e7c434c364
Summary:
Summary:
Added a new option to ColumnFamllyOptions - optimize_filters_for_hits. This option can be used in the case where most
accesses to the store are key hits and we dont need to optimize performance for key misses.
This is useful when you have a very large database and most of your lookups succeed. The option allows the store to
not store and use filters in the last level (the largest level which contains data). These filters can take a large amount of
space for large databases (in memory and on-disk). For the last level, these filters are only useful for key misses and not
for key hits. If we are not optimizing for key misses, we can choose to not store these filters for that level.
This option is only provided for BlockBasedTable. We skip the filters when we are compacting
Test Plan:
1. Modified db_test toalso run tests with an additonal option (skip_filters_on_last_level)
2. Added another unit test to db_test which specifically tests that filters are being skipped
Reviewers: rven, igor, sdong
Reviewed By: sdong
Subscribers: lgalanis, yoshinorim, MarkCallaghan, rven, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D33717
80 lines
2.9 KiB
C++
80 lines
2.9 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#pragma once
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#include <stdint.h>
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#include <memory>
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#include <string>
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#include "rocksdb/flush_block_policy.h"
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#include "rocksdb/table.h"
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#include "db/dbformat.h"
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namespace rocksdb {
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struct EnvOptions;
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using std::unique_ptr;
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class BlockBasedTableBuilder;
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class BlockBasedTableFactory : public TableFactory {
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public:
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explicit BlockBasedTableFactory(
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const BlockBasedTableOptions& table_options = BlockBasedTableOptions());
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~BlockBasedTableFactory() {}
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const char* Name() const override { return "BlockBasedTable"; }
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Status NewTableReader(const ImmutableCFOptions& ioptions,
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const EnvOptions& soptions,
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const InternalKeyComparator& internal_comparator,
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unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
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unique_ptr<TableReader>* table_reader) const override {
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return NewTableReader(ioptions, soptions, internal_comparator,
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std::move(file), file_size, table_reader,
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/*prefetch_index_and_filter=*/true);
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}
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// This is a variant of virtual member function NewTableReader function with
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// added capability to disable pre-fetching of blocks on BlockBasedTable::Open
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Status NewTableReader(const ImmutableCFOptions& ioptions,
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const EnvOptions& soptions,
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const InternalKeyComparator& internal_comparator,
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unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
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unique_ptr<TableReader>* table_reader,
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bool prefetch_index_and_filter) const;
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TableBuilder* NewTableBuilder(
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const ImmutableCFOptions& ioptions,
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const InternalKeyComparator& internal_comparator, WritableFile* file,
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const CompressionType compression_type,
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const CompressionOptions& compression_opts,
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const bool skip_filters = false) const override;
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// Sanitizes the specified DB Options.
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Status SanitizeOptions(const DBOptions& db_opts,
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const ColumnFamilyOptions& cf_opts) const override;
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std::string GetPrintableTableOptions() const override;
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const BlockBasedTableOptions& GetTableOptions() const;
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private:
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BlockBasedTableOptions table_options_;
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};
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extern const std::string kHashIndexPrefixesBlock;
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extern const std::string kHashIndexPrefixesMetadataBlock;
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extern const std::string kPropTrue;
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extern const std::string kPropFalse;
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} // namespace rocksdb
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