Due to the architectural upgrades and reorganization in OceanBase Database V4.x, many parameters or variables no longer function as intended. In V4.x, these ineffective parameters and variables have been removed or modified. For example, the parameter minor_freeze_times that triggers a major freeze has been deleted. Additionally, some default values of parameters have been adjusted. For instance, V4.x has been fundamentally improved to support large transactions, and transactions are no longer affected by freeze operations. Therefore, the default value of freeze_trigger_percentage has been changed to 20%.
Changes in related parameters in V4.x
Parameters replaced
The following table lists the parameters in V4.x that replace those in V3.x.
| Parameter in V3.x | Corresponding parameter in V4.x | Description |
|---|---|---|
| backup_concurrency | ha_low_thread_score | The corresponding parameter in V4.x is a tenant-level parameter. |
| clog_disk_utilization_threshold | log_disk_utilization_threshold | The corresponding parameter in V4.x is a tenant-level parameter. |
| clog_transport_compress_func | log_transport_compress_func | The corresponding parameter in V4.x is a tenant-level parameter. |
| data_copy_concurrency, fast_recovery_concurrency, restore_concurrency | ha_high_thread_score | The corresponding parameter in V4.x is a tenant-level parameter. |
| log_archive_checkpoint_interval | archive_lag_target | The corresponding parameter in V4.x is a tenant-level parameter. |
| merge_thread_count | compaction_low_thread_score | The corresponding parameter in V4.x is a tenant-level parameter. |
| migrate_concurrency, server_data_copy_out_concurrency, server_data_copy_in_concurrency | ha_mid_thread_score | The corresponding parameter in V4.x is a tenant-level parameter. |
| sql_audit_memory_limit | ob_sql_audit_percentage | The corresponding feature is provided by a tenant-level system variable instead of a parameter. |
| minor_merge_concurrency | compaction_mid_thread_score | The corresponding parameter in V4.x is a tenant-level parameter. |
| clog_persistence_compress_func | log_storage_compress_func | The corresponding parameter in V4.x is a tenant-level parameter. |
| enable_clog_persistence_compress | log_storage_compress_all | The corresponding parameter in V4.x is a tenant-level parameter. |
Parameters that have changed their names
The following table lists the parameters that have changed their names in V4.x.
| Parameter name (V3.x) | Parameter name (V4.x) | Description |
|---|---|---|
| tableapi_transport_compress_func | kv_transport_compress_func |
|
Parameters that change the scope
OceanBase Database is a multi-tenant architecture. Most users create multiple tenants in the same cluster and manage them based on their business types. To meet the needs of users who want each tenant to represent a business unit, the V4.x version of OceanBase Database splits cluster-level capabilities into tenant-level capabilities. Examples include tenant-level backup and minor compactions.
The following table lists the parameters that change the scope.
| Parameter | Description |
|---|---|
| backup_data_file_size |
|
| enable_rebalance | Starting from V4.2.0, the scope changed from cluster-level to tenant-level. |
| balancer_idle_time | Starting from V4.2.0, the scope changed from cluster-level to tenant-level. |
| log_archive_concurrency | Starting from V4.1.0, the scope changed from cluster-level to tenant-level. |
| log_restore_concurrency | Starting from V4.1.0, the scope changed from cluster-level to tenant-level. |
| major_compact_trigger | Starting from V4.0.0, the scope changed from cluster-level to tenant-level. |
| minor_compact_trigger | Starting from V4.0.0, the scope changed from cluster-level to tenant-level. |
Parameters whose effective mode can be changed
Parameters can be classified into two effective modes: dynamic and restart. Most parameters take effect dynamically, which means that they take effect without the need to restart the OBServer node.
The following table describes the parameters whose effective mode can be changed.
| Parameter | Description |
|---|---|
| enable_cgroup | For OceanBase Database V4.2.5, the effective mode has been changed from restart to immediate effective since V4.2.5 BP2. |
| server_cpu_quota_min |
|
| server_cpu_quota_max |
|
System parameters whose default values are changed
The following table describes the system parameters whose default values are changed.
| Parameter name | Description |
|---|---|
| compaction_dag_cnt_limit | For V4.2.5, the default value is changed from 15000 to 50000 starting from V4.2.5 BP5. |
| dump_data_dictionary_to_log_interval | For V4.2.5, the default value is changed from 24h to 0 starting from V4.2.5 BP1. |
| 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. |
System parameters that change their value ranges
The following table describes the system parameters that change their value ranges.
| Parameter name | Description |
|---|---|
| compaction_schedule_tablet_batch_cnt | For V4.2.5, the value range is adjusted from [10000, 200000] to [10000, 500000] starting from V4.2.5 BP5. |
| compaction_dag_cnt_limit | For V4.2.5, the value range is adjusted from [10000, 200000] to [10000, 500000] starting from V4.2.5 BP5. |
| dump_data_dictionary_to_log_interval | For V4.2.5, the value range is adjusted from (0s, +∞) to [0s, +∞) starting from V4.2.5 BP1. |
| 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 |
|
Configuration items with changed effective mode
The following table describes the parameters added in V4.x.
| Parameter | Introduced in | Description |
|---|---|---|
| enable_ls_leader_balance | For V4.2.5, this parameter is introduced starting from V4.2.5 BP6. | Specifies whether to enable automatic leader balancing for log streams. |
| enable_gts_standalone | For V4.2.5, this parameter is introduced starting from V4.2.5 BP5. | Specifies whether to enable the feature where the tenant GTS service exclusively occupies a group of units. |
| zone_deploy_mode | For V4.2.5, this parameter is introduced starting from V4.2.5 BP5. | Specifies the distribution mode of tenants across zones. |
| temporary_file_max_disk_size | For V4.2.5, this parameter is introduced starting from V4.2.5 BP3. | Specifies the maximum disk space that temporary files of a tenant can occupy on a single node. |
| enable_ps_parameterize | For V4.2.5, this parameter is introduced starting from V4.2.5 BP2. | Specifies whether to parameterize PS statements during parsing. |
| ls_scale_out_factor | For V4.2.5, this parameter is introduced starting from V4.2.5 BP1. | The scale-out factor of log streams, which controls the number of log streams of a tenant on each server. |
| arbitration_degradation_policy |
|
Specifies the automatic degradation policy. |
| ob_storage_s3_url_encode_type | For V4.2.1, this parameter is introduced starting from V4.2.1 BP9. For other versions of V4.2.x, this parameter is introduced starting from V4.2.5. | Specifies whether the URL encoding method used when a request is sent over the S3 protocol complies with the RFC 3986 standard. |
| log_storage_warning_trigger_percentage | For V4.2.1, this parameter is introduced starting from V4.2.1 BP7. For other versions of V4.2.x, this parameter is introduced starting from V4.2.5. | The write performance threshold in percentage for triggering a log disk fault. |
| replica_parallel_migration_mode | V4.2.5 | The parallel migration mode for log stream replicas. |
| sts_credential | V4.2.5 | The credential for accessing the Security Token Service (STS) provided by OceanBase Cloud Platform (OCP). |
| enable_lock_priority | V4.2.5 | Specifies whether to enable lock priorities. |
| unit_gc_wait_time | V4.2.5 | The maximum wait time before triggering unit GC. |
| query_memory_limit_percentage | V4.2.5 | The maximum percentage of tenant memory available for a single SQL query. |
| kv_group_commit_batch_size | V4.2.5 | The batch size for group commit in OBKV. |
| kv_group_commit_rw_mode | V4.2.5 | The operation types supported for group commit when the group commit feature is enabled. |
| recover_table_dop | V4.2.5 | The maximum degree of parallelism (DOP) for restoring a single table in the cross-tenant table import phase of a table-level restore. |
| recover_table_concurrency | V4.2.5 | The maximum number of tables that can be restored concurrently in the cross-tenant table import phase of a table-level restore. |
| audit_log_buffer_size | V4.2.4 | The buffer size for asynchronous writing of audit logs. |
| audit_log_compression | V4.2.4 | The algorithm for compressing audit logs. |
| audit_log_enable | V4.2.4 | Specifies whether to enable the audit feature. |
| audit_log_format | V4.2.4 | The file format of audit logs. |
| audit_log_max_size | V4.2.4 | The maximum size of audit logs that can be retained on a single OBServer node. |
| audit_log_path | V4.2.4 | The output directory of audit logs. |
| audit_log_prune_seconds | V4.2.4 | The maximum retention period of audit logs. |
| audit_log_query_sql | V4.2.4 | Specifies whether to record SQL statements in audit logs. |
| audit_log_rotate_on_size | V4.2.4 | The maximum size of a single audit log file. |
| audit_log_strategy | V4.2.4 | The strategy for writing audit logs. |
| alert_log_level |
|
The level of alert logs. |
| data_disk_write_limit_percentage |
|
The maximum percentage of data disk space allowed for data writes. |
| enable_global_background_resource_isolation |
|
Specifies whether to enable global resource isolation between foreground and background tasks. |
| global_background_cpu_quota |
|
The number of CPU cores for background tasks when global resource isolation is enabled between foreground and background tasks. |
| syslog_compress_func |
|
The algorithm for compressing system logs. |
| syslog_disk_size |
|
The maximum disk space available for system logs. |
| syslog_file_uncompressed_count |
|
The number of uncompressed system log files. |
| choose_migration_source_policy |
|
The prioritizing policy for selecting the source replica for migration. |
| enable_kv_group_commit | V4.2.3 | Specifies whether to enable the group commit feature. |
| lob_enable_block_cache_threshold |
|
The threshold for caching OUTROW LOB data read during queries. |
| strict_check_os_params | V4.2.2 | Specifies whether to enable checking of OS configuration parameters. |
| log_storage_compress_all |
|
Specifies whether to enable clog compression for storage. |
| log_storage_compress_func |
|
The algorithm for compressing clogs for storage. |
| sql_protocol_min_tls_version | V4.2.1 | Specifies the minimum SSL/TLS protocol version used when SQL connections use SSL. |
| compaction_dag_cnt_limit | V4.2.1 | Specifies the upper limit on the number of DAGs in the compaction DAG queue. |
| compaction_schedule_tablet_batch_cnt | V4.2.1 | Specifies the maximum number of tablets scheduled in each batch when compaction tasks are scheduled in batches. |
| enable_transfer | V4.2.1 | Specifies whether to allow Transfer within a tenant. |
| ttl_thread_score | V4.2.1 | Specifies the weight of thread time slices used by TTL tasks. |
| local_ip | V4.2.0 | Specifies the IP address of the OBServer host when a cluster is deployed. |
| observer_id | V4.2.0 | The unique identifier assigned by the root service to an OBServer node in a cluster. |
| standby_fetch_log_bandwidth_limit | V4.2.0 | Specifies the maximum bandwidth per second available for all servers in a standby tenant cluster to synchronize logs from the primary tenant. |
| storage_meta_cache_priority | V4.2.0 | Specifies the priority of the Meta Cache stored in the KV cache. |
| archive_lag_target | V4.2.0 | Specifies the delay time of log archiving for a tenant. |
| log_disk_throttling_maximum_duration | V4.2.0 | Specifies the maximum duration of log disk throttling after log write throttling is triggered. |
| log_disk_throttling_percentage | V4.2.0 | The percentage of non-recyclable log disk space that triggers log write throttling. |
| ls_gc_delay_time | V4.2.0 | Specifies the delay time for deleting log streams of a tenant. |
| partition_balance_schedule_interval | V4.2.0 | Specifies the scheduling interval of partition balancing. |
| range_optimizer_max_mem_size | V4.2.0 | Limits the memory used by the Query Range module. |
| standby_db_fetch_log_rpc_timeout | V4.2.0 | Specifies the timeout period of RPC for a standby database to fetch logs, to control the time when the standby log transfer service detects an unavailable primary server and switches to another server. |
| standby_db_preferred_upstream_log_region | V4.1.0 | Specifies the preferred region from which a standby tenant synchronizes upstream logs in a physical standby scenario. |
| log_storage_warning_tolerance_time | V4.1.0 | Specifies the period from log disk I/O failure to the time when the disk is marked as faulty and a primary switchover is triggered. |
| ob_startup_mode | V4.1.0 | Specifies the startup mode of an OBServer node and can be modified only when the node is started for the first time. |
| sql_net_thread_count | V4.1.0 | Specifies the number of MySQL cluster I/O threads, that is, the number of global_sql_nio_server threads. |
| arbitration_timeout | V4.1.0 | Specifies the timeout period for triggering automatic degradation. |
| dump_data_dictionary_to_log_interval | V4.1.0 | Specifies the interval for persisting tenant data dictionaries. |
| enable_user_defined_rewrite_rules | V4.1.0 | Specifies whether to enable user-defined rewrite rules. |
| log_transport_compress_all | V4.1.0 | Specifies whether to compress logs during log transport. |
| log_transport_compress_func | V4.1.0 | Specifies the compression algorithm used for log transport. |
| rpc_memory_limit_percentage | V4.1.0 | Specifies the maximum percentage of tenant memory that can be used by RPC. |
| tenant_sql_login_thread_count | V4.1.0 | Specifies the number of MySQL tenant login threads, that is, the number of mysql_queue threads. |
| tenant_sql_net_thread_count | V4.1.0 | Specifies the number of MySQL tenant I/O threads, that is, the number of sql_nio_server threads. |
| log_disk_percentage | V4.0.0 | Specifies the percentage of the total disk space occupied by redo logs on the log disk. |
| log_disk_size | V4.0.0 | Specifies the size of the log disk where redo logs are stored, namely, the total log disk space available for the current OBServer node. |
| ha_high_thread_score | V4.0.0 | Specifies the number of worker threads for high-availability high-priority tasks. |
| ha_low_thread_score | V4.0.0 | Specifies the number of worker threads for high-availability low-priority tasks. |
| ha_mid_thread_score | V4.0.0 | Specifies the number of worker threads for high-availability medium-priority tasks. |
Obsolete parameters
The following table describes the obsolete parameters in OceanBase Database V4.x.
| Parameter Name | Description |
|---|---|
| ob_ssl_invited_common_names | If you need to check specific fields in a client certificate, you can specify them when you create the user. It is no longer necessary to perform another tenant-level check when the user logs in. Therefore, this parameter has been deprecated since V4.2.5 BP2. |
| enable_kv_group_commit | Due to feature optimization, this parameter has been deprecated since V4.2.5. In V4.2.5 and later, you can use the kv_group_commit_batch_size and kv_group_commit_rw_mode parameters to control the group commit feature. |
| global_write_halt_residual_memory | Because the corresponding feature is no longer available, this parameter has been deprecated since V4.2.0. |
| max_px_worker_count | Because the corresponding feature is no longer available, this parameter has been deprecated since V4.2.0. |
| plan_cache_high_watermark | Because the corresponding feature has never been supported, this parameter has been deprecated since V4.2.0. |
| plan_cache_low_watermark | Because the corresponding feature has never been supported, this parameter has been deprecated since V4.2.0. |
| rootservice_memory_limit | Due to architecture upgrade, this parameter has been deprecated since V4.2.0. |
| system_trace_level | Due to changes of implementation logic, this parameter is no longer applicable and has been deprecated since V4.2.0. |
| token_reserved_percentage | Due to changes of implementation logic, this parameter is no longer applicable and has been deprecated since V4.2.0. |
| trace_log_sampling_interval | Due to changes of implementation logic, this parameter is no longer applicable and has been deprecated since V4.2.0. |
| io_category_config | Due to changes of implementation logic, this parameter is no longer applicable and has been deprecated since V4.2.0. |
| auto_broadcast_location_cache_rate_limit | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| auto_leader_switch_interval | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| auto_refresh_location_cache_rate_limit | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_backup_dest | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| backup_backup_dest_option | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| backup_dest_option | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_concurrency | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_low_thread_score parameter. |
| backup_dest | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_log_archive_option | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_net_limit | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_recovery_window | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_region | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| backup_zone | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| balance_blacklist_failure_threshold | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| balance_blacklist_retry_interval | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| balancer_emergency_percentage | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| balancer_timeout_check_interval | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| clog_disk_utilization_threshold | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the log_disk_utilization_threshold parameter. |
| clog_expire_days | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| clog_cache_priority | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| clog_disk_usage_limit_percentage | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| clog_transport_compress_func | Because the corresponding feature is not supported in V4.0.0, this parameter has been deprecated since V4.0.0. Starting from V4.1.0, it is replaced with the log_transport_compress_func parameter. |
| clog_max_unconfirmed_log_count | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_high_thread_score parameter. |
| clog_persistence_compress_func | Because the corresponding feature is not supported in V4.0.0, this parameter has been deprecated since V4.0.0. Starting from V4.2.1 (except V4.3.0), the feature is supported again and the parameter is replaced with log_storage_compress_func. |
| cpu_reserved | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| data_copy_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_high_thread_score parameter. |
| default_transport_compress_func | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| election_cpu_quota | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| election_blacklist_interval | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_auto_refresh_location_cache | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_auto_leader_switch | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_clog_persistence_compress | Because the corresponding feature is not supported in V4.0.0, this parameter has been deprecated since V4.0.0. Starting from V4.2.1 (except V4.3.0), the feature is supported again and the parameter is replaced with log_storage_compress_all. |
| enable_global_freeze_trigger | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_log_archive | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_election_group | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_merge_by_turn | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| enable_manual_merge | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| enable_one_phase_commit | Due to changes of implementation logic, the corresponding feature is no longer applicable, and this parameter has been deprecated since V4.0.0. |
| enable_pg | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_separate_sys_clog | Because the corresponding feature has never taken effect, this parameter has been deprecated since V4.0.0. |
| enable_smooth_leader_switch | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| enable_rootservice_standalone | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| fast_recovery_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_high_thread_score parameter. |
| flush_log_at_trx_commit | This parameter is rarely used and therefore has been deprecated since V4.0.0. |
| gc_wait_archive | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| global_index_build_single_replica_timeout | Due to changes of implementation logic, the corresponding feature is no longer applicable, and this parameter has been deprecated since V4.0.0. |
| global_major_freeze_residual_memory | This parameter is rarely used and therefore has been deprecated since V4.0.0. |
| get_leader_candidate_rpc_timeout | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| ignore_replica_checksum_error | This parameter is not recommended for use and therefore has been deprecated since V4.0.0. |
| index_clog_cache_priority | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| index_info_block_cache_priority | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| index_cache_priority | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| ilog_index_expire_time | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| location_cache_priority | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| location_cache_expire_time | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| log_archive_batch_buffer_limit | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| log_archive_checkpoint_interval | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the archive_lag_target parameter. |
| max_kept_major_version_number | This parameter is rarely used and therefore has been deprecated since V4.0.0. |
| merge_stat_sampling_ratio | Due to changes of implementation methods, this parameter has been deprecated since V4.0.0. |
| merge_thread_count | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the compaction_low_thread_score parameter. |
| merger_completion_percentage | This parameter is rarely used and therefore has been deprecated since V4.0.0. |
| merger_switch_leader_duration_time | Because the corresponding feature is no longer available, this parameter has been deprecated since V4.0.0. |
| merger_warm_up_duration_time | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| migrate_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_mid_thread_score parameter. |
| minor_deferred_gc_time | This parameter is not recommended for use and therefore has been deprecated since V4.0.0. |
| minor_freeze_times | This parameter has the same meaning as major_compact_trigger. To unify the semantics, this parameter has been deprecated since V4.0.0 and you can use major_compact_trigger instead. |
| minor_merge_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the compaction_mid_thread_score parameter. |
| minor_warm_up_duration_time | This parameter is not recommended for use and therefore has been deprecated since V4.0.0. |
| multiblock_read_gap_size | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| multiblock_read_size | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| ob_esi_rpc_port | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| enable_ob_esi_process | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| ob_esi_session_timeout | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| ob_esi_io_concurrency | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| ob_esi_memory_limit | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| ob_esi_syslog_level | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| ob_esi_max_syslog_file_count | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| ofs_list | Because the corresponding feature is no longer applicable, this parameter has been deprecated since V4.0.0. |
| partition_table_check_interval | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| rebuild_replica_data_lag_threshold | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| replica_safe_remove_time | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| resource_soft_limit | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| restore_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_high_thread_score parameter. |
| row_purge_thread_count | Because the corresponding feature has never been supported, this parameter has been deprecated since V4.0.0. |
| server_data_copy_out_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_mid_thread_score parameter. |
| server_data_copy_in_concurrency | Due to changes of implementation logic, this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ha_mid_thread_score parameter. |
| sql_audit_memory_limit | Due to changes of implementation logic, the corresponding feature is no longer applicable, and this parameter has been deprecated since V4.0.0. Starting from V4.0.0, it is replaced with the ob_sql_audit_percentage variable. |
| switchover_process_thread_count | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| sys_bkgd_io_high_percentage | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| sys_bkgd_io_low_percentage | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| sys_cpu_limit_trigger | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| system_cpu_quota | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| tenant_groups | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| trx_force_kill_threshold | Due to changes of implementation logic, the corresponding feature is no longer applicable, and this parameter has been deprecated since V4.0.0. |
| unit_balance_resource_weight | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| user_iort_up_percentage | Due to changes of implementation logic, the corresponding feature is no longer applicable, and this parameter has been deprecated since V4.0.0. |
| user_tab_col_stat_cache_priority | Due to changes of implementation logic, the corresponding feature is no longer applicable, and this parameter has been deprecated since V4.0.0. |
| wait_leader_batch_count | Due to architecture upgrade, this parameter has been deprecated since V4.0.0. |
| zone_merge_concurrency | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| zone_merge_order | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
| zone_merge_timeout | Because the corresponding feature is no longer supported, this parameter has been deprecated since V4.0.0. |
Changes to system variables in V4.x
To better adapt to various business scenarios, OceanBase Database has made a series of optimizations and adjustments to tenant variables, including their default values and value ranges. Notably, in earlier versions, undo_retention was introduced as a system variable. However, starting from V4.0.0, undo_retention has been adjusted to a tenant-level parameter.
System variables whose default values can be changed
The following table describes the system variables whose default values can be changed.
| Variable name | Description |
|---|---|
| ob_default_lob_inrow_threshold |
|
| sql_mode |
|
| optimizer_features_enable |
|
| secure_file_priv | Starting from V4.2.1, the default value is changed from NULL to "". |
| max_allowed_packet | Starting from V4.2.1, the default value is changed from 4194304 to 16777216. |
| ob_max_read_stale_time | Starting from V4.1.0, the default value is changed from 5000000 to -1. |
| ob_trx_idle_timeout | Starting from V4.0.0, the default value is changed from 120s to 1d. |
| ob_trx_timeout | Starting from V4.0.0, the default value of 100s is changed to 1d. |
System variables whose value ranges or meanings have changed
The following table describes the system variables whose value ranges or meanings have changed.
| Variable name | Description |
|---|---|
| secure_file_priv | Starting from V4.2.0, the meaning of the empty string ("") and NULL has been changed from "unrestricted" to "import and export disabled". |
| ob_max_read_stale_time | Starting from V4.1.0, the value range has been changed from [0, 9223372036854775807] to [-1, 9223372036854775807]. |
System variables whose privileges have changed
The following table describes the system variables whose privileges have changed.
| Variable name | Description |
|---|---|
| secure_file_priv | Starting from V4.2.0, the privilege required to modify this variable has been changed to only allow modification through a local Unix socket. |
New system variables
The following table describes the system variables introduced in V4.x.
| Variable name | Introduced in | Description |
|---|---|---|
| ob_enable_parameter_anonymous_block | V4.2.5 | Specifies whether to enable the anonymous block parameterization feature. |
| partition_index_dive_limit | For V4.2.1, this variable is introduced starting from V4.2.1 BP9. For other V4.2.x versions, it is introduced starting from V4.2.5. | Specifies the maximum number of partitions when the optimizer uses the storage layer to estimate cardinality. |
| range_index_dive_limit | For V4.2.1, this variable is introduced starting from V4.2.1 BP9. For other V4.2.x versions, it is introduced starting from V4.2.5. | Specifies the maximum number of ranges when the optimizer uses the storage layer to estimate cardinality. |
| cardinality_estimation_model | V4.2.4 | Specifies the correlation assumptions that the optimizer uses for cardinality estimation. |
| enable_sql_plan_monitor | V4.2.4 | Specifies whether to record the current session's SQL statements in the SQL plan monitor. |
| activate_all_roles_on_login |
|
Specifies whether to automatically enable all roles upon login. |
| innodb_stats_persistent |
|
Specifies whether to persist InnoDB index statistics to the disk. |
| ob_compatibility_control |
|
Specifies the behavior mode when a compatibility conflict occurs between MySQL 5.7 and MySQL 8.0. |
| ob_compatibility_version |
|
Specifies the OceanBase Database version that provides compatibility with product behavior changes. |
| ob_security_version |
|
Specifies the OceanBase Database version that provides compatibility with security features. |
| automatic_sp_privileges |
|
Specifies whether to automatically grant the ALTER and EXECUTE privileges to a stored procedure. |
| lc_time_names |
|
Specifies the language for displaying date and month names and abbreviations. |
| 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 | Specifies the optimizer features of different OceanBase Database versions. |
| parallel_degree_limit | V4.2.0 | Specifies the maximum degree of parallelism that the optimizer selects when the auto DOP strategy is used. |
| parallel_degree_policy | V4.2.0 | Specifies the degree of parallelism selection strategy. |
| parallel_min_scan_time_threshold | V4.2.0 | Specifies the minimum estimated execution time for parallel processing of the base table scan in the auto DOP strategy. |
| runtime_filter_type | V4.2.0 | Specifies the runtime filter type for the tenant. |
| runtime_filter_wait_time_ms | V4.2.0 | Specifies the maximum wait time for runtime filters. |
| runtime_filter_max_in_num | V4.2.0 | Specifies the number of NDV (number of different values in a column) for runtime in filters. |
| runtime_bloom_filter_max_size | V4.2.0 | Specifies the maximum memory usage of the runtime bloom filter in bytes. |
| cte_max_recursion_depth | V4.1.0 | Specifies the maximum recursion depth for common table expressions (CTEs). The server terminates any operations exceeding this CTE value. |
| ob_max_read_stale_time | V4.1.0 | Specifies the maximum latency threshold (in microseconds) for weak-consistency read queries. |
| regexp_stack_limit | V4.1.0 | Specifies the maximum available memory for the internal stack of regular expression matching operations, 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 perform parameterization when processing SQL statements. |
| innodb_strict_mode | V4.0.0 | Specifies the SQL check mode for specific syntaxes. |
| log_row_value_options | V4.0.0 | Specifies whether to use partial updates for LOBs. |
| ob_enable_rich_error_msg | V4.0.0 | Specifies whether to display information such as svr_ip, time, and trace_id when an SQL execution error occurs. |
Obsolete system variables
The following table lists the system variables deprecated in V4.x.
| Variable name | Description |
|---|---|
| ob_enable_trace_log | Architecture upgrade change. This variable is deleted starting from V4.1.0. |
| ob_create_table_strict_mode | Architecture upgrade change. This variable is deleted starting from V4.0.0. |
| ob_enable_blk_nestedloop_join | Logic change. The corresponding feature is no longer applicable. This variable is deleted starting from V4.0.0. |
| ob_enable_hash_group_by | Implementation change. This variable is deleted starting from V4.0.0. |
| ob_timestamp_service | Architecture upgrade change. This variable is deleted starting from V4.0.0. |