List of Engine Variables

The following tables list the sync engine variables and non-sync engine variables. Some variables have an in-depth description that supplements the description found in the table.

When reading or setting engine variables keep in mind that the values ON and 1 are synonymous, as are the values OFF and 0.

Sync Variables Lists

See the engine variables overview to learn how sync variables work.

Note

All of the sync variables listed in the following table are global variables, except when noted as a session variable that can also be set globally in the Description column.

You can set sync variables on the master aggregator, only. After you set a sync variable, the nodes affected by your update (all aggregators, all leaves, or both) depend on the variable’s type and the command you use to set the variable. Each variable’s type is indicated in the last sentence in the Description column in the following table.

Name	Description	Default
`active_query_users_blacklist`	Shows a JSON array of users whose query runs are not considered active to measure the cluster's idle time. This variable can sync to all nodes, including aggregator and leaf nodes.
`aes_default_encryption_mode`	You can use this variable to control the supported key size. It takes a value in aes-keylen-mode format, where keylen is the key length in bits and mode is the encryption mode. The value is not case-sensitive. Permitted keylen values are 128 and 256. Permitted mode values are ECB, GCM, and CBC. List of allowed values are: `aes-128-ecb`, `aes-256-ecb`, `aes-128-gcm`, `aes-256-gcm`, `aes-128-cbc`, `aes-256-cbc` Optionally an encryption mode string in the same format can be provided to the AES_ENCRYPT and AES_DECRYPT functions. If not provided, the default value from this variable will be used. In addition to the key, the initialization vector can be provided to the encryption/decryption function in GCM and CBC encryption modes. This variable can sync to all nodes, including aggregator and leaf nodes.	`aes-128-ecb`
`aggregator_failure_detection`	Deprecated in MemSQL 6.0, this is the timeout used when gathering workload management statistics from leaves. This variable can sync to all aggregators.	`ON`
`allow_modifying_sysvars_with_computed_shard_key`	Allows modification of global variables even in the presence of computed shard keys. Allowing changes to certain sysvars in the presence of computed shard key, only when this variable is set `ON` applies to all behavior changing sysvars. The behavior changing sysvars include: `data_conversion_compatibility_level` `json_compatibility_level` `highlight_allow_ascii_binary_strings` `regexp_output_validation_mode` `json_extract_string_collation`	`OFF`
`allow_proc_cpuinfo_errors`	Determines whether to allow errors while consuming '/proc/cpuinfo' to append CPU flags to the code generation's hash. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`auditlog_disk_sync`	Specifies if every audit log record is synchronously written and persisted to the disk. By default, it delays the audit log writes to the disk. For more information on this variable, see Configure Audit Logging. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`auditlog_retention_period`	Indicates the retention period (in days) for audit log files. This variable can sync to all nodes, including aggregator and leaf nodes.	`0` (store files indefinitely)
`auto_attach`	Specifies if the aggregator will try to attach a node automatically after it has been marked offline, but starts responding to heartbeats again. This variable can sync to all aggregators.	`ON`
`autostats_flush_interval_secs`	Number of seconds a table's incremental autostats can go unused before being flushed to disk. `0` means they will never be flushed. This variable can sync to all nodes, including aggregator and leaf nodes.	`600`
`attach_rebalance_delay_seconds`	Number of seconds to wait after a new node has attached to the cluster before running a rebalance. This mechanism is used to batch up rebalancing if many nodes fail and then come back online within a short period of time. This variable can sync to all aggregators.	`120`
`background_statistics_collection_interval`	How often (in seconds) background statistics will check for out-of-date statistics (rowstore only). This variable can sync to all aggregators.	`60`
`background_statistics_collection_threshold`	Threshold as a fraction of table row count triggering the collection of autostats. This variable can sync to all aggregators.	`0.5`
`backup_multipart_upload_concurrency`	Helps tune backup performance. It controls the number of subprocesses concurrently uploading the parts of a multipart upload done by a backup. A backup of a leaf uses one thread per partition and there is no restriction on the number of threads created (aside from system limitations). This variable's config depends on the `backup_max_threads` config. When `backup_max_threads` is zero implying all the backups run at full parallelism then this variable can be set in the range 1 to 5 inclusive. When `backup_max_threads` is not equal to zero implying a throttle is applied to the number of concurrent backups per leaf, then this variable will be taken as 1, irrespective of the value set. With an increased number of go routines the backup performance improves but it comes with an increased cost of CPU, memory, and network throughput. This variable can sync to all nodes, including aggregator and leaf nodes.	`3`
`batch_external_functions`	Determines if external functions are batched. The engine variable accepts `ALWAYS`, `AUTO`, and `NEVER` values. See CREATE [OR REPLACE] EXTERNAL FUNCTION for more information. This variable can sync to all nodes, including aggregator and leaf nodes.	`ALWAYS`
`batch_external_functions_size`	Deprecated. Use `external_functions_batch_size` instead.	`512`
`cardinality_estimation_level`	Possible values are `'6.0'`, `'6.5'`, `'7.0'`, `'7.1'`, and `'7.3'`. The behavior of each setting follows: `'6.0'`: Use legacy histograms; `'6.5'`: Use advanced histograms; `'7.0'`: Same use of histograms as 6.5; `'7.1'`: Use histograms for join estimation; `'7.3'`: Use sampling and histograms together (when both are available), to improve selectivity estimation. This variable can sync to all nodes, including aggregator and leaf nodes. This engine variable is configurable on SingleStore Helios.	`'7.3'`
`change_count_write_interval`	Maximum frequency (in seconds) that change count metadata will be written. Will never occur more frequently than `background_statistics_collection_interval`. This variable can sync to all aggregators.	`1200`
`character_set_server`	The character set of the node. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes. For more information, see Specifying Character Set and Collation for Clusters.	`utf8`
`clamp_histogram_date_estimates`	Specifies whether to use a heuristic to more accurately estimate date predicates that are larger than the histograms range. Available values are `AUTO`, `OFF`, and `ON`. This variable can sync to all nodes, including aggregator and leaf nodes. `AUTO` is `OFF`.	`AUTO`
`collation_connection`	Sets the collation that is used on the node. When you set this variable, `collation_database` and `collation_server` are automatically set to the same value. Although the collation variables are session variables, you must set the variable globally to avoid undesired behavior. An error is generated if any of these variables is set in a session to a value that does not match the value set globally. Change the value globally first, then change it in the session to match. This variable can sync to all nodes, including aggregator and leaf nodes. For more information, see Specifying Character Set and Collation for Clusters.	`utf8_general_ci`
`collation_database`	Sets the collation that is used on the node. When you set this variable, `collation_connection` and `collation_server` are automatically set to the same value. Although the collation variables are session variables, you must set the variable globally to avoid undesired behavior. An error is generated if any of these variables is set in a session to a value that does not match the value set globally. Change the value globally first, then change it in the session to match. This variable can sync to all nodes, including aggregator and leaf nodes. For more information, see Specifying Character Set and Collation for Clusters.	`utf8_general_ci`
`collation_server`	Sets the collation that is used on the node. When you set this variable, `collation_connection` and `collation_database` are automatically set to the same value. Although the collation variables are session variables, you must set the variable globally to avoid undesired behavior. An error is generated if any of these variables is set in a session to a value that does not match the value set globally. Change the value globally first, then change it in the session to match. This variable can sync to all nodes, including aggregator and leaf nodes. For more information, see Specifying Character Set and Collation for Clusters.	`utf8_general_ci`
`collect_average_size`	Sends `AVG(LENGTH())` queries to collect average serialization data for string columns. This variable can sync to all aggregators.	`FALSE`
`columnstore_disk_insert_threshold`	At this threshold (fraction of `columnstore_flush_bytes`), `INSERT`, `LOAD DATA`, and `UPDATE` queries to the columnstore will write straight to disk. For more information, see Advanced Columnstore Configuration Options. This variable can sync to all nodes, including aggregator and leaf nodes.	`0.5`
`columnstore_flush_bytes`	Controls the rowstore-backed segment size for columnstore tables. For more information, see Advanced Columnstore Configuration Options. This variable can sync to all nodes, including aggregator and leaf nodes.	`33554432`
`columnstore_ingest_management_queue_timeout`	Timeout (in seconds) to queue a columnstore ingest query before returning an error. This variable can sync to all nodes, including aggregator and leaf nodes.	`3600`
`columnstore_row_value_table_lock_threshold`	Sets the threshold at which multiple inserts to a columnstore table with unique keys will switch from row value lock to table lock. The value's metric is the number of rows for each partition in a database. This variable can sync to all nodes, including aggregator and leaf nodes.	`1000000` (rows per partition)
`columnstore_segment_rows`	Controls the maximum row count for a columnstore segment. For more information, see Advanced Columnstore Configuration Options. This variable can sync to all nodes, including aggregator and leaf nodes. Maximum value is 10000000.	`1024000`
`columnstore_small_blob_combination_threshold`	Maximum file size (in bytes) that two or more column blobs can be combined into. This variable can sync to all nodes, including aggregator and leaf nodes.	`33554432`
`columnstore_validate_blob_before_merge`	Verifies the checksum of a blob before merging it. For more information, see CHECK BLOB CHECKSUM and Columnstore. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`compiled_images_eviction_memory_limit_mb`	Sets a limit (in megabytes) for the memory amount used for query object code images. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`consensus_enabled`	Determines whether consensus can be configured or not. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`core_on_bad_errnos_in_file_io_apis`	Generates a core if a file IO API encounters `EFAULT`, `EBADF` , or `EINVAL`. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`core_on_stack_overflow`	Generates a core instead of throwing an error if a stack overflow occurs during query execution. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`critical_diagnostics_max_payload_size`	Limits the size of some critical diagnostics sent to SingleStore. This variable can sync to all nodes, including aggregator and leaf nodes.	`65536`
`data_conversion_compatibility_level`	Specifies the level of data conversion behavior to use. Higher levels throw error for integer under/overflow, illegal conversion of strings to integers, and string truncation issues. Values can be either: `'7.5'`,`'7.0'` , `'6.5'`, or `'6.0'`. This variable can sync to all nodes, including aggregator and leaf nodes. It’s recommended to set this to the highest available level for new application development. For more information, see Data Type Conversion. This variable can sync to all nodes, including aggregator and leaf nodes.	`'6.0'`
`deadlock_avoidance_strategy`	See Row Locking. This variable can sync to all nodes, including aggregator and leaf nodes.	`wait_die`
`default_autostats_columnstore_cardinality_mode`	Sets the default type of cardinality autostats for newly created columnstore tables. Values can be `OFF`, `INCREMENTAL` , or `PERIODIC`. This variable can sync to all aggregators.	`INCREMENTAL`
`default_autostats_columnstore_sampling`	Sets the default state for autostats sampling for newly created columnstore tables. This variable can sync to all aggregators.	l`ON`
`default_autostats_enabled`	Whether autostats is enabled by default on newly created tables. This variable can sync to all aggregators.	`ON`
`default_autostats_histogram_mode`	Sets the default type of automatic histograms on newly created tables. Values can be either `OFF`, `CREATE`, or `UPDATE`. This variable can sync to all aggregators.	`CREATE`
`default_autostats_rowstore_cardinality_mode`	Sets the default type of cardinality autostats for newly created rowstore tables. Values can be `OFF`, `INCREMENTAL` or `PERIODIC`. This variable can sync to all aggregators.	`PERIODIC`
`default_columnstore_table_lock_threshold`	Sets a threshold for the number of rows that are locked before a table lock is acquired when updating or deleting rows in a columnstore table. When set to 0, the threshold of 5000 rows is used. It is a session variable that can be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`default_distributed_ddl_timeout`	The time (in milliseconds) to wait for a distributed DDL transaction to commit. This value sets the timeout for both `ALTER TABLE` and `BACKUP` commands. If the timeout is reached, the transaction is rolled back. This variable can sync to all nodes, including aggregator and leaf nodes.	`180000`
`default_partitions_per_leaf`	The default number of partitions a newly created database will be created with. When you set this variable, its value is propagated to other aggregators only.	`8`
`default_storage_engine`	A global variable used for MySQL compatibility. This variable can sync to all nodes, including aggregator and leaf nodes.
`default_table_type`	The default table type to use when creating a new table. The value can be set to `columnstore` or `rowstore`. When the value is `columnstore` you can create a columnstore table using the standard CREATE TABLE syntax. This variable can sync to all aggregators.	`columnstore` for newly created clusters. When you upgrade a cluster, the setting of the variable does not change.
`default_user_require_ssl`	Controls the default value for `REQUIRE SSL` in the `CREATE USER` DDL statement. If it is enabled and `REQUIRE` is not specified in the `CREATE USER` statement, SSL will be required by default. Once it is turned on, it impacts only the newly created users. It will not enforce SSL for existing users. This variable can sync to all aggregators.	`OFF`
`disable_reference_table_leftjoin_where_pushdown`	Controls pushdown logic of pushing down reference table clauses to the leaves. When set to `OFF`, the logic is enabled. When set to `ON`, the logic is disabled. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`disable_remove_redundant_gby_rewrite`	Prevents the removal of `GROUP BY` columns when used in an `ORDER BY` clause. The default of AUTO is equal to `OFF`. To disable this behavior the variable must be set to `ON`. This variable can sync to all nodes, including aggregator and leaf nodes.	`AUTO`
`disable_subquery_merge_with_straight_joins`	Whether merging subqueries are disabled if they contain `STRAIGHT_JOIN`. Here, merging subqueries refers to removing unnecessary nested layers from joins including subqueries. For example, the query `select * from (select * from table_a straight_join table_b) table_c straight_join table_d` would be rewritten as `select * from table_a straight_join table_b straight_join table_d` if the engine variable `disable_subquery_merge_with_straight_joins` is set to `OFF`. If the variable is set to `ON`, the query would not be rewritten. The default setting `AUTO` is equivalent to `ON` in 7.3. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`AUTO`
`disable_update_delete_distributed_transactions`		`OFF`
`disk_plan_expiration_minutes`	The interval in which a query plan must be read from disk (plancache directory) before it is removed. This variable can sync to all nodes, including aggregator and leaf nodes.	`20160` (14 days)
`dist_txn_outcomes_keepalive_secs`	Controls how long (in seconds) an aggregator caches a distributed transaction outcome. This variable can sync to all nodes, including aggregator and leaf nodes.	`1800`
`distributed_commit_lock_timeout`	Deprecated in MemSQL 6.5. Replaced by `default_distributed_ddl_timeout`.
`distributed_heartbeat_timeout`	As of MemSQL 6.0, this is the timeout (in seconds) used when gathering workload management statistics from leaves. Before MemSQL 6.0 this was the timeout of the heartbeat query used to trigger failovers. This variable can sync to all aggregators.	`10`
`distributed_optimizer_broadcast_mult`	At a high level, this variable makes the optimizer more (lower) or less (higher) likely to consider a broadcast when planning distributed joins. SingleStore will choose a broadcast if it saves us moving more than repartitioning. As the default is the number of database partitions, setting the value to a high number (like 100,000) is an effective way to tell the optimizer to not broadcast data at all. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`distributed_optimizer_max_join_size`	This variable is deprecated but still exists for backward compatibility purposes. As of version 7.3 of SingleStore, it is replaced by two new variables that assist in leveraging significantly increased speed for optimization at large join sizes: `distributed_optimizer_unrestricted_search_threshold` and `singlebox_optimizer_cost_based_threshold`. The distributed optimizer works to minimize data movement across the cluster, while the singlebox optimizer makes decisions about how to physically execute a join such as choosing an index. Setting this depreciated variable will result in both new variables being set to the target value. This variable can sync to all nodes, including aggregator and leaf nodes.	`22`
`distributed_optimizer_min_join_size_run_initial_heuristics`	The minimum number of tables that must be present in a join for initial heuristics to be run before join optimization. This means a small cost is incurred for the initial use of these heuristics in excThis is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.hange for faster join optimization. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`16`
`distributed_optimizer_run_legacy_heuristic`	Enabling this variable will result in a return to pre-7.3 behavior through the use of heuristics to complete a faster, restricted search for a join plan, once the number of tables in a given join is greater than the threshold set for this with `distributed_optimizer_unrestricted_search_threshold`. This search is faster, but as the number of tables in a given join increases, the chance of a less optimal query plan also increases. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`distributed_optimizer_unrestricted_search_threshold`	The maximum number of tables present in a join that will result in an unrestricted search being performed to find the optimal query plan. A query with a greater number of tables will use heuristics to complete a search for a query plan. This restricted search is faster than previous versions of SingleStore. However, this may be at the cost of a less optimal query plan compared to an unrestricted search. `distributed_optimizer_run_legacy_heuristic` must be set to `FALSE` for this variable to take effect. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`22`
`dr_min_connection_timeout_ms`	Allows the user to set the minimum amount of time to wait for Disaster Recovery (DR) replication in milliseconds (ms). MS range is between 8 and 2000000. This variable can sync to all nodes, including aggregator and leaf nodes.	`8`
`enable_alias_space_trim`	Trims leading spaces for column name aliases. This engine variable is only used for backward compatibility. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`enable_auto_profile`	Profile results are not collected automatically. The PROFILE command must be used to run to review usage metrics. The only profile statistics that are saved are the most recent query plan's execution. Please note, a profiled query will have a different query plan than a non-profiled query. When a query is first profiled compilations of the query are triggered to generate new query plans. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`enable_background_plan_invalidation`	Controls whether the background statistics thread can invalidate plans automatically. This can improve plans if your data changes over time at the cost of spending time recompiling plans. This variable can sync to all aggregators.	`OFF`
`enable_background_statistics_collection`	If set to `ON`, background statistics are collected for all tables, unless disabled on the table level. If set to `OFF`, background statistics are not collected for any tables, and background statistics cannot be enabled for individual tables. This variable can sync to all aggregators.	`ON`
`enable_binary_protocol`	When this variable is set to `ON`, server-side prepared statements are enabled. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`enable_broadcast_left_join`	When this variable is set to `TRUE`, the query optimizer can choose the broadcast left join optimization. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`enable_columnstore_ingest_management`	Enables queuing on columnstore ingest queries when the background flusher is behind. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`enable_compiled_images_eviction`	Determines whether to use LRU (least recently used) eviction of query object code images. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`enable_disk_plan_expiration`	Enable removal of stale on-disk plans from the plancache directory based on the value of `disk_plan_expiration_minutes`. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`enable_disk_plan_explain`	Retains human-readable query plan summaries for compiled query plans. Retained information is available through the SHOW PLAN command. This variable can sync to all aggregators.	`OFF`
`enable_dml_query_forwarding`	When set to `ON`, forwards the Data Manipulation Language (DML) queries from a child aggregator to the master aggregator. Currently, this setting is used for write requests to reference tables, which cannot be executed on child aggregators. This variable can sync to all aggregators.	`ON`
`enable_external_functions`	See the Enabling External Functions section in CREATE [OR REPLACE] EXTERNAL FUNCTION. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`enable_histogram_to_unwrap_literals`	Enables the ability for histograms to estimate predicates using stored procedure parameters or implicit/explicit typecasted literals. This variable needs to be manually enabled by setting it to `ON`. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`enable_ir_cache`	Allows the on-disk IR cache to be enabled or disabled. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`enable_multipartition_queries`	When this variable is set to `ON`, queries are run per leaf instead of per partition on the leaf; the number of threads decreases and performance increases. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`enable_query_forwarding`	Enables the forwarding of DDL queries from a child aggregator to the master. `sync_permissions` must also be enabled for this variable to take effect; otherwise, an error is returned for DDL queries that are run on a child aggregator. For further information, see Cluster Management Commands This variable can sync to all aggregators.	`ON`
`enable_spilling`	Enables spilling onto disk for HashGroupBy operations during query processing. When `enable_spilling` is set to `ON`, the output of `SHOW PROFILE JSON` includes the following metrics: `spill_outputted_rows`: number of rows spilled to disk `spill_disk_usage`: number of bytes spilled to disk. The sync variables `spilling_node_memory_threshold_ratio` and `spilling_query_operator_memory_threshold` also define the threshold limit to start spilling onto disk. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`enable_subprocess_tracing`	Enables tracing in backup subprocesses. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`enable_varbuffer_dictionary_compression`	Enables compressing identical strings on `VARCHAR`, `VARBINARY`, `LONGTEXT`, `LONGBLOB`, `MEDIUMBLOB`, `BLOB`, `TINYBLOB`, `MEDIUMTEXT`, `TEXT`, and `TINYTEXT` columns. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`estimate_zero_rows_when_sampling_data_is_missing`	Uses heuristic or histogram to estimate missing sampling data instead of returning zero rows. False enables new estimating behavior. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`exclude_scalar_subselects_from_filters`	Specifies how SingleStore estimates the equality predicate for uncorrelated scalar subselects. When set to `TRUE`, the engine estimates scalar subselects as non-selective. When set to `FALSE`, the engine estimates the equality predicate for uncorrelated scalar subselects as 1/cardinality, and uses heuristics for all other scalar subselect predicates. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`expected_leaf_core_count`	Number of cpu cores expected on each leaf. This variable can sync to all nodes, including aggregator and leaf nodes.	`8`
`explain_expression_limit`	Specifies the maximum number of characters to be used by expressions when outputting the `EXPLAIN` for a query. This variable can sync to all nodes, including aggregator and leaf nodes.	`500`
`explicit_defaults_for_timestamp`	Specifies whether the server disables certain nonstandard behaviors for default values and NULL-value handling in `TIMESTAMP` columns. See Timestamp Behavior for details on this variable. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`exporter_port`	Port number to use for prometheus exporter http endpoint. This variable can sync to all aggregators.	`0`
`exporter_ssl_ca`	Path to user CA file to use for prometheus exporter connection. This variable can sync to all aggregators.
`exporter_ssl_capath`	Path to user directory with CA files to use for prometheus exporter connection. This variable can sync to all aggregators.
`exporter_ssl_cert`	Provides the path to the ssl certificate. This variable can sync to all aggregators.
`exporter_ssl_key`	Used by the monitoring process when a user selects what entity to trust for the custom private key. This variable can sync to all aggregators.
`exporter_ssl_key_passphrase`	Used when the `exporter_ssl_key` is encrypted so the monitoring process can decrypt it. This variable can sync to all aggregators.
`exporter_use_https`	Adds the ability to use HTTPS. The default is `FALSE`, set to `TRUE` to enable. This variable is used in conjunction with engine variables `exporter_ssl_cert` and `exporter_ssl_key`. This variable can sync to all aggregators.	`FALSE`
`external_functions_allowlist`	See the Enabling External Functions section in CREATE [OR REPLACE] EXTERNAL FUNCTION. This variable can sync to all nodes, including aggregator and leaf nodes.
`external_functions_batch_size`	Assists with controlling the batch size while making external function calls. This variable can sync to all nodes, including aggregator and leaf nodes.	`512` (rows)
`failover_initial_grace_interval_seconds`	If a node moves offline a second time after just failing and then coming back online failover won’t be triggered again if it happens within `grace_interval_seconds`. This is to avoid a cycle of a problem node failing and coming back online. This variable can sync to all aggregators.	`300`
`failover_on_low_disk`	Controls whether the cluster fails over if disk use falls below `minimal_disk_space`. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`force_bushy_join_table_limit`	Maximum number of tables in a join which SingleStore will still cost bushy joins. Above this threshold, all possible bushy joins will be chosen regardless of cost. This variable can sync to all nodes, including aggregator and leaf nodes.	`18`
`geo_sphere_radius`	The radius of the sphere is used for distance calculation, in meters. (Defaults to average Earth radius.) This variable can sync to all nodes, including aggregator and leaf nodes.	`6367444.657120`
`group_concat_max_len`	This variable is the maximum length string `GROUP_CONCAT()` can return (in bytes). It is a session variable that can be set globally and can be set to any value smaller than or equal to `max_allowed_packet`. For more information on this variable see `max_allowed_packet` in the previous section and the GROUP_CONCAT SQL reference. This variable should be updated on all nodes and requires a restart to pick up the new value. This variable can sync to all nodes, including aggregator and leaf nodes.	`16777216`
`highlight_fragment_size`	The size of a block of characters used to logically divide up string columns when using the full-text search highlight functionality. The minimum value is 10 and the maximum value is 65535. This variable can sync to all nodes, including aggregator and leaf nodes.	`100`
`highlight_max_number_fragments`	Maximum number of fragments to return from highlight function. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`histogram_column_correlation`	This variable controls the assumed correlation between columns when using histograms for selectivity estimation. This variable can sync to all nodes, including aggregator and leaf nodes.	`0.5`
`ignore_insert_into_computed_column`	When this variable is set to `ON`, an `INSERT` into a computed column succeeds and the `INSERT` ignores the computed column. When this variable is set to `OFF`, an `INSERT` into a computed column fails with an error. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`inlist_precision_limit`	Specifies the maximum number of list values to consider during histogram estimation for a query with an `IN` list; a smaller limit will result in a faster compilation time but may also give a less accurate estimate. NOTE: If you adjust this variable, existing queries will need to be recompiled. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`10000`
`internal_columnstore_idle_flush_wait_seconds`	Amount of time (in seconds) the background thread waits before trying to flush on a table with data less than `columnstore_flush_bytes`. Must be a value between 30 and 86400, and evenly divisible by 5. This variable can sync to all nodes, including aggregator and leaf nodes.	`125`
`internal_max_cte_depth`	Specifies the maximum number of nested common table expressions (CTEs). For more information, refer to the WITH topic. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`128`
`jwks_endpoint`	The endpoint to get JWKS updates from. If empty, JWKS update from the endpoint does not happen. This variable can sync to all nodes, including aggregator and leaf nodes.
`jwks_ssl_ca_certificate`	The CA certificate file to be used for SSL JWKS endpoint host verification when HTTPS protocol is used. This variable can sync to all nodes, including aggregator and leaf nodes.
`jwks_update_interval`	The JWKS update interval in seconds. If set to 0, JWKS refresh does not happen. This variable can sync to all nodes, including aggregator and leaf nodes.	`3600`
`leaf_failure_detection`	Whether or not the master aggregator should detect leaf failures and trigger failovers. WARNING: Turning this variable `OFF` disables failover. This variable can sync to all aggregators.	`ON`
`leaf_failover_fanout`	Specifies the placement of replica partitions in a cluster. It can be set to the following modes: `paired` and `load_balanced`. For more information, see Enabling High Availability. This variable can sync to all nodes, including aggregator and leaf nodes.	`paired`
`license_visibility`	Hides license-related variables from `SHOW` commands. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`load_data_errors_retention_minutes`	The amount of time, in minutes, that a `LOAD DATA` error is stored on disk. This variable must be set to at least `0`. These errors are surfaced in information_schema.LOAD_DATA_ERRORS as long as they are stored on disk. This variable can sync to all nodes, including aggregator and leaf nodes.	`1440`
`load_data_internal_compression`	If this variable is set to `ON` and a network bottleneck is detected, `LOAD DATA` compresses data on the aggregator before forwarding it to the leaves. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`load_data_max_buffer_size`	Maximum number of unparsed bytes read by `LOAD DATA` before throwing an error. This variable can sync to all nodes, including aggregator and leaf nodes.	`1073741823`
`load_data_read_size`	Number of bytes read at a time by `LOAD DATA`. This variable can sync to all nodes, including aggregator and leaf nodes.	`8192`
`load_data_write_size`	Number of bytes written at a time by `LOAD DATA`. This variable can sync to all nodes, including aggregator and leaf nodes.	`8192`
`local_file_system_access_restricted`	Restricts access to the local file system. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`lock_wait_timeout`	Time (in seconds) to wait for a row lock before returning an error. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`30`
`lockfree_backup`	Determines whether to use the lockfree backup implementation that is introduced in version 7.5. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`log_file_size_partitions`	Specifies the log file size (in bytes) for partitions. Can be set to a minimum of 1 MB (in bytes) to a maximum of 1 TB (in bytes), in multiples of 1 MB. A MB contains 1048576 bytes. Each partition is pre-allocated to two log files. Each of these log files has the size `log_file_size_partitions`. By default, `log_file_size_partitions` is 256 MB. Changes in the log file size will not affect the sizes of the partitions that are used by existing databases. Use caution when adjusting this variable as it can result in large log files and thus consume more disk space. This variable can sync to all aggregators.	`268435456`
`log_file_size_ref_dbs`	Specifies the log file size (in bytes) for reference databases. Can be set to a minimum of 1 MB (in bytes) to maximum of 1 TB (in bytes), in multiples of 1 MB. A MB contains 1048576 bytes. Each reference database is pre-allocated two log files. Each of these log files has the size `log_file_size_ref_dbs`. By default, `log_file_size_ref_dbs` is 64 MB. Changes in the log file size will not affect existing databases. Use caution when adjusting this variable as it can result in large log files and thus consume more disk space. This variable can sync to all aggregators.	`67108864`
`master_promote_kill_timeout_seconds`	Specifies the amount of time online failover will wait to drain open transactions on a master partition (whether running or idle) before killing them. This variable can sync to all nodes, including aggregator and leaf nodes.	`120`
`max_async_compilation_concurrency`	The number of compiles that can run asynchronously at a given time on each node, when `interpreter_mode` is set to `interpret_first`. Its effective value is capped at the number of cores on the host machine. If set to 0, it takes the default value. This variable can sync to all nodes, including aggregator and leaf nodes.	Half the number of cores on the host machine.
`max_compilation_memory_mb`	The maximum amount of memory (in megabytes) used to compile a query. An error is returned if the query reaches the specified memory limit. This variable can sync to all nodes, including aggregator and leaf nodes.	`4096`
`max_compilation_time_s`	The maximum time allowed (in seconds) to compile a query. An error is returned if the query reaches the specified compilation time limit, and any subsequent attempts to compile the query fail. This variable can sync to all nodes, including aggregator and leaf nodes.	`600`
`max_connect_errors`	If the number of interrupted connections from a host exceeds the value of `max_connect_errors` this host will be blocked from further connections. This variable can sync to all nodes, including aggregator and leaf nodes.	`10`
`max_prefetch_threads`	Sets the maximum number of threads to use for pre-fetching per scan. This variable can sync to all nodes, including aggregator and leaf nodes.	`1`
`max_prepared_stmt_count`	Sets the maximum number of simultaneous prepared statements. This variable can sync to all nodes, including aggregator and leaf nodes.	`16382`
`memsql_original_server_version`	Displays the version of SingleStore initially installed. This variable can sync to all nodes, including aggregator and leaf nodes.
`memsql_snapshot_trigger_size`	Indicates the size (in bytes) of the SingleStore database log upon which a new snapshot will be kicked off. The minimum value this engine variable can be set is `65536`. This variable can sync to all nodes, including aggregator and leaf nodes.	`134217728`
`monitoring_retention_period`	The period in minutes to keep historical monitoring data. Stored procedures reference this variable to purge values. This variable can sync to all aggregators.	`10080`
`multi_insert_tuple_count`	Preferred number of tuples in multi-inserts that aggregators send to leaves. This variable can sync to all nodes, including aggregator and leaf nodes.	`20000`
`multi_statement_xact_idle_timeout`	Time (in seconds) that is allowed for a multi-statement transaction to remain idle while holding locks. This is a session variable that can also be set globally. This variable can sync to all aggregators.	`300`
`node_degree_of_parallelism`	Controls the number of threads per leaf node for parallel columnstore scans. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`null_timestamps_for_testing`	Variable to write default `TIMESTAMP` columns during testing. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`num_background_merger_threads`	Controls the number of background merger threads to start for each node. The default value of 2 implies two threads run on each node and the work is bound to 2 CPUs. On large nodes, with many CPUs, it is easier for nodes to outpace two merger threads. When there is a high-throughput ingest workload, the merger cannot keep up and query processing gets slower as the data is not well merged. Use the `mv_columnstore_merge_status` view to find out if the merger process is slow. If it gets behind, try increasing the value of this variable. For example, if with 32 core nodes, you find the merger is not keeping up then increase it from 2 to 8 and observe if the merger is keeping up with the ingest workload. Only 2 merger threads per partition per table are allowed at a time. Hence more partitions per node can use more threads. For one partition on one table increasing the value of this variable will not make any difference. The allowed values range between 2 and 64. This variable can sync to all nodes, including aggregator and leaf nodes.	`2`
`optimize_stmt_threshold`	A statement count threshold for a procedure or function. When the threshold is exceeded, the procedure or function compiles faster, but the highest level of code optimizations is not applied; however, SQL query optimizations are still in effect. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`50`
`optimizer_beam_width`	Controls the beam search width. The default value is `10`. Setting this to `1` reverts to the previous behavior (prior to v7.5). Higher values (maximum is `1024`) will make the one-time query optimization time slower. This variable can sync to all nodes, including aggregator and leaf nodes.	`10`
`optimizer_disable_subselect_to_join`	Setting this to `ON` disables the optimizer rewrite that converts subselect to joins automatically. Disabling this rewrite may cause queries to fail if they require the rewrite to run. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`optimizer_empty_tables_limit`	Sets a threshold for the number of empty tables that must be present in a query before the optimizer falls back to being rule-based, instead of cost-based. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`optimizer_min_reference_rows_for_gathered_join`	The minimum total number of rows estimates in joined reference tables for gathering non-reference tables to be considered. This variable can sync to all nodes, including aggregator and leaf nodes.	`1000000`
`optimizer_min_reference_tables_for_gathered_join`	The minimum number of reference tables joined in a query that will be considered before gathering non-reference tables. 0 disables this feature. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`parametrizer_query_max_params`	The maximum number of scalar constants a single query can contain. Any query with more than `parametrizer_query_max_params` will be failed with an error. This variable can sync to all aggregators.	`1048576`
`plan_expiration_minutes`	The interval in which a query plan must be reused at least once or it gets unloaded from the query plan cache. This variable can sync to all nodes, including aggregator and leaf nodes.	`720`
`preserve_original_colstore_json`	A global variable that preserves `NULL` values and empty arrays in a JSON object that is written to a columnstore table. Set this variable to `OFF` to disable this setting. For more information on this variable, see the JSON Guide. This variable can sync to all nodes, including aggregator and leaf nodes.	`AUTO` (same as ON)
`privilege_transfer_mode`	A global variable that controls whether privilege transferability is determined by `GRANT OPTION` or `TRANSFERABLE` keyword in the GRANT security management command. The allowed values for this variable are `grant_option` (default) or `per_privilege`. Note: This global variable can be set on a SingleStorecluster. This variable can sync to all nodes, including aggregator and leaf nodes.	`grant_option`
`processlist_rpc_json_max_size`	The maximum number of bytes available to the `rpc_info` column of `information_schema.mv_processlist`. This variable can sync to all nodes, including aggregator and leaf nodes.	`2048`
`promote_aggregator_timeout_ms`	Default timeout (in milliseconds) to wait for a `PROMOTE AGGREGATOR` operation to finish before giving up. This variable can sync to all aggregators.	`180000`
`query_parallelism`	This variable is deprecated. Use `query_parallelism_per_leaf_core` instead. Maximum number of simultaneous running queries. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`query_parallelism_per_leaf_core`	The fraction of available cores that will be used on each leaf for a single query. The available values are any decimal from 0 to 1. If this value is set a 0, flexible parallelism is turned off. If this value is set at 1, all of the available core's processing power will work on a single query. This is a session variable that can be set on aggregators only.	`1.0`
`query_shape_serialization_enabled`	Serializes query shape metadata to disk. Available values are `AUTO`, `ON`, and `OFF`. This variable can sync to all nodes, including aggregator and leaf nodes.	`AUTO`
`query_shape_serialization_file_size_cap`	Maximum size (in bytes) for each query shape in a serialization file. This variable can sync to all nodes, including aggregator and leaf nodes.	`1048576`
`query_shape_serialization_show_parameters`	Stores actual parameter values to on-disk query shape metadata serialization. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`read_advanced_counters`	If `ON`, this variable enables thecollection of advanced statistics. For more information, see the Advanced Statistics section of the Management View Statistics Reference topic. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`redundancy_level`	If set to 1, there is no redundancy across leaves. If set to 2, turns on SingleStore’s High Availability mode. When you set this variable, its value is propagated to other aggregators only. For more information on this variable, see the Managing High Availability topic. This variable can sync to all nodes, including aggregator and leaf nodes.	`1`
`regexp_compile_mem_mb`	Specifies the heap allocation limit of the regexp compiler (in megabytes). This variable can sync to all nodes, including aggregator and leaf nodes.	`2`
`regexp_format`	Specifies the regular expression format to be used by regular expression functions that you call. Possible values are `'extended'` and `'advanced'`. When you set this variable, its value is propagated to all nodes. For more information on this variable, see the Regular Expression Functions topic. This variable can sync to all nodes, including aggregator and leaf nodes.	`'extended'`
`regexp_output_validation_mode`	This variable controls the output behavior of `REGEXP_REPLACE` and `REGEXP_SUBSTR` expressions if a returned string is invalid under its collation setting. Currently, regular expression built-ins could produce non-utf8 strings since they don't have full support for multi-byte characters. Possible values are `skip`, `return_null`, and `throw_error`. `skip` means no extra validation checks are performed and invalid strings will be allowed. `return_null` means "`SQL-NULL`" will be returned in such cases. `throw_error` means an error will be reported. This variable can sync to all nodes, including aggregator and leaf nodes.	`throw_error`
`resource_governor_cpu_limit_mode`	Determines whether the mode of control over the `CPU` for resource pools is `HARD` or `SOFT`. For more information on this variable, see CREATE RESOURCE POOL. This variable can sync to all nodes, including aggregator and leaf nodes.	`SOFT`
`resource_pool_statement_selector_function`	The function that is executed at runtime that selects the resource pool to use when the user runs a query. The `resource_pool` variable must be set to `system_auto` for the `resource_pool_statement_selector_function` to be used. This variable can sync to all nodes, including aggregator and leaf nodes. For more information on this variable, see the Setting Resource Limits topic.
`result_table_error_lifetime`	Sets the lifetime (in seconds) of a result table error before garbage collection. This variable can sync to all nodes, including aggregator and leaf nodes.	`1000`
`service_edition`	Displays the service edition: `STANDARD` or `ENTERPRISE`. This variable can sync to all nodes, including aggregator and leaf nodes.	`STANDARD`
`set_global_variables_allowed_list`	A JSON array of strings, where each string is the name of an engine variable. This list provides a means of access to engine variables that are not normally settable by SingleStore Helios users. The contents of the list can be set only by SingleStore customer support engineers. In consultation with SingleStore support engineers, this can allow you to set certain variables yourself -- providing you have `SYSTEM_VARIABLES_ADMIN` privilege -- that would not be otherwise available for you to control. This variable can sync to all nodes, including aggregator and leaf nodes.
`show_with_portability_comments`	Adds conditional compatibility comments to outputs like `SHOW CREATE TABLE` to help with portability. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`singlebox_optimizer_cost_based_threshold`	Maximum number of tables present in a join which will utilize the cost-based singlebox join optimizer. For joins with more than this many tables, singlebox join optimization will use an alternate, rule-based algorithm which is faster but less effective. The singlebox join optimizer is responsible for making decisions about the local aspects of how to efficiently execute a join, such as choosing an index. This variable must be set between 0 and 30 tables. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`18`
`skip_segelim_with_inlist_threshold`	Controls when segment elimination will not use an `IN` clause that is too large. This variable can sync to all nodes, including aggregator and leaf nodes.	`1000` (elements)
`snapshot_trigger_size`	The aggregate size of transaction logs (in bytes) which, when reached, will trigger a new snapshot. This variable can sync to all nodes, including aggregator and leaf nodes.	`2147483648`
`snapshot_wait_for_blob_gc_seconds`	Specifies how much time (in seconds) to wait between snapshots before taking a snapshot for blob garbage collection from previous snapshots. This variable can sync to all nodes, including aggregator and leaf nodes.	`180`
`snapshots_to_keep`	Number of snapshot and log files to keep for backup and replication. This variable may be set live. This variable can sync to all nodes, including aggregator and leaf nodes.	`2`
`sp_query_dynamic_param`	Specifies whether different query plans are generated for `CALL` queries when arguments to the stored procedure are `NULL` or not `NULL` arguments. If enabled, queries that use variables inside stored procedures will use the same query plan. For more details, see the In-Depth Variable Definitions section below. This variable can sync to all aggregators.	`AUTO`
`spilling_node_memory_threshold_ratio`	Memory threshold (ratio of total node memory, 0 - 1) to start spilling. This variable can sync to all nodes, including aggregator and leaf nodes.	`0.75`
`spilling_query_operator_memory_threshold`	Memory threshold (bytes) for a query operator to be considered for spilling. This variable can sync to all nodes, including aggregator and leaf nodes.	`104857600`
`sql_select_limit`	The maximum number of rows returned by a `SELECT` query. If the `LIMIT` clause is specified in a `SELECT` query, the value in the `LIMIT` clause overrides `sql_select_limit`. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`2^64-1`
`sub_to_physical_partition_ratio`	The number of sub-partitions per physical partition that a new database will be created with. It must be set at 0 or a power of 2 value of the physical partition count. The available values are 2, 4, 8, 16, 32, and 64. This variable can sync to all nodes, including aggregator and leaf nodes.	`4`
`subproc_abridged_errors`	Makes subprocess errors easier to read. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`subprocess_azure_retries`	This engine variable is deprecated. Maximum retries for Azure operations. This variable can sync to all nodes, including aggregator and leaf nodes.	`10`
`subprocess_backup_retries`	The maximum number of retries for `BACKUP` upload and download subprocesses. This variable can sync to all nodes, including aggregator and leaf nodes.	`3`
`subprocess_ec2_metadata_timeout_ms`	The maximum amount of time (in milliseconds) the engine waits for or retries a request before timing out to return metadata used to verify the cluster is on ec2 from which implicit credentials can be obtained. This variable can sync to all nodes, including aggregator and leaf nodes.	`60000`
`subprocess_io_idle_timeout_ms`	The maximum amount of time (in milliseconds) the engine waits for or retries a request before timing out and failing the backup when connecting to cloud providers. When you set this variable, its value is propagated to all nodes. This variable can sync to all nodes, including aggregator and leaf nodes.	`600000`
`subprocess_max_retries`	This variable is the setting for the `MaxRetries` parameter for S3 and GCS. Connectivity issues that are retry-able will automatically try to connect the default number of times. This variable can sync to all nodes, including aggregator and leaf nodes.	`10`
`subquery_merge_with_outer_joins`	This session variable fine-tunes the behavior of the rewrite `SubQueryMerge`. If the variable is set to `ON`, always merge the sub-select with outer join(s). If the variable is set to `HEURISTIC`, check to see if merging the sub-select with outer join(s) will cause negative performance for the overall query. If the variable is set to `OFF`, don’t merge sub-selects with outer join(s). If the variable is set to `AUTO` (this is the default); for v7.5 and previous versions, `AUTO` will behave like `ON`. For versions after v7.5, `AUTO` will behave like `HEURISTIC`. This variable can sync to all nodes, including aggregator and leaf nodes.	`AUTO`
`sync_permissions`	This aggregator will synchronize its permissions with other aggregators. When ON, this variable also enables DDL forwarding. See Synchronizing Permissions Across Your Cluster for more information about utilizing this variable. This variable can sync to all aggregators.	`OFF`
`sync_slave_timeout`	This engine variable is deprecated. Maximum amount of time (in milliseconds) for the primary to wait for acknowledgment from the synchronous replica. This variable can sync to all nodes, including aggregator and leaf nodes.	`10000`
`table_name_case_sensitivity`	Sets the case-sensitivity for database object names. If set to `OFF`, tables, views, table aliases, and user-defined table-valued functions (TVFs) are not case-sensitive. For details on case-sensitivity, refer to Database Object Case-Sensitivity. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`transaction_isolation`	Transaction isolation level. This is a session variable that can also be set globally. This variable can sync to all aggregators. This engine variable is configurable on SingleStore Helios.	`READ-COMMITTED`
`tx_isolation`	Transaction isolation level. This is a session variable that can also be set globally. This variable can sync to all aggregators. This engine variable has been deprecated. It is being kept for backward compatibility. Please see the `transaction_isolation` engine variable.	`READ-COMMITTED`
`trim_malloc`	Determines whether `malloc_active_memory` usage is trimmed periodically. See SHOW STATUS EXTENDED for more information. This variable can sync to all nodes, including aggregator and leaf nodes.	`TRUE`
`use_vectorized_join`	This variable has been deprecated and is no longer operational in SingleStore version 5.0 or newer. This variable can sync to all nodes, including aggregator and leaf nodes.	`ON`
`verify_fields_in_transitivity`	Limits the application of join predicate transitivity to predicates that may be estimated. To use, set this variable to `ON`. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`wait_die_retry_on_die_sleep_factor`	Controls how much time (in milliseconds) a transaction waits on a rowlock before giving up when the decision is "die". The value of the variable is multiplied by the number of locks that the transaction already holds, so if a transaction already has a lot of locks, it will wait longer. The purpose of this mechanism is to avoid unnecessary rollbacks because sometimes there is no real deadlock and instead of giving up right away we wait a bit for the lock to be released before rolling back all the work that was done. This variable can sync to all nodes, including aggregator and leaf nodes.	`250`
`cluster_name`	Specifies the cluster name used by the backup. This variable can sync to all nodes, including aggregator and leaf nodes.

JSON Sync Variables

Name	Description	Default
`json_compatibility_level`	Controls whether the `JSON_SET_<type>` function creates a keypath if it does not exist. The default is `7.8`, which means missing keypaths are not created. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`7.8`
`json_extract_string_collation`	Controls the collation setting for the `JSON_EXTRACT_STRING` function. This variable can sync to all nodes, including aggregator and leaf nodes. For versions before 7.8.21, the default is `AUTO`. In version 7.8.21 and forward `SERVER_V2` is the default. For more details, see the In-Depth Variable Definitions section below. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.	`auto/SERVER_V2`

Name

Description

Default

json_compatibility_level

Controls whether the JSON_SET_<type> function creates a keypath if it does not exist. The default is 7.8, which means missing keypaths are not created. This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.

7.8

json_extract_string_collation

Controls the collation setting for the JSON_EXTRACT_STRING function. This variable can sync to all nodes, including aggregator and leaf nodes. For versions before 7.8.21, the default is AUTO. In version 7.8.21 and forward SERVER_V2 is the default. For more details, see the In-Depth Variable Definitions section below.

This is a session variable that can also be set globally. This variable can sync to all nodes, including aggregator and leaf nodes.

auto/SERVER_V2

Password Complexity Sync Variables

For information about how to configure a password complexity policy, see Configuring a Password Policy.

Name	Description	Default
`password_max_consec_repeat_chars`	The maximum number of consecutive repeated characters allowed (`0` to `100`). For example, if set to 3, passwords with 4 or more consecutive repeated characters (e.g., aaaa or 1111) are disallowed. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`password_max_consec_sequential_chars`	The maximum number of consecutive characters allowed (`0` to `100`). For example, if set to 3, passwords with a 4-letter sequence or longer (e.g. 1234 or abcd) are disallowed. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`password_min_length`	The minimum number of characters required (`0` to `100`). This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`password_min_lowercase_chars`	The minimum number of lowercase characters required (`0` to `100`). This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`password_min_numeric_chars`	The minimum number of numeric digit characters required (`0` to `100`). This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`password_min_special_chars`	The minimum number of special (non-alphanumeric) characters required (`0` to `100`). This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`password_min_uppercase_chars`	The minimum number of uppercase characters required (`0` to `100`). This variable can sync to all nodes, including aggregator and leaf nodes.	`0`

Pipelines Sync Variables

You cannot set a variable for a specific pipeline – each variable setting applies to all pipelines in the cluster.

Name	Description	Default
`advanced_hdfs_pipelines`	Specifies whether to enable security features for HDFS pipelines. See Enabling Wire Encryption and Kerberos on HDFS Pipelines for more information. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`custom_java_pipelines`	Allows custom java pipelines. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`ingest_errors_max_disk_space_mb`	The maximum amount of disk space (in megabytes) that is used to log errors for pipelines. This variable can sync to all nodes, including aggregator and leaf nodes.	`102400`
`java_pipelines_extractor_class`	Implements an extractor interface used for experimental Java pipelines. This variable can sync to all nodes, including aggregator and leaf nodes.
`java_pipelines_heap_size`	Heap size (in megabytes) for HDFS pipelines. This variable can sync to all nodes, including aggregator and leaf nodes.	`8`
`pipelines_batches_metadata_to_keep`	The number of batch metadata entries to persist per partition, per pipeline before they are overwritten by incoming batches. As data is extracted from a source, it’s written in batches to a destination table on a leaf node. Metadata about these batches is temporarily persisted in the master aggregator’s `information_schema.PIPELINES_BATCHES` table. As new batches are loaded into the database, the oldest batch metadata entries will be removed from the `information_schema.PIPELINES_BATCHES` table. See the PIPELINES_BATCHES section for more information about this metadata. This variable can sync to all nodes, including aggregator and leaf nodes.	`1000`
`pipelines_deskew_batch_partitions_threshold`	For keyless sharded destination tables, if less than this fraction of batch partitions are active, reshuffle to avoid skew. This variable can sync to all nodes, including aggregator and leaf nodes.	`0.75`
`pipelines_errors_retention_minutes`	The amount of time in minutes that a pipeline error is stored on disk. These errors are surfaced in PIPELINES_ERRORS as long as they are stored on disk. This variable must be set to at least `0`. This variable can sync to all nodes, including aggregator and leaf nodes.	`1440`
`pipelines_extractor_core_on_timeout`	Generates core dumps on pipeline extractor operations that timeout. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`pipelines_extractor_debug_logging`	Specifies whether to enable extractor debugging for Kafka or HDFS pipelines. This variable currently does not apply to S3 pipelines. This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`pipelines_extractor_get_offsets_timeout_ms`	The maximum time (in milliseconds) to wait for offset data to be returned from the data source before returning an error. Increase this value if you experience timeout errors, such as `ERROR 1970 (HY000): Subprocess timed out.` Use the value `0` to indicate no timeout. This variable can sync to all aggregators.	`35000`
`pipelines_extractor_idle_timeout_ms`	The maximum time (in milliseconds) that a pipeline will wait for more data from an external source. Use the value `0` to indicate no timeout. This variable can sync to all nodes, including aggregator and leaf nodes.	`120000`
`pipelines_extractor_max_memory`	Maximum memory of a pipeline extractor (in megabytes). Minimum value for this engine variable is `1`. This variable can sync to all nodes, including aggregator and leaf nodes.	`500`
`pipelines_gc_max_files`	Max number of files that will be garbage collected in one iteration. Minimum value for this engine variable is `1`. This variable can sync to all aggregators.	`10000`
`pipelines_kafka_version`	The Kafka version used for the Kafka extractor. This variable can sync to all nodes, including aggregator and leaf nodes. This variable is not applicable to current (>= 0.10.0.10) Kafka versions as SingleStore requests a list of supported Kafka broker features using the `ApiVersionRequest`. For legacy Kafka, `pipelines_kafka_version` or `kafka_version` from a pipeline config is used to determine the list of supported features.	`0.10.0.10`
`pipelines_max_concurrent`	The maximum number of pipelines running concurrently. See Load Data with Pipelines page for more information. This variable can sync to all nodes, including aggregator and leaf nodes.	`50`
`pipelines_max_concurrent_batch_partitions`	The maximum number of pipeline batch partitions running concurrently. The number of partitions when using the default setting (0) is 2, or the number of leaves on the cluster times the `default_partitions_per_leaf` setting, whichever is higher. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`pipelines_max_errors_per_partition`	Deprecated in MemSQL 6.7. The maximum number of error event rows per leaf node partition to persist before they are deleted. Once the specified number of rows in the `information_schema.PIPELINES_ERRORS` table is reached, the database will eventually remove the oldest rows from the table. The removal mechanism for older error data is based on heuristics. Old errors are guaranteed to exist up to the specified number, but they may not immediately be removed. This variable can sync to all nodes, including aggregator and leaf nodes.	`1000`
`pipelines_max_offsets_per_batch_partition`	The maximum number of data source partition offsets to extract in a single batch transaction. If the data source’s partition contains fewer than the specified number of offsets, all of the partition’s offsets will be batched into the destination table. This variable applies only to Kafka pipelines. This variable can sync to all aggregators.	`1000000`
`pipelines_max_pooled_extractors`	Max pooled extractors for Kafka pipelines. The value must be set to at least `1`. This variable can sync to all nodes, including aggregator and leaf nodes.	`256`
`pipelines_max_retries_per_batch_partition`	The number of retry attempts for writing batch partition data to the destination table. If `pipelines_stop_on_error` is set to `OFF` and the specified retry number is reached without success, the batch partition will be skipped and will not appear in the destination table. If a batch partition is skipped, data loss can occur. If `pipelines_stop_on_error` is set to `ON` and the specified retry number is reached without success, the pipeline will stop. No batch partition data will be skipped. This configuration variable applies to the entire batch transaction, which includes extraction from a data source, optional transformation, and loading of the data into the destination table. If the batch transaction fails at any point during extraction, transformation, or loading, it will be retried up to the specified number. This variable can sync to all aggregators.	`4`
`pipelines_offsets_gc_skew_time_minutes`	Amount of time in minutes allowed for pipeline metadata timestamp skew. The minimum value for this engine variable is `1`. This variable can sync to all aggregators.	`1440`
`pipelines_pooled_extractor_batches`	Max number of batches for a pooled extractor for Kafka pipelines. The value must be set to between `1` and `2048`. This variable can sync to all nodes, including aggregator and leaf nodes.	`256`
`pipelines_stderr_bufsize`	The buffer size for standard error output (in bytes). Error messages that exceed this size will be truncated when written to the `information_schema.PIPELINES_ERRORS` table. However, the complete standard error text can be viewed by using the `BATCH_ID` and querying the `information_schema.PIPELINES_BATCHES` table. This variable can sync to all nodes, including aggregator and leaf nodes.	`65535`
`pipelines_stop_on_error`	Specifies whether or not each pipeline in the cluster should stop when an error occurs. If set to `OFF`, batches will be retried up to the number specified in the `pipelines_max_retries_per_batch_partition` variable. After all retries have failed, the batch will be skipped. When a batch is skipped, data loss can occur. If set to `ON`, the batch transaction that caused the error will be retried up to the number specified in the `pipelines_max_retries_per_batch_partition` variable. After all retries have failed, the pipeline will enter a `Stopped` state and must be manually started. This variable can sync to all aggregators.	`ON`
`pipelines_stored_proc_exactly_once`	If set to `ON`, run stored procedures from pipelines in a transaction. If this variable is OFF and there is a stored procedure attached to a pipeline, it may only partially succeed. If the procedure fails only the data that was written will remain, instead of rolling back on failure. This variable can sync to all aggregators.	`ON`

Unlimited Storage Database (Bottomless) and Point-in-Time Restore Variables

Name	Description	Default
`blob_cache_threadpool_max_concurrent`	Controls the maximum number of threads available for downloading blobs from unlimited storage. This variable can sync to all nodes, including aggregator and leaf nodes.	`32`
`bottomless_api_request_timeout_ms`	Sets the timeout, in milliseconds, for CURL HTTP requests made by the unlimited storage cloud API (AWS/Azure). This variable can sync to all nodes, including aggregator and leaf nodes.	`600000`
`bottomless_cloud_debug_tracing`	Turns on full debug tracing in an unlimited storage cloud API (AWS/Azure). This variable can sync to all nodes, including aggregator and leaf nodes.	`OFF`
`bottomless_gc_retention_period_minutes`	Specifies the amount of time, in minutes, a restore point for a remote storage database is retained after it is created. This determines how far back in time you can do a PITR. For example, to configure retention for 90 days, you should set the value to 902460 = 129600 minutes. This variable can sync to all nodes, including aggregator and leaf nodes.	`1440`
`bottomless_idle_upload_ms`	Number of milliseconds elapsed between unlimited storage uploads. After which, unlimited storage will upload what's queued. This variable can sync to all nodes, including aggregator and leaf nodes.	`60000`
`bottomless_incremental_download_max_buffer_size`	Maximum size (in bytes) an unlimited storage download's buffer can grow to. This variable can sync to all nodes, including aggregator and leaf nodes.	`1048576`
`bottomless_skip_create_database_api_checks`	Skips API checks when creating a new bottomless database. This variable can sync to all nodes, including aggregator and leaf nodes.	`FALSE`
`bottomless_snapshot_trigger_log_chunks`	Determines how often snapshot files are uploaded to the object store. A higher value will cause snapshot files to be uploaded less frequently. Snapshot files are used during recovery. For example, copying bucket files in an object store to a new location and then running `ATTACH` at the new location will trigger recovery. This variable can sync to all nodes, including aggregator and leaf nodes.	`300`
`bottomless_upload_max_concurrent`	A higher value can increase the concurrency of uploading data updates made on the cluster to the object store. A higher value will increase the CPU and memory usage, and potentially the network usage on the cluster. This variable can sync to all nodes, including aggregator and leaf nodes.	`8`
`bottomless_upload_throttle_hard_limit_secs`	Amount of lag (in seconds) after which all columnstore ingest is throttled, subject to `bottomless_upload_throttle_min_disk_limit_mb`. This variable can sync to all nodes, including aggregator and leaf nodes.	`1800`
`bottomless_upload_throttle_min_disk_limit_mb`	Minimum disk space when an unlimited storage columnstore ingest kicks in. A value of `0` means there is no minimum and ingest is throttled subject to the hard and soft time limits. This variable can sync to all nodes, including aggregator and leaf nodes.	`0`
`bottomless_upload_throttle_soft_limit_secs`	Amount of lag (in seconds) after which some columnstore ingest may be throttled, subject to `bottomless_upload_throttle_min_disk_limit_mb`. This engine variable has no effect if the value is higher than the value set for `bottomless_upload_throttle_hard_limit_secs`. This variable can sync to all nodes, including aggregator and leaf nodes.	`600`

Workload Management Sync Variables

Name	Description	Default
`resource_usage_model`	Whether to train or enable the resource usage model for workload management. When set to `ON`, workload management will estimate memory usage and queue queries that are estimated to use too much. When set to `TRAINONLY`, PROFILE can be run on queries to compare the estimated memory usage of queries with their actual use. This is recommended when upgrading from any version prior to 6.7, to allow for the workload manager to do the necessary machine learning for accurate estimates. Once estimated memory use in `PROFILE` begins matching actual use, consider setting this variable to `ON`. This variable can sync to all aggregators.	`OFF`
`workload_management`	Specifies whether to enable workload management for the cluster. If this variable is set to `ON`, the other workload management engine variables will affect the way a query is executed. If set to `OFF`, the feature is disabled and no queueing or system resource optimization will occur. This variable can sync to all aggregators.	`ON`
`workload_management_available_leaf_memory_ratio`	Sets the ratio of the available leaf memory for workload_management to use when queuing queries. Valid ranges are [0.0 to 1.0]. The variable sets the ratio of the total amount of memory workload management uses when deciding to queue queries. For example, if it is set 0.9, then SingleStore will assume there is only 90% of the total leaf memory available, and will end up running fewer queries before hitting the limit and needing to queue. This variable can sync to all aggregators.	`1.0`
`workload_management_dynamic_resource_allocation`	Enables/disables the dynamic reuse of WM queues feature. This variable can sync to all aggregators.	`OFF`
`workload_management_enable_static_partitioning`	Enables static resource partitioning for deterministic behavior by workload management. This variable can sync to all aggregators.	`FALSE`
`workload_management_max_connections_per_leaf`	The maximum number of connections to use per leaf node in the cluster. This variable can sync to all aggregators.	`10000`
`workload_management_max_queue_depth`	The maximum depth of the query queue, which is the maximum number of queries that can be queued. If this number is reached, additional queries will not execute, and an `ER_TOO_MANY_QUEUED_QUERIES` error will appear. This variable can sync to all aggregators.	`100`
`workload_management_max_threads_per_leaf`	The maximum number of threads to use per leaf. This number correlates with the `max_connection_threads` engine variable, and they should generally be set to the same value. This variable can sync to all aggregators.	`8192`
`workload_management_memory_queue_threshold`	Percentage of memory a query can use before it will get queued. If an individual query is projected to use more than `workload_management_memory_queue_threshold * (leaf_maximum_memory - leaf_current_table_memory) / workload_management_expected_aggregators`, then it will be queued. This variable can sync to all aggregators.	`0.01`
`workload_management_memory_queuing`	Whether to turn on queuing based on memory usage of queries. This variable can sync to all aggregators.	`ON`
`workload_management_queue_size_allow_upgrade`	Workload management contains two queues for execution and depending on the amount of resources required for query execution, a query will be in one of the two available queues (MEDIUM or LARGE). If the MEDIUM queue is saturated and the LARGE queue is less than the value of `workload_management_queue_size_allow_upgrade`, the query will move from the MEDIUM queue to the LARGE queue. This variable can sync to all aggregators.	`1`
`workload_management_queue_time_warning_ratio`	Specifies when a warning will appear based on the ratio of time spent by a query in the queue versus the actual execution time of the query. For example, if a query waits in the queue for one second and it takes four seconds to execute, the ratio is 1:4 or 0.25. Once the specified ratio is reached for a query, a `ER_QUERY_QUEUED_WARNING` warning will appear. This variable can sync to all aggregators.	`0.5`
`workload_management_queue_timeout`	The time duration (in seconds) after which a query times out and is removed from the queue without being executed. This variable can sync to all aggregators.	`3600`

Non-Sync Variables List

See the engine variables overview to learn how non-sync variables work.

Note

All of the non-sync variables listed in the following table are global variables, except when noted as a session variable that can also be set globally in the Description column.

The variables listed in the following tables can be set to take effect on node startup and can be set to take effect while the node is running. Exceptions are noted in the fourth column.

Basic Variables

Name	Description	Default	Exceptions to When Variable can be Set
`bind_address`	Defines the IP address to use to listen for incoming connections. If the address is 0.0.0.0, SingleStore accepts connections on all network interfaces; otherwise, it only accepts connections for the given IP address.	`0.0.0.0`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`datadir`	Directory path for the data directory. This directory contains snapshots, logs, and columnstore segments.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`div_precision_increment`	The number of digits by which to increase the scale of division results performed with the division (/) operator.	`4`	You can set this variable but it is currently not supported in SingleStore. SingleStore always returns the results to the fourth precision value.
`flush_before_replicate`	If `ON`, data is written and flushed to disk locally before being replicated. This will increase replication latency but will guarantee that replicas will not flush data to disk before the master does.	`OFF`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`master_aggregator`	Appending `master_aggregator` (with no arguments) to the end of a node’s memsql.cnf specifies that node as the cluster’s master aggregator. For more information on this variable, see Master Aggregator.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`maximum_blob_cache_size_mb`	Specifies the maximum blob cache size per leaf node. The cache stores recently accessed columnstore data objects and is located on the cluster's local storage. The cache exists in `datadir`. The cache size is limited by available space in `datadir`. `maximum_blob_cache_size_percent`setting overrides this variable.	Version <=7.9 For disk range 0-40GB, cache value is 100% of disk. For disk range 40GB+, cache value is 80% of disk. Version =>8.0 For disk range 0-40GB, cache value is 100% of disk. For disk range 40-140GB, cache value is 40GB. For disk range 140-666GB, cache value is 75% of disk. For disk range 667GB+, cache value is 90% of disk - 100GB.
`maximum_memory`	Maximum memory SingleStore will use, in MB. WARNING: Do not set it to more than the default.	90% of System RAM or System RAM minus 10 GB, whichever is greater	You are required to restart a node only when the variable is being reduced.
`maximum_table_memory`	Maximum memory SingleStore will use for table storage, in MB. WARNING: Do not set it to more than the default.	If `maximum_memory` >= 10 GB, then 90% of `maximum_memory`. Else if `maximum_memory` >= 1.25 GB, then `maximum_memory` - 1 GB	You are required to restart a node only when the variable is being reduced.
`port`	SingleStore port number.	`3306`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`reported_hostname`	The hostname or IP of the machine in use.
`plancachedir`	Directory path for the plancache directory. This directory contains compiled plans used for codegen.	`./plancache`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`tracelogsdir`	Directory path for the tracelogs directory. This directory contains log files, including memsql.log and the query log.	`./tracelogs`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.

Connection Management Variables

Name	Description	Default	Exceptions to When Variable can be Set
`connect_timeout`	The number of seconds the node’s SingleStore waits for a connection packet before sending back a `Bad handshake` response.	`10`
`max_allowed_packet`	Maximum allowed protocol packet size (in bytes). This is a session variable that can also be set globally. The maximum value is 1GB.	`104857600`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`max_connections`	The number of simultaneous clients allowed. For more, see In-Depth Variable Definitions.	`100000`
`max_connection_threads`	The maximum number of kernel threads for processing queries. For more, see In-Depth Variable Definitions.	`8192`
`max_dedicated_admin_connections`	Specifies the number of connections reserved for admin users (users granted the `SUPER` permission). This is the number of connections over and above the `max_connections`. Its purpose is to allow admin users to login even if `max_connections` number of non-admin users are already logged in. For example, if `max_connections` is set to `100` and `max_dedicated_admin_connections` is set to `5`, then even if 100 non-admin user connections are active at any time, 5 admin users can still log in. This is to prevent administrative users from being locked out of the system during heavy traffic. You connect via a socket file, for example: `mysql -u root --socket ‘/home/xyz/memsql/bincache/cluster_10000/10000/data/memsql.sock'` instead of using `mysql -u root -h <host> --port <port>` Refer to the Dedicated Admin Connections page for how to create dedicated admin connections.	`5`
`max_pooled_connections`	The maximum number of stashed connections per leaf. For more information on this variable, see In-Depth Variable Definitions.	`1024`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`skip_name_resolve`	Controls whether to perform name resolution. By default, `AUTO` will only perform a reverse Domain Name System (DNS) lookup if there are any host-based security rules. Options include `AUTO`, `OFF`, or `ON`. For more information on this variable, see In-Depth Variable Definitions.	`AUTO`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.

Database Optimization Variables

Name	Description	Default
`columnar_segment_rows`	Deprecated alias to `columnstore_segment_rows`.	`1024000`
`columnstore_window_size`	This variable has been deprecated and is no longer operational in SingleStore.
`enable_sort_on_load`	Whether to merge the newly loaded data segments (for `LOAD DATA`, `INSERT SELECT`, and `PIPELINE` statements) into a single sorted run.	`ON`
`net_first_packet_read_timeout`	Number of seconds an online failover will wait to drain open idle write transactions before issuing a kill to those transactions. After the idle write transactions are killed, an application-level retry is required.	`30`
`net_read_timeout`	Number of seconds to wait for more data from a connection before aborting the read. This is a session variable that can also be set globally.	`3600`
`net_write_timeout`	Number of seconds to wait for a block to be written to a connection before aborting the write. This is a session variable that can also be set globally.	`3600`
`optimize_columnar_tables`	This variable has been deprecated and is no longer operational in SingleStore.
`transaction_buffer`	This variable has been deprecated and is no longer operational in SingleStore.

Logging Variables

Name	Description	Default
`core_file`	Turning `core_file` on or off determines whether or not full core dumps are produced upon a crash.	`ON`
`critical_diagnostics`	Sends usage and critical error diagnostics to SingleStore.	`ON`
`general_log`	If set to `ON`, every query will be logged to a table or log file. If set to `PARTIAL`, will only log when load is light. `OFF` turns off logging.	`OFF`
`general_log_file`	Log connections and queries to a given file.	`'./query.log'`
`warn_level`	Defines how SingleStore behaves when it encounters unsupported functionality. For more information, visit the Unsupported Feature List section of the Unsupported MySQL Features topic.	`WARNINGS`

Password Complexity Non-Sync Variables

Name	Description	Default
`expire_root_password`	Specifies whether the root password can expire. If set to `ON`, the root password will expire after the `password_expiration_seconds` duration is reached.	`OFF`
`password_expiration_seconds`	The time (in seconds) before a password expires. The value `0` indicates that the password will never expire.	`0`
`password_history_count`	The number of previous passwords per user that SingleStore will store and disallow from reuse. The value `0` indicates that any previous password can be reused. The maximum is `10`.	`0`

Pipelines Non-Sync Variables

You cannot set a variable for a specific pipeline – each variable setting applies to all pipelines in the cluster.

Name	Description	Default Setting	Exceptions to When Variable can be Set
`java_pipelines_java_home`	Specifies the value that SingleStore sets the node’s operating system environment variable `JAVA_HOME` to. If `java_pipelines_java_home` is not set, SingleStore does not set `JAVA_HOME`.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`java_pipelines_java_path`	Specifies the path that the HDFS extractor uses to run Java.

Security Variables

Name	Description	Default	Exceptions to When Variable can be Set
`node_replication_ssl_only`	When this variable is set to `ON` (assuming that SSL is enabled), SSL is used for cross-cluster replication, but not for intra-cluster communication. When the variable is `OFF`, SSL is used for both cross-cluster as well as intra-cluster replication.	`OFF`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_ca`	CA file to be used for SSL connections.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_capath`	CA directory to be used for SSL connections.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_cert`	Certificate file to be used for SSL connections.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_cipher`	Cipher to be used for SSL/TLS connections. You must manually enumerate all desired cipher suites. For example: ssl_cipher = DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384 This will enable only the enumerated cipher suites in both the SingleStore engine and websocket proxy.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_fips_mode`	When this variable is set to `ON`, FIPS mode is enabled.	`OFF`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_key`	Public-private key pair file to be used for SSL connections.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_key_passphrase`	Passphrase for encrypted `ssl_key`.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`ssl_last_reload_attempt_time`	Contains the sequence number of reload attempts.
`ssl_last_successful_reload_time`	Contains the date/time of the last successful reload.

Other Variables

Name	Description	Default	Exceptions to When Variable can be Set
`allow_unsupported_filesystem`	Enables support for filesystems without `fallocate` support.	`FALSE`
`activities_delta_sleep_s`	`activities_delta_sleep_s` specifies an interval of time (in seconds) which is used by the `mv_activities_cumulative` variable to determine recent resource usage. For more information, see Management View Reference. This is a session variable that can also be set globally.	`1`
`auditlogsdir`	Specifies the local or network directory to write log files. For more information on this variable, see Configure Audit Logging.	`/<path-to-node-directory>/auditlogs`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`auditlog_level`	`auditlog_level` is used to specify the level of logging in a node. There are 11 logging levels. For more information on this variable, see Audit Logging Levels.	`OFF`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`auditlog_rotation_size`	Specifies the maximum size per log file (in bytes). Required if logging is enabled. For more information on this variable, see Configure Audit Logging.	`134217728`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`auditlog_rotation_time`	Specifies the maximum time duration to write to a single log file (in seconds). For more information on this variable, see Configure Audit Logging.	`3600`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`autocommit`	If `ON`, individual SQL statements are run in a single transaction that commits when the statement finishes. If `OFF`, individual SQL statements run in a multi-statement transaction by default, which must be ended explicitly with `COMMIT` or `ROLLBACK`. Note: If `BEGIN` is used to start a transaction, it overrides the behavior of `autocommit` engine variable for this transaction, and the transaction must be ended explicitly with `COMMIT` or `ROLLBACK`.	`ON`
`backup_max_threads`	Specifies the maximum number of concurrent threads, per leaf, used to run a backup on each leaf. By default, a backup of a leaf uses one thread per partition and there is no restriction on the number of threads created (aside from system limitations). The number of threads, if set, is shared among active backups, with the first backup using as many as it needs. The remainder, if any, goes to the next backup, etc.	`0`
`basedir`	Specifies the path where the installation directory can be found.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`compat_version`	This variable exists for backwards compatibility with MySQL. It specifies the MySQL compatibility version.
`compile_only`	If `ON`, SingleStore will compile, but not run, each query it receives. This is a session variable that can also be set globally.	`OFF`	You cannot set this variable while the node is offline.
`convert_nonunique_hash_to_skiplist`	When this variable is set as `TRUE`, any non-unique hash index will be recovered as a skiplist index. Any newly created table will also have its non-unique hash indexes created as skiplists.	`TRUE`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`core_file_mode`	Specifies the type of core dump to generate if SingleStore terminates abnormally. Options include `NONE`, `PARTIAL`, or `FULL`. `PARTIAL` omits most user data to keep the dump small, while a `FULL` core dump uses the equivalent amount of disk space as the amount of memory used by SingleStore.	`PARTIAL`	You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`default_time_zone`	This is a configuration variable that is used to set the time zone on a host by specifying an offset from UTC time. Refer to the Setting the Time Zone page for details on this variable.
`flat_plancache`	This variable has been deprecated and is no longer operational in SingleStore version 5.0 or newer.
`gssapi_keytab_path`	The local path to the keytab file created on the KDC. For more information on this variable, see Kerberos Authentication.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`gssapi_principal_name`	The SPN for SingleStore that was created on the KDC. For more information on this variable, see Kerberos Authentication.		You can only set this variable while the node is offline. The changes to this variable will take effect on the next start of the node.
`hostname`	Speficies the server hostname at startup. This variable is read-only.
`http_api`	Enables SingleStore's Data API endpoints on the built-in HTTP server when used in conjunction with the `https_proxy_port` or the `http_proxy_port` variable. This variable must be set locally on each aggregator node on which the Data API needs to be run.	`ON`
`http_api_max_idle_seconds`	Controls how long a pooled connection can remain idle (or unused) before it will be closed. `0` means the connection will remain open. Please contact SingleStore Customer Support if you need to change this value.	`86400`
`http_api_max_lifetime_seconds`	Controls how long a pooled connection can remain open. `0` means the connection wil

List of Engine Variables

On this page

Sync Variables Lists

JSON Sync Variables

Password Complexity Sync Variables

Pipelines Sync Variables

Unlimited Storage Database (Bottomless) and Point-in-Time Restore Variables

Workload Management Sync Variables

Non-Sync Variables List

Basic Variables

Connection Management Variables

Database Optimization Variables

Logging Variables

Password Complexity Non-Sync Variables

Pipelines Non-Sync Variables

Security Variables

Other Variables