MyRocks System Variables

This page documents system variables related to the MyRocks storage engine. See Server System Variables for a complete list of system variables and instructions on setting them.

See also the Full list of MariaDB options, system and status variables.

rocksdb_access_hint_on_compaction_start

• Description: DBOptions::access_hint_on_compaction_start for RocksDB. Specifies the file access pattern, applied to all input files, once a compaction starts.

• Command line: --rocksdb-access-hint-on-compaction-start=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1

• Range: 0 to 3

rocksdb_advise_random_on_open

• Description: DBOptions::advise_random_on_open for RocksDB.

• Command line: --rocksdb-advise-random-on-open={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_allow_concurrent_memtable_write

• Description: DBOptions::allow_concurrent_memtable_write for RocksDB.

• Command line: --rocksdb-allow-concurrent-memtable-write={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_allow_mmap_reads

• Description: DBOptions::allow_mmap_reads for RocksDB

• Command line: --rocksdb-allow-mmap-reads={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_allow_mmap_writes

• Description: DBOptions::allow_mmap_writes for RocksDB

• Command line: --rocksdb-allow-mmap-writes={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_allow_to_start_after_corruption

• Description: Allow server still to start successfully even if RocksDB corruption is detected.

• Command line: --rocksdb-allow-to-start-after-corruption={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_background_sync

• Description: Turns on background syncs for RocksDB

• Command line: --rocksdb-background-sync={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

• Removed: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_base_background_compactions

• Description: DBOptions::base_background_compactions for RocksDB

• Command line: --rocksdb-base-background-compactions=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1

• Range: -1 to 64

• Removed: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_blind_delete_primary_key

• Description: Deleting rows by primary key lookup, without reading rows (Blind Deletes). Blind delete is disabled if the table has secondary key.

• Command line: --rocksdb-blind-delete-primary-key={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_block_cache_size

• Description: Block_cache size for RocksDB (block size 1024)

• Command line: --rocksdb-block-cache-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 536870912

• Range: 1024 to 9223372036854775807

To see the statistics of block cache usage, check SHOW ENGINE ROCKSDB STATUS output (search for lines starting with rocksdb.block.cache).

One can check the size of data of the block cache in DB_BLOCK_CACHE_USAGE column of the INFORMATION_SCHEMA.ROCKSDB_DBSTATS table.

rocksdb_block_restart_interval

• Description: BlockBasedTableOptions::block_restart_interval for RocksDB

• Command line: --rocksdb-block-restart-interval=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 16

• Range: 1 to 2147483647

rocksdb_block_size

• Description: BlockBasedTableOptions::block_size for RocksDB

• Command line: --rocksdb-block-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 4096

• Range: 1 to 18446744073709551615

rocksdb_block_size_deviation

• Description: BlockBasedTableOptions::block_size_deviation for RocksDB

• Command line: --rocksdb-block-size-deviation=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 10

• Range: 0 to 2147483647

rocksdb_bulk_load

• Description: Use bulk-load mode for inserts. This disables unique_checks and enables rocksdb_commit_in_the_middle.

• Command line: --rocksdb-bulk-load={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_bulk_load_allow_sk

• Description: Allow bulk loading of sk keys during bulk-load. Can be changed only when bulk load is disabled.

• Command line: --rocksdb-bulk-load_allow_sk={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_bulk_load_allow_unsorted

• Description: Allow unsorted input during bulk-load. Can be changed only when bulk load is disabled.

• Command line: --rocksdb-bulk-load_allow_unsorted={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_bulk_load_size

• Description: Maximum number of records in a batch for bulk-load mode.

• Command line: --rocksdb-bulk-load-size=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1000

• Range: 1 to 1073741824

rocksdb_bytes_per_sync

• Description: DBOptions::bytes_per_sync for RocksDB.

• Command line: --rocksdb-bytes-per-sync=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_cache_dump

• Description: Include RocksDB block cache content in core dump.

• Command line: --rocksdb-cache-dump={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

rocksdb_cache_high_pri_pool_ratio

• Description: Specify the size of block cache high-pri pool.

• Command line: --rocksdb-cache-high-pri-pool-ratio=#

• Scope: Global

• Dynamic: Yes

• Data Type: double

• Default Value: 0.000000

• Range: 0 to 1

rocksdb_cache_index_and_filter_blocks

• Description: BlockBasedTableOptions::cache_index_and_filter_blocks for RocksDB.

• Command line: --rocksdb-cache-index-and-filter-blocks={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_cache_index_and_filter_with_high_priority

• Description: cache_index_and_filter_blocks_with_high_priority for RocksDB.

• Command line: --rocksdb-cache-index-and-filter-with-high-priority={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_checksums_pct

• Description: Percentage of rows to be checksummed.

• Command line: --rocksdb-checksums-pct=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 100

• Range: 0 to 100

rocksdb_collect_sst_properties

• Description: Enables collecting SST file properties on each flush.

• Command line: --rocksdb-collect-sst-properties={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_commit_in_the_middle

• Description: Commit rows implicitly every rocksdb_bulk_load_size, on bulk load/insert, update and delete.

• Command line: --rocksdb-commit-in-the-middle={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_commit_time_batch_for_recovery

• Description: TransactionOptions::commit_time_batch_for_recovery for RocksDB.

• Command line: --rocksdb-commit-time-batch-for-recovery={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_compact_cf

• Description: Compact column family.

• Command line: --rocksdb-compact-cf=value

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: (Empty)

rocksdb_compaction_readahead_size

• Description: DBOptions::compaction_readahead_size for RocksDB.

• Command line: --rocksdb-compaction-readahead-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_compaction_sequential_deletes

• Description: RocksDB will trigger compaction for the file if it has more than this number sequential deletes per window.

• Command line: --rocksdb-compaction-sequential-deletes=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 2000000

rocksdb_compaction_sequential_deletes_count_sd

• Description: Counting SingleDelete as rocksdb_compaction_sequential_deletes.

• Command line: --rocksdb-compaction-sequential-deletes-count-sd={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_compaction_sequential_deletes_file_size

• Description: Minimum file size required for compaction_sequential_deletes.

• Command line: --rocksdb-compaction-sequential-deletes-file-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: -1 to 9223372036854775807

rocksdb_compaction_sequential_deletes_window

• Description: Size of the window for counting rocksdb_compaction_sequential_deletes.

• Command line: --rocksdb-compaction-sequential-deletes-window=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 2000000

rocksdb_concurrent_prepare

• Description: DBOptions::concurrent_prepare for RocksDB.

• Command line: --rocksdb-coconcurrent-prepare={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: 1

• Removed: MariaDB 10.3.7, MariaDB 10.2.15

rocksdb_create_checkpoint

• Description: Checkpoint directory.

• Command line: --rocksdb-create-checkpoint=value

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: (Empty)

rocksdb_create_if_missing

• Description: DBOptions::create_if_missing for RocksDB.

• Command line: --rocksdb-create-if-missing={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_create_missing_column_families

• Description: DBOptions::create_missing_column_families for RocksDB.

• Command line: --rocksdb-create-missing-column-families={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_datadir

• Description: RocksDB data directory.

• Command line: --rocksdb-datadir[=value]

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: ./#rocksdb

rocksdb_db_write_buffer_size

• Description: DBOptions::db_write_buffer_size for RocksDB.

• Command line: --rocksdb-db-write-buffer-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_deadlock_detect

• Description: Enables deadlock detection.

• Command line: --rocksdb-deadlock-detect={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_deadlock_detect_depth

• Description: Number of transactions deadlock detection will traverse through before assuming deadlock.

• Command line: --rocksdb-deadlock-detect-depth=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 50

• Range: 2 to 18446744073709551615

rocksdb_debug_manual_compaction_delay

• Description: For debugging purposes only. Sleeping specified seconds for simulating long running compactions.

• Command line: --rocksdb-debug_manual_compaction_delay=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 4294967295

rocksdb_debug_optimizer_no_zero_cardinality

• Description: If cardinality is zero, override it with some value.

• Command line: --rocksdb-debug-optimizer-no-zero-cardinality={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

rocksdb_debug_ttl_ignore_pk

• Description: For debugging purposes only. If true, compaction filtering will not occur on PK TTL data. This variable is a no-op in non-debug builds.

• Command line: --rocksdb-debug-ttl-ignore-pk={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_debug_ttl_read_filter_ts

• Description: For debugging purposes only. Overrides the TTL read filtering time to time + debug_ttl_read_filter_ts. A value of 0 denotes that the variable is not set. This variable is a no-op in non-debug builds.

• Command line: --rocksdb-debug-ttl-read-filter-ts=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: -3600 to 3600

rocksdb_debug_ttl_rec_ts

• Description: For debugging purposes only. Overrides the TTL of records to now() + debug_ttl_rec_ts. The value can be +/- to simulate a record inserted in the past vs a record inserted in the 'future'. A value of 0 denotes that the variable is not set. This variable is a no-op in non-debug builds.

• Command line: --rocksdb-debug-ttl-read-filter-ts=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: -3600 to 3600

rocksdb_debug_ttl_snapshot_ts

• Description: For debugging purposes only. Sets the snapshot during compaction to now() + debug_set_ttl_snapshot_ts. The value can be positive or negative to simulate a snapshot in the past vs a snapshot created in the 'future'. A value of 0 denotes that the variable is not set. This variable is a no-op in non-debug builds.

• Command line: --rocksdb-debug-ttl-snapshot-ts=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: -3600 to 3600

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_default_cf_options

• Description: Default cf options for RocksDB.

• Command line: --rocksdb-default-cf-options=value

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: (Empty)

rocksdb_delayed_write_rate

• Description: DBOptions::delayed_write_rate.

• Command line: --rocksdb-delayed-write-rate=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0 (Previously 16777216)

• Range: 0 to 18446744073709551615

rocksdb_delete_cf

• Description: Delete column family.

• Command line: --rocksdb-delete-cf=val

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: (Empty string)

• Introduced: MariaDB 10.4.7, MariaDB 10.3.17, MariaDB 10.2.26

rocksdb_delete_obsolete_files_period_micros

• Description: DBOptions::delete_obsolete_files_period_micros for RocksDB.

• Command line: --rocksdb-delete-obsolete-files-period-micros=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 21600000000

• Range: 0 to 9223372036854775807

rocksdb_enable_2pc

• Description: Enable two phase commit for MyRocks. When set, MyRocks will keep its data consistent with the binary log (in other words, the server are a crash-safe master). The consistency is achieved by doing two-phase XA commit with the binary log.

• Command line: --rocksdb-enable-2pc={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

rocksdb_enable_bulk_load_api

• Description: Enables using SstFileWriter for bulk loading.

• Command line: --rocksdb-enable-bulk-load-api={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_enable_insert_with_update_caching

• Description: Whether to enable optimization where we cache the read from a failed insertion attempt in INSERT ON DUPLICATE KEY UPDATE.

• Command line: --rocksdb-enable-insert-with-update-caching={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 10.4.7, MariaDB 10.3.17, MariaDB 10.2.26

rocksdb_enable_thread_tracking

• Description: DBOptions::enable_thread_tracking for RocksDB.

• Command line: --rocksdb-enable-thread-tracking={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_enable_ttl

• Description: Enable expired TTL records to be dropped during compaction.

• Command line: --rocksdb-enable-ttl={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_enable_ttl_read_filtering

• Description: For tables with TTL, expired records are skipped/filtered out during processing and in query results. Disabling this will allow these records to be seen, but as a result rows may disappear in the middle of transactions as they are dropped during compaction. Use with caution.

• Command line: --rocksdb-enable-ttl-read-filtering={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_enable_write_thread_adaptive_yield

• Description: DBOptions::enable_write_thread_adaptive_yield for RocksDB.

• Command line: --rocksdb-enable-write-thread-adaptive-yield={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_error_if_exists

• Description: DBOptions::error_if_exists for RocksDBB.

• Command line: --rocksdb-error-if-exists={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_error_on_suboptimal_collation

• Description: Raise an error instead of warning if a sub-optimal collation is used.

• Command line: --rocksdb-error-on-suboptimal-collation={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 10.3.10, MariaDB 10.2.18

rocksdb_flush_log_at_trx_commit

• Description: Sync on transaction commit. Similar to innodb_flush_log_at_trx_commit. One can check the flushing by examining the rocksdb_wal_synced and rocksdb_wal_bytes status variables.

  • 1: Always sync on commit (the default).

  • 0: Never sync.

  • 2: Sync based on a timer controlled via rocksdb-background-sync.

• Command line: --rocksdb-flush-log-at-trx-commit=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 0 to 2

rocksdb_flush_memtable_on_analyze

• Description: Forces memtable flush on ANALZYE table to get accurate cardinality.

• Command line: --rocksdb-flush-memtable-on-analyze={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

• Removed: MariaDB 10.3.7, MariaDB 10.2.15

rocksdb_force_compute_memtable_stats

• Description: Force to always compute memtable stats.

• Command line: --rocksdb-force-compute-memtable-stats={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

rocksdb_force_compute_memtable_stats_cachetime

• Description: Time in usecs to cache memtable estimates.

• Command line: --rocksdb-force-compute-memtable-stats-cachetime=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 60000000

• Range: 0 to 2147483647

rocksdb_force_flush_memtable_and_lzero_now

• Description: Acts similar to force_flush_memtable_now, but also compacts all L0 files.

• Command line: --rocksdb-force-flush-memtable-and-lzero-now={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_force_flush_memtable_now

• Description: Forces memstore flush which may block all write requests so be careful.

• Command line: --rocksdb-force-flush-memtable-now={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_force_index_records_in_range

• Description: Used to override the result of records_in_range() when FORCE INDEX is used.

• Command line: --rocksdb-force-index-records-in-range=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 2147483647

rocksdb_git_hash

• Description: Git revision of the RocksDB library used by MyRocks.

• Command line: --rocksdb-git-hash=value=#

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: As per git revision.

rocksdb_hash_index_allow_collision

• Description: BlockBasedTableOptions::hash_index_allow_collision for RocksDB.

• Command line: --rocksdb-hash-index-allow-collision={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_ignore_unknown_options

• Description: Enable ignoring unknown options passed to RocksDB.

• Command line: --rocksdb-ignore-unknown-options={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 10.3.7, MariaDB 10.2.15

rocksdb_index_type

• Description: BlockBasedTableOptions::index_type for RocksDB.

• Command line: --rocksdb-index-type=value

• Scope: Global

• Dynamic: No

• Data Type: enum

• Default Value: kBinarySearch

• Valid Values: kBinarySearch, kHashSearch

rocksdb_info_log_level

• Description: Filter level for info logs to be written mysqld error log. Valid values include 'debug_level', 'info_level', 'warn_level', 'error_level' and 'fatal_level'.

• Command line: --rocksdb-info-log-level=value

• Scope: Global

• Dynamic: Yes

• Data Type: enum

• Default Value: error_level

• Valid Values: error_level, debug_level, info_level, warn_level, fatal_level

rocksdb_io_write_timeout

• Description: Timeout for experimental I/O watchdog.

• Command line: --rocksdb-io-write-timeout=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Valid Values: 0 to 4294967295

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_is_fd_close_on_exec

• Description: DBOptions::is_fd_close_on_exec for RocksDB.

• Command line: --rocksdb-is-fd-close-on-exec={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_keep_log_file_num

• Description: DBOptions::keep_log_file_num for RocksDB.

• Command line: --rocksdb-keep-log-file-num=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1000

• Range: 0 to 18446744073709551615

rocksdb_large_prefix

• Description: Support large index prefix length of 3072 bytes. If off, the maximum index prefix length is 767.

• Command line: --rocksdb-large_prefix={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_lock_scanned_rows

• Description: Take and hold locks on rows that are scanned but not updated.

• Command line: --rocksdb-lock-scanned-rows={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_lock_wait_timeout

• Description: Number of seconds to wait for lock.

• Command line: --rocksdb-lock-wait-timeout=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 1 to 1073741824

rocksdb_log_dir

• Description: DBOptions::log_dir for RocksDB. Where the log files are stored. An empty value implies rocksdb_datadir is used as the directory.

• Command line: --rocksdb-log-dir=#

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: (Empty)

• Introduced: MariaDB 10.9.1

rocksdb_log_file_time_to_roll

• Description: DBOptions::log_file_time_to_roll for RocksDB.

• Command line: --rocksdb-log-file-time-to_roll=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_manifest_preallocation_size

• Description: DBOptions::manifest_preallocation_size for RocksDB.

• Command line: --rocksdb-manifest-preallocation-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 4194304

• Range: 0 to 18446744073709551615

rocksdb_manual_compaction_threads

• Description: How many rocksdb threads to run for manual compactions.

• Command line: --rocksdb-manual-compation-threads=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 128

• Introduced: MariaDB 10.3.10, MariaDB 10.2.18

rocksdb_manual_wal_flush

• Description: DBOptions::manual_wal_flush for RocksDB.

• Command line: --rocksdb-manual-wal-flush={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_master_skip_tx_api

• Description: Skipping holding any lock on row access. Not effective on slave.

• Command line: --rocksdb-master-skip-tx-api={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_max_background_compactions

• Description: DBOptions::max_background_compactions for RocksDB.

• Command line: --rocksdb-max-background-compactions=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 1 to 64

• Removed: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_max_background_flushes

• Description: DBOptions::max_background_flushes for RocksDB.

• Command line: --rocksdb-max-background-flushes=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1

• Range: 1 to 64

• Removed: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_max_background_jobs

• Description: DBOptions::max_background_jobs for RocksDB.

• Command line: --rocksdb-max-background-jobs=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 2

• Range: -1 to 64

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_max_latest_deadlocks

• Description: Maximum number of recent deadlocks to store.

• Command line: --rocksdb-max-latest-deadlocks=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 5

• Range: 0 to 4294967295

rocksdb_max_log_file_size

• Description: DBOptions::max_log_file_size for RocksDB.

• Command line: --rocksdb-max-log-file-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_max_manifest_file_size

• Description: DBOptions::max_manifest_file_size for RocksDB.

• Command line: --rocksdb-manifest-log-file-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1073741824

• Range: 0 to 18446744073709551615

rocksdb_max_manual_compactions

• Description: Maximum number of pending + ongoing number of manual compactions..

• Command line: --rocksdb-manual_compactions=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 10

• Range: 0 to 4294967295

• Introduced: MariaDB 10.3.10, MariaDB 10.2.18

rocksdb_max_open_files

• Description: DBOptions::max_open_files for RocksDB.

• Command line: --rocksdb-max-open-files=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: -2

• Range: -2 to 2147483647

rocksdb_max_row_locks

• Description: Maximum number of locks a transaction can have.

• Command line: --rocksdb-max-row-locks=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1048576

• Range:

  • 1 to 1073741824 (>= MariaDB 10.3.10, MariaDB 10.2.18)

  • 1 to 1048576 (<= MariaDB 10.3.9, MariaDB 10.2.17)

rocksdb_max_subcompactions

• Description: DBOptions::max_subcompactions for RocksDB.

• Command line: --rocksdb-max-subcompactions=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1

• Range: 1 to 64

rocksdb_max_total_wal_size

• Description: DBOptions::max_total_wal_size for RocksDB. The maximum size limit for write-ahead-log files. Once this limit is reached, RocksDB forces the flushing of memtables.

• Command line: --rocksdb-max-total-wal-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 9223372036854775807

rocksdb_merge_buf_size

• Description: Size to allocate for merge sort buffers written out to disk during inplace index creation.

• Command line: --rocksdb-merge-buf-size=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 67108864

• Range: 100 to 18446744073709551615

rocksdb_merge_combine_read_size

• Description: Size that we have to work with during combine (reading from disk) phase of external sort during fast index creation.

• Command line: --rocksdb-merge-combine-read-size=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1073741824

• Range: 100 to 18446744073709551615

rocksdb_merge_tmp_file_removal_delay_ms

• Description: Fast index creation creates a large tmp file on disk during index creation. Removing this large file all at once when index creation is complete can cause trim stalls on Flash. This variable specifies a duration to sleep (in milliseconds) between calling chsize() to truncate the file in chunks. The chunk size is the same as merge_buf_size.

• Command line: --rocksdb-merge-tmp-file-removal-delay-ms=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_new_table_reader_for_compaction_inputs

• Description: DBOptions::new_table_reader_for_compaction_inputs for RocksDB.

• Command line: --rocksdb-new-table-reader-for-compaction-inputs={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_no_block_cache

• Description: BlockBasedTableOptions::no_block_cache for RocksDB.

• Command line: --rocksdb-no-block-cache={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_override_cf_options

• Description: Option overrides per cf for RocksDB. Note that the rocksdb-override-cf-options syntax is quite strict, and any typos will result in a parse error, and the MyRocks plugin will not be loaded. Depending on your configuration, the server may still start. If it does start, you can use this command to check if the plugin is loaded: select * from information_schema.plugins where plugin_name='ROCKSDB' (note that you need the "ROCKSDB" plugin. Other auxiliary plugins like "ROCKSDB_TRX" might still get loaded). Another way is to detect the error is check the error log.

• Command line: --rocksdb-override-cf-options=value

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: (Empty)

rocksdb_paranoid_checks

• Description: DBOptions::paranoid_checks for RocksDB.

• Command line: --rocksdb-paranoid-checks={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_pause_background_work

• Description: Disable all rocksdb background operations.

• Command line: --rocksdb-pause-background-work={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_perf_context_level

• Description: Perf Context Level for rocksdb internal timer stat collection.

• Command line: --rocksdb-perf-context-level=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 5

rocksdb_persistent_cache_path

• Description: Path for BlockBasedTableOptions::persistent_cache for RocksDB.

• Command line: --rocksdb-persistent-cache-path=value

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: (Empty)

rocksdb_persistent_cache_size_mb

• Description: Size of cache in MB for BlockBasedTableOptions::persistent_cache for RocksDB.

• Command line: --rocksdb-persistent-cache-size-mb=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_pin_l0_filter_and_index_blocks_in_cache

• Description: pin_l0_filter_and_index_blocks_in_cache for RocksDB.

• Command line: --rocksdb-pin-l0-filter-and-index-blocks-in-cache={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_print_snapshot_conflict_queries

• Description: Logging queries that got snapshot conflict errors into *.err log.

• Command line: --rocksdb-print-snapshot-conflict-queries={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_rate_limiter_bytes_per_sec

• Description: DBOptions::rate_limiter bytes_per_sec for RocksDB.

• Command line: --rocksdb-rate-limiter-bytes-per-sec=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 9223372036854775807

rocksdb_read_free_rpl_tables

• Description: List of tables that will use read-free replication on the slave (i.e. not lookup a row during replication).

• Command line: --rocksdb-read-free-rpl-tables=value

• Scope: Global, Session

• Dynamic: Yes

• Data Type: string

• Default Value: (Empty)

• Removed: MariaDB 10.4.7, MariaDB 10.3.17, MariaDB 10.2.26

rocksdb_records_in_range

• Description: Used to override the result of records_in_range(). Set to a positive number to override.

• Command line: --rocksdb-records-in-range=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 2147483647

rocksdb_remove_mariadb-backup_checkpoint

• Description: Remove mariadb-backup checkpoint.

• Command line: --rocksdb-remove-mariadb-backup-checkpoint={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 10.3.8, MariaDB 10.2.16

rocksdb_reset_stats

• Description: Reset the RocksDB internal statistics without restarting the DB.

• Command line: --rocksdb-reset-stats={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_rollback_on_timeout

• Description: Whether to roll back the complete transaction or a single statement on lock wait timeout (a single statement by default).

• Command line: --rocksdb-rollback-on-timeout={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 10.4.7, MariaDB 10.3.17, MariaDB 10.2.26

rocksdb_seconds_between_stat_computes

• Description: Sets a number of seconds to wait between optimizer stats recomputation. Only changed indexes are refreshed.

• Command line: --rocksdb-seconds-between-stat-computes=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 3600

• Range: 0 to 4294967295

rocksdb_signal_drop_index_thread

• Description: Wake up drop index thread.

• Command line: --rocksdb-signal-drop-index-thread={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_sim_cache_size

• Description: Simulated cache size for RocksDB.

• Command line: --rocksdb-sim-cache-size=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 9223372036854775807

rocksdb_skip_bloom_filter_on_read

• Description: Skip using bloom filter for reads.

• Command line: --rocksdb-skip-bloom-filter-on_read={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_skip_fill_cache

• Description: Skip filling block cache on read requests.

• Command line: --rocksdb-skip-fill-cache={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_skip_unique_check_tables

• Description: Skip unique constraint checking for the specified tables.

• Command line: --rocksdb-skip-unique-check-tables=value

• Scope: Global, Session

• Dynamic: Yes

• Data Type: string

• Default Value: .*

rocksdb_sst_mgr_rate_bytes_per_sec

• Description: DBOptions::sst_file_manager rate_bytes_per_sec for RocksDB

• Command line: --rocksdb-sst-mgr-rate-bytes-per-sec=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_stats_dump_period_sec

• Description: DBOptions::stats_dump_period_sec for RocksDB.

• Command line: --rocksdb-stats-dump-period-sec=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 600

• Range: 0 to 2147483647

rocksdb_stats_level

• Description: Statistics Level for RocksDB. Default is 0 (kExceptHistogramOrTimers).

• Command line: --rocksdb-stats-level=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 4

• Introduced: MariaDB 10.4.7, MariaDB 10.3.17, MariaDB 10.2.26

rocksdb_stats_recalc_rate

• Description: The number of indexes per second to recalculate statistics for. 0 to disable background recalculation.

• Command line: --rocksdb-stats-recalc_rate=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 4294967295

• Introduced: MariaDB 10.3.10 MariaDB 10.2.18

rocksdb_store_row_debug_checksums

• Description: Include checksums when writing index/table records.

• Command line: --rocksdb-store-row-debug-checksums={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_strict_collation_check

• Description: Enforce case sensitive collation for MyRocks indexes.

• Command line: --rocksdb-strict-collation-check={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

rocksdb_strict_collation_exceptions

• Description: List of tables (using regex) that are excluded from the case sensitive collation enforcement.

• Command line: --rocksdb-strict-collation-exceptions=value

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: (Empty)

rocksdb_supported_compression_types

• Description: Compression algorithms supported by RocksDB. Note that RocksDB does not make use of MariaDB 10.7 compression-plugins.

• Command line: --rocksdb-supported-compression-types=value

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: Snappy,Zlib,ZSTDNotFinal

rocksdb_table_cache_numshardbits

• Description: DBOptions::table_cache_numshardbits for RocksDB.

• Command line: --rocksdb-table-cache-numshardbits=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 6

• Range: 0 to 19

rocksdb_table_stats_sampling_pct

• Description: Percentage of entries to sample when collecting statistics about table properties. Specify either 0 to sample everything or percentage [1..100]. By default 10% of entries are sampled.

• Command line: --rocksdb-table-stats-sampling-pct=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 10

• Range: 0 to 100

rocksdb_tmpdir

• Description: Directory for temporary files during DDL operations.

• Command line: --rocksdb-tmpdir[=value]

• Scope: Global, Session

• Dynamic: Yes

• Data Type: string

• Default Value: (Empty)

rocksdb_trace_sst_api

• Description: Generate trace output in the log for each call to the SstFileWriter.

• Command line: --rocksdb-trace-sst-api={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_two_write_queues

• Description: DBOptions::two_write_queues for RocksDB.

• Command line: --rocksdb-two-write-queues={0|1}

• Scope: Global,

• Dynamic: No

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 10.3.7, MariaDB 10.2.15

rocksdb_unsafe_for_binlog

• Description: Allowing statement based binary logging which may break consistency.

• Command line: --rocksdb-unsafe-for-binlog={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_update_cf_options

• Description: Option updates per column family for RocksDB.

• Command line: --rocksdb-update-cf-options=value

• Scope: Global

• Dynamic: Yes

• Data Type: varchar

• Default Value: (Empty)

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_use_adaptive_mutex

• Description: DBOptions::use_adaptive_mutex for RocksDB.

• Command line: --rocksdb-use-adaptive-mutex={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_use_clock_cache

• Description: Use ClockCache instead of default LRUCache for RocksDB.

• Command line: --rocksdb-use-clock-cache={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_use_direct_io_for_flush_and_compaction

• Description: DBOptions::use_direct_io_for_flush_and_compaction for RocksDB.

• Command line: --rocksdb-use-direct-io-for-flush-and-compaction={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_use_direct_reads

• Description: DBOptions::use_direct_reads for RocksDB.

• Command line: --rocksdb-use-direct-reads={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_use_direct_writes

• Description: DBOptions::use_direct_writes for RocksDB.

• Command line: --rocksdb-use-direct-reads={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

• Removed: MariaDB 10.3.1, MariaDB 10.2.8

rocksdb_use_fsync

• Description: DBOptions::use_fsync for RocksDB.

• Command line: --rocksdb-use-fsync={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

rocksdb_validate_tables

• Description: Verify all .frm files match all RocksDB tables (0 means no verification, 1 means verify and fail on error, and 2 means verify but continue.

• Command line: --rocksdb-validate-tables=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 1

• Range: 0 to 2

rocksdb_verify_row_debug_checksums

• Description: Verify checksums when reading index/table records.

• Command line: --rocksdb-verify-row-debug-checksums={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_wal_bytes_per_sync

• Description: DBOptions::wal_bytes_per_sync for RocksDB.

• Command line: --rocksdb-wal-bytes-per-sync=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_wal_dir

• Description: DBOptions::wal_dir for RocksDB. Directory where the write-ahead-log files are stored.

• Command line: --rocksdb-wal-dir=value

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: (Empty)

rocksdb_wal_recovery_mode

• Description: DBOptions::wal_recovery_mode for RocksDB. Default is kAbsoluteConsistency. Records that are not yet committed are stored in the Write-Ahead-Log (WAL). If the server is not cleanly shut down, the recovery mode will determine the WAL recovery behavior.

  • 1: kAbsoluteConsistency. Will not start if any corrupted entries (including incomplete writes) are detected (the default).

  • 0: kTolerateCorruptedTailRecords. Ignores any errors found at the end of the WAL

  • 2: kPointInTimeRecovery. Replay of the WAL is halted after finding an error. The system are recovered to the latest consistent point-in-time. Data from a replica can used to replay past the point-in-time.

  • 3: kSkipAnyCorruptedRecords. A risky option where any corrupted entries are skipped while subsequent healthy WAL entries are applied.

• Command line: --rocksdb-wal-recovery-mode=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 0 to 3

rocksdb_wal_size_limit_mb

• Description: DBOptions::WAL_size_limit_MB for RocksDB. Write-ahead-log files are moved to an archive directory once their memtables are flushed. This variable specifies the largest size, in MB, that the archive can be.

• Command line: --rocksdb-wal-size-limit-mb=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 9223372036854775807

rocksdb_wal_ttl_seconds

• Description: DBOptions::WAL_ttl_seconds for RocksDB. Oldest time, in seconds, that a write-ahead-log file should exist.

• Command line: --rocksdb-wal-ttl-seconds=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 9223372036854775807

rocksdb_whole_key_filtering

• Description: BlockBasedTableOptions::whole_key_filtering for RocksDB. If set (the default), the bloomfilter to use the whole key (rather than only the prefix) for filtering is enabled. Lookups should use the whole key for matching to make best use of this setting.

• Command line: --rocksdb-whole-key-filtering={0|1}

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

rocksdb_write_batch_max_bytes

• Description: Maximum size of write batch in bytes. 0 means no limit.

• Command line: --rocksdb-write-batch-max-bytes=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

rocksdb_write_disable_wal

• Description: WriteOptions::disableWAL for RocksDB.

• Command line: --rocksdb-write-disable-wal={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_write_ignore_missing_column_families

• Description: WriteOptions::ignore_missing_column_families for RocksDB.

• Command line: --rocksdb-write-ignore-missing-column-families={0|1}

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

rocksdb_write_policy

• Description: DBOptions::write_policy for RocksDB.

• Command line: --rocksdb-write-policy=val

• Scope: Global

• Dynamic: No

• Data Type: enum

• Default Value: write_committed

• Valid Values: write_committed, write_prepared, write_unprepared

• Introduced: MariaDB 10.3.10, MariaDB 10.2.18

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