d659faad54
Summary: Level-based L0->L0 compaction operates on spans of files that aren't currently being compacted. It reduces the number of L0 files, thus making write stall conditions harder to reach. - L0->L0 is triggered when base level is unavailable due to pending compactions - L0->L0 always outputs one file of at most `max_level0_burst_file_size` bytes. - Subcompactions are disabled for L0->L0 since we want to output one file. - Input files are chosen as the longest span of available files that will fit within the size limit. This minimizes number of files in L0. Closes https://github.com/facebook/rocksdb/pull/2027 Differential Revision: D4760318 Pulled By: ajkr fbshipit-source-id: 9d07183
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/