325dcdf2e5
Summary: based on the option comment, `ignore_range_deletions` was added due to the overhead of range deletions in read path when a DB does not use DeleteRange(). The current implementation should not have a noticeable performance difference in this case. `experimental::PromoteL0()` can be replaced by doing a manual compaction with proper CompactRangeOptions. There are some internal use of these option and API so we will remove them later after the usages are updated. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13500 Test Plan: comment change only. Performance: benchmark the performance difference with `ignore_range_deletions` and without (borrowed flag `universal_incremental` for this purpose), ran at the same time on the same machine. - random point get: - ignore_range_deletions=false: 343078 ops/sec - ignore_range_deletions=true: 340219 ops/sec (0.8% slower) ``` (for I in $(seq 1 1); do TEST_TMPDIR=/dev/shm/t1 /data/users/changyubi/vscode-root/rocksdb/db_bench --benchmarks=fillseq,waitforcompaction,readrandom --write_buffer_size=67108864 --writes=1000000 --num=2000000 --reads=1000000 --seed=1723056275 --universal_incremental=false 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; ``` - sequential scan: - ignore_range_deletions=false: 5378104 ops/sec - ignore_range_deletions=true: 5393809 ops/sec (0.3% faster) ``` (for I in $(seq 1 10); do TEST_TMPDIR=/dev/shm/t1 /data/users/changyubi/vscode-root/rocksdb/db_bench --benchmarks=fillseq,waitforcompaction,readseq[-X10] --write_buffer_size=67108864 --writes=1000000 --num=2000000 --universal_incremental=true --seed=1723056275 2>1 | grep "\[AVG 10 runs\]"; done;) | awk '{ t += $6; c++; print; } END { printf "%.0f\n", 1.0 * t / c }'; ``` The difference in ops/sec for the two benchmarks is likely noise. Reviewed By: hx235 Differential Revision: D72069223 Pulled By: cbi42 fbshipit-source-id: ad82a051aa4682790d2178cd4fb2d1467397fbb5
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key-value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it especially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/main/examples
See the github wiki for more explanation.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.
License
RocksDB is dual-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). You may select, at your option, one of the above-listed licenses.