092f417037
Summary: RocksDB has historically stored uncompression dictionary objects in the block cache as opposed to storing just the block contents. This neccesitated evicting the object upon table close. With the new code, only the raw blocks are stored in the cache, eliminating the need for eviction. In addition, the patch makes the following improvements: 1) Compression dictionary blocks are now prefetched/pinned similarly to index/filter blocks. 2) A copy operation got eliminated when the uncompression dictionary is retrieved. 3) Errors related to retrieving the uncompression dictionary are propagated as opposed to silently ignored. Note: the patch temporarily breaks the compression dictionary evicition stats. They will be fixed in a separate phase. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5584 Test Plan: make asan_check Differential Revision: D16344151 Pulled By: ltamasi fbshipit-source-id: 2962b295f5b19628f9da88a3fcebbce5a5017a7b
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.