d758273ceb
Summary: If user-defined timestamp is enabled, current implementation can expose newer data to queries even if an older sequence number is specified via read_options.snapshot. This PR makes Get() respect sequence-number-based snapshot. Solution is simple. Besides using <ukey, ts, seq> to search the index for the key, we also verify that the candidate result's seq is smaller than or equal to seq. This requires passing a seq via `GetContext`, which results in the majority of code change caused by this PR. Also added a few unit tests to demonstrate standard visibility during point lookup and range scan when timestamp and snapshot are both present. Test plan (devserver): ``` make check $./db_bench --benchmarks=fillseq,readrandom -cache_size=$[64*1024*1024] ``` Result this PR: readrandom : 4.827 micros/op 207180 ops/sec; 22.9 MB/s (1000000 of 1000000 found) master: readrandom : 4.936 micros/op 202610 ops/sec; 22.4 MB/s (1000000 of 1000000 found) Pull Request resolved: https://github.com/facebook/rocksdb/pull/7227 Reviewed By: ltamasi Differential Revision: D23015242 Pulled By: riversand963 fbshipit-source-id: ea7b85a728654553ba357d2e6a207b5e40f7376a |
||
|---|---|---|
| .circleci | ||
| .github/workflows | ||
| buckifier | ||
| build_tools | ||
| cache | ||
| cmake | ||
| coverage | ||
| db | ||
| db_stress_tool | ||
| docs | ||
| env | ||
| examples | ||
| file | ||
| hdfs | ||
| include/rocksdb | ||
| java | ||
| logging | ||
| memory | ||
| memtable | ||
| monitoring | ||
| options | ||
| port | ||
| table | ||
| test_util | ||
| third-party | ||
| tools | ||
| trace_replay | ||
| util | ||
| utilities | ||
| .clang-format | ||
| .gitignore | ||
| .lgtm.yml | ||
| .travis.yml | ||
| .watchmanconfig | ||
| appveyor.yml | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| DEFAULT_OPTIONS_HISTORY.md | ||
| defs.bzl | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
| INSTALL.md | ||
| issue_template.md | ||
| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
| src.mk | ||
| TARGETS | ||
| thirdparty.inc | ||
| USERS.md | ||
| Vagrantfile | ||
| WINDOWS_PORT.md | ||
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 especially 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/ and https://rocksdb.slack.com/
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.