rocksdb/options/options.cc
Siying Dong ed9f5e21aa Change OptimizeForPointLookup() and OptimizeForSmallDb() (#5165)
Summary:
Change the behavior of OptimizeForSmallDb() so that it is less likely to go out of memory.
Change the behavior of OptimizeForPointLookup() to take advantage of the new memtable whole key filter, and move away from prefix extractor as well as hash-based indexing, as they are prone to misuse.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5165

Differential Revision: D14880709

Pulled By: siying

fbshipit-source-id: 9af30e3c9e151eceea6d6b38701a58f1f9fb692d
2019-04-11 10:45:36 -07:00

617 lines
25 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "rocksdb/options.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <limits>
#include "monitoring/statistics.h"
#include "options/db_options.h"
#include "options/options_helper.h"
#include "rocksdb/cache.h"
#include "rocksdb/compaction_filter.h"
#include "rocksdb/comparator.h"
#include "rocksdb/env.h"
#include "rocksdb/memtablerep.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
#include "rocksdb/slice_transform.h"
#include "rocksdb/sst_file_manager.h"
#include "rocksdb/table.h"
#include "rocksdb/table_properties.h"
#include "rocksdb/wal_filter.h"
#include "table/block_based_table_factory.h"
#include "util/compression.h"
namespace rocksdb {
AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions() {
assert(memtable_factory.get() != nullptr);
}
AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions(const Options& options)
: max_write_buffer_number(options.max_write_buffer_number),
min_write_buffer_number_to_merge(
options.min_write_buffer_number_to_merge),
max_write_buffer_number_to_maintain(
options.max_write_buffer_number_to_maintain),
inplace_update_support(options.inplace_update_support),
inplace_update_num_locks(options.inplace_update_num_locks),
inplace_callback(options.inplace_callback),
memtable_prefix_bloom_size_ratio(
options.memtable_prefix_bloom_size_ratio),
memtable_whole_key_filtering(options.memtable_whole_key_filtering),
memtable_huge_page_size(options.memtable_huge_page_size),
memtable_insert_with_hint_prefix_extractor(
options.memtable_insert_with_hint_prefix_extractor),
bloom_locality(options.bloom_locality),
arena_block_size(options.arena_block_size),
compression_per_level(options.compression_per_level),
num_levels(options.num_levels),
level0_slowdown_writes_trigger(options.level0_slowdown_writes_trigger),
level0_stop_writes_trigger(options.level0_stop_writes_trigger),
target_file_size_base(options.target_file_size_base),
target_file_size_multiplier(options.target_file_size_multiplier),
level_compaction_dynamic_level_bytes(
options.level_compaction_dynamic_level_bytes),
max_bytes_for_level_multiplier(options.max_bytes_for_level_multiplier),
max_bytes_for_level_multiplier_additional(
options.max_bytes_for_level_multiplier_additional),
max_compaction_bytes(options.max_compaction_bytes),
soft_pending_compaction_bytes_limit(
options.soft_pending_compaction_bytes_limit),
hard_pending_compaction_bytes_limit(
options.hard_pending_compaction_bytes_limit),
compaction_style(options.compaction_style),
compaction_pri(options.compaction_pri),
compaction_options_universal(options.compaction_options_universal),
compaction_options_fifo(options.compaction_options_fifo),
max_sequential_skip_in_iterations(
options.max_sequential_skip_in_iterations),
memtable_factory(options.memtable_factory),
table_properties_collector_factories(
options.table_properties_collector_factories),
max_successive_merges(options.max_successive_merges),
optimize_filters_for_hits(options.optimize_filters_for_hits),
paranoid_file_checks(options.paranoid_file_checks),
force_consistency_checks(options.force_consistency_checks),
report_bg_io_stats(options.report_bg_io_stats),
ttl(options.ttl),
periodic_compaction_seconds(options.periodic_compaction_seconds),
sample_for_compression(options.sample_for_compression) {
assert(memtable_factory.get() != nullptr);
if (max_bytes_for_level_multiplier_additional.size() <
static_cast<unsigned int>(num_levels)) {
max_bytes_for_level_multiplier_additional.resize(num_levels, 1);
}
}
ColumnFamilyOptions::ColumnFamilyOptions()
: compression(Snappy_Supported() ? kSnappyCompression : kNoCompression),
table_factory(
std::shared_ptr<TableFactory>(new BlockBasedTableFactory())) {}
ColumnFamilyOptions::ColumnFamilyOptions(const Options& options)
: ColumnFamilyOptions(*static_cast<const ColumnFamilyOptions*>(&options)) {}
DBOptions::DBOptions() {}
DBOptions::DBOptions(const Options& options)
: DBOptions(*static_cast<const DBOptions*>(&options)) {}
void DBOptions::Dump(Logger* log) const {
ImmutableDBOptions(*this).Dump(log);
MutableDBOptions(*this).Dump(log);
} // DBOptions::Dump
void ColumnFamilyOptions::Dump(Logger* log) const {
ROCKS_LOG_HEADER(log, " Options.comparator: %s",
comparator->Name());
ROCKS_LOG_HEADER(log, " Options.merge_operator: %s",
merge_operator ? merge_operator->Name() : "None");
ROCKS_LOG_HEADER(log, " Options.compaction_filter: %s",
compaction_filter ? compaction_filter->Name() : "None");
ROCKS_LOG_HEADER(
log, " Options.compaction_filter_factory: %s",
compaction_filter_factory ? compaction_filter_factory->Name() : "None");
ROCKS_LOG_HEADER(log, " Options.memtable_factory: %s",
memtable_factory->Name());
ROCKS_LOG_HEADER(log, " Options.table_factory: %s",
table_factory->Name());
ROCKS_LOG_HEADER(log, " table_factory options: %s",
table_factory->GetPrintableTableOptions().c_str());
ROCKS_LOG_HEADER(log, " Options.write_buffer_size: %" ROCKSDB_PRIszt,
write_buffer_size);
ROCKS_LOG_HEADER(log, " Options.max_write_buffer_number: %d",
max_write_buffer_number);
if (!compression_per_level.empty()) {
for (unsigned int i = 0; i < compression_per_level.size(); i++) {
ROCKS_LOG_HEADER(
log, " Options.compression[%d]: %s", i,
CompressionTypeToString(compression_per_level[i]).c_str());
}
} else {
ROCKS_LOG_HEADER(log, " Options.compression: %s",
CompressionTypeToString(compression).c_str());
}
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression: %s",
bottommost_compression == kDisableCompressionOption
? "Disabled"
: CompressionTypeToString(bottommost_compression).c_str());
ROCKS_LOG_HEADER(
log, " Options.prefix_extractor: %s",
prefix_extractor == nullptr ? "nullptr" : prefix_extractor->Name());
ROCKS_LOG_HEADER(log,
" Options.memtable_insert_with_hint_prefix_extractor: %s",
memtable_insert_with_hint_prefix_extractor == nullptr
? "nullptr"
: memtable_insert_with_hint_prefix_extractor->Name());
ROCKS_LOG_HEADER(log, " Options.num_levels: %d", num_levels);
ROCKS_LOG_HEADER(log, " Options.min_write_buffer_number_to_merge: %d",
min_write_buffer_number_to_merge);
ROCKS_LOG_HEADER(log, " Options.max_write_buffer_number_to_maintain: %d",
max_write_buffer_number_to_maintain);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.window_bits: %d",
bottommost_compression_opts.window_bits);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.level: %d",
bottommost_compression_opts.level);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.strategy: %d",
bottommost_compression_opts.strategy);
ROCKS_LOG_HEADER(
log,
" Options.bottommost_compression_opts.max_dict_bytes: "
"%" PRIu32,
bottommost_compression_opts.max_dict_bytes);
ROCKS_LOG_HEADER(
log,
" Options.bottommost_compression_opts.zstd_max_train_bytes: "
"%" PRIu32,
bottommost_compression_opts.zstd_max_train_bytes);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.enabled: %s",
bottommost_compression_opts.enabled ? "true" : "false");
ROCKS_LOG_HEADER(log, " Options.compression_opts.window_bits: %d",
compression_opts.window_bits);
ROCKS_LOG_HEADER(log, " Options.compression_opts.level: %d",
compression_opts.level);
ROCKS_LOG_HEADER(log, " Options.compression_opts.strategy: %d",
compression_opts.strategy);
ROCKS_LOG_HEADER(
log,
" Options.compression_opts.max_dict_bytes: %" PRIu32,
compression_opts.max_dict_bytes);
ROCKS_LOG_HEADER(log,
" Options.compression_opts.zstd_max_train_bytes: "
"%" PRIu32,
compression_opts.zstd_max_train_bytes);
ROCKS_LOG_HEADER(log,
" Options.compression_opts.enabled: %s",
compression_opts.enabled ? "true" : "false");
ROCKS_LOG_HEADER(log, " Options.level0_file_num_compaction_trigger: %d",
level0_file_num_compaction_trigger);
ROCKS_LOG_HEADER(log, " Options.level0_slowdown_writes_trigger: %d",
level0_slowdown_writes_trigger);
ROCKS_LOG_HEADER(log, " Options.level0_stop_writes_trigger: %d",
level0_stop_writes_trigger);
ROCKS_LOG_HEADER(
log, " Options.target_file_size_base: %" PRIu64,
target_file_size_base);
ROCKS_LOG_HEADER(log, " Options.target_file_size_multiplier: %d",
target_file_size_multiplier);
ROCKS_LOG_HEADER(
log, " Options.max_bytes_for_level_base: %" PRIu64,
max_bytes_for_level_base);
ROCKS_LOG_HEADER(log, "Options.level_compaction_dynamic_level_bytes: %d",
level_compaction_dynamic_level_bytes);
ROCKS_LOG_HEADER(log, " Options.max_bytes_for_level_multiplier: %f",
max_bytes_for_level_multiplier);
for (size_t i = 0; i < max_bytes_for_level_multiplier_additional.size();
i++) {
ROCKS_LOG_HEADER(
log, "Options.max_bytes_for_level_multiplier_addtl[%" ROCKSDB_PRIszt
"]: %d",
i, max_bytes_for_level_multiplier_additional[i]);
}
ROCKS_LOG_HEADER(
log, " Options.max_sequential_skip_in_iterations: %" PRIu64,
max_sequential_skip_in_iterations);
ROCKS_LOG_HEADER(
log, " Options.max_compaction_bytes: %" PRIu64,
max_compaction_bytes);
ROCKS_LOG_HEADER(
log,
" Options.arena_block_size: %" ROCKSDB_PRIszt,
arena_block_size);
ROCKS_LOG_HEADER(log,
" Options.soft_pending_compaction_bytes_limit: %" PRIu64,
soft_pending_compaction_bytes_limit);
ROCKS_LOG_HEADER(log,
" Options.hard_pending_compaction_bytes_limit: %" PRIu64,
hard_pending_compaction_bytes_limit);
ROCKS_LOG_HEADER(log, " Options.rate_limit_delay_max_milliseconds: %u",
rate_limit_delay_max_milliseconds);
ROCKS_LOG_HEADER(log, " Options.disable_auto_compactions: %d",
disable_auto_compactions);
const auto& it_compaction_style =
compaction_style_to_string.find(compaction_style);
std::string str_compaction_style;
if (it_compaction_style == compaction_style_to_string.end()) {
assert(false);
str_compaction_style = "unknown_" + std::to_string(compaction_style);
} else {
str_compaction_style = it_compaction_style->second;
}
ROCKS_LOG_HEADER(log,
" Options.compaction_style: %s",
str_compaction_style.c_str());
const auto& it_compaction_pri =
compaction_pri_to_string.find(compaction_pri);
std::string str_compaction_pri;
if (it_compaction_pri == compaction_pri_to_string.end()) {
assert(false);
str_compaction_pri = "unknown_" + std::to_string(compaction_pri);
} else {
str_compaction_pri = it_compaction_pri->second;
}
ROCKS_LOG_HEADER(log,
" Options.compaction_pri: %s",
str_compaction_pri.c_str());
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.size_ratio: %u",
compaction_options_universal.size_ratio);
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.min_merge_width: %u",
compaction_options_universal.min_merge_width);
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.max_merge_width: %u",
compaction_options_universal.max_merge_width);
ROCKS_LOG_HEADER(
log,
"Options.compaction_options_universal."
"max_size_amplification_percent: %u",
compaction_options_universal.max_size_amplification_percent);
ROCKS_LOG_HEADER(
log,
"Options.compaction_options_universal.compression_size_percent: %d",
compaction_options_universal.compression_size_percent);
const auto& it_compaction_stop_style = compaction_stop_style_to_string.find(
compaction_options_universal.stop_style);
std::string str_compaction_stop_style;
if (it_compaction_stop_style == compaction_stop_style_to_string.end()) {
assert(false);
str_compaction_stop_style =
"unknown_" + std::to_string(compaction_options_universal.stop_style);
} else {
str_compaction_stop_style = it_compaction_stop_style->second;
}
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.stop_style: %s",
str_compaction_stop_style.c_str());
ROCKS_LOG_HEADER(
log, "Options.compaction_options_fifo.max_table_files_size: %" PRIu64,
compaction_options_fifo.max_table_files_size);
ROCKS_LOG_HEADER(log,
"Options.compaction_options_fifo.allow_compaction: %d",
compaction_options_fifo.allow_compaction);
std::string collector_names;
for (const auto& collector_factory : table_properties_collector_factories) {
collector_names.append(collector_factory->Name());
collector_names.append("; ");
}
ROCKS_LOG_HEADER(
log, " Options.table_properties_collectors: %s",
collector_names.c_str());
ROCKS_LOG_HEADER(log,
" Options.inplace_update_support: %d",
inplace_update_support);
ROCKS_LOG_HEADER(
log,
" Options.inplace_update_num_locks: %" ROCKSDB_PRIszt,
inplace_update_num_locks);
// TODO: easier config for bloom (maybe based on avg key/value size)
ROCKS_LOG_HEADER(
log, " Options.memtable_prefix_bloom_size_ratio: %f",
memtable_prefix_bloom_size_ratio);
ROCKS_LOG_HEADER(log,
" Options.memtable_whole_key_filtering: %d",
memtable_whole_key_filtering);
ROCKS_LOG_HEADER(log, " Options.memtable_huge_page_size: %" ROCKSDB_PRIszt,
memtable_huge_page_size);
ROCKS_LOG_HEADER(log,
" Options.bloom_locality: %d",
bloom_locality);
ROCKS_LOG_HEADER(
log,
" Options.max_successive_merges: %" ROCKSDB_PRIszt,
max_successive_merges);
ROCKS_LOG_HEADER(log,
" Options.optimize_filters_for_hits: %d",
optimize_filters_for_hits);
ROCKS_LOG_HEADER(log, " Options.paranoid_file_checks: %d",
paranoid_file_checks);
ROCKS_LOG_HEADER(log, " Options.force_consistency_checks: %d",
force_consistency_checks);
ROCKS_LOG_HEADER(log, " Options.report_bg_io_stats: %d",
report_bg_io_stats);
ROCKS_LOG_HEADER(log, " Options.ttl: %" PRIu64,
ttl);
ROCKS_LOG_HEADER(log,
" Options.periodic_compaction_seconds: %" PRIu64,
periodic_compaction_seconds);
} // ColumnFamilyOptions::Dump
void Options::Dump(Logger* log) const {
DBOptions::Dump(log);
ColumnFamilyOptions::Dump(log);
} // Options::Dump
void Options::DumpCFOptions(Logger* log) const {
ColumnFamilyOptions::Dump(log);
} // Options::DumpCFOptions
//
// The goal of this method is to create a configuration that
// allows an application to write all files into L0 and
// then do a single compaction to output all files into L1.
Options*
Options::PrepareForBulkLoad()
{
// never slowdown ingest.
level0_file_num_compaction_trigger = (1<<30);
level0_slowdown_writes_trigger = (1<<30);
level0_stop_writes_trigger = (1<<30);
soft_pending_compaction_bytes_limit = 0;
hard_pending_compaction_bytes_limit = 0;
// no auto compactions please. The application should issue a
// manual compaction after all data is loaded into L0.
disable_auto_compactions = true;
// A manual compaction run should pick all files in L0 in
// a single compaction run.
max_compaction_bytes = (static_cast<uint64_t>(1) << 60);
// It is better to have only 2 levels, otherwise a manual
// compaction would compact at every possible level, thereby
// increasing the total time needed for compactions.
num_levels = 2;
// Need to allow more write buffers to allow more parallism
// of flushes.
max_write_buffer_number = 6;
min_write_buffer_number_to_merge = 1;
// When compaction is disabled, more parallel flush threads can
// help with write throughput.
max_background_flushes = 4;
// Prevent a memtable flush to automatically promote files
// to L1. This is helpful so that all files that are
// input to the manual compaction are all at L0.
max_background_compactions = 2;
// The compaction would create large files in L1.
target_file_size_base = 256 * 1024 * 1024;
return this;
}
Options* Options::OptimizeForSmallDb() {
// 16MB block cache
std::shared_ptr<Cache> cache = NewLRUCache(16 << 20);
ColumnFamilyOptions::OptimizeForSmallDb(&cache);
DBOptions::OptimizeForSmallDb(&cache);
return this;
}
Options* Options::OldDefaults(int rocksdb_major_version,
int rocksdb_minor_version) {
ColumnFamilyOptions::OldDefaults(rocksdb_major_version,
rocksdb_minor_version);
DBOptions::OldDefaults(rocksdb_major_version, rocksdb_minor_version);
return this;
}
DBOptions* DBOptions::OldDefaults(int rocksdb_major_version,
int rocksdb_minor_version) {
if (rocksdb_major_version < 4 ||
(rocksdb_major_version == 4 && rocksdb_minor_version < 7)) {
max_file_opening_threads = 1;
table_cache_numshardbits = 4;
}
if (rocksdb_major_version < 5 ||
(rocksdb_major_version == 5 && rocksdb_minor_version < 2)) {
delayed_write_rate = 2 * 1024U * 1024U;
} else if (rocksdb_major_version < 5 ||
(rocksdb_major_version == 5 && rocksdb_minor_version < 6)) {
delayed_write_rate = 16 * 1024U * 1024U;
}
max_open_files = 5000;
wal_recovery_mode = WALRecoveryMode::kTolerateCorruptedTailRecords;
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OldDefaults(
int rocksdb_major_version, int rocksdb_minor_version) {
if (rocksdb_major_version < 5 ||
(rocksdb_major_version == 5 && rocksdb_minor_version <= 18)) {
compaction_pri = CompactionPri::kByCompensatedSize;
}
if (rocksdb_major_version < 4 ||
(rocksdb_major_version == 4 && rocksdb_minor_version < 7)) {
write_buffer_size = 4 << 20;
target_file_size_base = 2 * 1048576;
max_bytes_for_level_base = 10 * 1048576;
soft_pending_compaction_bytes_limit = 0;
hard_pending_compaction_bytes_limit = 0;
}
if (rocksdb_major_version < 5) {
level0_stop_writes_trigger = 24;
} else if (rocksdb_major_version == 5 && rocksdb_minor_version < 2) {
level0_stop_writes_trigger = 30;
}
return this;
}
// Optimization functions
DBOptions* DBOptions::OptimizeForSmallDb(std::shared_ptr<Cache>* cache) {
max_file_opening_threads = 1;
max_open_files = 5000;
// Cost memtable to block cache too.
std::shared_ptr<rocksdb::WriteBufferManager> wbm =
std::make_shared<rocksdb::WriteBufferManager>(
0, (cache != nullptr) ? *cache : std::shared_ptr<Cache>());
write_buffer_manager = wbm;
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeForSmallDb(
std::shared_ptr<Cache>* cache) {
write_buffer_size = 2 << 20;
target_file_size_base = 2 * 1048576;
max_bytes_for_level_base = 10 * 1048576;
soft_pending_compaction_bytes_limit = 256 * 1048576;
hard_pending_compaction_bytes_limit = 1073741824ul;
BlockBasedTableOptions table_options;
table_options.block_cache =
(cache != nullptr) ? *cache : std::shared_ptr<Cache>();
table_options.cache_index_and_filter_blocks = true;
// Two level iterator to avoid LRU cache imbalance
table_options.index_type =
BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
table_factory.reset(new BlockBasedTableFactory(table_options));
return this;
}
#ifndef ROCKSDB_LITE
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeForPointLookup(
uint64_t block_cache_size_mb) {
BlockBasedTableOptions block_based_options;
block_based_options.data_block_index_type =
BlockBasedTableOptions::kDataBlockBinaryAndHash;
block_based_options.data_block_hash_table_util_ratio = 0.75;
block_based_options.filter_policy.reset(NewBloomFilterPolicy(10));
block_based_options.block_cache =
NewLRUCache(static_cast<size_t>(block_cache_size_mb * 1024 * 1024));
table_factory.reset(new BlockBasedTableFactory(block_based_options));
memtable_prefix_bloom_size_ratio = 0.02;
memtable_whole_key_filtering = true;
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeLevelStyleCompaction(
uint64_t memtable_memory_budget) {
write_buffer_size = static_cast<size_t>(memtable_memory_budget / 4);
// merge two memtables when flushing to L0
min_write_buffer_number_to_merge = 2;
// this means we'll use 50% extra memory in the worst case, but will reduce
// write stalls.
max_write_buffer_number = 6;
// start flushing L0->L1 as soon as possible. each file on level0 is
// (memtable_memory_budget / 2). This will flush level 0 when it's bigger than
// memtable_memory_budget.
level0_file_num_compaction_trigger = 2;
// doesn't really matter much, but we don't want to create too many files
target_file_size_base = memtable_memory_budget / 8;
// make Level1 size equal to Level0 size, so that L0->L1 compactions are fast
max_bytes_for_level_base = memtable_memory_budget;
// level style compaction
compaction_style = kCompactionStyleLevel;
// only compress levels >= 2
compression_per_level.resize(num_levels);
for (int i = 0; i < num_levels; ++i) {
if (i < 2) {
compression_per_level[i] = kNoCompression;
} else {
compression_per_level[i] = kSnappyCompression;
}
}
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeUniversalStyleCompaction(
uint64_t memtable_memory_budget) {
write_buffer_size = static_cast<size_t>(memtable_memory_budget / 4);
// merge two memtables when flushing to L0
min_write_buffer_number_to_merge = 2;
// this means we'll use 50% extra memory in the worst case, but will reduce
// write stalls.
max_write_buffer_number = 6;
// universal style compaction
compaction_style = kCompactionStyleUniversal;
compaction_options_universal.compression_size_percent = 80;
return this;
}
DBOptions* DBOptions::IncreaseParallelism(int total_threads) {
max_background_jobs = total_threads;
env->SetBackgroundThreads(total_threads, Env::LOW);
env->SetBackgroundThreads(1, Env::HIGH);
return this;
}
#endif // !ROCKSDB_LITE
ReadOptions::ReadOptions()
: snapshot(nullptr),
iterate_lower_bound(nullptr),
iterate_upper_bound(nullptr),
readahead_size(0),
max_skippable_internal_keys(0),
read_tier(kReadAllTier),
verify_checksums(true),
fill_cache(true),
tailing(false),
managed(false),
total_order_seek(false),
prefix_same_as_start(false),
pin_data(false),
background_purge_on_iterator_cleanup(false),
ignore_range_deletions(false),
iter_start_seqnum(0) {}
ReadOptions::ReadOptions(bool cksum, bool cache)
: snapshot(nullptr),
iterate_lower_bound(nullptr),
iterate_upper_bound(nullptr),
readahead_size(0),
max_skippable_internal_keys(0),
read_tier(kReadAllTier),
verify_checksums(cksum),
fill_cache(cache),
tailing(false),
managed(false),
total_order_seek(false),
prefix_same_as_start(false),
pin_data(false),
background_purge_on_iterator_cleanup(false),
ignore_range_deletions(false),
iter_start_seqnum(0) {}
} // namespace rocksdb