ExRocket Option Reference

This is the canonical public option inventory for ExRocket 0.5.0. The CI option inventory test compares every key below with the native decoders. Unknown keys return {:error, {:unknown_option, key}}; malformed values return {:error, {:invalid_option, key}} before a database is opened or mutated.

Database option keys intentionally mirror the maintained rust-rocksdb API. There are no shortened aliases such as max_open_files or write_buffer_size. set_use_fsync chooses RocksDB's synchronization mechanism; it does not make each write synchronous. Use write_batch/3 with %{sync: true} for a synchronous write boundary.

Database And Column-Family Options

All keys are optional. nil below means the option is not applied and RocksDB's native default remains in effect. ExRocket's only explicit database default is create_if_missing: true.

String constraints:

Compression: None, Snappy, Zlib, Bz2, Lz4, Lz4hc, or Zstd (case-insensitive).
set_log_level: Debug, Info, Warn, Error, Fatal, or Header.
set_compaction_style: Level, Universal, or Fifo.
set_wal_recovery_mode: TolerateCorruptedTailRecords, AbsoluteConsistency, PointInTime, or SkipAnyCorruptedRecord.
merge_operator: counter_merge_operator, erlang_merge_operator, or bitset_merge_operator.
set_max_bytes_for_level_multiplier_additional: comma-separated i32 values.
set_ratelimiter: exactly three comma-separated integers representing bytes per second, refill period in microseconds, and fairness.

Key	Elixir value type	ExRocket default	Native mapping
`create_if_missing`	`boolean()`	`true`	`Options::create_if_missing`
`create_missing_column_families`	`boolean()`	`nil`	`Options::create_missing_column_families`
`set_error_if_exists`	`boolean()`	`nil`	`Options::set_error_if_exists`
`set_paranoid_checks`	`boolean()`	`nil`	`Options::set_paranoid_checks`
`increase_parallelism`	`integer()`	`nil`	`Options::increase_parallelism`
`optimize_level_style_compaction`	`non_neg_integer()`	`nil`	`Options::optimize_level_style_compaction`
`optimize_universal_style_compaction`	`non_neg_integer()`	`nil`	`Options::optimize_universal_style_compaction`
`set_compression_type`	`String.t()`	`nil`	`Options::set_compression_type`
`set_bottommost_compression_type`	`String.t()`	`nil`	`Options::set_bottommost_compression_type`
`set_zstd_max_train_bytes`	`integer()`	`nil`	`Options::set_zstd_max_train_bytes`
`set_compaction_readahead_size`	`non_neg_integer()`	`nil`	`Options::set_compaction_readahead_size`
`set_level_compaction_dynamic_level_bytes`	`boolean()`	`nil`	`Options::set_level_compaction_dynamic_level_bytes`
`set_optimize_filters_for_hits`	`boolean()`	`nil`	`Options::set_optimize_filters_for_hits`
`set_delete_obsolete_files_period_micros`	`non_neg_integer()`	`nil`	`Options::set_delete_obsolete_files_period_micros`
`set_max_open_files`	`integer()`	`nil`	`Options::set_max_open_files`
`set_max_file_opening_threads`	`integer()`	`nil`	`Options::set_max_file_opening_threads`
`set_use_fsync`	`boolean()`	`nil`	`Options::set_use_fsync`
`set_db_log_dir`	`String.t()`	`nil`	`Options::set_db_log_dir`
`set_log_level`	`String.t()`	`nil`	`Options::set_log_level`
`set_bytes_per_sync`	`non_neg_integer()`	`nil`	`Options::set_bytes_per_sync`
`set_wal_bytes_per_sync`	`non_neg_integer()`	`nil`	`Options::set_wal_bytes_per_sync`
`set_writable_file_max_buffer_size`	`non_neg_integer()`	`nil`	`Options::set_writable_file_max_buffer_size`
`set_allow_concurrent_memtable_write`	`boolean()`	`nil`	`Options::set_allow_concurrent_memtable_write`
`set_enable_write_thread_adaptive_yield`	`boolean()`	`nil`	`Options::set_enable_write_thread_adaptive_yield`
`set_max_sequential_skip_in_iterations`	`non_neg_integer()`	`nil`	`Options::set_max_sequential_skip_in_iterations`
`set_use_direct_reads`	`boolean()`	`nil`	`Options::set_use_direct_reads`
`set_use_direct_io_for_flush_and_compaction`	`boolean()`	`nil`	`Options::set_use_direct_io_for_flush_and_compaction`
`set_is_fd_close_on_exec`	`boolean()`	`nil`	`Options::set_is_fd_close_on_exec`
`set_table_cache_num_shard_bits`	`integer()`	`nil`	`Options::set_table_cache_num_shard_bits`
`set_target_file_size_multiplier`	`integer()`	`nil`	`Options::set_target_file_size_multiplier`
`set_min_write_buffer_number`	`integer()`	`nil`	`Options::set_min_write_buffer_number`
`set_max_write_buffer_number`	`integer()`	`nil`	`Options::set_max_write_buffer_number`
`set_write_buffer_size`	`non_neg_integer()`	`nil`	`Options::set_write_buffer_size`
`set_db_write_buffer_size`	`non_neg_integer()`	`nil`	`Options::set_db_write_buffer_size`
`set_max_bytes_for_level_base`	`non_neg_integer()`	`nil`	`Options::set_max_bytes_for_level_base`
`set_max_bytes_for_level_multiplier`	`float()`	`nil`	`Options::set_max_bytes_for_level_multiplier`
`set_max_manifest_file_size`	`non_neg_integer()`	`nil`	`Options::set_max_manifest_file_size`
`set_target_file_size_base`	`non_neg_integer()`	`nil`	`Options::set_target_file_size_base`
`set_min_write_buffer_number_to_merge`	`integer()`	`nil`	`Options::set_min_write_buffer_number_to_merge`
`set_level_zero_file_num_compaction_trigger`	`integer()`	`nil`	`Options::set_level_zero_file_num_compaction_trigger`
`set_level_zero_slowdown_writes_trigger`	`integer()`	`nil`	`Options::set_level_zero_slowdown_writes_trigger`
`set_level_zero_stop_writes_trigger`	`integer()`	`nil`	`Options::set_level_zero_stop_writes_trigger`
`set_compaction_style`	`String.t()`	`nil`	`Options::set_compaction_style`
`set_unordered_write`	`boolean()`	`nil`	`Options::set_unordered_write`
`set_max_subcompactions`	`non_neg_integer()`	`nil`	`Options::set_max_subcompactions`
`set_max_background_jobs`	`integer()`	`nil`	`Options::set_max_background_jobs`
`set_disable_auto_compactions`	`boolean()`	`nil`	`Options::set_disable_auto_compactions`
`set_memtable_huge_page_size`	`non_neg_integer()`	`nil`	`Options::set_memtable_huge_page_size`
`set_max_successive_merges`	`non_neg_integer()`	`nil`	`Options::set_max_successive_merges`
`set_bloom_locality`	`non_neg_integer()`	`nil`	`Options::set_bloom_locality`
`set_inplace_update_support`	`boolean()`	`nil`	`Options::set_inplace_update_support`
`set_inplace_update_locks`	`non_neg_integer()`	`nil`	`Options::set_inplace_update_locks`
`set_max_bytes_for_level_multiplier_additional`	`String.t()`	`nil`	`Options::set_max_bytes_for_level_multiplier_additional`
`set_max_write_buffer_size_to_maintain`	`integer()`	`nil`	`Options::set_max_write_buffer_size_to_maintain`
`set_enable_pipelined_write`	`boolean()`	`nil`	`Options::set_enable_pipelined_write`
`set_min_level_to_compress`	`integer()`	`nil`	`Options::set_min_level_to_compress`
`set_report_bg_io_stats`	`boolean()`	`nil`	`Options::set_report_bg_io_stats`
`set_max_total_wal_size`	`non_neg_integer()`	`nil`	`Options::set_max_total_wal_size`
`set_wal_recovery_mode`	`String.t()`	`nil`	`Options::set_wal_recovery_mode`
`enable_statistics`	`boolean()`	`nil`	`Options::enable_statistics`
`set_stats_dump_period_sec`	`non_neg_integer()`	`nil`	`Options::set_stats_dump_period_sec`
`set_stats_persist_period_sec`	`non_neg_integer()`	`nil`	`Options::set_stats_persist_period_sec`
`set_advise_random_on_open`	`boolean()`	`nil`	`Options::set_advise_random_on_open`
`set_use_adaptive_mutex`	`boolean()`	`nil`	`Options::set_use_adaptive_mutex`
`set_num_levels`	`integer()`	`nil`	`Options::set_num_levels`
`set_memtable_prefix_bloom_ratio`	`float()`	`nil`	`Options::set_memtable_prefix_bloom_ratio`
`set_max_compaction_bytes`	`non_neg_integer()`	`nil`	`Options::set_max_compaction_bytes`
`set_wal_dir`	`String.t()`	`nil`	`Options::set_wal_dir`
`set_wal_ttl_seconds`	`non_neg_integer()`	`nil`	`Options::set_wal_ttl_seconds`
`set_wal_size_limit_mb`	`non_neg_integer()`	`nil`	`Options::set_wal_size_limit_mb`
`set_manifest_preallocation_size`	`non_neg_integer()`	`nil`	`Options::set_manifest_preallocation_size`
`set_skip_stats_update_on_db_open`	`boolean()`	`nil`	`Options::set_skip_stats_update_on_db_open`
`set_keep_log_file_num`	`non_neg_integer()`	`nil`	`Options::set_keep_log_file_num`
`set_allow_mmap_writes`	`boolean()`	`nil`	`Options::set_allow_mmap_writes`
`set_allow_mmap_reads`	`boolean()`	`nil`	`Options::set_allow_mmap_reads`
`set_manual_wal_flush`	`boolean()`	`nil`	`Options::set_manual_wal_flush`
`set_atomic_flush`	`boolean()`	`nil`	`Options::set_atomic_flush`
`set_ratelimiter`	`String.t()`	`nil`	`Options::set_ratelimiter`
`set_max_log_file_size`	`non_neg_integer()`	`nil`	`Options::set_max_log_file_size`
`set_log_file_time_to_roll`	`non_neg_integer()`	`nil`	`Options::set_log_file_time_to_roll`
`set_recycle_log_file_num`	`non_neg_integer()`	`nil`	`Options::set_recycle_log_file_num`
`set_soft_pending_compaction_bytes_limit`	`non_neg_integer()`	`nil`	`Options::set_soft_pending_compaction_bytes_limit`
`set_hard_pending_compaction_bytes_limit`	`non_neg_integer()`	`nil`	`Options::set_hard_pending_compaction_bytes_limit`
`set_arena_block_size`	`non_neg_integer()`	`nil`	`Options::set_arena_block_size`
`set_dump_malloc_stats`	`boolean()`	`nil`	`Options::set_dump_malloc_stats`
`set_memtable_whole_key_filtering`	`boolean()`	`nil`	`Options::set_memtable_whole_key_filtering`
`set_enable_blob_files`	`boolean()`	`nil`	`Options::set_enable_blob_files`
`set_min_blob_size`	`non_neg_integer()`	`nil`	`Options::set_min_blob_size`
`set_blob_file_size`	`non_neg_integer()`	`nil`	`Options::set_blob_file_size`
`set_blob_compression_type`	`String.t()`	`nil`	`Options::set_blob_compression_type`
`set_enable_blob_gc`	`boolean()`	`nil`	`Options::set_enable_blob_gc`
`set_blob_gc_age_cutoff`	`float()`	`nil`	`Options::set_blob_gc_age_cutoff`
`set_blob_gc_force_threshold`	`float()`	`nil`	`Options::set_blob_gc_force_threshold`
`set_blob_compaction_readahead_size`	`non_neg_integer()`	`nil`	`Options::set_blob_compaction_readahead_size`
`set_prefix_extractor_prefix_length`	`non_neg_integer()`	`nil`	`Options::set_prefix_extractor_prefix_length`
`merge_operator`	`String.t()`	`nil`	merge callback registration

Range-Iterator Read Options

Key	Type	Default	Meaning
`iterate_lower_bound`	`String.t()`	`nil`	RocksDB inclusive iterator lower bound.
`iterate_upper_bound`	`String.t()`	`nil`	RocksDB exclusive iterator upper bound.

Binary range boundaries should normally be passed through the explicit from and to arguments of iterator_range/5; these two compatibility options retain their existing string contract.

Batch Write Options

Key	Type	Default	Meaning
`sync`	`boolean()`	`false`	Request a synchronous WAL flush before success.
`disable_wal`	`boolean()`	`false`	Disable WAL for rebuildable bulk-load data.

sync: true with disable_wal: true is rejected as {:error, :invalid_write_options}.

Iterator-Take Options

Key	Type	Default	Meaning
`max_entries`	`1..100_000`	required	Maximum rows copied in one call.
`max_bytes`	`1..67_108_864`	none	Maximum combined key/value payload, except one oversized first row.

Malformed bounds return {:error, :invalid_iterator_options}. Byte limits exclude normal Erlang term overhead.

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