Peter Dillinger 68a9c186d0 FilterPolicy API changes for 7.0 (#9501)
Summary:
* Inefficient block-based filter is no longer customizable in the public
API, though (for now) can still be enabled.
  * Removed deprecated FilterPolicy::CreateFilter() and
  FilterPolicy::KeyMayMatch()
  * Removed `rocksdb_filterpolicy_create()` from C API
* Change meaning of nullptr return from GetBuilderWithContext() from "use
block-based filter" to "generate no filter in this case." This is a
cleaner solution to the proposal in https://github.com/facebook/rocksdb/issues/8250.
  * Also, when user specifies bits_per_key < 0.5, we now round this down
  to "no filter" because we expect a filter with >= 80% FP rate is
  unlikely to be worth the CPU cost of accessing it (esp with
  cache_index_and_filter_blocks=1 or partition_filters=1).
  * bits_per_key >= 0.5 and < 1.0 is still rounded up to 1.0 (for 62% FP
  rate)
  * This also gives us some support for configuring filters from OPTIONS
  file as currently saved: `filter_policy=rocksdb.BuiltinBloomFilter`.
  Opening from such an options file will enable reading filters (an
  improvement) but not writing new ones. (See Customizable follow-up
  below.)
* Also removed deprecated functions
  * FilterBitsBuilder::CalculateNumEntry()
  * FilterPolicy::GetFilterBitsBuilder()
  * NewExperimentalRibbonFilterPolicy()
* Remove default implementations of
  * FilterBitsBuilder::EstimateEntriesAdded()
  * FilterBitsBuilder::ApproximateNumEntries()
  * FilterPolicy::GetBuilderWithContext()
* Remove support for "filter_policy=experimental_ribbon" configuration
string.
* Allow "filter_policy=bloomfilter:n" without bool to discourage use of
block-based filter.

Some pieces for https://github.com/facebook/rocksdb/issues/9389

Likely follow-up (later PRs):
* Refactoring toward FilterPolicy Customizable, so that we can generate
filters with same configuration as before when configuring from options
file.
* Remove support for user enabling block-based filter (ignore `bool
use_block_based_builder`)
  * Some months after this change, we could even remove read support for
  block-based filter, because it is not critical to DB data
  preservation.
* Make FilterBitsBuilder::FinishV2 to avoid `using
FilterBitsBuilder::Finish` mess and add support for specifying a
MemoryAllocator (for cache warming)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9501

Test Plan:
A number of obsolete tests deleted and new tests or test
cases added or updated.

Reviewed By: hx235

Differential Revision: D34008011

Pulled By: pdillinger

fbshipit-source-id: a39a720457c354e00d5b59166b686f7f59e392aa
2022-02-08 13:56:46 -08:00
2022-02-04 17:13:10 -08:00
2022-02-04 17:13:10 -08:00
2022-02-04 17:13:10 -08:00
2022-01-12 09:31:12 -08:00
2022-02-04 17:13:10 -08:00
2017-10-18 14:42:10 -07:00
2022-02-04 17:13:10 -08:00
2019-08-29 23:21:01 -07:00
2017-12-05 18:42:35 -08:00
2017-04-27 18:06:12 -07:00
2017-07-15 16:11:23 -07:00
2019-06-24 17:40:32 -07:00
2021-10-01 16:10:35 -07:00

RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

CircleCI Status TravisCI Status Appveyor Build status PPC64le Build Status

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/main/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.

Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.

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.

Description
A library that provides an embeddable, persistent key-value store for fast storage.
Readme 271 MiB
Languages
C++ 82.1%
Java 10.3%
C 2.5%
Python 1.7%
Perl 1.1%
Other 2.1%