Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/12143 https://github.com/facebook/rocksdb/pull/11982 changed `WriteBatchWithIndex::MultiGetFromBatchDB` to preallocate space in the `autovector`s `key_contexts` and `merges` in order to prevent any reallocations, both as an optimization and in order to prevent pointers into the container from being invalidated during subsequent insertions. On second thought, this preallocation can actually be a pessimization in cases when only a small subset of keys require querying the underlying database. To prevent any memory regressions, the PR reverts this preallocation. In addition, it makes some small code hygiene improvements like incorporating the `PinnableWideColumns` object into `MergeTuple`. Reviewed By: jaykorean Differential Revision: D52136513 fbshipit-source-id: 21aa835084433feab27b501d9d1fc5434acea609
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.