OceanBase Database V4.x has undergone architectural changes and reorganization. As a result, many parameters and system variables are no longer applicable. V4.x has removed and modified these invalid parameters and variables. For example, the parameter minor_freeze_times used to trigger major freeze has been deleted. Additionally, we have adjusted the default values of some parameters. For instance, in V4.x, the underlying support for large transactions has been resolved, and transactions are no longer affected by freeze operations. Therefore, the default value of freeze_trigger_percentage has been adjusted to 20%.
Changes related to parameters in V4.x
Replaced parameters
The following table lists the parameters in V4.x that replace those in V3.x.
Parameters changed in name
The following table lists the parameters changed in name in V4.x.
Parameter (V3.x) |
Parameter (V4.x) |
Description |
|---|---|---|
| tableapi_transport_compress_func | kv_transport_compress_func |
|
Parameters changed in scope
OceanBase Database is a multi-tenant architecture. Most users create multiple tenants within the same cluster and manage them based on different business types. To meet the requirement where one tenant represents one business unit, in V4.x, cluster-level capabilities are split into tenant-level capabilities. For example, tenant-level backup, tenant-level dump, and tenant-level major compaction.
The following table lists the parameters changed in scope.
Parameter |
Description |
|---|---|
| backup_data_file_size |
|
| enable_rebalance | Starting from V4.2.0, the scope was changed from cluster-level to tenant-level. |
| balancer_idle_time | Starting from V4.2.0, the scope was changed from cluster-level to tenant-level. |
| log_archive_concurrency | Starting from V4.1.0, the scope was changed from cluster-level to tenant-level. |
| log_restore_concurrency | Starting from V4.1.0, the scope was changed from cluster-level to tenant-level. |
| major_compact_trigger | Starting from V4.0.0, the scope was changed from cluster-level to tenant-level. |
| minor_compact_trigger | Starting from V4.0.0, the scope was changed from cluster-level to tenant-level. |
Parameters changed in mode
Most parameters take effect in dynamic mode, which means that you do not need to restart an OBServer node. A few parameters take effect in restart mode, which means that you need to restart an OBServer node.
The following table lists the parameters changed in mode.
Parameter |
Description |
|---|---|
| server_cpu_quota_min |
|
| server_cpu_quota_max |
|
Parameters with changed default values
The following table lists the parameters with changed default values.
Parameter name |
Description |
|---|---|
| compaction_dag_cnt_limit | For V4.3.5, the default value is changed from 15000 to 50000 starting from V4.3.5 BP3. |
| kv_group_commit_batch_size | For V4.3.5, the default value is changed from 1 to 10 starting from V4.3.5 BP1. |
| direct_load_allow_fallback | Starting from V4.3.5, the default value is changed from False to True. |
| memstore_limit_percentage |
|
| range_optimizer_max_mem_size |
|
| ls_gc_delay_time |
|
| enable_monotonic_weak_read | Starting from V4.2.1, the default value is changed from true to false. |
| location_refresh_thread_count | Starting from V4.2.0, the default value is changed from 4 to 2. |
| enable_record_trace_id | Starting from V4.2.0, the default value is changed from true to false. |
| plan_cache_evict_interval | Starting from V4.2.0, the default value is changed from 1s to 5s. |
| tenant_task_queue_size | Starting from V4.1.0, the default value is changed from 65536 to 16384. |
| server_cpu_quota_min |
|
| writing_throttling_maximum_duration | Starting from V4.0.0, the default value is changed from 1h to 2h. |
| writing_throttling_trigger_percentage | Starting from V4.0.0, the default value is changed from 100 to 60. |
| freeze_trigger_percentage | Starting from V4.0.0, the default value is changed from 70 to 20. |
Parameters that change the value range
The following table lists the parameters that change the value range.
Parameter |
Description |
|---|---|
| compaction_schedule_tablet_batch_cnt | For V4.3.5, from V4.3.5 BP3, the value range is adjusted from [10000, 200000] to [10000, 500000]. |
| compaction_dag_cnt_limit | For V4.3.5, from V4.3.5 BP3, the value range is adjusted from [10000, 200000] to [10000, 500000]. |
| ob_startup_mode | Starting from V4.3.4, the value range includes SHARED_STORAGE. |
| large_query_threshold |
|
| memstore_limit_percentage |
|
| range_optimizer_max_mem_size |
|
| job_queue_processes |
|
| memory_limit_percentage | Starting from V4.2.1, the value range is adjusted from [10, 90] to [10, 95]. |
| cpu_quota_concurrency | Starting from V4.2.0, the value range is adjusted from [1,10] to [1,20]. |
| memory_limit | Starting from V4.1.0, the value range is adjusted from [4G, +∞) to [1G, +∞). |
| server_cpu_quota_min |
|
Parameters with changed semantics
The following table lists the parameters whose semantics have changed in V4.x.
Configuration Item |
Description |
|---|---|
| datafile_maxsize | Starting from V4.3.4, in Shared-Nothing (SN) mode, the semantics of this parameter remain unchanged. In Shared-Storage (SS) mode, this parameter is no longer applicable. |
| datafile_next | Starting from V4.3.4, in Shared-Nothing (SN) mode, the semantics of this parameter remain unchanged. In Shared-Storage (SS) mode, this parameter is no longer applicable. |
| datafile_disk_percentage | Starting from V4.3.4, in Shared-Nothing (SN) mode, the semantics of this parameter remain unchanged. In Shared-Storage (SS) mode, this parameter is used to set the percentage of local available cache space relative to the total disk space. |
| datafile_size | Starting from V4.3.4, in Shared-Nothing (SN) mode, the semantics of this parameter remain unchanged. In Shared-Storage (SS) mode, this parameter is used to set the size of the local cache space. |
New parameters
The following table lists the new parameters in V4.x.
Parameter |
Introduced in |
Description |
|---|---|---|
| enable_lock_priority | V4.3.5 BP2 | The lock priority switch. |
| enable_adaptive_plan_cache | V4.3.5 BP2 | Specifies whether to enable the adaptive plan cache feature for a tenant. |
| global_index_auto_split_policy | V4.3.5 BP2 | Specifies whether to enable the automatic partitioning feature for new global indexes. |
| default_storage_cache_policy | V4.3.5 BP2 | Specifies the default cache strategy. |
| enable_manual_storage_cache_policy | V4.3.5 BP2 | Specifies whether to enable the user-specified hot cache strategy. |
| suspend_storage_cache_task | V4.3.5 BP2 | Specifies whether to suspend the background cache task. |
| clog_io_isolation_mode | V4.3.5 BP2 | Specifies whether to isolate I/O requests for the clog disk based on whether the clog disk and data disk are independent. You can adjust the value of this parameter based on the actual deployment of the system to balance performance and resource utilization. |
| default_table_organization | V4.3.5 BP1 | Specifies the default table organization mode for tables. |
| px_node_policy | V4.3.5 BP1 | Specifies the candidate pool for PX computing nodes. |
| ob_enable_java_env | V4.3.5 BP1 | Specifies whether to enable the Java environment required for external tables such as HDFS/MaxCompute (ODPS). |
| ob_java_home | V4.3.5 BP1 | Specifies the Java home path required for JNI operations. This parameter is valid only when ob_enable_java_env is enabled. |
| ob_java_opts | V4.3.5 BP1 | Specifies the JVM startup options, such as memory size and garbage collection algorithm. This parameter is valid only when ob_enable_java_env is enabled. |
| ob_java_connector_path | V4.3.5 BP1 | Specifies the path of the jar package required for the external table connector. This parameter is valid only when ob_enable_java_env is enabled. |
| temporary_file_max_disk_size | V4.3.5 BP1 | Specifies the maximum disk space that a single node of a tenant can occupy for temporary files. |
| package_state_sync_max_size | V4.3.5 BP1 | Specifies the maximum length of the package state synchronization package variable value. If the value exceeds the specified value, the package variable will not be synchronized. |
| unit_gc_wait_time |
|
Specifies the maximum wait time for Unit GC. If the wait time exceeds the specified value, a forced GC is triggered. |
| recover_table_concurrency |
|
Specifies the maximum number of tables that can be restored in parallel during the cross-tenant data import stage of table-level restore. |
| recover_table_dop |
|
Specifies the maximum number of tables that can be restored in parallel during the cross-tenant data import stage of table-level restore. |
| query_memory_limit_percentage |
|
Specifies the percentage of tenant memory that can be used for a single SQL statement. |
| replica_parallel_migration_mode |
|
Specifies the mode of the log stream replica parallel migration feature. |
| sts_credential |
|
Specifies the credentials for accessing the STS service provided by OCP. |
| arbitration_degradation_policy | V4.3.4 | Specifies the auto-degradation policy. |
| kv_hbase_client_scanner_timeout_period | V4.3.4 | Specifies the timeout period for OBKV-HBase streaming queries. |
| default_load_mode | V4.3.4 | Controls whether to use the hint specified in the parameter when no hint is specified for the data import operation. |
| direct_load_allow_fallback | V4.3.4 | Controls whether to return an error when the direct load operation is not supported in the data import scenario. |
| enable_auto_split | V4.3.4 | Controls whether to enable the auto-partitioning feature for the table. |
| auto_split_tablet_size | V4.3.4 | Specifies the threshold for triggering a split after the auto-partitioning feature is enabled for the tenant. |
| sync_io_thread_count | V4.3.4 | Specifies the number of threads for synchronous I/O requests. |
| ob_encoding_granularity | V4.3.3 | Specifies the maximum percentage of memory resources that the vector index module can use. |
| ob_storage_s3_url_encode_type | V4.3.3 | Specifies whether the URL encoding method used for sending requests to S3 is compatible with the RFC 3986 standard. |
| ob_vector_memory_limit_percentage | V4.3.3 | Specifies the threshold for memory resource usage of the vector index module (unit: percentage). |
| storage_rowsets_size | V4.3.2 | Specifies the number of rows processed in a single vectorized batch by the columnar engine. |
| alert_log_level |
|
The log level of the warning logs. |
| enable_global_background_resource_isolation |
|
Specifies whether to enable the global foreground and background resource isolation feature. |
| global_background_cpu_quota |
|
The number of CPU cores allocated to background tasks when the global foreground and background resource isolation feature is enabled. |
| choose_migration_source_policy |
|
The priority strategy for selecting the source replica during migration. |
| lob_enable_block_cache_threshold |
|
The threshold for the LOB query cache of the OUTROW storage. |
| spill_compression_codec | V4.3.1 | The compression algorithm for data disk spilling during SQL execution. |
| max_partition_num |
|
The maximum number of partitions allowed in MySQL mode. |
| log_storage_compress_all |
|
Specifies whether to enable the clog storage compression feature. |
| syslog_compress_func |
|
The compression algorithm for system logs. |
| syslog_disk_size |
|
The maximum disk space for system logs. |
| syslog_file_uncompressed_count |
|
The maximum number of system log files that are not compressed. |
| log_storage_compress_func |
|
The compression algorithm for clog storage compression. |
| enable_dblink |
|
Specifies whether to enable the DBLink feature. |
| data_disk_write_limit_percentage |
|
Specifies the write limit percentage of the data disk. |
| strict_check_os_params |
|
Specifies whether to enable the OS configuration parameter check feature. |
| default_table_store_format | V4.3.0 | Specifies the default table format for user tenants. The table format can be rowstore, columnstore, or redundant rowstore/columnstore. |
| enable_rpc_authentication_bypass | V4.3.0 | If the RPC authentication feature is enabled for the OBServer cluster, specifies whether to allow the OMS migration service and OBKV service to bypass the RPC authentication and connect to the cluster. |
| sql_protocol_min_tls_version | V4.2.1 | Specifies the minimum SSL/TLS protocol version for SSL connections to the database. |
| compaction_dag_cnt_limit | V4.2.1 | Specifies the maximum number of DAGs in the Compaction DAG queue. |
| compaction_schedule_tablet_batch_cnt | V4.2.1 | Specifies the maximum number of tablets in each batch for Compaction scheduling. |
| enable_transfer | V4.2.1 | Specifies whether to allow Transfer operations within a tenant. |
| ttl_thread_score | V4.2.1 | Specifies the number of threads used for TTL tasks. |
| local_ip | V4.2.0 | Specifies the IP address of the server where the ObServer is deployed. |
| observer_id | V4.2.0 | The unique identifier assigned to the OBServer node by the RS. |
| standby_fetch_log_bandwidth_limit | V4.2.0 | Specifies the maximum bandwidth per second that can be occupied in total by all servers in the standby tenant cluster when pulling logs from the primary tenant. |
| storage_meta_cache_priority | V4.2.0 | Specifies the priority of the storage Meta Cache in the kvcache. |
| archive_lag_target | V4.2.0 | Specifies the log archive delay time for a tenant. |
| log_disk_throttling_maximum_duration | V4.2.0 | Specifies the maximum available time for the log disk after triggering log throttling. |
| log_disk_throttling_percentage | V4.2.0 | The percentage of unrecoverable log disk space that triggers log write throttling. |
| ls_gc_delay_time | V4.2.0 | The delay time for log stream garbage collection. |
| partition_balance_schedule_interval | V4.2.0 | The partition balancing scheduling cycle. |
| range_optimizer_max_mem_size | V4.2.0 | The maximum memory size for the Query Range module. |
| standby_db_fetch_log_rpc_timeout | V4.2.0 | The timeout for log fetching RPCs from standby databases, used to control when the standby log transport service detects that a server of the primary is unavailable and switches to another server. |
| standby_db_preferred_upstream_log_region | V4.1.0 | The preferred region for log synchronization in physical standby databases. |
| log_storage_warning_tolerance_time | V4.1.0 | The time from log disk I/O failure to when the disk is marked as bad and a leader switch is triggered. |
| ob_startup_mode | V4.1.0 | The startup mode for OBServer nodes, modifiable only on the first startup. |
| sql_net_thread_count | V4.1.0 | The number of MySQL cluster I/O threads, i.e., global_sql_nio_server threads. |
| arbitration_timeout | V4.1.0 | The timeout for triggering automatic downgrade. |
| dump_data_dictionary_to_log_interval | V4.1.0 | The interval for tenant data dictionary persistence. |
| enable_user_defined_rewrite_rules | V4.1.0 | Whether to enable user-defined rewrite rules. |
| log_transport_compress_all | V4.1.0 | Whether to compress log transport. |
| log_transport_compress_func | V4.1.0 | The compression algorithm for log transport. |
| rpc_memory_limit_percentage | V4.1.0 | The maximum RPC memory as a percentage of tenant total memory. |
| tenant_sql_login_thread_count | V4.1.0 | The number of MySQL tenant login threads, i.e., mysql_queue threads. |
| tenant_sql_net_thread_count | V4.1.0 | The number of MySQL tenant I/O threads, i.e., sql_nio_server threads. |
| log_disk_percentage | V4.0.0 | Sets the percentage of the total disk space occupied by the redo log. |
| log_disk_size | V4.0.0 | Sets the size of the redo log disk, which is the total space available for logs on the current OBServer node. |
| ha_high_thread_score | V4.0.0 | Sets the current number of working threads for high-priority threads in high availability. |
| ha_low_thread_score | V4.0.0 | Sets the current number of working threads for low-priority threads in high availability. |
| ha_mid_thread_score | V4.0.0 | Sets the current number of working threads for medium-priority threads in high availability. |
| query_memory_limit_percentage |
|
Specifies the percentage of tenant memory available for a single SQL statement. |
Deprecated parameters
The following table lists the parameters that are deprecated in V4.x.
Parameter |
Description |
|---|---|
| global_write_halt_residual_memory | This parameter is no longer supported and has been removed since V4.2.0. |
| max_px_worker_count | This parameter is no longer supported and has been removed since V4.2.0. |
| plan_cache_high_watermark | This parameter is not supported and has been removed since V4.2.0. |
| plan_cache_low_watermark | This parameter is not supported and has been removed since V4.2.0. |
| rootservice_memory_limit | This parameter has been removed since V4.2.0 due to architecture upgrades. |
| system_trace_level | This parameter is no longer supported and has been removed since V4.2.0. |
| token_reserved_percentage | This parameter is no longer supported and has been removed since V4.2.0. |
| trace_log_sampling_interval | This parameter is no longer supported and has been removed since V4.2.0. |
| io_category_config | This parameter is no longer supported and has been removed since V4.2.0. |
| auto_broadcast_location_cache_rate_limit | This parameter has been removed since V4.0.0 due to architecture upgrades. |
| auto_leader_switch_interval | This parameter has been removed since V4.0.0 due to architecture upgrades. |
| auto_refresh_location_cache_rate_limit | This parameter has been removed since V4.0.0 due to architecture upgrades. |
| backup_backup_dest | This parameter is no longer supported and has been removed since V4.0.0. |
| backup_backup_dest_option | This parameter is no longer supported and has been removed since V4.0.0. |
| backup_dest_option | This parameter has been removed since V4.0.0 due to architecture upgrades. |
| backup_concurrency | This parameter is deprecated in V4.0.0. It is replaced by the ha_low_thread_score parameter in V4.0.0. |
| backup_dest | This parameter is deprecated in V4.0.0. |
| backup_log_archive_option | This parameter is deprecated in V4.0.0. |
| backup_net_limit | This parameter is deprecated in V4.0.0. |
| backup_recovery_window | This parameter is deprecated in V4.0.0. |
| backup_region | This parameter is deprecated in V4.0.0. |
| backup_zone | This parameter is deprecated in V4.0.0. |
| balance_blacklist_failure_threshold | This parameter is deprecated in V4.0.0. |
| balance_blacklist_retry_interval | This parameter is deprecated in V4.0.0. |
| balancer_emergency_percentage | This parameter is deprecated in V4.0.0. |
| balancer_timeout_check_interval | This parameter is deprecated in V4.0.0. |
| clog_disk_utilization_threshold | This parameter is deprecated in V4.0.0. It is replaced by the log_disk_utilization_threshold parameter in V4.0.0. |
| clog_expire_days | This parameter is deprecated in V4.0.0. |
| clog_cache_priority | This parameter is deprecated in V4.0.0. |
| clog_disk_usage_limit_percentage | This parameter is deprecated in V4.0.0. |
| clog_transport_compress_func | This parameter is deprecated in V4.0.0. It is replaced by the log_transport_compress_func parameter in V4.1.0. |
| clog_max_unconfirmed_log_count | The feature is no longer supported and has been removed since V4.0.0. |
| clog_persistence_compress_func | The feature is no longer supported and has been removed since V4.0.0. It is supported again since V4.2.1 (excluding V4.3.0) and log_storage_compress_func is provided instead. |
| cpu_reserved | The feature is no longer supported and has been removed since V4.0.0. |
| data_copy_concurrency | The feature is no longer supported and has been removed since V4.0.0. ha_high_thread_score is provided instead. |
| default_transport_compress_func | The feature is no longer supported and has been removed since V4.0.0. |
| election_cpu_quota | The feature is no longer supported and has been removed since V4.0.0. |
| election_blacklist_interval | The feature is no longer supported and has been removed since V4.0.0. |
| enable_auto_refresh_location_cache | The feature is no longer supported and has been removed since V4.0.0. |
| enable_auto_leader_switch | The feature is no longer supported and has been removed since V4.0.0. |
| enable_clog_persistence_compress | The feature is no longer supported and has been removed since V4.0.0. It is supported again since V4.2.1 (excluding V4.3.0) and log_storage_compress_all is provided instead. |
| enable_global_freeze_trigger | The feature is no longer supported and has been removed since V4.0.0. |
| enable_log_archive | The feature is no longer supported and has been removed since V4.0.0. |
| enable_election_group | The feature is no longer supported and has been removed since V4.0.0. |
| enable_merge_by_turn | The feature is no longer supported and has been removed since V4.0.0. |
| enable_manual_merge | The feature is no longer supported and has been removed since V4.0.0. |
| enable_one_phase_commit | Implemented as a logical change, the corresponding feature is no longer applicable and was removed starting from V4.0.0. |
| enable_pg | Architecture upgrade change, removed starting from V4.0.0. |
| enable_separate_sys_clog | The corresponding feature has never been effective and was removed starting from V4.0.0. |
| enable_smooth_leader_switch | Architecture upgrade change, removed starting from V4.0.0. |
| enable_rootservice_standalone | Architecture upgrade change, removed starting from V4.0.0. |
| fast_recovery_concurrency | Implemented as a logical change, the corresponding feature is no longer applicable and was removed starting from V4.0.0. The parameter ha_high_thread_score was added starting from V4.0.0 to replace this parameter. |
| flush_log_at_trx_commit | Low usage, removed starting from V4.0.0. |
| gc_wait_archive | Architecture upgrade change, removed starting from V4.0.0. |
| global_index_build_single_replica_timeout | Implemented as a logical change, the corresponding feature is no longer applicable and was removed starting from V4.0.0. |
| global_major_freeze_residual_memory | Low usage, removed starting from V4.0.0. |
| get_leader_candidate_rpc_timeout | Architecture upgrade change, removed starting from V4.0.0. |
| ignore_replica_checksum_error | Not recommended, removed starting from V4.0.0. |
| index_clog_cache_priority | Architecture upgrade change, removed starting from V4.0.0. |
| index_info_block_cache_priority | Architecture upgrade change, removed starting from V4.0.0. |
| index_cache_priority | Architecture upgrade change, removed starting from V4.0.0. |
| ilog_index_expire_time | Architecture upgrade change, removed starting from V4.0.0. |
| location_cache_priority | Architecture upgrade change, removed starting from V4.0.0. |
| location_cache_expire_time | The parameter is deprecated and removed in V4.0.0. |
| log_archive_batch_buffer_limit | The parameter is deprecated and removed in V4.0.0. |
| log_archive_checkpoint_interval | The parameter is deprecated and removed in V4.0.0. The parameter archive_lag_target is introduced in V4.0.0. |
| max_kept_major_version_number | The parameter is deprecated and removed in V4.0.0. |
| merge_stat_sampling_ratio | The parameter is deprecated and removed in V4.0.0. |
| merge_thread_count | The parameter is deprecated and removed in V4.0.0. The parameter compaction_low_thread_score is introduced in V4.0.0. |
| merger_completion_percentage | The parameter is deprecated and removed in V4.0.0. |
| merger_switch_leader_duration_time | The parameter is deprecated and removed in V4.0.0. |
| merger_warm_up_duration_time | The parameter is deprecated and removed in V4.0.0. |
| migrate_concurrency | The parameter is deprecated and removed in V4.0.0. The parameter ha_mid_thread_score is introduced in V4.0.0. |
| minor_deferred_gc_time | The parameter is deprecated and removed in V4.0.0. |
| minor_freeze_times | The parameter is deprecated and removed in V4.0.0. The parameter major_compact_trigger is used instead. |
| minor_merge_concurrency | The parameter is deprecated and removed in V4.0.0. The parameter compaction_mid_thread_score is introduced in V4.0.0. |
| minor_warm_up_duration_time | The parameter is deprecated and removed in V4.0.0. |
| multiblock_read_gap_size | The parameter is deprecated and removed in V4.0.0. |
| multiblock_read_size | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ob_esi_rpc_port | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| enable_ob_esi_process | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ob_esi_session_timeout | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ob_esi_io_concurrency | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ob_esi_memory_limit | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ob_esi_syslog_level | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ob_esi_max_syslog_file_count | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| ofs_list | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| partition_table_check_interval | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| rebuild_replica_data_lag_threshold | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| replica_safe_remove_time | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| resource_soft_limit | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| restore_concurrency | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. The new parameter ha_high_thread_score is introduced in OceanBase Database V4.0.0. |
| row_purge_thread_count | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. |
| server_data_copy_out_concurrency | This parameter is deprecated and removed starting from OceanBase Database V4.0.0. The new parameter ha_mid_thread_score is introduced in OceanBase Database V4.0.0. |
| server_data_copy_in_concurrency | This parameter is deprecated in V4.0.0. The new parameter ha_mid_thread_score is introduced in V4.0.0. |
| sql_audit_memory_limit | This parameter is deprecated in V4.0.0. The new variable ob_sql_audit_percentage is introduced in V4.0.0. |
| switchover_process_thread_count | This parameter is deprecated in V4.0.0. |
| sys_bkgd_io_high_percentage | This parameter is deprecated in V4.0.0. |
| sys_bkgd_io_low_percentage | This parameter is deprecated in V4.0.0. |
| sys_cpu_limit_trigger | This parameter is deprecated in V4.0.0. |
| system_cpu_quota | This parameter is deprecated in V4.0.0. |
| tenant_groups | This parameter is deprecated in V4.0.0. |
| trx_force_kill_threshold | This parameter is deprecated in V4.0.0. |
| unit_balance_resource_weight | This parameter is deprecated in V4.0.0. |
| user_iort_up_percentage | This parameter is deprecated in V4.0.0. |
| user_tab_col_stat_cache_priority | This parameter is deprecated in V4.0.0. |
| wait_leader_batch_count | This parameter is deprecated in V4.0.0. |
| zone_merge_concurrency | This parameter is deprecated in V4.0.0. |
| zone_merge_order | This parameter is deprecated in V4.0.0. |
| zone_merge_timeout | This parameter is deprecated in V4.0.0. |
Changes to system variables in V4.x
To better adapt to various business scenarios, OceanBase Database has optimized and adjusted the default values and value ranges of tenant variables. Specifically, in previous versions, undo_retention was introduced as a system variable. However, starting from V4.0.0 in the V4.x series, undo_retention has been adjusted to a tenant-level parameter.
System variables with changed default values
The following table lists the system variables with changed default values.
Variable name |
Description |
|---|---|
| ob_default_lob_inrow_threshold |
|
| sql_mode |
|
| optimizer_features_enable |
|
| secure_file_priv | Starting from V4.2.1, the default value changed from NULL to "". |
| max_allowed_packet | Starting from V4.2.1, the default value changed from 4194304 to 16777216. |
| ob_max_read_stale_time | Starting from V4.1.0, the default value changed from 5000000 to -1. |
| ob_trx_idle_timeout | Starting from V4.0.0, the default value changed from 120s to 1d. |
| ob_trx_timeout | Starting from V4.0.0, the default value changed from 100s to 1d. |
System variables with changed value range or value meaning
The following table lists the system variables with changed value range or value meaning.
Variable name |
Description |
|---|---|
| secure_file_priv | Starting from V4.2.0, the meaning of the empty string ("") and NULL values changed from "unrestricted" to "import and export are disabled". |
| ob_max_read_stale_time | Starting from V4.1.0, the value range changed from [0, 9223372036854775807] to [-1, 9223372036854775807]. |
System variables with changed permission requirements
The following table lists the system variables with changed permission requirements.
Variable name |
Description |
|---|---|
| secure_file_priv | Starting from V4.2.0, only local Unix Socket connections are allowed to modify this variable. |
New system variables
The following table lists the new system variables in V4.x.
Variable name |
Introduced in |
Description |
|---|---|---|
| event_scheduler | V4.3.5 BP2 | Indicates whether the event scheduler is enabled and running on the server. |
| ob_enable_ps_parameter_anonymous_block | V4.3.5 BP2 | Controls whether to parameterize anonymous blocks and call statements in PS mode during parsing. |
| ob_sparse_drop_ratio_search | V4.3.5 BP2 | Sets the default extra info threshold for HNSW indexes. |
| ob_ivf_nprobes | V4.3.5 BP1 | Specifies how many nearest cluster centers to search during vector index queries. |
| mview_refresh_dop | V4.3.5 BP1 | Controls the default refresh parallelism for materialized views. |
| enable_optimizer_rowgoal | V4.3.5 BP1 | Controls whether the optimizer considers row goals (such as LIMIT operators) during cardinality estimation. |
| pid_file |
|
Specifies the path to the file where the server writes its process ID. |
| port |
|
Specifies the TCP/IP port number for the server when deploying an OBServer node. |
| socket |
|
Specifies the name of the local client connection socket file. |
| ob_hnsw_ef_search | V4.3.3 | Specifies the number of neighbor nodes to consider during HNSW vector index searches. |
| ob_table_access_policy | V4.3.3 | Controls the preferred storage format for base tables when the optimizer generates a plan. |
| cardinality_estimation_model |
|
Controls the correlation model used for row estimation by the optimizer. |
| activate_all_roles_on_login |
|
Controls whether all roles are automatically enabled upon login. |
| innodb_stats_persistent |
|
Controls whether InnoDB index statistics are persisted to disk. |
| ob_compatibility_control |
|
Controls the behavior when there are compatibility conflicts between MySQL 5.7 and MySQL 8.0. |
| ob_compatibility_version |
|
Controls the OceanBase Database version that is compatible with the feature that changes the product behavior. |
| ob_security_version |
|
Specifies the OceanBase Database version that is compatible with the security features. |
| automatic_sp_privileges |
|
Specifies whether to grant the ALTER and EXECUTE privileges to stored procedures automatically. |
| lc_time_names |
|
Specifies the language for displaying the names and abbreviations of dates and months. |
| ob_enable_pl_cache |
|
Specifies whether to enable the PL cache module. |
| optimizer_dynamic_sampling | V4.2.0 | Specifies the level of dynamic sampling. |
| optimizer_features_enable | V4.2.0 | Enables the optimizer features of different OceanBase Database versions. |
| parallel_degree_limit | V4.2.0 | Specifies the maximum parallelism degree that the optimizer can select when the Auto DOP strategy is used. |
| parallel_degree_policy | V4.2.0 | Specifies the parallelism degree selection strategy. |
| parallel_min_scan_time_threshold | V4.2.0 | Specifies the minimum estimated execution time for parallel processing of base table scans. This parameter is used in the Auto DOP strategy. |
| runtime_filter_type | V4.2.0 | Specifies the Runtime Filter type at the tenant level. |
| runtime_filter_wait_time_ms | V4.2.0 | Specifies the maximum wait time for a Runtime Filter. |
| runtime_filter_max_in_num | V4.2.0 | Specifies the number of distinct values (NDV) for a Runtime In Filter. |
| runtime_bloom_filter_max_size | V4.2.0 | Specifies the maximum memory usage of a Runtime Bloom Filter, in bytes. |
| cte_max_recursion_depth | V4.1.0 | Specifies the maximum recursion depth of a common table expression (CTE). The server terminates the execution of any operation exceeding this CTE value. |
| ob_max_read_stale_time | V4.1.0 | Specifies the maximum delay threshold (us) for weakly consistent reads. |
| regexp_stack_limit | V4.1.0 | Specifies the maximum available memory for the internal stack of a regular expression matching operation, in bytes by default. |
| ob_enable_show_trace | V4.1.0 | Specifies whether to use the Show Trace log. |
| cursor_sharing | V4.0.0 | Specifies whether to parameterize SQL statements. |
| innodb_strict_mode | V4.0.0 | Specifies the SQL syntax checking mode. |
| log_row_value_options | V4.0.0 | Specifies whether to use partial updates for LOB data. |
Deprecated system variables
The following table lists the system variables that are deprecated in V4.x.
Variable name |
Description |
|---|---|
| ob_enable_trace_log | Removed since V4.1.0 due to architecture upgrades. |
| ob_create_table_strict_mode | Removed since V4.0.0 due to architecture upgrades. |
| ob_enable_blk_nestedloop_join | Removed since V4.0.0 due to implementation logic changes; the corresponding feature is no longer applicable. |
| ob_enable_hash_group_by | Removed since V4.0.0 due to implementation changes. |
| ob_timestamp_service | Removed since V4.0.0 due to architecture upgrades. |