ed5aec5ba3
Summary: Since a range tombstone seen at one level will cover all keys in the range at lower levels, there was a short-circuiting check in Get that reported a key was not found at most one file after the range tombstone was discovered. However, this was incorrect for merge operands, since a deletion might only cover some merge operands, which implies that the key should be found. This PR fixes this logic in the Version portion of Get, and removes the logic from the MemTable portion of Get, since the perforamnce benefit provided there is minimal. Pull Request resolved: https://github.com/facebook/rocksdb/pull/4698 Differential Revision: D13142484 Pulled By: abhimadan fbshipit-source-id: cbd74537c806032f2bfa564724d01a80df7c8f10
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.