1f802773bc
Summary: In the past, we assume that a job modifies a single column family. Therefore, a job can create at most one superversion since each superversion corresponds to one column family. This assumption leads to the fact that a `JobContext` has only one member variable called `superversion_context`. Now we want to support group flush of column families, indicating that each job can create multiple superversions. Therefore, we need to make the following change to accommodate this new feature. Add a vector of `SuperVersionContext` to `JobContext` to support installing superversions for multiple column families in one job context. This PR is a subset of [PR 3752](https://github.com/facebook/rocksdb/pull/3752). Pull Request resolved: https://github.com/facebook/rocksdb/pull/3949 Differential Revision: D8864895 Pulled By: riversand963 fbshipit-source-id: 5937a48817276370d3c8172db9c8aafc826d97ca
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.