Overview

2025-11-27 07:27:57  Updated

This topic lists the cluster-level parameters and tenant-level parameters of OceanBase Database.

Cluster-level parameters

Security parameters

Parameter Description
mysql_port The SQL port.
rpc_port The remote procedure call (RPC) port.
sql_protocol_min_tls_version The minimum version of the SSL/TLS protocol used by SSL connections for SQL statements.
ssl_client_authentication Specifies whether to enable SSL authentication.
ssl_external_kms_info The information that the SSL feature of OceanBase Database relies on, which is recorded in JSON strings for different SSL modes. Such a JSON string contains at least the ssl_mode field.
enable_sql_audit Specifies whether to enable SQL audit.

Backup and restore parameters

Parameter Description
backup_backup_dest The destination for second backup.
backup_backup_dest_option The parameters for second backup.
backup_dest_option The parameters for backup.
backup_concurrency The concurrency of data writes to the file system during backup.
backup_dest The path for baseline data backup and log archiving.
backup_log_archive_option The options for log archiving during backup.
backup_net_limit The total bandwidth for cluster backup.
backup_recovery_window The time window in which backups can be restored.
backup_region The region for which backup tasks are run.
backup_zone The zone for which backup tasks are run.
log_archive_batch_buffer_limit The maximum memory available for log archiving on a single server.
log_archive_checkpoint_interval The interval between log archiving checkpoints of cold data.
restore_concurrency The maximum concurrency of tenant data restore from backups.

Cgroup parameters

Parameter Description
enable_cgroup Specifies whether to enable the control group (cgroup) feature for the OBServer node.

CPU parameters

Parameter Description
cpu_count The total number of CPU cores in the system. If the parameter is set to 0, the system automatically detects the number of CPU cores.
server_balance_cpu_mem_tolerance_percent The tolerance of CPU and memory resource imbalance in the node load balancing strategy.
server_cpu_quota_max The maximum CPU quota for the system.
server_cpu_quota_min The minimum CPU quota for the system. The system automatically reserves the quota.
token_reserved_percentage The percentage of idle tokens reserved for tenants in the scheduling of CPU resources for the tenants.
workers_per_cpu_quota The number of worker threads allocated to each CPU quota.
cpu_reserved The number of CPU cores reserved in the system. The remaining CPU cores are exclusively occupied by OceanBase Database.
sys_cpu_limit_trigger The CPU utilization threshold. When CPU utilization reaches the threshold, background tasks in the system are suspended.
system_cpu_quota The CPU quota for the sys tenant.
tenant_cpu_variation_per_server The variation allowed for CPU quota scheduling among multiple units of a tenant.

Read/Write and query parameters

Parameter Description
weak_read_version_refresh_interval The version refresh interval for weak-consistency reads. This parameter affects the latency of weak-consistency reads.
large_query_worker_percentage The percentage of worker threads reserved for large queries.
large_query_threshold The execution time threshold to identify a large query.
trace_log_slow_query_watermark The execution time threshold to identify a slow query. Trace logs of slow queries are written to system logs.

Load balancing parameters

Parameter Description
balancer_log_interval The interval for printing statistical logs generated by the threads of disaster recovery tasks.
balancer_task_timeout The timeout period of background tasks such as load balancing.
balancer_tolerance_percentage The tolerance for disk imbalance among multiple units of a tenant, which is set in the load balancing strategy. If the imbalance is within the range that starts at the average value minus the tolerance and ends at the average value plus the tolerance, no balancing action is triggered.
server_balance_critical_disk_waterlevel The disk usage threshold that triggers disk load balancing.
server_balance_disk_tolerance_percent The tolerance for disk load imbalance among nodes, which is set in the load balancing strategy.
resource_hard_limit The overprovisioning percentage of CPU resources.
enable_sys_unit_standalone Specifies whether the unit of the sys tenant exclusively occupies a node.
balancer_emergency_percentage The load threshold of each unit. When the load of a unit exceeds the specified threshold, you can enable replica migration to an external system for load balancing even during a major compaction.
balancer_timeout_check_interval The interval for checking whether background tasks such as load balancing time out.
data_copy_concurrency The maximum number of concurrent data migration and replication tasks allowed in the system.
tenant_groups The tenant groups used in the load balancing strategy.
unit_balance_resource_weight The weights of resources in unit load balancing strategies. Usually, you do not need to set this parameter.
resource_soft_limit Specifies whether to enable unit balancing.

Replica parameters

Parameter Description
enable_rereplication Specifies whether to enable automatic data synchronization to replicas.
ls_meta_table_check_interval The interval at which the background inspection threads inspect the DBA_OB_LS_LOCATIONS or CDB_OB_LS_LOCATIONS view.
sys_bkgd_migration_change_member_list_timeout The timeout period for modifying the Paxos member list during replica migration.
sys_bkgd_migration_retry_num The maximum number of retries after a replica migration task fails.
balance_blacklist_failure_threshold The maximum number of consecutive failures of a background task such as replica migration upon which the task is added to the blocklist.
balance_blacklist_retry_interval The retry interval for a background task such as replica migration that is added to the blocklist.
election_cpu_quota The CPU quota allocated to background tasks related to replica election.
election_blacklist_interval The interval during which the dismissed leader cannot be re-elected as the leader.
enable_auto_leader_switch Specifies whether to enable automatic leader switchover.
enable_smooth_leader_switch Specifies whether to enable smooth leader switchover.
global_index_build_single_replica_timeout The timeout period for creating a replica during global index creation.
get_leader_candidate_rpc_timeout The timeout period of an internal request for obtaining the leader candidate in the automatic leader switchover strategy.
migrate_concurrency The maximum concurrency for internal data migration.
rebuild_replica_data_lag_threshold The threshold of the size difference of transaction logs between the leader and a follower. When the difference reaches the threshold, replica reconstruction is triggered.
server_data_copy_out_concurrency The maximum concurrency for data migration from a single node.
server_data_copy_in_concurrency The maximum concurrency for data migration to a single node.
replica_safe_remove_time The retention period of a deleted replica before it can be cleared.

Cache parameters

Parameter Description
bf_cache_miss_count_threshold The number of macroblock misses that triggers the creation of the Bloom filter cache.
bf_cache_priority The priority of the Bloom filter cache.
cache_wash_threshold The remaining capacity threshold that triggers cache cleanup.
fuse_row_cache_priority The priority of the fuse row cache in the cache system.
user_row_cache_priority The priority of the baseline data row cache in the cache system.
autoinc_cache_refresh_interval The refresh interval for the auto-increment column cache.
plan_cache_evict_interval The eviction interval for the execution plan cache.
index_block_cache_priority The priority of the microblock cache for metadata indexes.
opt_tab_stat_cache_priority The priority of the statistics cache.
tablet_ls_cache_priority The priority of the tablet mapping cache.
user_block_cache_priority The priority of the data block cache in the cache system.
index_info_block_cache_priority The priority of the block index cache in the cache system.
index_cache_priority The priority of the index cache in the cache system.
user_tab_col_stat_cache_priority The priority of the statistics cache in the cache system.
plan_cache_high_watermark The memory threshold to trigger plan cache eviction. Automatic eviction is triggered when the memory occupied by the plan cache reaches the specified threshold.
plan_cache_low_watermark The memory threshold to stop plan cache eviction. The eviction is stopped when the memory occupied by the plan cache decreases to the specified threshold.

Partition parameters

Parameter Description
tablet_meta_table_check_interval The interval at which the background inspection threads inspect the DBA_OB_TABLET_REPLICAS or CDB_OB_TABLET_REPLICAS view.
tablet_meta_table_scan_batch_count The number of tablets cached in memory when the tablet meta table iterator is working.
tablet_size The size of each shard during intra-partition parallel processing such as parallel compactions and queries.
auto_broadcast_location_cache_rate_limit The maximum number of partitions whose location changes can be broadcast on each OBServer node per second.
auto_refresh_location_cache_rate_limit The maximum number of partitions for which automatic refresh can be triggered per second on each OBServer node.
enable_pg Specifies whether to enable the partition group feature.
gc_wait_archive Specifies whether to start garbage collection for a partition until all the logs in the partition have been archived.
partition_table_check_interval The interval at which the OBServer node deletes non-existent replicas from a partitioned table.

Background execution thread parameters

Parameter Description
sql_net_thread_count The number of I/O threads for the MySQL cluster, namely the number of global_sql_nio_server threads. The default value 0 indicates that the value of the parameter is the same as that of net_thread_count.
auto_leader_switch_interval The working interval of the background thread for automatic leader switchover.
switchover_process_thread_count The size of the thread pool for primary/standby database switchover.

I/O parameters

Parameter Description
rdma_io_thread_count The number of RDMA I/O threads for Libeasy.
syslog_io_bandwidth_limit The maximum I/O bandwidth available for system logs. If this value is reached, the remaining system logs are discarded.
disk_io_thread_count The number of disk I/O threads. The value must be an even number.
net_thread_count The number of network I/O threads.
data_storage_error_tolerance_time The tolerance period after which the status of an abnormal data disk is set to ERROR.
sys_bkgd_io_high_percentage The highest percentage of I/O resources that can be occupied by background tasks
sys_bkgd_io_low_percentage The lowest percentage of I/O resources that can be occupied by background tasks
user_iort_up_percentage The I/O latency threshold for the user disk. When the I/O latency of the user disk reaches this threshold, the traffic of background I/O operations is throttled.
ob_esi_rpc_port The communication port between the obesi process and the observer process.
enable_ob_esi_process Specifies whether to enable the obesi process (external storage API).
ob_esi_session_timeout The timeout period of the active session resources for the obesi process.
ob_esi_io_concurrency The I/O concurrency for the obesi process.
ob_esi_syslog_level The current log level for the obesi process.
ob_esi_max_syslog_file_count The maximum number of log files that can be retained for the obesi process.
multiblock_read_gap_size The size of multiple block caches from which data can be read in one I/O operation.
multiblock_read_size The I/O aggregate throughput in data access.

Cluster parameters

Parameter Description
all_server_list The IP addresses of all servers in the cluster.
cluster The name of the current OceanBase cluster.
cluster_id The ID of the current OceanBase cluster.
rpc_timeout The timeout period of an internal request in the cluster.
all_cluster_list The list of servers that access the same URL specified for config_url.
enable_election_group Specifies whether to enable the election group strategy.
local_ip The IP address of the server where OceanBase Database is installed.
observer_id The unique identifier that RootService assigns to the OBServer node in the cluster.
min_observer_version The earliest OBServer node version in the cluster.

Bandwidth parameters

Parameter Description
enable_ob_ratelimit Specifies whether to enable rate limiting between regions in an RPC connection.
ob_ratelimit_stat_period The time interval at which an OBServer node calculates and updates the maximum bandwidth.

Location cache parameters

Parameter Description
virtual_table_location_cache_expire_time The validity period of the location cache of the virtual table.
location_cache_refresh_rpc_timeout The timeout period for refreshing the location cache through RPC.
location_cache_refresh_sql_timeout The timeout period for refreshing the location cache through SQL.
location_cache_refresh_min_interval The minimum interval for sending location cache refresh requests, which prevents excessive refresh requests from overloading the system.
location_cache_cpu_quota The CPU quota for the location cache module.
location_fetch_concurrency The maximum number of concurrent requests for refreshing the location cache on a single server.
location_refresh_thread_count The number of threads used by the OBServer node to obtain partition location information from RootService.
enable_auto_refresh_location_cache Specifies whether to enable automatic refresh of the location cache.

Directory parameters

Parameter Description
config_additional_dir The local directories for storing multiple copies of configuration files for redundancy.
data_dir The directory for storing SSTables and other data.

Memory parameters

Parameter Description
datafile_disk_percentage The percentage of used space to the total space of the disk where the data_dir directory is located. This disk is initialized for data storage by the OceanBase Database system.
data_disk_usage_limit_percentage The percentage of data write space to the total space of the disk. When the data write space reaches the threshold, data can no longer be written to the disk.
enable_sql_operator_dump Specifies whether to allow intermediate SQL processing results to be written to the disk to release the memory.
global_write_halt_residual_memory The global available memory threshold that triggers the suspension of write operations of user tenants. (The sys tenant is not affected.)
leak_mod_to_check The internal debugging feature used for memory leakage check.
memory_chunk_cache_size The total cache size of the memory allocator.
memory_limit The total size of available memory.
memory_limit_percentage The percentage of available memory to total memory in the system.
memory_reserved The memory size reserved by the system for KVCache.
memstore_limit_percentage The percentage of the memory that can be occupied by the MemStore to the total available memory of a tenant.
system_memory The memory size reserved by the system for the sys500 tenant.
use_large_pages Manages the use of large memory pages by the database.
datafile_maxsize The maximum space allowed in automatic scaling for disk files.
datafile_next The step size of automatic scaling for disk files.
storage_meta_cache_priority The priority of the storage meta cache in KVCache.

PX parameters

Parameter Description
px_workers_per_cpu_quota The proportion of parallel execution (PX) worker threads.
px_task_size The amount of data processed by the SQL parallel query engine in each task.
max_px_worker_count The maximum number of threads for the SQL parallel query engine.

Other parameters

Parameter Description
builtin_db_data_verify_cycle The cycle of a bad block check in the unit of days. When the value is set to 0, bad block checks are not performed.
data_storage_warning_tolerance_time The tolerance period after which the data disk is set to the WARNING state.
dead_socket_detection_timeout The interval for detecting invalid sockets.
migration_disable_time The period during which data migration is suspended for a node after data migration to the node fails due to reasons such as full disk usage.
schema_history_expire_time The validity period of history metadata.
datafile_size The size of a data file. This parameter is generally left unspecified.
devname The name of the network interface card (NIC) to which the service process is bound.
enable_perf_event Specifies whether to enable the information collection feature for performance events.
enable_record_trace_id Specifies whether to record the trace ID configured by the application.
enable_upgrade_mode Specifies whether to enable the upgrade mode. In upgrade mode, some background system features are suspended.
enable_ddl Specifies whether to allow the execution of DDL statements.
high_priority_net_thread_count The number of network threads with a high priority. When this parameter is set to 0, this feature is disabled.
obconfig_url The URL of the OBConfig service.
rpc_port The RPC port.
stack_size The size of the function call stack for programs.
tenant_task_queue_size The request queue size of each tenant.
zone The name of the zone where the node is located. This parameter is generally left unspecified.
recyclebin_object_expire_time The period during which a schema object can be retained in the recycle bin. After the period elapses, the object is purged from the recycle bin.
default_row_format The default row format used in table creation in MySQL mode.
sys_bkgd_net_percentage The maximum percentage of network bandwidth for background system tasks.
schema_history_recycle_interval The interval for recycling schema multi-version history files.
enable_asan_for_memory_context Specifies whether to enable ObAsanAllocator when ob_asan is working. By default, ObAllocator is the allocator of MemoryContext.
ofs_list The list of URLs for connecting to the OceanBase File System (OFS) of all the zones so that RootService can access files across zones in OFS deployment mode. OFS is a distributed storage system independently designed for OceanBase Database.

RootService parameters

Parameter Description
rootservice_async_task_queue_size The size of the internal asynchronous task queue for RootService.
rootservice_async_task_thread_count The size of the thread pool for internal asynchronous tasks of RootService.
rootservice_list The list of servers where RootService and its replicas are deployed.
rootservice_ready_check_interval The wait time after RootService is started, during which the cluster status is checked.
rootservice_memory_limit The maximum memory available to RootService.
lease_time The heartbeat lease period.
server_check_interval The interval at which the server checks the table consistency.
server_permanent_offline_time The time threshold for heartbeat missing at which a server is considered permanently offline. Data replicas on a permanently offline server must be automatically supplemented.
ob_event_history_recycle_interval The interval at which historical events are recycled.
enable_rootservice_standalone Specifies whether to allow the sys tenant and RootService to exclusively occupy an OBServer node.
fast_recovery_concurrency The maximum concurrency for executing quick restore tasks scheduled by RootService on an OBServer node.
wait_leader_batch_count The maximum number of partitions to which RootService can send a command for leader switchover.

RPC authentication parameters

Parameter Description
rpc_client_authentication_method The security authentication method of the RPC client.
rpc_server_authentication_method The security authentication method of the RPC server.

SQL request parameters

Parameter Description
sql_login_thread_count The number of threads for processing SQL login requests.
sql_audit_memory_limit The maximum memory available for SQL audit data.
enable_sys_table_ddl Specifies whether to enable manual creation of system tables.
internal_sql_execute_timeout The interval of DML requests in the system.

Transaction and transaction log parameters

Parameter Description
log_disk_size The size of the log disk where redo logs are stored.
log_disk_percentage The percentage of the total disk space occupied by redo logs.
dtl_buffer_size The size of the cache allocated to the SQL data transmission module.
ignore_replay_checksum_error Specifies whether to ignore checksum errors that occur during transaction log replay.
trx_2pc_retry_interval The interval for retrying a failed two-phase commit task.
standby_fetch_log_bandwidth_limit The maximum bandwidth per second available for the total traffic of synchronizing logs from the primary tenant by all servers in the cluster where the standby tenant resides.
log_storage_warning_tolerance_time The maximum duration of I/O failures tolerable on the log disk before the log disk is considered damaged and follower-to-leader switchover is triggered.
clog_disk_utilization_threshold The usage of the clog or ilog disk space that triggers disk space reuse.
clog_expire_days The retention period of clog files. When the retention period of a clog file expires, the file is deleted.
clog_cache_priority The priority of the transaction log cache.
clog_disk_usage_limit_percentage The maximum percentage of disk space available for transaction logs.
clog_sync_time_warn_threshold The warning threshold of time consumed for synchronizing transaction logs. When the consumed time reaches the threshold, a WARN-level log is generated.
clog_transport_compress_func The algorithm for compressing transaction logs for internal transmission.
enable_one_phase_commit Specifies whether to enable one-phase commit.
enable_separate_sys_clog Specifies whether to separately store system transaction logs and user transaction logs.
flush_log_at_trx_commit The transaction log write strategy adopted when transactions are committed.
ignore_replay_checksum_error Specifies whether to ignore checksum errors that occur during transaction log replay.
index_clog_cache_priority The priority of the transaction log index cache in the cache system.
ilog_index_expire_time The validity period of ilog files on OBServer nodes. Expired files can no longer be read.
trx_force_kill_threshold The maximum amount of time that the system waits before killing transactions for a freeze or leader switchover.

Lock parameters

Parameter Description
trx_try_wait_lock_timeout The maximum amount of time that a statement waits for a locked row to be unlocked.

Debugging parameters

Parameter Description
debug_sync_timeout The timeout period for a Debug Sync operation. When the value is set to 0, Debug Sync is disabled.
enable_rich_error_msg Specifies whether to add debugging information, such as the server address, error time, and trace ID, to the client message.

TCP parameters

Parameter Description
enable_tcp_keepalive Specifies whether to enable the keepalive mechanism for client connections.
tcp_keepidle The interval in seconds before sending a keepalive probe packet when no data is sent on a client connection.
tcp_keepintvl The interval between two probes in seconds when you enable the keepalive mechanism for client connections.
tcp_keepcnt The maximum number of retries before terminating a non-active connection.

System log parameters

Parameter Description
alert_log_level The level of alert logs.
enable_record_trace_log Specifies whether to record trace logs.
enable_async_syslog Specifies whether to enable asynchronous writing of system logs.
enable_syslog_recycle Specifies whether to record the logs generated before the startup of the OBServer node.
enable_syslog_wf Specifies whether to print system logs at the WARN level or above to a separate log file.
max_string_print_length The maximum length of a single row when system logs are printed.
max_syslog_file_count The maximum number of log files that can be retained.
syslog_level The level of system logs.
trace_log_sampling_interval The interval at which trace logs are printed.
diag_syslog_per_error_limit The number of DIAG system logs allowed for each error code per second. When this threshold is reached, no more logs are printed.
enable_log_archive Specifies whether to enable log archiving.
system_trace_level The level of system trace logs to be printed.

Compression algorithm parameters

Parameter Description
default_compress_func The default algorithm for compressing table data. You can also specify another compression algorithm when creating a table.
default_compress The default compression strategy used during table creation in Oracle mode.
tableapi_transport_compress_func The algorithm for compressing OBKV-Table query results for transmission.
default_transport_compress_func The RPC compression algorithm for the entire cluster.

Minor and major compaction parameters

Parameter Description
enable_major_freeze Specifies whether to enable automatic global freezing.
micro_block_merge_verify_level The verification level of macroblocks in a major compaction.
row_compaction_update_limit The number of data updates that triggers a major compaction of rows in the memory.
enable_global_freeze_trigger Specifies whether to enable automatic triggering of a global freeze.
enable_merge_by_turn Specifies whether to enable the rotating compaction strategy.
enable_manual_merge Specifies whether to enable manual major compaction.
global_major_freeze_residual_memory The threshold of remaining memory for triggering a global freeze. When the available memory is less than this threshold, a global freeze is triggered.
minor_deferred_gc_time The interval between the time when garbage collection starts for SSTables and the time when the major compaction ends.
zone_merge_concurrency The number of zones supported in a major compaction. If this parameter is set to 0, the system determines the best level of concurrency based on the actual deployment status.
zone_merge_order The order of zones in a rotating compaction. If you do not specify a value, the system determines the parameter value.
zone_merge_timeout The timeout period for the major compaction of a zone.
minor_freeze_times The number of minor compactions that triggers a major compaction.
minor_merge_concurrency The number of concurrent threads in a minor compaction.
minor_warm_up_duration_time The preload time of the new MemTable generated after a minor compaction.
row_purge_thread_count The maximum number of worker threads for a major compaction of rows in the memory.

Arbitration service parameters

Parameter Description
ob_startup_mode The startup mode of the OBServer node. This parameter can be modified only when the OBServer node is started for the first time.

Resource isolation parameters

Parameter Description
enable_global_background_resource_isolation Specifies whether to enable global resource isolation between foreground and background tasks.
global_background_cpu_quota The CPU quota for background tasks when global resource isolation is enabled between foreground and background tasks.

Tenant-level parameters

Security parameters

Parameter Description
external_kms_info The key management information.
tde_method The encryption method for a transparent tablespace.
audit_sys_operations Specifies whether to track the operations of the SYS user.
audit_trail Specifies whether to enable database audit.

CPU parameters

Parameter Description
cpu_quota_concurrency The maximum concurrency allowed for each CPU quota of a tenant.

Read/Write and query parameters

Parameter Description
enable_monotonic_weak_read Specifies whether to enable monotonic reads.
query_response_time_stats Specifies whether to collect the statistics of the information_schema.QUERY_RESPONSE_TIME view.
query_response_time_flush Specifies whether to refresh the information_schema.QUERY_RESPONSE_TIME view and re-read query_response_time_range_base.
query_response_time_range_base The time interval at which the time parameters of the information_schema.QUERY_RESPONSE_TIME view are collected.

Load balancing parameters

Parameter Description
balancer_idle_time The interval for waking up the idle threads of background tasks such as load balancing.
enable_rebalance Specifies whether to enable automatic load balancing.
enable_transfer Specifies whether to allow transfer within a tenant. This parameter is invalid when enable_rebalance is set to False.
partition_balance_schedule_interval The scheduling interval of partition-level load balancing.

Replica parameters

Parameter Description
choose_migration_source_policy The prioritizing strategy for selecting the source replica for migration.

Backup and restore parameters

Parameter Description
log_restore_concurrency The concurrency of log restore.
log_archive_concurrency The concurrency of log archiving.
backup_data_file_size The size of the backup data files.

Background execution thread parameters

Parameter Description
ddl_thread_score The weight of the CPU time slice occupied by the worker threads for DDL tasks.
compaction_low_thread_score The weight of the CPU time slice occupied by the worker threads for low-priority compaction tasks.
compaction_high_thread_score The weight of the CPU time slice occupied by the worker threads for high-priority compaction tasks.
compaction_mid_thread_score The weight of the CPU time slice occupied by the worker threads for medium-priority compaction tasks.
ha_high_thread_score The number of worker threads for high-availability high-priority tasks.
ha_mid_thread_score The number of worker threads for high-availability medium-priority tasks.
ha_low_thread_score The number of worker threads for high-availability low-priority tasks.
ob_compaction_schedule_interval The time interval for compaction scheduling.
compaction_dag_cnt_limit The maximum number of directed acyclic graphs (DAGs) allowed in a compaction DAG queue.
compaction_schedule_tablet_batch_cnt The maximum number of partitions that can be scheduled per batch during batch scheduling for compactions.
tenant_sql_login_thread_count The number of login threads of a MySQL tenant, namely the number of mysql_queue threads. The default value 0 indicates that the value of the parameter is the same as that of unit_min_cpu.
tenant_sql_net_thread_count The number of I/O threads of a MySQL tenant, namely the number of sql_nio_server threads. The default value 0 indicates that the value of the parameter is the same as that of unit_min_cpu.

I/O parameters

Parameter Description
io_category_config The percentages of all types of I/O requests.

Compatibility parameters

Note

The parameters described in the following table take effect only in MySQL mode.

Parameter Description
enable_sql_extension Specifies whether to enable SQL extension for tenants.
compatible Controls the compatibility of related features in a tenant. This parameter cannot be set.

Routing parameters

Parameter Description
ob_proxy_readonly_transaction_routing_policy Specifies whether OceanBase Database Proxy (ODP) routes a transaction based on read-only statements.

LOB data parameters

Parameter Description
lob_enable_block_cache_threshold The threshold for caching the LOB data stored in OUTROW mode that is read during a query.

Memory parameters

Parameter Description
rpc_memory_limit_percentage The percentage of the maximum RPC memory in the tenant to the total tenant memory.
range_optimizer_max_mem_size The maximum memory space available for the Query Range module.

OBKV parameters

Parameter Description
kv_ttl_duty_duration The time period during which scheduled daily time-to-live (TTL) tasks are to be triggered.
kv_ttl_history_recycle_interval The retention period of historical TTL tasks.
enable_kv_ttl Specifies whether to enable background TTL tasks. This parameter is applicable to periodic TTL tasks. User management commands are not limited by this parameter.
ttl_thread_score The weight for using time slices by threads of TTL tasks.

PL parameters

Parameter Description
plsql_code_type The compilation mode of PL/SQL code.
plsql_debug Specifies whether to compile code for debugging.
plsql_optimize_level The compilation optimization level.
plsql_v2_compatibility Specifies whether compatibility with Oracle 8 is supported.

Other parameters

Parameter Description
enable_early_lock_release Specifies whether to enable the early lock release (ELR) feature.
workarea_size_policy Specifies whether the size of an SQL workarea is manually or automatically adjusted.
open_cursors The maximum number of cursors that can be concurrently opened in a single session.
ob_ssl_invited_common_names The list of identities of applications running under the current tenant. The identity of an application comes from the cn (common name) field of the subject of the client certificate in two-way SSL authentication.
ob_enable_batched_multi_statement Specifies whether to enable group-based execution optimization for the batch processing feature.
job_queue_processes The maximum number of concurrent tasks that can be run under each tenant. You can set this parameter to prevent tenant resources from being excessively occupied by tasks.
default_auto_increment_mode The default auto-increment mode of auto-increment columns.
ob_query_switch_leader_retry_timeout The maximum retry period for failed queries, in μs.
default_enable_extended_rowid Specifies whether to create the table in Extended ROWID mode.
dump_data_dictionary_to_log_interval The interval of data dictionary persistence for the tenant.
enable_user_defined_rewrite_rules Specifies whether to enable user-defined rules.
storage_rowsets_size The maximum number of rows allowed in a batch for vectorized processing in the columnstore engine.

Transaction and transaction log parameters

Parameter Description
log_disk_utilization_limit_threshold The maximum usage of the tenant log disk. When the occupied space of the tenant log disk exceeds its total space multiplied by the specified value, log write is not allowed.
log_disk_utilization_threshold The usage threshold of the tenant log disk. When the occupied space of the tenant log disk exceeds its total space multiplied by the specified value, log files are reused.
writing_throttling_maximum_duration The time required for allocating the remaining memory of the MemStore after the write speed is limited. This parameter controls the write speed by controlling the memory allocation progress.
writing_throttling_trigger_percentage The upper limit of the write speed.
standby_db_fetch_log_rpc_timeout The timeout period of RPC requests sent by a standby cluster for pulling logs. If the specified timeout period is elapsed, the log transfer service of the standby cluster determines that the requested server in the primary cluster is unavailable and switches to another server.
log_disk_throttling_percentage The percentage of unrecyclable disk space that triggers log write throttling.
log_transport_compress_all Specifies whether to compress logs for transmission.
log_transport_compress_func The algorithm for compressing logs for transmission.
clog_max_unconfirmed_log_count The maximum number of unconfirmed logs allowed in the transaction module.
clog_persistence_compress_func The algorithm for compressing transaction logs for storage.
enable_clog_persistence_compress Specifies whether to compress transaction logs for storage.

System log parameters

Parameter Description
log_disk_throttling_maximum_duration The maximum available duration of the log disk after log throttling is triggered.
ls_gc_delay_time The delay time before the log stream of a tenant is deleted.
standby_db_preferred_upstream_log_region The preferred region for the standby tenant to synchronize upstream logs in a Physical Standby Database scenario.
archive_lag_target The delay time of log archiving in a tenant.

User login parameters

Note

The parameters described in the following table take effect only in MySQL mode.

Parameter Description
connection_control_failed_connections_threshold The threshold of failed login attempts.
connection_control_min_connection_delay The minimum lock period for an account whose number of failed login attempts reaches the specified threshold.
connection_control_max_connection_delay The maximum lock period for an account whose number of failed login attempts reaches the specified threshold.

Compression algorithm parameters

Parameter Description
spill_compression_codec The algorithm for compressing data for storage during SQL statement execution.

Minor and major compaction parameters

Parameter Description
default_progressive_merge_num The default number of progressive compactions during table creation.
major_freeze_duty_time The time for triggering a daily freeze and compaction.
major_compact_trigger The number of minor compactions that triggers a global major compaction.
minor_compact_trigger The threshold for triggering the next-level compaction in hierarchical minor compactions.
undo_retention The time range in seconds of data versions to be retained by the system. This parameter is used to control the collection of data of multiple versions in minor compactions.
merger_check_interval The interval for scheduling the thread for checking the major compaction status.
freeze_trigger_percentage The threshold of memory used by tenants for triggering a global freeze.
max_kept_major_version_number The number of frozen data versions to be retained.
merge_stat_sampling_ratio The sampling rate of data column statistics in a major compaction.
merge_thread_count The number of worker threads for the daily compaction.
merger_completion_percentage The percentage of compacted replicas at which the major compaction task is considered completed.
merger_switch_leader_duration_time The interval for a batch leader switchover in a daily compaction.
merger_warm_up_duration_time The preload time of new baseline data in a major compaction.

Arbitration service parameters

Parameter Description
arbitration_timeout The timeout period for triggering an automatic downgrade.

Unsupported parameters

Parameter Description
sql_work_area The workarea memory of a tenant.
max_stale_time_for_weak_consistency The maximum latency allowed in weak-consistency reads.

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