Skip bottom-level filter block caching when hit-optimized

Summary:
When Get() or NewIterator() trigger file loads, skip caching the filter block if
(1) optimize_filters_for_hits is set and (2) the file is on the bottommost
level. Also skip checking filters under the same conditions, which means that
for a preloaded file or a file that was trivially-moved to the bottom level, its
filter block will eventually expire from the cache.

- added parameters/instance variables in various places in order to propagate the config ("skip_filters") from version_set to block_based_table_reader
- in BlockBasedTable::Rep, this optimization prevents filter from being loaded when the file is opened simply by setting filter_policy = nullptr
- in BlockBasedTable::Get/BlockBasedTable::NewIterator, this optimization prevents filter from being used (even if it was loaded already) by setting filter = nullptr

Test Plan:
updated unit test:

  $ ./db_test --gtest_filter=DBTest.OptimizeFiltersForHits

will also run 'make check'

Reviewers: sdong, igor, paultuckfield, anthony, rven, kradhakrishnan, IslamAbdelRahman, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D51633

db/db_test.cc

@@ -7986,6 +7986,7 @@ TEST_F(DBTest, OptimizeFiltersForHits) {
   options.compaction_style = kCompactionStyleLevel;
   options.level_compaction_dynamic_level_bytes = true;
   BlockBasedTableOptions bbto;
+  bbto.cache_index_and_filter_blocks = true;
   bbto.filter_policy.reset(NewBloomFilterPolicy(10, true));
   bbto.whole_key_filtering = true;
   options.table_factory.reset(NewBlockBasedTableFactory(bbto));
@@ -8034,13 +8035,118 @@ TEST_F(DBTest, OptimizeFiltersForHits) {
   ASSERT_EQ(0, TestGetTickerCount(options, GET_HIT_L2_AND_UP));
 
   // Now we have three sorted run, L0, L5 and L6 with most files in L6 have
-  // no blooom filter. Most keys be checked bloom filters twice.
+  // no bloom filter. Most keys be checked bloom filters twice.
   ASSERT_GT(TestGetTickerCount(options, BLOOM_FILTER_USEFUL), 65000 * 2);
   ASSERT_LT(TestGetTickerCount(options, BLOOM_FILTER_USEFUL), 120000 * 2);
 
   for (int i = 0; i < numkeys; i += 2) {
     ASSERT_EQ(Get(1, Key(i)), "val");
   }
+
+  // Part 2 (read path): rewrite last level with blooms, then verify they get
+  // cached only if !optimize_filters_for_hits
+  options.disable_auto_compactions = true;
+  options.num_levels = 9;
+  options.optimize_filters_for_hits = false;
+  options.statistics = CreateDBStatistics();
+  bbto.block_cache.reset();
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+
+  ReopenWithColumnFamilies({"default", "mypikachu"}, options);
+  MoveFilesToLevel(7 /* level */, 1 /* column family index */);
+
+  std::string value = Get(1, Key(0));
+  int prev_cache_filter_hits =
+      TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT);
+  value = Get(1, Key(0));
+  ASSERT_EQ(prev_cache_filter_hits + 1,
+            TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
+
+  // Now that we know the filter blocks exist in the last level files, see if
+  // filter caching is skipped for this optimization
+  options.optimize_filters_for_hits = true;
+  options.statistics = CreateDBStatistics();
+  bbto.block_cache.reset();
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+
+  ReopenWithColumnFamilies({"default", "mypikachu"}, options);
+
+  value = Get(1, Key(0));
+  ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
+  ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
+  ASSERT_EQ(2 /* index and data block */,
+            TestGetTickerCount(options, BLOCK_CACHE_ADD));
+
+  // Check filter block ignored for files preloaded during DB::Open()
+  options.max_open_files = -1;
+  options.statistics = CreateDBStatistics();
+  bbto.block_cache.reset();
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+
+  ReopenWithColumnFamilies({"default", "mypikachu"}, options);
+
+  int prev_cache_filter_misses =
+      TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS);
+  prev_cache_filter_hits = TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT);
+  Get(1, Key(0));
+  ASSERT_EQ(prev_cache_filter_misses,
+            TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
+  ASSERT_EQ(prev_cache_filter_hits,
+            TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
+
+  // Check filter block ignored for file trivially-moved to bottom level
+  bbto.block_cache.reset();
+  options.max_open_files = 100;  // setting > -1 makes it not preload all files
+  options.statistics = CreateDBStatistics();
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+
+  ReopenWithColumnFamilies({"default", "mypikachu"}, options);
+
+  ASSERT_OK(Put(1, Key(numkeys + 1), "val"));
+  ASSERT_OK(Flush(1));
+
+  int32_t trivial_move = 0;
+  int32_t non_trivial_move = 0;
+  rocksdb::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::BackgroundCompaction:TrivialMove",
+      [&](void* arg) { trivial_move++; });
+  rocksdb::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::BackgroundCompaction:NonTrivial",
+      [&](void* arg) { non_trivial_move++; });
+  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
+
+  CompactRangeOptions compact_options;
+  compact_options.bottommost_level_compaction =
+      BottommostLevelCompaction::kSkip;
+  compact_options.change_level = true;
+  compact_options.target_level = 7;
+  db_->CompactRange(compact_options, handles_[1], nullptr, nullptr);
+
+  ASSERT_EQ(trivial_move, 1);
+  ASSERT_EQ(non_trivial_move, 0);
+
+  prev_cache_filter_hits = TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT);
+  prev_cache_filter_misses =
+      TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS);
+  value = Get(1, Key(numkeys + 1));
+  ASSERT_EQ(prev_cache_filter_hits,
+            TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
+  ASSERT_EQ(prev_cache_filter_misses,
+            TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
+
+  // Check filter block not cached for iterator
+  bbto.block_cache.reset();
+  options.statistics = CreateDBStatistics();
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+
+  ReopenWithColumnFamilies({"default", "mypikachu"}, options);
+
+  std::unique_ptr<Iterator> iter(db_->NewIterator(ReadOptions(), handles_[1]));
+  iter->SeekToFirst();
+  ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_MISS));
+  ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_HIT));
+  ASSERT_EQ(2 /* index and data block */,
+            TestGetTickerCount(options, BLOCK_CACHE_ADD));
 }
 #endif  // ROCKSDB_LITE
 

db/table_cache.cc

@@ -88,7 +88,7 @@ Status TableCache::GetTableReader(
     const EnvOptions& env_options,
     const InternalKeyComparator& internal_comparator, const FileDescriptor& fd,
     bool sequential_mode, bool record_read_stats, HistogramImpl* file_read_hist,
-    unique_ptr<TableReader>* table_reader) {
+    unique_ptr<TableReader>* table_reader, bool skip_filters) {
   std::string fname =
       TableFileName(ioptions_.db_paths, fd.GetNumber(), fd.GetPathId());
   unique_ptr<RandomAccessFile> file;
@@ -108,7 +108,8 @@ Status TableCache::GetTableReader(
                                    ioptions_.statistics, record_read_stats,
                                    file_read_hist));
     s = ioptions_.table_factory->NewTableReader(
-        TableReaderOptions(ioptions_, env_options, internal_comparator),
+        TableReaderOptions(ioptions_, env_options, internal_comparator,
+                           skip_filters),
         std::move(file_reader), fd.GetFileSize(), table_reader);
     TEST_SYNC_POINT("TableCache::GetTableReader:0");
   }
@@ -119,7 +120,7 @@ Status TableCache::FindTable(const EnvOptions& env_options,
                              const InternalKeyComparator& internal_comparator,
                              const FileDescriptor& fd, Cache::Handle** handle,
                              const bool no_io, bool record_read_stats,
-                             HistogramImpl* file_read_hist) {
+                             HistogramImpl* file_read_hist, bool skip_filters) {
   PERF_TIMER_GUARD(find_table_nanos);
   Status s;
   uint64_t number = fd.GetNumber();
@@ -135,7 +136,7 @@ Status TableCache::FindTable(const EnvOptions& env_options,
     unique_ptr<TableReader> table_reader;
     s = GetTableReader(env_options, internal_comparator, fd,
                        false /* sequential mode */, record_read_stats,
-                       file_read_hist, &table_reader);
+                       file_read_hist, &table_reader, skip_filters);
     if (!s.ok()) {
       assert(table_reader == nullptr);
       RecordTick(ioptions_.statistics, NO_FILE_ERRORS);
@@ -153,7 +154,7 @@ InternalIterator* TableCache::NewIterator(
     const ReadOptions& options, const EnvOptions& env_options,
     const InternalKeyComparator& icomparator, const FileDescriptor& fd,
     TableReader** table_reader_ptr, HistogramImpl* file_read_hist,
-    bool for_compaction, Arena* arena) {
+    bool for_compaction, Arena* arena, bool skip_filters) {
   PERF_TIMER_GUARD(new_table_iterator_nanos);
 
   if (table_reader_ptr != nullptr) {
@@ -176,10 +177,10 @@ InternalIterator* TableCache::NewIterator(
   } else {
     table_reader = fd.table_reader;
     if (table_reader == nullptr) {
-      Status s =
-          FindTable(env_options, icomparator, fd, &handle,
-                    options.read_tier == kBlockCacheTier /* no_io */,
-                    !for_compaction /* record read_stats */, file_read_hist);
+      Status s = FindTable(env_options, icomparator, fd, &handle,
+                           options.read_tier == kBlockCacheTier /* no_io */,
+                           !for_compaction /* record read_stats */,
+                           file_read_hist, skip_filters);
       if (!s.ok()) {
         return NewErrorInternalIterator(s, arena);
       }
@@ -187,7 +188,8 @@ InternalIterator* TableCache::NewIterator(
     }
   }
 
-  InternalIterator* result = table_reader->NewIterator(options, arena);
+  InternalIterator* result =
+      table_reader->NewIterator(options, arena, skip_filters);
 
   if (create_new_table_reader) {
     assert(handle == nullptr);
@@ -209,7 +211,8 @@ InternalIterator* TableCache::NewIterator(
 Status TableCache::Get(const ReadOptions& options,
                        const InternalKeyComparator& internal_comparator,
                        const FileDescriptor& fd, const Slice& k,
-                       GetContext* get_context, HistogramImpl* file_read_hist) {
+                       GetContext* get_context, HistogramImpl* file_read_hist,
+                       bool skip_filters) {
   TableReader* t = fd.table_reader;
   Status s;
   Cache::Handle* handle = nullptr;
@@ -258,14 +261,14 @@ Status TableCache::Get(const ReadOptions& options,
   if (!t) {
     s = FindTable(env_options_, internal_comparator, fd, &handle,
                   options.read_tier == kBlockCacheTier /* no_io */,
-                  true /* record_read_stats */, file_read_hist);
+                  true /* record_read_stats */, file_read_hist, skip_filters);
     if (s.ok()) {
       t = GetTableReaderFromHandle(handle);
     }
   }
   if (s.ok()) {
     get_context->SetReplayLog(row_cache_entry);  // nullptr if no cache.
-    s = t->Get(options, k, get_context);
+    s = t->Get(options, k, get_context, skip_filters);
     get_context->SetReplayLog(nullptr);
     if (handle != nullptr) {
       ReleaseHandle(handle);

db/table_cache.h

@@ -44,30 +44,35 @@ class TableCache {
   // the returned iterator.  The returned "*tableptr" object is owned by
   // the cache and should not be deleted, and is valid for as long as the
   // returned iterator is live.
+  // @param skip_filters Disables loading/accessing the filter block
   InternalIterator* NewIterator(
       const ReadOptions& options, const EnvOptions& toptions,
       const InternalKeyComparator& internal_comparator,
       const FileDescriptor& file_fd, TableReader** table_reader_ptr = nullptr,
       HistogramImpl* file_read_hist = nullptr, bool for_compaction = false,
-      Arena* arena = nullptr);
+      Arena* arena = nullptr, bool skip_filters = false);
 
   // If a seek to internal key "k" in specified file finds an entry,
   // call (*handle_result)(arg, found_key, found_value) repeatedly until
   // it returns false.
+  // @param skip_filters Disables loading/accessing the filter block
   Status Get(const ReadOptions& options,
              const InternalKeyComparator& internal_comparator,
              const FileDescriptor& file_fd, const Slice& k,
-             GetContext* get_context, HistogramImpl* file_read_hist = nullptr);
+             GetContext* get_context, HistogramImpl* file_read_hist = nullptr,
+             bool skip_filters = false);
 
   // Evict any entry for the specified file number
   static void Evict(Cache* cache, uint64_t file_number);
 
   // Find table reader
+  // @param skip_filters Disables loading/accessing the filter block
   Status FindTable(const EnvOptions& toptions,
                    const InternalKeyComparator& internal_comparator,
                    const FileDescriptor& file_fd, Cache::Handle**,
                    const bool no_io = false, bool record_read_stats = true,
-                   HistogramImpl* file_read_hist = nullptr);
+                   HistogramImpl* file_read_hist = nullptr,
+                   bool skip_filters = false);
 
   // Get TableReader from a cache handle.
   TableReader* GetTableReaderFromHandle(Cache::Handle* handle);
@@ -100,7 +105,8 @@ class TableCache {
                         const InternalKeyComparator& internal_comparator,
                         const FileDescriptor& fd, bool sequential_mode,
                         bool record_read_stats, HistogramImpl* file_read_hist,
-                        unique_ptr<TableReader>* table_reader);
+                        unique_ptr<TableReader>* table_reader,
+                        bool skip_filters = false);
 
   const ImmutableCFOptions& ioptions_;
   const EnvOptions& env_options_;

db/version_set.cc

@@ -475,19 +475,21 @@ class LevelFileNumIterator : public InternalIterator {
 
 class LevelFileIteratorState : public TwoLevelIteratorState {
  public:
+  // @param skip_filters Disables loading/accessing the filter block
   LevelFileIteratorState(TableCache* table_cache,
                          const ReadOptions& read_options,
                          const EnvOptions& env_options,
                          const InternalKeyComparator& icomparator,
                          HistogramImpl* file_read_hist, bool for_compaction,
-                         bool prefix_enabled)
+                         bool prefix_enabled, bool skip_filters)
       : TwoLevelIteratorState(prefix_enabled),
         table_cache_(table_cache),
         read_options_(read_options),
         env_options_(env_options),
         icomparator_(icomparator),
         file_read_hist_(file_read_hist),
-        for_compaction_(for_compaction) {}
+        for_compaction_(for_compaction),
+        skip_filters_(skip_filters) {}
 
   InternalIterator* NewSecondaryIterator(const Slice& meta_handle) override {
     if (meta_handle.size() != sizeof(FileDescriptor)) {
@@ -499,7 +501,7 @@ class LevelFileIteratorState : public TwoLevelIteratorState {
       return table_cache_->NewIterator(
           read_options_, env_options_, icomparator_, *fd,
           nullptr /* don't need reference to table*/, file_read_hist_,
-          for_compaction_);
+          for_compaction_, nullptr /* arena */, skip_filters_);
     }
   }
 
@@ -514,6 +516,7 @@ class LevelFileIteratorState : public TwoLevelIteratorState {
   const InternalKeyComparator& icomparator_;
   HistogramImpl* file_read_hist_;
   bool for_compaction_;
+  bool skip_filters_;
 };
 
 // A wrapper of version builder which references the current version in
@@ -792,7 +795,8 @@ void Version::AddIterators(const ReadOptions& read_options,
                                  cfd_->internal_comparator(),
                                  cfd_->internal_stats()->GetFileReadHist(level),
                                  false /* for_compaction */,
-                                 cfd_->ioptions()->prefix_extractor != nullptr);
+                                 cfd_->ioptions()->prefix_extractor != nullptr,
+                                 IsFilterSkipped(level));
       mem = arena->AllocateAligned(sizeof(LevelFileNumIterator));
       auto* first_level_iter = new (mem) LevelFileNumIterator(
           cfd_->internal_comparator(), &storage_info_.LevelFilesBrief(level));
@@ -895,7 +899,8 @@ void Version::Get(const ReadOptions& read_options, const LookupKey& k,
   while (f != nullptr) {
     *status = table_cache_->Get(
         read_options, *internal_comparator(), f->fd, ikey, &get_context,
-        cfd_->internal_stats()->GetFileReadHist(fp.GetHitFileLevel()));
+        cfd_->internal_stats()->GetFileReadHist(fp.GetHitFileLevel()),
+        IsFilterSkipped(static_cast<int>(fp.GetHitFileLevel())));
     // TODO: examine the behavior for corrupted key
     if (!status->ok()) {
       return;
@@ -952,6 +957,13 @@ void Version::Get(const ReadOptions& read_options, const LookupKey& k,
   }
 }
 
+bool Version::IsFilterSkipped(int level) {
+  // Reaching the bottom level implies misses at all upper levels, so we'll
+  // skip checking the filters when we predict a hit.
+  return cfd_->ioptions()->optimize_filters_for_hits &&
+         level == storage_info_.num_non_empty_levels() - 1;
+}
+
 void VersionStorageInfo::GenerateLevelFilesBrief() {
   level_files_brief_.resize(num_non_empty_levels_);
   for (int level = 0; level < num_non_empty_levels_; level++) {
@@ -2124,7 +2136,8 @@ Status VersionSet::LogAndApply(ColumnFamilyData* column_family_data,
       // unlimited table cache. Pre-load table handle now.
       // Need to do it out of the mutex.
       builder_guard->version_builder()->LoadTableHandlers(
-          column_family_data->internal_stats());
+          column_family_data->internal_stats(),
+          column_family_data->ioptions()->optimize_filters_for_hits);
     }
 
     // This is fine because everything inside of this block is serialized --
@@ -3270,7 +3283,8 @@ InternalIterator* VersionSet::MakeInputIterator(Compaction* c) {
                 cfd->table_cache(), read_options, env_options_,
                 cfd->internal_comparator(),
                 nullptr /* no per level latency histogram */,
-                true /* for_compaction */, false /* prefix enabled */),
+                true /* for_compaction */, false /* prefix enabled */,
+                false /* skip_filters */),
             new LevelFileNumIterator(cfd->internal_comparator(),
                                      c->input_levels(which)));
       }

db/version_set.h

@@ -522,6 +522,12 @@ class Version {
                       InternalIterator* level_iter,
                       const Slice& internal_prefix) const;
 
+  // Returns true if the filter blocks in the specified level will not be
+  // checked during read operations. In certain cases (trivial move or preload),
+  // the filter block may already be cached, but we still do not access it such
+  // that it eventually expires from the cache.
+  bool IsFilterSkipped(int level);
+
   // The helper function of UpdateAccumulatedStats, which may fill the missing
   // fields of file_mata from its associated TableProperties.
   // Returns true if it does initialize FileMetaData.

table/block_based_table_factory.cc

@@ -57,7 +57,8 @@ Status BlockBasedTableFactory::NewTableReader(
   return BlockBasedTable::Open(
       table_reader_options.ioptions, table_reader_options.env_options,
       table_options_, table_reader_options.internal_comparator, std::move(file),
-      file_size, table_reader, prefetch_enabled);
+      file_size, table_reader, prefetch_enabled,
+      table_reader_options.skip_filters);
 }
 
 TableBuilder* BlockBasedTableFactory::NewTableBuilder(

table/block_based_table_reader.cc

@@ -338,11 +338,11 @@ class HashIndexReader : public IndexReader {
 struct BlockBasedTable::Rep {
   Rep(const ImmutableCFOptions& _ioptions, const EnvOptions& _env_options,
       const BlockBasedTableOptions& _table_opt,
-      const InternalKeyComparator& _internal_comparator)
+      const InternalKeyComparator& _internal_comparator, bool skip_filters)
       : ioptions(_ioptions),
         env_options(_env_options),
         table_options(_table_opt),
-        filter_policy(_table_opt.filter_policy.get()),
+        filter_policy(skip_filters ? nullptr : _table_opt.filter_policy.get()),
         internal_comparator(_internal_comparator),
         filter_type(FilterType::kNoFilter),
         whole_key_filtering(_table_opt.whole_key_filtering),
@@ -486,7 +486,8 @@ Status BlockBasedTable::Open(const ImmutableCFOptions& ioptions,
                              unique_ptr<RandomAccessFileReader>&& file,
                              uint64_t file_size,
                              unique_ptr<TableReader>* table_reader,
-                             const bool prefetch_index_and_filter) {
+                             const bool prefetch_index_and_filter,
+                             const bool skip_filters) {
   table_reader->reset();
 
   Footer footer;
@@ -503,8 +504,8 @@ Status BlockBasedTable::Open(const ImmutableCFOptions& ioptions,
 
   // We've successfully read the footer and the index block: we're
   // ready to serve requests.
-  Rep* rep = new BlockBasedTable::Rep(
-      ioptions, env_options, table_options, internal_comparator);
+  Rep* rep = new BlockBasedTable::Rep(ioptions, env_options, table_options,
+                                      internal_comparator, skip_filters);
   rep->file = std::move(file);
   rep->footer = footer;
   rep->index_type = table_options.index_type;
@@ -1076,18 +1077,19 @@ InternalIterator* BlockBasedTable::NewDataBlockIterator(
 class BlockBasedTable::BlockEntryIteratorState : public TwoLevelIteratorState {
  public:
   BlockEntryIteratorState(BlockBasedTable* table,
-                          const ReadOptions& read_options)
-      : TwoLevelIteratorState(
-          table->rep_->ioptions.prefix_extractor != nullptr),
+                          const ReadOptions& read_options, bool skip_filters)
+      : TwoLevelIteratorState(table->rep_->ioptions.prefix_extractor !=
+                              nullptr),
         table_(table),
-        read_options_(read_options) {}
+        read_options_(read_options),
+        skip_filters_(skip_filters) {}
 
   InternalIterator* NewSecondaryIterator(const Slice& index_value) override {
     return NewDataBlockIterator(table_->rep_, read_options_, index_value);
   }
 
   bool PrefixMayMatch(const Slice& internal_key) override {
-    if (read_options_.total_order_seek) {
+    if (read_options_.total_order_seek || skip_filters_) {
       return true;
     }
     return table_->PrefixMayMatch(internal_key);
@@ -1097,6 +1099,7 @@ class BlockBasedTable::BlockEntryIteratorState : public TwoLevelIteratorState {
   // Don't own table_
   BlockBasedTable* table_;
   const ReadOptions read_options_;
+  bool skip_filters_;
 };
 
 // This will be broken if the user specifies an unusual implementation
@@ -1187,9 +1190,11 @@ bool BlockBasedTable::PrefixMayMatch(const Slice& internal_key) {
 }
 
 InternalIterator* BlockBasedTable::NewIterator(const ReadOptions& read_options,
-                                               Arena* arena) {
-  return NewTwoLevelIterator(new BlockEntryIteratorState(this, read_options),
-                             NewIndexIterator(read_options), arena);
+                                               Arena* arena,
+                                               bool skip_filters) {
+  return NewTwoLevelIterator(
+      new BlockEntryIteratorState(this, read_options, skip_filters),
+      NewIndexIterator(read_options), arena);
 }
 
 bool BlockBasedTable::FullFilterKeyMayMatch(FilterBlockReader* filter,
@@ -1209,11 +1214,13 @@ bool BlockBasedTable::FullFilterKeyMayMatch(FilterBlockReader* filter,
   return true;
 }
 
-Status BlockBasedTable::Get(
-    const ReadOptions& read_options, const Slice& key,
-    GetContext* get_context) {
+Status BlockBasedTable::Get(const ReadOptions& read_options, const Slice& key,
+                            GetContext* get_context, bool skip_filters) {
   Status s;
-  auto filter_entry = GetFilter(read_options.read_tier == kBlockCacheTier);
+  CachableEntry<FilterBlockReader> filter_entry;
+  if (!skip_filters) {
+    filter_entry = GetFilter(read_options.read_tier == kBlockCacheTier);
+  }
   FilterBlockReader* filter = filter_entry.value;
 
   // First check the full filter

table/block_based_table_reader.h

@@ -64,27 +64,32 @@ class BlockBasedTable : public TableReader {
   // If there was an error while initializing the table, sets "*table_reader"
   // to nullptr and returns a non-ok status.
   //
-  // *file must remain live while this Table is in use.
-  // *prefetch_blocks can be used to disable prefetching of index and filter
-  //  blocks at statup
+  // @param file must remain live while this Table is in use.
+  // @param prefetch_index_and_filter can be used to disable prefetching of
+  //    index and filter blocks at startup
+  // @param skip_filters Disables loading/accessing the filter block. Overrides
+  //    prefetch_index_and_filter, so filter will be skipped if both are set.
   static Status Open(const ImmutableCFOptions& ioptions,
                      const EnvOptions& env_options,
                      const BlockBasedTableOptions& table_options,
                      const InternalKeyComparator& internal_key_comparator,
                      unique_ptr<RandomAccessFileReader>&& file,
                      uint64_t file_size, unique_ptr<TableReader>* table_reader,
-                     bool prefetch_index_and_filter = true);
+                     bool prefetch_index_and_filter = true,
+                     bool skip_filters = false);
 
   bool PrefixMayMatch(const Slice& internal_key);
 
   // Returns a new iterator over the table contents.
   // The result of NewIterator() is initially invalid (caller must
   // call one of the Seek methods on the iterator before using it).
-  InternalIterator* NewIterator(const ReadOptions&,
-                                Arena* arena = nullptr) override;
+  // @param skip_filters Disables loading/accessing the filter block
+  InternalIterator* NewIterator(const ReadOptions&, Arena* arena = nullptr,
+                                bool skip_filters = false) override;
 
+  // @param skip_filters Disables loading/accessing the filter block
   Status Get(const ReadOptions& readOptions, const Slice& key,
-             GetContext* get_context) override;
+             GetContext* get_context, bool skip_filters = false) override;
 
   // Pre-fetch the disk blocks that correspond to the key range specified by
   // (kbegin, kend). The call will return return error status in the event of

table/cuckoo_table_reader.cc

@@ -128,7 +128,7 @@ CuckooTableReader::CuckooTableReader(
 }
 
 Status CuckooTableReader::Get(const ReadOptions& readOptions, const Slice& key,
-                              GetContext* get_context) {
+                              GetContext* get_context, bool skip_filters) {
   assert(key.size() == key_length_ + (is_last_level_ ? 8 : 0));
   Slice user_key = ExtractUserKey(key);
   for (uint32_t hash_cnt = 0; hash_cnt < num_hash_func_; ++hash_cnt) {
@@ -358,7 +358,7 @@ extern InternalIterator* NewErrorInternalIterator(const Status& status,
                                                   Arena* arena);
 
 InternalIterator* CuckooTableReader::NewIterator(
-    const ReadOptions& read_options, Arena* arena) {
+    const ReadOptions& read_options, Arena* arena, bool skip_filters) {
   if (!status().ok()) {
     return NewErrorInternalIterator(
         Status::Corruption("CuckooTableReader status is not okay."), arena);

table/cuckoo_table_reader.h

@@ -42,10 +42,10 @@ class CuckooTableReader: public TableReader {
   Status status() const { return status_; }
 
   Status Get(const ReadOptions& read_options, const Slice& key,
-             GetContext* get_context) override;
+             GetContext* get_context, bool skip_filters = false) override;
 
-  InternalIterator* NewIterator(const ReadOptions&,
-                                Arena* arena = nullptr) override;
+  InternalIterator* NewIterator(const ReadOptions&, Arena* arena = nullptr,
+                                bool skip_filters = false) override;
   void Prepare(const Slice& target) override;
 
   // Report an approximation of how much memory has been used.

table/mock_table.cc

@@ -28,13 +28,13 @@ stl_wrappers::KVMap MakeMockFile(
   return stl_wrappers::KVMap(l, stl_wrappers::LessOfComparator(&icmp_));
 }
 
-InternalIterator* MockTableReader::NewIterator(const ReadOptions&,
-                                               Arena* arena) {
+InternalIterator* MockTableReader::NewIterator(const ReadOptions&, Arena* arena,
+                                               bool skip_filters) {
   return new MockTableIterator(table_);
 }
 
 Status MockTableReader::Get(const ReadOptions&, const Slice& key,
-                            GetContext* get_context) {
+                            GetContext* get_context, bool skip_filters) {
   std::unique_ptr<MockTableIterator> iter(new MockTableIterator(table_));
   for (iter->Seek(key); iter->Valid(); iter->Next()) {
     ParsedInternalKey parsed_key;

table/mock_table.h

@@ -40,10 +40,11 @@ class MockTableReader : public TableReader {
  public:
   explicit MockTableReader(const stl_wrappers::KVMap& table) : table_(table) {}
 
-  InternalIterator* NewIterator(const ReadOptions&, Arena* arena) override;
+  InternalIterator* NewIterator(const ReadOptions&, Arena* arena,
+                                bool skip_filters = false) override;
 
-  Status Get(const ReadOptions&, const Slice& key,
-             GetContext* get_context) override;
+  Status Get(const ReadOptions&, const Slice& key, GetContext* get_context,
+             bool skip_filters = false) override;
 
   uint64_t ApproximateOffsetOf(const Slice& key) override { return 0; }
 

table/plain_table_reader.cc

@@ -188,7 +188,8 @@ void PlainTableReader::SetupForCompaction() {
 }
 
 InternalIterator* PlainTableReader::NewIterator(const ReadOptions& options,
-                                                Arena* arena) {
+                                                Arena* arena,
+                                                bool skip_filters) {
   if (options.total_order_seek && !IsTotalOrderMode()) {
     return NewErrorInternalIterator(
         Status::InvalidArgument("total_order_seek not supported"), arena);
@@ -531,7 +532,7 @@ void PlainTableReader::Prepare(const Slice& target) {
 }
 
 Status PlainTableReader::Get(const ReadOptions& ro, const Slice& target,
-                             GetContext* get_context) {
+                             GetContext* get_context, bool skip_filters) {
   // Check bloom filter first.
   Slice prefix_slice;
   uint32_t prefix_hash;

table/plain_table_reader.h

@@ -78,13 +78,13 @@ class PlainTableReader: public TableReader {
                      size_t index_sparseness, size_t huge_page_tlb_size,
                      bool full_scan_mode);
 
-  InternalIterator* NewIterator(const ReadOptions&,
-                                Arena* arena = nullptr) override;
+  InternalIterator* NewIterator(const ReadOptions&, Arena* arena = nullptr,
+                                bool skip_filters = false) override;
 
   void Prepare(const Slice& target) override;
 
-  Status Get(const ReadOptions&, const Slice& key,
-             GetContext* get_context) override;
+  Status Get(const ReadOptions&, const Slice& key, GetContext* get_context,
+             bool skip_filters = false) override;
 
   uint64_t ApproximateOffsetOf(const Slice& key) override;
 

table/table_builder.h

@@ -25,16 +25,21 @@ class Slice;
 class Status;
 
 struct TableReaderOptions {
+  // @param skip_filters Disables loading/accessing the filter block
   TableReaderOptions(const ImmutableCFOptions& _ioptions,
                      const EnvOptions& _env_options,
-                     const InternalKeyComparator& _internal_comparator)
+                     const InternalKeyComparator& _internal_comparator,
+                     bool _skip_filters = false)
       : ioptions(_ioptions),
         env_options(_env_options),
-        internal_comparator(_internal_comparator) {}
+        internal_comparator(_internal_comparator),
+        skip_filters(_skip_filters) {}
 
   const ImmutableCFOptions& ioptions;
   const EnvOptions& env_options;
   const InternalKeyComparator& internal_comparator;
+  // This is only used for BlockBasedTable (reader)
+  bool skip_filters;
 };
 
 struct TableBuilderOptions {
@@ -57,6 +62,7 @@ struct TableBuilderOptions {
       int_tbl_prop_collector_factories;
   CompressionType compression_type;
   const CompressionOptions& compression_opts;
+  // This is only used for BlockBasedTableBuilder
   bool skip_filters = false;
 };
 

table/table_reader.h

@@ -35,8 +35,11 @@ class TableReader {
   //        When destroying the iterator, the caller will not call "delete"
   //        but Iterator::~Iterator() directly. The destructor needs to destroy
   //        all the states but those allocated in arena.
+  // skip_filters: disables checking the bloom filters even if they exist. This
+  //               option is effective only for block-based table format.
   virtual InternalIterator* NewIterator(const ReadOptions&,
-                                        Arena* arena = nullptr) = 0;
+                                        Arena* arena = nullptr,
+                                        bool skip_filters = false) = 0;
 
   // Given a key, return an approximate byte offset in the file where
   // the data for that key begins (or would begin if the key were
@@ -67,8 +70,10 @@ class TableReader {
   //
   // readOptions is the options for the read
   // key is the key to search for
+  // skip_filters: disables checking the bloom filters even if they exist. This
+  //               option is effective only for block-based table format.
   virtual Status Get(const ReadOptions& readOptions, const Slice& key,
-                     GetContext* get_context) = 0;
+                     GetContext* get_context, bool skip_filters = false) = 0;
 
   // Prefetch data corresponding to a give range of keys
   // Typically this functionality is required for table implementations that

tools/sst_dump_tool.cc

@@ -91,7 +91,8 @@ Status SstFileReader::NewTableReader(
 
   if (block_table_factory) {
     return block_table_factory->NewTableReader(
-        TableReaderOptions(ioptions_, soptions_, internal_comparator_),
+        TableReaderOptions(ioptions_, soptions_, internal_comparator_,
+                           /*skip_filters=*/false),
         std::move(file_), file_size, &table_reader_, /*enable_prefetch=*/false);
   }