edcbb36944
Summary: Three small optimizations: (1) iter_->IsKeyPinned() shouldn't be called if read_options.pin_data is not true. This may trigger function call all the way down the iterator tree. (2) reuse the iterator key object in DBIter::FindNextUserEntryInternal(). The constructor of the class has some overheads. (3) Move the switching direction logic in MergingIterator::Next() to a separate function. These three in total improves readseq performance by about 3% in my benchmark setting. Closes https://github.com/facebook/rocksdb/pull/2880 Differential Revision: D5829252 Pulled By: siying fbshipit-source-id: 991aea10c6d6c3b43769cb4db168db62954ad1e3
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/