rocksdb/DEFAULT_OPTIONS_HISTORY.md

## Unreleased
* options.write_buffer_size changes from 4MB to 64MB
* options.target_file_size_base changes from 2MB to 64MB
* options.max_bytes_for_level_base changes from 10MB to 256MB
* options.soft_pending_compaction_bytes_limit changes from 0 (disabled) to 64GB
* options.hard_pending_compaction_bytes_limit changes from 0 (disabled) to 256GB
* table_cache_numshardbits changes from 4 to 6
* max_file_opening_threads changes from 1 to 16
Change some RocksDB default options Summary: Change some RocksDB default options to make it more friendly to server workloads. Test Plan: Run all existing tests Reviewers: yhchiang, IslamAbdelRahman Reviewed By: IslamAbdelRahman Subscribers: sumeet, muthu, benj, MarkCallaghan, igor, leveldb, andrewkr, dhruba Differential Revision: https://reviews.facebook.net/D55941 2016-03-24 20:45:50 +01:00			`## Unreleased`
			`* options.write_buffer_size changes from 4MB to 64MB`
			`* options.target_file_size_base changes from 2MB to 64MB`
			`* options.max_bytes_for_level_base changes from 10MB to 256MB`
			`* options.soft_pending_compaction_bytes_limit changes from 0 (disabled) to 64GB`
Change default number of cache shard bit to be 6 and max_file_opening_threads to be 16. Summary: Cache shard bit 4 is sometimes too small and 6 is a more common value picked by users. Make that default. It shouldn't hurt much to change options.max_file_opening_threads default to be 16, which will reduce the worst case DB open time. Test Plan: Run all existing tests. Reviewers: IslamAbdelRahman, yhchiang, kradhakrishnan, igor, andrewkr Reviewed By: andrewkr Subscribers: andrewkr, MarkCallaghan, leveldb, dhruba Differential Revision: https://reviews.facebook.net/D55047 2016-04-07 22:51:47 +02:00			`* options.hard_pending_compaction_bytes_limit changes from 0 (disabled) to 256GB`
			`* table_cache_numshardbits changes from 4 to 6`
			`* max_file_opening_threads changes from 1 to 16`