mirror of https://github.com/facebook/rocksdb.git
e6be168aa5
Summary: This saves up to two key comparisons in block seeks. The first key comparison saved is a redundant key comparison against the restart key where the linear scan starts. This comparison is saved in all cases except when the found key is in the first restart interval. The second key comparison saved is a redundant key comparison against the restart key where the linear scan ends. This is only saved in cases where all keys in the restart interval are less than the target (probability roughly `1/restart_interval`). Pull Request resolved: https://github.com/facebook/rocksdb/pull/6646 Test Plan: ran a benchmark with mostly default settings and counted key comparisons before: `user_key_comparison_count = 19399529` after: `user_key_comparison_count = 18431498` setup command: ``` $ TEST_TMPDIR=/dev/shm/dbbench ./db_bench -benchmarks=fillrandom,compact -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -max_background_jobs=12 -level_compaction_dynamic_level_bytes=true -num=10000000 ``` benchmark command: ``` $ TEST_TMPDIR=/dev/shm/dbbench/ ./db_bench -use_existing_db=true -benchmarks=readrandom -disable_auto_compactions=true -num=10000000 -compression_type=none -reads=1000000 -perf_level=3 ``` Reviewed By: pdillinger Differential Revision: D20849707 Pulled By: ajkr fbshipit-source-id: 1f01c5cd99ea771fd27974046e37b194f1cdcfac |
||
|---|---|---|
| .. | ||
| adaptive | ||
| block_based | ||
| cuckoo | ||
| plain | ||
| block_fetcher.cc | ||
| block_fetcher.h | ||
| block_fetcher_test.cc | ||
| cleanable_test.cc | ||
| format.cc | ||
| format.h | ||
| get_context.cc | ||
| get_context.h | ||
| internal_iterator.h | ||
| iter_heap.h | ||
| iterator.cc | ||
| iterator_wrapper.h | ||
| merger_test.cc | ||
| merging_iterator.cc | ||
| merging_iterator.h | ||
| meta_blocks.cc | ||
| meta_blocks.h | ||
| mock_table.cc | ||
| mock_table.h | ||
| multiget_context.h | ||
| persistent_cache_helper.cc | ||
| persistent_cache_helper.h | ||
| persistent_cache_options.h | ||
| scoped_arena_iterator.h | ||
| sst_file_reader.cc | ||
| sst_file_reader_test.cc | ||
| sst_file_writer.cc | ||
| sst_file_writer_collectors.h | ||
| table_builder.h | ||
| table_properties.cc | ||
| table_properties_internal.h | ||
| table_reader.h | ||
| table_reader_bench.cc | ||
| table_reader_caller.h | ||
| table_test.cc | ||
| two_level_iterator.cc | ||
| two_level_iterator.h | ||