45f213b558
Summary: When there are no range deletions, flush and compaction perform a binary search on an effectively empty map every time they call ShouldDelete. This PR lazily initializes each stripe map entry so that the binary search can be elided in these cases. After this PR, the total amount of time spent in compactions is 52.541331s, and the total amount of time spent in flush is 5.532608s, the former of which is a significant improvement from the results after #4495. Pull Request resolved: https://github.com/facebook/rocksdb/pull/4497 Differential Revision: D10428610 Pulled By: abhimadan fbshipit-source-id: 6f7e1ce3698fac3ef86d1197955e6b72e0931a0f
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 specially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/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.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/
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.