6595267980
Summary: Add a threshold timestamp, full_history_ts_low_ of type `std::string*` to `CompactionIterator`, so that RocksDB can also perform garbage collection during compaction. * If full_history_ts_low_ is nullptr, then compaction iterator does not perform GC, preserving all timestamp history for all keys. Compaction iterator will treat user key with different timestamps as different user keys. * If full_history_ts_low_ is not nullptr, then compaction iterator performs GC. GC will look at keys older than `*full_history_ts_low_` and determine their eligibility based on factors including snapshots. Current rules of GC: * If an internal key is in the same snapshot as a previous counterpart with the same user key, and this key is eligible for GC, and the key is not single-delete or merge operand, then this key can be dropped. Note that the previous internal key cannot be a merge operand either. * If a tombstone is the most recent one in the earliest snapshot and it is eligible for GC, and keyNotExistsBeyondLevel() is true, then this tombstone can be dropped. * If a tombstone is the most recent one in a snapshot and it is eligible for GC, and the compaction is at bottommost level, then all other older internal keys of the same user key must also be eligible for GC, thus can be dropped * Single-delete, delete-range and merge are not currently supported. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7556 Test Plan: make check Reviewed By: ltamasi Differential Revision: D24507728 Pulled By: riversand963 fbshipit-source-id: 3c09c7301f41eed76dfcf4d1527e68cf6e0a8bb3 |
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.. | ||
compaction_iteration_stats.h | ||
compaction_iterator_test.cc | ||
compaction_iterator.cc | ||
compaction_iterator.h | ||
compaction_job_stats_test.cc | ||
compaction_job_test.cc | ||
compaction_job.cc | ||
compaction_job.h | ||
compaction_picker_fifo.cc | ||
compaction_picker_fifo.h | ||
compaction_picker_level.cc | ||
compaction_picker_level.h | ||
compaction_picker_test.cc | ||
compaction_picker_universal.cc | ||
compaction_picker_universal.h | ||
compaction_picker.cc | ||
compaction_picker.h | ||
compaction.cc | ||
compaction.h | ||
sst_partitioner.cc |