* Remove DBOptions::preserved_deletes and DB::SetPreserveDeletesSequenceNumber().
* Remove DBOptions::preserved_deletes and DB::SetPreserveDeletesSequenceNumber().
* Remove deprecated API AdvancedColumnFamilyOptions::rate_limit_delay_max_milliseconds.
* Remove deprecated API AdvancedColumnFamilyOptions::rate_limit_delay_max_milliseconds.
* Removed timestamp from WriteOptions. Accordingly, added to DB APIs Put, Delete, SingleDelete, etc. accepting an additional argument 'timestamp'. Added Put, Delete, SingleDelete, etc to WriteBatch accepting an additional argument 'timestamp'. Removed WriteBatch::AssignTimestamps(vector<Slice>) API. Renamed WriteBatch::AssignTimestamp() to WriteBatch::UpdateTimestamps() with clarified comments.
* Removed timestamp from WriteOptions. Accordingly, added to DB APIs Put, Delete, SingleDelete, etc. accepting an additional argument 'timestamp'. Added Put, Delete, SingleDelete, etc to WriteBatch accepting an additional argument 'timestamp'. Removed WriteBatch::AssignTimestamps(vector<Slice>) API. Renamed WriteBatch::AssignTimestamp() to WriteBatch::UpdateTimestamps() with clarified comments.
* Remove default implementation of Name() from FileSystemWrapper.
### Behavior Changes
### Behavior Changes
* Disallow the combination of DBOptions.use_direct_io_for_flush_and_compaction == true and DBOptions.writable_file_max_buffer_size == 0. This combination can cause WritableFileWriter::Append() to loop forever, and it does not make much sense in direct IO.
* Disallow the combination of DBOptions.use_direct_io_for_flush_and_compaction == true and DBOptions.writable_file_max_buffer_size == 0. This combination can cause WritableFileWriter::Append() to loop forever, and it does not make much sense in direct IO.