System Variables for MariaDB Xpand 23.09

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The parent of this page is: Reference for MariaDB Xpand 23.09

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Overview
System Variables for MariaDB Xpand 23.09

Overview

MariaDB Xpand supports system variables for configuration and monitoring. Many of the system variables are intended to function like the system variables in MariaDB Enterprise Server, but MariaDB Xpand also supports its own unique system variables.

System variables can be used to configure and monitor MariaDB Xpand 23.09.

Reference material is available for MariaDB Xpand 23.09.

System Variables for MariaDB Xpand 23.09

Variable	Description
activate_all_roles_on_login	Determines whether to automatically activate roles on login
alter_hold_until_checkpoint	Hold alter statement completion until all transactions prior to alter have committed
alter_lock	Specifies the implicit locking strategy for `ALTER` when the `LOCK` syntax is omitted. WARNING: changing this variable can result in unexpected table locks. Choices: `NONE`, `SHARED`, `AUTO`
arp_period_ms	Period for heartbeat packets
autocommit	Each statement will be its own transaction, and automatically applied to the database
consistent_order	Force consistent ordering. See Guide.
cost_node
cost_read_columnar
default_password_lifetime	Number of days before passwords expire by default. Zero means automatic password expiration is disabled.
default_storage_engine	Dummy variable for compatibility
device_temporary_space_limit_bytes	Maximum number of bytes allowed to be used for temporary containers
discourage_non_sarge_threshold	Discourage a non sarged plan if the table cardinality is less than or equal to this threshold
enable_rule_eliminate_inner_join_rule	Enable rule eliminate_inner_join_rule to fire
enable_rule_filter_or_rewrite_to_and	Enable rule filter_or_rewrite_to_and to fire
enable_rule_join_commute_mtable_rule	Enable rule join_commute_mtable_rule to fire
foreign_key_checks	Enable/Disable foreign key checks
gtm_pc_max_per_node_mb	gtm program cache uses this much memory per node in quorum
hash_aggregate_partial_skiplist_threshold	The number of slices per node above which hash_aggregate_partial automatically uses sigma skiplist, or 0 means to not automatically determine
interactive_timeout	Dummy variable for compatibility
ldap_cache_enabled	Cache the results returned by LDAP search operations
ldap_cache_entry_lifetime_s	Duration that entries in the LDAP query cache are valid for, in seconds
ldap_cache_max_bytes	Maximum size of the LDAP query cache, in bytes
ldap_enabled	Enable authentication using LDAP
ldap_group_query	Template string that specifies an RFC 4516-formatted LDAP query URL for obtaining the LDAP groups a user belongs to
ldap_group_to_xpand_role	Regex for transforming an LDAP group DN into an Xpand role
ldap_network_timeout_s	The seconds value used to time out network connections to the LDAP server. 0 specifies an infinite timeout
ldap_query_password	The password used with ldap_query_user when binding to an LDAP server to perform search operations. If this or ldap_query_user is empty, search operations are performed anonymously.
ldap_query_user	DN of the LDAP user to bind as when performing search operations on an LDAP server. If this or ldap_query_password is empty, search operations are performed anonymously.
ldap_servers	Comma-separated list of LDAP servers, each of the form 'protocol://hostname[:port]'. If multiple servers are specified, each node will round-robin its LDAP queries among the list.
ldap_tls_cacert	By default, Xpand will use the system defaults in order to determine CA trust when establishing TLS connections with an LDAP server. If set, this should specify a path to a file containing the trusted CA certificates. This can be useful if your LDAP server's TLS certificate is self-signed. This option is commonly referred to as TLS_CACERT in other LDAP client documentation.
ldap_user_lookup	Strategy for deriving the LDAP user DN. Choices: substitution, query.
ldap_user_lookup_query	Regex for transforming a username of the form 'username@hostname' into an RFC 4516-formatted LDAP query URL that obtains an LDAP user DN. Used when ldap_user_lookup = query.
ldap_user_lookup_substitution	Regex for transforming a username of the form 'username@hostname' into an LDAP user DN. Used when ldap_user_lookup = substitution.
lockman_max_locks	The maximum number of locks the lock manager will hold on each node in the cluster
lockman_max_transaction_locks	The maximum number of locks a single transaction can hold on each node in the cluster
max_allowed_packet	Maximum allowed query size
max_connections	The maximum number of connections allowed per node
max_sierra_opt_mem_MiB	Cease Sierra planner optimization attempts once we have used this many total MiB and attempt to continue with the best plan found so far
max_sierra_parse_mem_MiB	Halt the Sierra planner and return an error to the user if this many MiB have been consumed during the initial parse phase. This variable is independent of the other max_sierra_%_mem_MiB variables.
max_sierra_plan_s	Stop the sierra planner once the planner has been working this long on a plan. Specify 0 to disable this check.
max_sierra_tot_mem_MiB	Halt the Sierra planner and return an error to the user once this many total MiB have been used. The system will ensure that this value is at least 100MB greater than max_sierra_opt_mem_MiB.
max_sierra_working_mem_MiB	Halt the Sierra planner and return an error to the user if the working set memory exceeds this many MiB limit. This variable is independent of the other max_sierra_%_mem_MiB variables.
mysql_version	The reported MySQL server version
proc_vrels_disable
queue_daddy_replay_concurrency	how many replays to run at a time
queue_daddy_replay_limit_ms	only start a replay this often
rebalancer_optional_tasks_enabled	Controls whether non-essential rebalancer tasks should be running
rebalancer_split_threshold_kb	Default size at which the rebalancer splits slices
session_log_slow_threshold_ms	Query duration threshold in milliseconds before logging this query
sierra_flt_over_join_card_adj	Use different card adjustment when filter is over join
sierra_join_swap_threshold	If number of tables_exceeds - swap filtering tables only
sierra_limit_join_swap	Limit non-filtering join swaps
sierra_min_nlj_outer
sierra_new_card_override	Override setting of new_card_estimation
sierra_systab_def_card	Default system table size
simple_password_check_digits	Number of digits that passwords must contain
simple_password_check_letters_same_case	Passwords must contain this number of upper-case letters and this number of lower-case letters
simple_password_check_minimal_length	Number of total characters that passwords must contain
simple_password_check_other_characters	Number of non-letter and non-digit characters that passwords must contain
storage_engine	Dummy variable for compatibility
strict_password_validation	Passwords may not be set with hashes if password validation is enabled
system_time_zone	Time Zone. Must be set in Olson time zone format. See Guide.
task_rebalancer_rebalance_regions_interval_ms	Milliseconds between runs of periodic task "rebalancer_rebalance_regions". Specify 0 to disable periodic task.
tracefile	Path to log trace data to
vrel_enable_cache	enable caching for certain virtual relations
vrel_timeout_ms	timeout for timeout-enabled virtual relations
wait_timeout	Number of seconds to wait for activity on a connection before closing it

To see system variables supported in other versions, see "System Variables by Xpand Version".