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由 Igor Canadi 提交于
options.level_compaction_dynamic_level_bytes to allow RocksDB to pick size bases of levels dynamically. Summary: When having fixed max_bytes_for_level_base, the ratio of size of largest level and the second one can range from 0 to the multiplier. This makes LSM tree frequently irregular and unpredictable. It can also cause poor space amplification in some cases. In this improvement (proposed by Igor Kabiljo), we introduce a parameter option.level_compaction_use_dynamic_max_bytes. When turning it on, RocksDB is free to pick a level base in the range of (options.max_bytes_for_level_base/options.max_bytes_for_level_multiplier, options.max_bytes_for_level_base] so that real level ratios are close to options.max_bytes_for_level_multiplier. Test Plan: New unit tests and pass tests suites including valgrind. Reviewers: MarkCallaghan, rven, yhchiang, igor, ikabiljo Reviewed By: ikabiljo Subscribers: yoshinorim, ikabiljo, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D31437
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