600ca9a439
Summary: `CollapsedRangeDelMap` internally uses seqno zero as a sentinel value to denote a gap between range tombstones or the end of range tombstones. It therefore expects to never have consecutive sentinel tombstones. However, since `DeleteRange` is now supported in `SstFileWriter`, an ingested file may contain range tombstones, and that ingested file may be assigned global seqno zero. When such tombstones are added to the collapsed map, they resemble sentinel tombstones due to having seqno zero. Then, the invariant mentioned above about never having consecutive sentinel tombstones can be violated. The symptom of this violation was dereferencing the `end()` iterator (#4204). The fix in this PR is to not add range tombstones with seqno zero to the collapsed map. They're not needed anyways since they can't possibly cover anything (in case of a key and a range tombstone with the same seqno, the key is visible). Pull Request resolved: https://github.com/facebook/rocksdb/pull/4216 Differential Revision: D9121716 Pulled By: ajkr fbshipit-source-id: f5b78a70bea9527354603ea7ac8542a7e2b6a210
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.