rocksdb/db/compaction
Yanqin Jin 82b3888433 Enable backward iterator for keys with user-defined timestamp (#8035)
Summary:
This PR does the following:

- Enable backward iteration for keys with user-defined timestamp. Note that merge, single delete, range delete are not supported yet.
- Introduces a new helper API `Comparator::EqualWithoutTimestamp()`.
- Fix a typo in `SetTimestamp()`.
- Add/update unit tests

Run db_bench (built with DEBUG_LEVEL=0) to demonstrate that no overhead is introduced for CPU-intensive workloads with a lot of `Prev()`. Also provided results of iterating keys with timestamps.

1. Disable timestamp, run:
```
./db_bench -db=/dev/shm/rocksdb -disable_wal=1 -benchmarks=fillseq,seekrandom[-W1-X6] -reverse_iterator=1 -seek_nexts=5
```
Results:
> Baseline
> - seekrandom [AVG    6 runs] : 96115 ops/sec;   53.2 MB/sec
> - seekrandom [MEDIAN 6 runs] : 98075 ops/sec;   54.2 MB/sec
>
> This PR
> - seekrandom [AVG    6 runs] : 95521 ops/sec;   52.8 MB/sec
> - seekrandom [MEDIAN 6 runs] : 96338 ops/sec;   53.3 MB/sec

2. Enable timestamp, run:
```
./db_bench -user_timestamp_size=8  -db=/dev/shm/rocksdb -disable_wal=1 -benchmarks=fillseq,seekrandom[-W1-X6] -reverse_iterator=1 -seek_nexts=5
```
Result:
> Baseline: not supported
>
> This PR
> - seekrandom [AVG    6 runs] : 90514 ops/sec;   50.1 MB/sec
> - seekrandom [MEDIAN 6 runs] : 90834 ops/sec;   50.2 MB/sec

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8035

Reviewed By: ltamasi

Differential Revision: D26926668

Pulled By: riversand963

fbshipit-source-id: 95330cc2242397c03e09d29e5417dfb0adc98ef5
2021-03-10 11:15:46 -08:00
..
compaction.cc Expand effect of dictionary settings in ColumnFamilyOptions::compression_opts (#7619) 2020-11-02 19:21:11 -08:00
compaction.h SST Partitioner interface that allows to split SST files (#6957) 2020-07-24 13:44:49 -07:00
compaction_iteration_stats.h Update compaction statistics to include the amount of data read from blob files (#8022) 2021-03-04 00:43:48 -08:00
compaction_iterator.cc Enable backward iterator for keys with user-defined timestamp (#8035) 2021-03-10 11:15:46 -08:00
compaction_iterator.h Add a SystemClock class to capture the time functions of an Env (#7858) 2021-01-25 22:09:11 -08:00
compaction_iterator_test.cc Fix a SingleDelete related optimization for blob indexes (#7904) 2021-01-29 12:41:25 -08:00
compaction_job.cc Update compaction statistics to include the amount of data read from blob files (#8022) 2021-03-04 00:43:48 -08:00
compaction_job.h Add a SystemClock class to capture the time functions of an Env (#7858) 2021-01-25 22:09:11 -08:00
compaction_job_stats_test.cc Add more tests to ASSERT_STATUS_CHECKED (3), API change (#7715) 2021-01-06 14:15:02 -08:00
compaction_job_test.cc Remove Legacy and Custom FileWrapper classes from header files (#7851) 2021-01-28 22:10:32 -08:00
compaction_picker.cc Always apply bottommost_compression_opts when enabled (#7633) 2020-11-11 20:32:28 -08:00
compaction_picker.h Make max_subcompactions dynamically changeable (#7159) 2020-07-22 18:32:52 -07:00
compaction_picker_fifo.cc Make max_subcompactions dynamically changeable (#7159) 2020-07-22 18:32:52 -07:00
compaction_picker_fifo.h Make max_subcompactions dynamically changeable (#7159) 2020-07-22 18:32:52 -07:00
compaction_picker_level.cc Make max_subcompactions dynamically changeable (#7159) 2020-07-22 18:32:52 -07:00
compaction_picker_level.h Make max_subcompactions dynamically changeable (#7159) 2020-07-22 18:32:52 -07:00
compaction_picker_test.cc Add more tests for assert status checked (#7524) 2020-12-22 23:45:58 -08:00
compaction_picker_universal.cc Make sure assert(false) handles failures too (#7483) 2020-10-06 13:52:42 -07:00
compaction_picker_universal.h Make max_subcompactions dynamically changeable (#7159) 2020-07-22 18:32:52 -07:00
sst_partitioner.cc SST Partitioner interface that allows to split SST files (#6957) 2020-07-24 13:44:49 -07:00