TableConstructor: public Constructor {
     builder.reset(ioptions.table_factory->NewTableBuilder(
         TableBuilderOptions(ioptions, internal_comparator,
                             &int_tbl_prop_collector_factories,
-                            options.compression, CompressionOptions(), false),
+                            options.compression, CompressionOptions(), 
+                            false, options.skip_table_builder_flush),
         TablePropertiesCollectorFactory::Context::kUnknownColumnFamily,
         file_writer_.get()));
 
@@ -1845,7 +1846,8 @@ TEST_F(PlainTableTest, BasicPlainTableProperties) {
       int_tbl_prop_collector_factories;
   std::unique_ptr<TableBuilder> builder(factory.NewTableBuilder(
       TableBuilderOptions(ioptions, ikc, &int_tbl_prop_collector_factories,
-                          kNoCompression, CompressionOptions(), false),
+                          kNoCompression, CompressionOptions(),
+                          false, options.skip_table_builder_flush),
       TablePropertiesCollectorFactory::Context::kUnknownColumnFamily,
       file_writer.get()));
 
diff --git a/tools/sst_dump_test.cc b/tools/sst_dump_test.cc
index b40a3346c..dce863ff0 100644
--- a/tools/sst_dump_test.cc
+++ b/tools/sst_dump_test.cc
@@ -61,7 +61,7 @@ void createSST(const std::string& file_name,
   tb.reset(opts.table_factory->NewTableBuilder(
       TableBuilderOptions(imoptions, ikc, &int_tbl_prop_collector_factories,
                           CompressionType::kNoCompression, CompressionOptions(),
-                          false),
+                          false, env_options.skip_table_builder_flush),
       TablePropertiesCollectorFactory::Context::kUnknownColumnFamily,
       file_writer.get()));
 
diff --git a/tools/sst_dump_tool.cc b/tools/sst_dump_tool.cc
index ae22da36d..b7abbcd98 100644
--- a/tools/sst_dump_tool.cc
+++ b/tools/sst_dump_tool.cc
@@ -177,7 +177,7 @@ int SstFileReader::ShowAllCompressionSizes(size_t block_size) {
                                     : CompressionType(i + 1)) {
     CompressionOptions compress_opt;
     TableBuilderOptions tb_opts(imoptions, ikc, &block_based_table_factories, i,
-                                compress_opt, false);
+                                compress_opt, false, false);
     uint64_t file_size = CalculateCompressedTableSize(tb_opts, block_size);
     fprintf(stdout, "Compression: %s", compress_type.find(i)->second);
     fprintf(stdout, " Size: %" PRIu64 "\n", file_size);
diff --git a/util/env.cc b/util/env.cc
index f6cc40893..1f4b9c2a3 100644
--- a/util/env.cc
+++ b/util/env.cc
@@ -296,6 +296,9 @@ void AssignEnvOptions(EnvOptions* env_options, const DBOptions& options) {
   env_options->random_access_max_buffer_size =
       options.random_access_max_buffer_size;
   env_options->rate_limiter = options.rate_limiter.get();
+  env_options->writable_file_max_buffer_size = 
+                  options.writable_file_max_buffer_size;
+  env_options->skip_table_builder_flush = options.skip_table_builder_flush;
   env_options->allow_fallocate = options.allow_fallocate;
 }
 
diff --git a/util/file_reader_writer.cc b/util/file_reader_writer.cc
index 050473bd2..f5c178896 100644
--- a/util/file_reader_writer.cc
+++ b/util/file_reader_writer.cc
@@ -21,10 +21,6 @@
 
 namespace rocksdb {
 
-namespace {
-  const size_t c_OneMb = (1 << 20);
-}
-
 Status SequentialFileReader::Read(size_t n, Slice* result, char* scratch) {
   Status s = file_->Read(n, result, scratch);
   IOSTATS_ADD(bytes_read, result->size());
@@ -76,9 +72,9 @@ Status WritableFileWriter::Append(const Slice& data) {
       }
     }
 
-    if (buf_.Capacity() < c_OneMb) {
+    if (buf_.Capacity() < max_buffer_size_) {
       size_t desiredCapacity = buf_.Capacity() * 2;
-      desiredCapacity = std::min(desiredCapacity, c_OneMb);
+      desiredCapacity = std::min(desiredCapacity, max_buffer_size_);
       buf_.AllocateNewBuffer(desiredCapacity);
     }
     assert(buf_.CurrentSize() == 0);
@@ -102,9 +98,9 @@ Status WritableFileWriter::Append(const Slice& data) {
         // We double the buffer here because
         // Flush calls do not keep up with the incoming bytes
         // This is the only place when buffer is changed with unbuffered I/O
-        if (buf_.Capacity() < c_OneMb) {
+        if (buf_.Capacity() < max_buffer_size_) {
           size_t desiredCapacity = buf_.Capacity() * 2;
-          desiredCapacity = std::min(desiredCapacity, c_OneMb);
+          desiredCapacity = std::min(desiredCapacity, max_buffer_size_);
           buf_.AllocateNewBuffer(desiredCapacity);
         }
       }
@@ -156,7 +152,6 @@ Status WritableFileWriter::Close() {
   return s;
 }
 
-
 // write out the cached data to the OS cache
 Status WritableFileWriter::Flush() {
   Status s;
diff --git a/util/file_reader_writer.h b/util/file_reader_writer.h
index 9a076af56..720979099 100644
--- a/util/file_reader_writer.h
+++ b/util/file_reader_writer.h
@@ -93,6 +93,7 @@ class WritableFileWriter {
  private:
   std::unique_ptr<WritableFile> writable_file_;
   AlignedBuffer           buf_;
+  size_t                  max_buffer_size_;
   // Actually written data size can be used for truncate
   // not counting padding data
   uint64_t                filesize_;
@@ -113,6 +114,7 @@ class WritableFileWriter {
                      const EnvOptions& options)
       : writable_file_(std::move(file)),
         buf_(),
+        max_buffer_size_(options.writable_file_max_buffer_size),
         filesize_(0),
         next_write_offset_(0),
         pending_sync_(false),
diff --git a/util/options.cc b/util/options.cc
index 126aa2121..026f8d812 100644
--- a/util/options.cc
+++ b/util/options.cc
@@ -251,6 +251,8 @@ DBOptions::DBOptions()
       new_table_reader_for_compaction_inputs(false),
       compaction_readahead_size(0),
       random_access_max_buffer_size(1024 * 1024),
+      writable_file_max_buffer_size(1024 * 1024),
+      skip_table_builder_flush(false),
       use_adaptive_mutex(false),
       bytes_per_sync(0),
       wal_bytes_per_sync(0),
@@ -313,6 +315,8 @@ DBOptions::DBOptions(const Options& options)
           options.new_table_reader_for_compaction_inputs),
       compaction_readahead_size(options.compaction_readahead_size),
       random_access_max_buffer_size(options.random_access_max_buffer_size),
+      writable_file_max_buffer_size(options.writable_file_max_buffer_size),
+      skip_table_builder_flush(options.skip_table_builder_flush),
       use_adaptive_mutex(options.use_adaptive_mutex),
       bytes_per_sync(options.bytes_per_sync),
       wal_bytes_per_sync(options.wal_bytes_per_sync),
@@ -412,6 +416,13 @@ void DBOptions::Dump(Logger* log) const {
         "               Options.random_access_max_buffer_size: %" ROCKSDB_PRIszt
         "d",
         random_access_max_buffer_size);
+    Header(log,
+         "              Options.writable_file_max_buffer_size: %" ROCKSDB_PRIszt
+         "d",
+         writable_file_max_buffer_size);
+    Header(log,
+         "              Options.skip_table_builder_flush: %d",
+         skip_table_builder_flush);
     Header(log, "                      Options.use_adaptive_mutex: %d",
         use_adaptive_mutex);
     Header(log, "                            Options.rate_limiter: %p",
diff --git a/util/options_helper.h b/util/options_helper.h
index 6df914241..169de4e74 100644
--- a/util/options_helper.h
+++ b/util/options_helper.h
@@ -183,6 +183,12 @@ static std::unordered_map<std::string, OptionTypeInfo> db_options_type_info = {
     {"random_access_max_buffer_size",
      {offsetof(struct DBOptions, random_access_max_buffer_size),
       OptionType::kSizeT, OptionVerificationType::kNormal}},
+    {"writable_file_max_buffer_size",
+     {offsetof(struct DBOptions, writable_file_max_buffer_size),  
+      OptionType::kSizeT, OptionVerificationType::kNormal}},
+    {"skip_table_builder_flush",
+     {offsetof(struct DBOptions, skip_table_builder_flush),  
+      OptionType::kBoolean, OptionVerificationType::kNormal}},
     {"use_adaptive_mutex",
      {offsetof(struct DBOptions, use_adaptive_mutex), OptionType::kBoolean,
       OptionVerificationType::kNormal}},
diff --git a/util/options_test.cc b/util/options_test.cc
index 0f2bbf8b3..ac4a63582 100644
--- a/util/options_test.cc
+++ b/util/options_test.cc
@@ -340,6 +340,8 @@ TEST_F(OptionsTest, GetOptionsFromMapTest) {
       {"new_table_reader_for_compaction_inputs", "true"},
       {"compaction_readahead_size", "100"},
       {"random_access_max_buffer_size", "3145728"},
+      {"writable_file_max_buffer_size", "314159"},
+      {"skip_table_builder_flush", "true"},
       {"bytes_per_sync", "47"},
       {"wal_bytes_per_sync", "48"},
   };
@@ -451,6 +453,8 @@ TEST_F(OptionsTest, GetOptionsFromMapTest) {
   ASSERT_EQ(new_db_opt.new_table_reader_for_compaction_inputs, true);
   ASSERT_EQ(new_db_opt.compaction_readahead_size, 100);
   ASSERT_EQ(new_db_opt.random_access_max_buffer_size, 3145728);
+  ASSERT_EQ(new_db_opt.writable_file_max_buffer_size, 314159);
+  ASSERT_EQ(new_db_opt.skip_table_builder_flush, true);
   ASSERT_EQ(new_db_opt.bytes_per_sync, static_cast<uint64_t>(47));
   ASSERT_EQ(new_db_opt.wal_bytes_per_sync, static_cast<uint64_t>(48));
 }