Improve performance with default configuration

[mdcallag]

For background see http://smalldatum.blogspot.com/2018/07/default-options-in-myrocks.html . I want MyRocks to have better default behavior without setting rocksdb_default_cf_options. These are default values that are lousy for performance and we when discussing with early evaluators we usually suggest they get changed. We also set them in our tuning guide. It is much better to enable them by default.

• bloom filters disabled
• level_compaction_dynamic_level_bytes=false
• optimize_filters_for_hits=false (which is fine because BF aren't used)
• compaction_pri=kByCompensatedSize
• compression disabled

Also, the features to improve tombstone handling are also disabled by default:

rocksdb_compaction_sequential_deletes 0 rocksdb_compaction_sequential_deletes_count_sd OFF rocksdb_compaction_sequential_deletes_file_size 0 rocksdb_compaction_sequential_deletes_window 0

My requests are

1. we enable all of this by default
2. make many of these options easier to set (rocksdb_default_cf_options is not easy to set) by giving them top-level settings (rocksdb_bloom_filters, etc)
3. tombstone optimizations should be on/off not set via 4 options

[amitwdh]

I am looking to enable above features. I want to configure them through rocksdb java api. Can someone please provide way to configure them?