In OceanBase Database V4.x, the architecture was upgraded and refactored. As a result, many parameters or variables are no longer effective, and V4.x has deleted or modified them. For example, the parameter minor_freeze_times, which was used to trigger a major freeze, has been removed. Additionally, we have adjusted the default values of some parameters. For instance, V4.x fundamentally supports large transactions at the underlying level, so transactions are no longer affected by freeze operations. Therefore, the default value of freeze_trigger_percentage has been adjusted to 20%.
Parameter-related changes in V4.x
Replaced parameters
The following table lists the parameters in V4.x that replace those in V3.x.
Renamed parameters
The following table lists the parameters that have been renamed in V4.x.
Parameter name (V3.x) |
Parameter name (V4.x) |
Description |
|---|---|---|
| tableapi_transport_compress_func | kv_transport_compress_func |
|
Parameters with changed scope of effect
OceanBase Database is a multi-tenant architecture. Most users choose to create multiple tenants within the same cluster and manage them separately based on different business types. To meet the requirement that one tenant represents a business unit, V4.x splits cluster-level capabilities into tenant-level capabilities, such as tenant-level backup, tenant-level minor compaction, and tenant-level major compaction.
The following table lists the parameters with changed scope of effect.
Parameter name |
Description |
|---|---|
| backup_data_file_size |
|
| enable_rebalance | Starting from V4.2.0, the permission has been changed from cluster-level to tenant-level. |
| balancer_idle_time | Starting from V4.2.0, the permission has been changed from cluster-level to tenant-level. |
| log_archive_concurrency | Starting from V4.1.0, the scope has been changed from cluster-level to tenant-level. |
| log_restore_concurrency | Starting from V4.1.0, the scope has been changed from cluster-level to tenant-level. |
| major_compact_trigger | Starting from V4.0.0, the scope has been changed from cluster-level to tenant-level. |
| minor_compact_trigger | Starting from V4.0.0, the scope has been changed from cluster-level to tenant-level. |
Parameters with changed activation mode
Parameters generally have two activation modes: dynamic activation and restart activation. Most parameters use dynamic activation, meaning they take effect without restarting the OBServer node.
The following table lists the parameters with changed activation mode.
Parameter name |
Description |
|---|---|
| net_thread_count | Starting from V4.4.0, the effective mode has changed from restart-effective to immediate-effective. |
| 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 |
|---|---|
| ob_storage_s3_url_encode_type | For V4.6.x, starting from V4.6.0, the default value has been changed from default to compliantRfc3986Encoding. |
| compaction_dag_cnt_limit | Starting from V4.4.0, the default value has been adjusted from 15000 to 50000. |
| kv_group_commit_batch_size | For V4.3.5, starting from V4.3.5 BP1, the default value has been adjusted from 1 to 10. |
| direct_load_allow_fallback | Starting from V4.3.5, the default value has been 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 has been changed from true to false. |
| location_refresh_thread_count | Starting from V4.2.0, the default value has been adjusted from 4 to 2. |
| enable_record_trace_id | Starting from V4.2.0, the default value has been changed from true to false. |
| plan_cache_evict_interval | Starting from V4.2.0, the default value has been adjusted from 1s to 5s. |
| tenant_task_queue_size | Starting from V4.1.0, the default value has been adjusted from 65536 to 16384. |
| server_cpu_quota_min |
|
| writing_throttling_maximum_duration | Starting from V4.0.0, the default value has been adjusted from 1h to 2h. |
| writing_throttling_trigger_percentage | Starting from V4.0.0, the default value has been adjusted from 100 to 60. |
| freeze_trigger_percentage | Starting from V4.0.0, the default value has been adjusted from 70 to 20. |
Parameters with changed value ranges
The following table lists the parameters with changed value ranges.
Parameter name |
Description |
|---|---|
| compaction_schedule_tablet_batch_cnt | Starting from V4.4.0, the value range has been adjusted from [10000, 200000] to [10000, 500000]. |
| compaction_dag_cnt_limit | Starting from V4.4.0, the value range has been adjusted from [10000, 200000] to [10000, 500000]. |
| net_thread_count | Starting from V4.3.5 BP2, the value range has been adjusted from [0, 64] to [0, 128]. |
| ob_startup_mode | Starting from V4.3.4, the value range has been expanded to includeSHARED_STORAGEThe value of . |
| 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 has been adjusted from [10, 90] to [10, 95]. |
| cpu_quota_concurrency | Starting from V4.2.0, the value range has been adjusted from [1,10] to [1,20]. |
| memory_limit | Starting from V4.1.0, the value range has been adjusted from [4G, +∞) to [1G, +∞). |
| server_cpu_quota_min |
|
New parameters
The following table lists the new parameters introduced in V4.x.
Parameter name |
Import version |
Description |
|---|---|---|
| zone_disk_balance_tolerance_percentage |
|
It is used to control the tolerance of the inter-zone table group disk balancing algorithm for imbalance. |
| enable_ttl | V4.6.0 | This parameter specifies whether to enable the TTL feature in SQL mode. |
| ttl_duty_time | V4.6.0 | It specifies the time point at which the backend periodically triggers the execution of the TTL task based on the TTL value. |
| enable_window_compaction | V4.6.0 | Specifies whether the current tenant uses window merging. |
| enable_ls_leader_balance |
|
Controls whether to enable automatic leader balancing for log streams. |
| enable_gts_standalone |
|
It specifies whether to enable the feature that allows the tenant's GTS service to exclusively use a dedicated set of units. |
| zone_deploy_mode |
|
Sets the distribution pattern of tenants across zones. |
| mds_minor_compact_trigger | V4.4.1 | Controls the number of SSTables that trigger a minor compaction for MDS. |
| mds_compaction_mid_thread_score | V4.4.1 | Sets the number of DAG threads for medium-priority MDS compaction. |
| mds_compaction_high_thread_score | V4.4.1 | Sets the number of DAG (direct acyclic graph) threads for high-priority MDS compaction. |
| ls_scale_out_factor |
|
The scaling factor of log streams, which controls the number of log streams for a tenant on each service node. |
| external_table_io_hole_size | V4.4.0 | Sets the maximum distance (in bytes) between two consecutive I/O ranges. |
| external_table_io_range_size | V4.4.0 | Sets the maximum size of a major compaction range in bytes. If merging two consecutive ranges would result in a range larger than this size, they will not be merged. |
| async_ps_cursor_max_count | V4.4.0 | Controls the maximum number of asynchronous PS cursors allowed on a single node. |
| ob_enable_java_udf | V4.4.0 | This parameter specifies whether to enable or disable Java UDF. |
| load_data_diagnosis_log_compression | V4.4.0 | Specifies the compression algorithm used for diagnostic logs. |
| load_data_diagnosis_log_max_size | V4.4.0 | Specifies the maximum size of a diagnostic log file. |
| result_cache_max_size | V4.4.0 | Used to controlresult cacheThe maximum amount of memory that the module can use. |
| result_cache_max_result | V4.4.0 | Used to control the maximum number of objects that can be cached in a single result cache.result_cache_max_sizeThe memory usage of the process. |
| ob_result_cache_evict_percentage | V4.4.0 | Used to setresult cacheMemory eviction watermark. |
| ob_deterministic_udf_cache_max_size | V4.4.0 | Used to mark the statement execution period. AlldeterministicThe maximum total memory size (in bytes) that the cache pool of UDFs can use. If this parameter is set to 0, the runtime caching feature is disabled. |
| enable_lock_priority | V4.3.5 BP2 | Table lock priority switch. |
| enable_adaptive_plan_cache | V4.3.5 BP2 | Controls whether to enable adaptive plan cache for a tenant. |
| global_index_auto_split_policy | V4.3.5 BP2 | It specifies whether to enable automatic partitioning for a newly created global index.
NoticeStarting from V4.4.1, in the open-source mode, the default value of this parameter has been changed to |
| clog_io_isolation_mode | V4.3.5 BP2 | Determines whether I/O requests to the clog disk are subject to resource isolation based on whether the clog disk and data disk are independent. You can adjust the value of this parameter according to your system deployment to balance performance and resource utilization. |
| default_table_organization | V4.3.5 BP1 | The default table organization mode that can be set for the table. |
| px_node_policy | V4.3.5 BP1 | The candidate pool for determining PX compute nodes. |
| ob_enable_java_env | V4.3.5 BP1 | Controls whether to enable the Java environment required for external table capabilities such as HDFS and MaxCompute (ODPS). |
| ob_java_home | V4.3.5 BP1 | To set the Java Home path required for JNI runtime dependencies, you must configure this parameter when ob_enable_java_env is enabled. |
| ob_java_opts | V4.3.5 BP1 | To set JVM startup parameters such as memory size and garbage collection algorithms, you must enable ob_enable_java_env. |
| ob_java_connector_path | V4.3.5 BP1 | Set the path of the jar package that the external table connector depends on. This configuration is required when ob_enable_java_env is enabled. |
| temporary_file_max_disk_size | V4.3.5 BP1 | Sets the maximum disk space that temporary files on a single node of a tenant can occupy. |
| package_state_sync_max_size | V4.3.5 BP1 | Controls the maximum length for synchronizing package variable values during package state synchronization. If a package variable value exceeds this limit, it will not be synchronized. |
| unit_gc_wait_time |
|
Specifies the maximum wait duration for a minor GC. If the minor GC does not complete within this duration, a forced GC is triggered. |
| recover_table_concurrency |
|
Sets the maximum number of tables allowed for parallel recovery during the cross-tenant table import phase of table-level restore. |
| recover_table_dop |
|
Specifies the maximum number of tables that can be restored in parallel during the cross-tenant table import phase of table-level restore. |
| query_memory_limit_percentage |
|
Specifies the percentage of tenant memory available for a single SQL statement. |
| replica_parallel_migration_mode |
|
Specifies the mode for the parallel migration of log stream replicas. |
| sts_credential |
|
Specifies the credentials for accessing the STS service provided by OCP. |
| arbitration_degradation_policy | V4.3.4 | It is used to set the automatic downgrade strategy. |
| kv_hbase_client_scanner_timeout_period | V4.3.4 | Sets the timeout period for an OBKV-HBase streaming query. |
| default_load_mode | V4.3.4 | Controls the hint to be used when no hint is specified for the data import operation. |
| direct_load_allow_fallback | V4.3.4 | Controls whether to report an error when direct load is not supported in the data import scenario. |
| enable_auto_split | V4.3.4 | Controls whether to enable automatic partitioning for this table.
NoticeStarting from V4.4.1, for clusters created using the KV template, the default value of this parameter has changed to true. |
| auto_split_tablet_size | V4.3.4 | Controls the threshold for triggering a split after the auto-partitioning feature is enabled for a tenant.
NoticeStarting from V4.4.1, the default value of this parameter has been changed to 2 GB. |
| sync_io_thread_count | V4.3.4 | Configures the number of threads for synchronizing 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 to use the RFC 3986 standard for URL encoding when sending requests over S3. |
| ob_vector_memory_limit_percentage | V4.3.3 | Configure the threshold for memory resource usage by the vector index module (in percentage). |
| storage_rowsets_size | V4.3.2 | Controls the number of rows processed in a vectorized batch by the columnar storage engine. |
| alert_log_level |
|
Sets the warning log level. |
| enable_global_background_resource_isolation |
|
Controls whether to enable global resource isolation for foreground and background processes. |
| global_background_cpu_quota |
|
Controls the number of CPU cores for background tasks when global foreground-background resource isolation is enabled. |
| choose_migration_source_policy |
|
Specifies the priority strategy for selecting source replicas during migration. |
| lob_enable_block_cache_threshold |
|
Sets the threshold for caching LOB queries stored in OUTROW format. |
| spill_compression_codec | V4.3.1 | Specifies the compression algorithm type to implement data compression during SQL execution. |
| max_partition_num |
|
Controls the maximum number of partitions allowed in MySQL-compatible mode. |
| log_storage_compress_all |
|
Controls whether to enable the clog storage compression feature. |
| syslog_compress_func |
|
Sets the compression algorithm for system logs. |
| syslog_disk_size |
|
Sets the maximum disk space for system logs. |
| syslog_file_uncompressed_count |
|
Specifies the number of files for which system logs are not compressed. |
| log_storage_compress_func |
|
Sets the compression algorithm for clog storage. |
| enable_dblink |
|
Controls whether to enable the DBLink feature. |
| data_disk_write_limit_percentage |
|
Controls the percentage of data disk write throttling. |
| strict_check_os_params |
|
Controls whether to enable the feature to check OS configuration parameters. |
| default_table_store_format | V4.3.0 | Specifies the default table creation format for a user tenant, including row-based storage, pure columnar storage, and hybrid row-column storage. |
| enable_rpc_authentication_bypass | V4.3.0 | When RPC security authentication is enabled in the OBServer cluster, this parameter specifies whether to allow the OMS migration service and the OBKV service to bypass RPC security authentication when connecting to the cluster. |
| sql_protocol_min_tls_version | V4.2.1 | Sets the minimum version of the SSL/TLS protocol to be used for SSL connections in SQL statements. |
| compaction_dag_cnt_limit | V4.2.1 | Configure the maximum number of DAGs allowed in the Compaction DAG queue. |
| compaction_schedule_tablet_batch_cnt | V4.2.1 | The maximum number of partitions scheduled for compaction in each batch. |
| enable_transfer | V4.2.1 | Controls whether transfers are allowed within a tenant. |
| ttl_thread_score | V4.2.1 | Set the number of worker threads used by the TTL task. |
| local_ip | V4.2.0 | The IP address of the server where the OBServer node is deployed. |
| observer_id | V4.2.0 | The unique identifier assigned by the cluster to the OBServer node for resource scheduling. |
| standby_fetch_log_bandwidth_limit | V4.2.0 | Sets the maximum bandwidth that can be occupied per second by the total log synchronization traffic from all servers in the cluster where the standby tenant resides to the primary tenant. |
| storage_meta_cache_priority | V4.2.0 | Controls the priority of storing Meta Cache in KVCache. |
| archive_lag_target | V4.2.0 | Controls the delay for tenant log archiving. |
| log_disk_throttling_maximum_duration | V4.2.0 | Maximum available time of the log disk after triggering the log throttling. |
| log_disk_throttling_percentage | V4.2.0 | The percentage of disk space occupied by unreclaimable logs that triggers the log write throttling. |
| ls_gc_delay_time | V4.2.0 | Configure the time after which tenant log streams are deleted. |
| partition_balance_schedule_interval | V4.2.0 | Set the partition balancing scheduling cycle. |
| 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 | Sets the RPC timeout period for log pulling from the standby database, which controls how quickly the standby database's log transfer service detects that a primary server is unavailable and switches to another server. |
| standby_db_preferred_upstream_log_region | V4.1.0 | Configure the preferred region for the standby tenant to synchronize upstream logs in a physical standby database scenario. |
| log_storage_warning_tolerance_time | V4.1.0 | Sets the time before a leader switchover is triggered when I/O failures from the log disk persist until the disk is marked as faulty. |
| ob_startup_mode | V4.1.0 | Sets the startup mode of the OBServer node. This setting can only be modified during the first startup. |
| sql_net_thread_count | V4.1.0 | Set the number of I/O threads in the MySQL cluster, that is,global_sql_nio_serverThe number of threads. |
| arbitration_timeout | V4.1.0 | Set the timeout period for triggering automatic downgrade. |
| dump_data_dictionary_to_log_interval | V4.1.0 | Controls the persistence cycle of tenant data dictionaries. |
| enable_user_defined_rewrite_rules | V4.1.0 | A switch to control whether user-defined rules are enabled. |
| log_transport_compress_all | V4.1.0 | Specifies whether to compress log data during transmission. |
| log_transport_compress_func | V4.1.0 | Specifies the compression algorithm for log transmission. |
| rpc_memory_limit_percentage | V4.1.0 | Sets the maximum percentage of memory for RPCs in a tenant relative to the total memory of the tenant. |
| tenant_sql_login_thread_count | V4.1.0 | Set the number of threads for MySQL tenant login, that is,mysql_queueThe number of threads. |
| tenant_sql_net_thread_count | V4.1.0 | The number of I/O threads in the MySQL-compatible tenant, that is,sql_nio_serverThe number of threads. |
| log_disk_percentage | V4.0.0 | Sets the percentage of total disk space occupied by redo logs. |
| log_disk_size | V4.0.0 | Sets the size of the redo log disk, which is the total space available for logs on this OBServer node. |
| ha_high_thread_score | V4.0.0 | Sets the current number of worker threads for high-priority threads in high-availability mode. |
| ha_low_thread_score | V4.0.0 | Sets the current number of worker threads for high-availability low-priority threads. |
| ha_mid_thread_score | V4.0.0 | Sets the current number of worker threads for priority threads in high availability mode. |
| query_memory_limit_percentage |
|
Specify the percentage of tenant memory available for a single SQL statement. |
Deprecated parameters
The following table lists the deprecated parameters in V4.x.
Parameter name |
Description |
|---|---|
| global_write_halt_residual_memory | This feature is deprecated and will be removed starting from V4.2.0. |
| max_px_worker_count | This feature is deprecated and will be removed starting from V4.2.0. |
| plan_cache_high_watermark | This feature has never been supported and was removed starting from V4.2.0. |
| plan_cache_low_watermark | This feature has never been supported and was removed starting from V4.2.0. |
| rootservice_memory_limit | Architecture upgrade changes have been removed since version V4.2.0. |
| system_trace_level | Implement logic change. This parameter is no longer applicable and has been removed since V4.2.0. |
| token_reserved_percentage | Implement logic change. This parameter is no longer applicable and has been removed since V4.2.0. |
| trace_log_sampling_interval | Implement logic change. This parameter is no longer applicable and has been removed since V4.2.0. |
| io_category_config | Implement logic change. This parameter is no longer applicable and has been removed since V4.2.0. |
| auto_broadcast_location_cache_rate_limit | Architecture upgrade changes, deleted starting from version V4.0.0. |
| auto_leader_switch_interval | Architecture upgrade changes, deleted starting from version V4.0.0. |
| auto_refresh_location_cache_rate_limit | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_backup_dest | This feature is no longer supported and has been removed since V4.0.0. |
| backup_backup_dest_option | This feature is no longer supported and has been removed since V4.0.0. |
| backup_dest_option | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_concurrency | The architecture upgrade change has been removed since V4.0.0. Starting from V4.0.0, the parameter ha_low_thread_score has been added to replace this configuration item. |
| backup_dest | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_log_archive_option | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_net_limit | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_recovery_window | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_region | Architecture upgrade changes, deleted starting from version V4.0.0. |
| backup_zone | Architecture upgrade changes, deleted starting from version V4.0.0. |
| balance_blacklist_failure_threshold | Architecture upgrade changes, deleted starting from version V4.0.0. |
| balance_blacklist_retry_interval | Architecture upgrade changes, deleted starting from version V4.0.0. |
| balancer_emergency_percentage | Architecture upgrade changes, deleted starting from version V4.0.0. |
| balancer_timeout_check_interval | Architecture upgrade changes, deleted starting from version V4.0.0. |
| clog_disk_utilization_threshold | The architecture upgrade change has been removed since V4.0.0. Starting from V4.0.0, the new parameter log_disk_utilization_threshold has been added to replace this parameter. |
| clog_expire_days | Architecture upgrade changes, deleted starting from version V4.0.0. |
| clog_cache_priority | Architecture upgrade changes, deleted starting from version V4.0.0. |
| clog_disk_usage_limit_percentage | Architecture upgrade changes, deleted starting from version V4.0.0. |
| clog_transport_compress_func | This feature is not supported in OceanBase Database V4.0.0 and has been removed since that version. Starting from V4.1.0, the parameter log_transport_compress_func has been introduced to replace it. |
| clog_max_unconfirmed_log_count | The implementation logic has changed, and the related feature is no longer applicable. It has been removed since V4.0.0. |
| clog_persistence_compress_func | This feature was not supported in V4.0.0 and was removed starting from that version. It was re-enabled starting from V4.2.1 (excluding V4.3.0), with the addition of the log_storage_compress_func parameter to replace this configuration item. |
| cpu_reserved | Architecture upgrade changes, deleted starting from version V4.0.0. |
| data_copy_concurrency | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the new parameter ha_high_thread_score was added to replace this parameter. |
| default_transport_compress_func | Architecture upgrade changes, deleted starting from version V4.0.0. |
| election_cpu_quota | Architecture upgrade changes, deleted starting from version V4.0.0. |
| election_blacklist_interval | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_auto_refresh_location_cache | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_auto_leader_switch | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_clog_persistence_compress | This feature was not supported in V4.0.0 and was removed starting from that version. It was reintroduced starting from V4.2.1 (excluding V4.3.0), with the addition of the new parameter log_storage_compress_all to replace it. |
| enable_global_freeze_trigger | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_log_archive | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_election_group | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_merge_by_turn | This feature is no longer supported and has been removed since V4.0.0. |
| enable_manual_merge | This feature is no longer supported and has been removed since V4.0.0. |
| enable_one_phase_commit | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. |
| enable_pg | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_separate_sys_clog | This feature has never worked and was removed starting from V4.0.0. |
| enable_smooth_leader_switch | Architecture upgrade changes, deleted starting from version V4.0.0. |
| enable_rootservice_standalone | Architecture upgrade changes, deleted starting from version V4.0.0. |
| fast_recovery_concurrency | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the new parameter ha_high_thread_score was added to replace this parameter. |
| flush_log_at_trx_commit | This feature has a low usage rate and was removed starting from V4.0.0. |
| gc_wait_archive | Architecture upgrade changes, deleted starting from version V4.0.0. |
| global_index_build_single_replica_timeout | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. |
| global_major_freeze_residual_memory | This feature has a low usage rate and was removed starting from V4.0.0. |
| get_leader_candidate_rpc_timeout | Architecture upgrade changes, deleted starting from version V4.0.0. |
| ignore_replica_checksum_error | Not recommended. This feature has been deprecated since V4.0.0 and will be removed in later versions. |
| index_clog_cache_priority | Architecture upgrade changes, deleted starting from version V4.0.0. |
| index_info_block_cache_priority | Architecture upgrade changes, deleted starting from version V4.0.0. |
| index_cache_priority | Architecture upgrade changes, deleted starting from version V4.0.0. |
| ilog_index_expire_time | Architecture upgrade changes, deleted starting from version V4.0.0. |
| location_cache_priority | Architecture upgrade changes, deleted starting from version V4.0.0. |
| location_cache_expire_time | Architecture upgrade changes, deleted starting from version V4.0.0. |
| log_archive_batch_buffer_limit | Architecture upgrade changes, deleted starting from version V4.0.0. |
| log_archive_checkpoint_interval | The architecture upgrade change has been removed since V4.0.0. Starting from V4.0.0, the new parameter archive_lag_target has been added to replace this parameter. |
| max_kept_major_version_number | This feature has a low usage rate and was removed starting from V4.0.0. |
| merge_stat_sampling_ratio | The implementation method has changed and is removed starting from V4.0.0. |
| merge_thread_count | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the new parameter compaction_low_thread_score was added to replace this parameter. |
| merger_completion_percentage | This feature has a low usage rate and was removed starting from V4.0.0. |
| merger_switch_leader_duration_time | This feature is no longer supported and has been removed since V4.0.0. |
| merger_warm_up_duration_time | Architecture upgrade changes, deleted starting from version V4.0.0. |
| migrate_concurrency | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the parameter ha_mid_thread_score was added to replace this configuration item. |
| minor_deferred_gc_time | Not recommended. This feature has been deprecated since V4.0.0 and will be removed in later versions. |
| minor_freeze_times | Parametermajor_compact_triggerThe meaning is consistent. Starting from V4.0.0, this parameter has been removed and replaced with the unified parametermajor_compact_trigger. |
| minor_merge_concurrency | The implementation logic change feature has been removed since V4.0.0. Starting from V4.0.0, the new parameter compaction_mid_thread_score has been added to replace it. |
| minor_warm_up_duration_time | Not recommended. This feature has been deprecated since V4.0.0 and will be removed in later versions. |
| multiblock_read_gap_size | Architecture upgrade changes, deleted starting from version V4.0.0. |
| multiblock_read_size | Architecture upgrade changes, deleted starting from version V4.0.0. |
| ob_esi_rpc_port | This feature is no longer supported and has been removed since V4.0.0. |
| enable_ob_esi_process | This feature is no longer supported and has been removed since V4.0.0. |
| ob_esi_session_timeout | This feature is no longer supported and has been removed since V4.0.0. |
| ob_esi_io_concurrency | This feature is no longer supported and has been removed since V4.0.0. |
| ob_esi_memory_limit | This feature is no longer supported and has been removed since V4.0.0. |
| ob_esi_syslog_level | This feature is no longer supported and has been removed since V4.0.0. |
| ob_esi_max_syslog_file_count | This feature is no longer supported and has been removed since V4.0.0. |
| ofs_list | This feature is no longer applicable and has been removed since V4.0.0. |
| partition_table_check_interval | Architecture upgrade changes, deleted starting from version V4.0.0. |
| rebuild_replica_data_lag_threshold | Architecture upgrade changes, deleted starting from version V4.0.0. |
| replica_safe_remove_time | Architecture upgrade changes, deleted starting from version V4.0.0. |
| resource_soft_limit | Architecture upgrade changes, deleted starting from version V4.0.0. |
| restore_concurrency | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the new parameter ha_high_thread_score was added to replace this parameter. |
| row_purge_thread_count | This feature has never been supported and was removed starting from V4.0.0. |
| server_data_copy_out_concurrency | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the parameter ha_mid_thread_score was added to replace this configuration item. |
| server_data_copy_in_concurrency | The implementation logic change was removed starting from V4.0.0. Starting from V4.0.0, the parameter ha_mid_thread_score was added to replace this configuration item. |
| sql_audit_memory_limit | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. Starting from V4.0.0, the variable ob_sql_audit_percentage has been added to replace this parameter. |
| switchover_process_thread_count | Architecture upgrade changes, deleted starting from version V4.0.0. |
| sys_bkgd_io_high_percentage | Architecture upgrade changes, deleted starting from version V4.0.0. |
| sys_bkgd_io_low_percentage | Architecture upgrade changes, deleted starting from version V4.0.0. |
| sys_cpu_limit_trigger | Architecture upgrade changes, deleted starting from version V4.0.0. |
| system_cpu_quota | Architecture upgrade changes, deleted starting from version V4.0.0. |
| tenant_groups | This feature is no longer supported and has been removed since V4.0.0. |
| trx_force_kill_threshold | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. |
| unit_balance_resource_weight | Architecture upgrade changes, deleted starting from version V4.0.0. |
| user_iort_up_percentage | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. |
| user_tab_col_stat_cache_priority | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. |
| wait_leader_batch_count | Architecture upgrade changes, deleted starting from version V4.0.0. |
| zone_merge_concurrency | This feature is no longer supported and has been removed since V4.0.0. |
| zone_merge_order | This feature is no longer supported and has been removed since V4.0.0. |
| zone_merge_timeout | This feature is no longer supported and has been removed since V4.0.0. |
Changes to system variables in V4.x
To better adapt to user business scenarios, OceanBase Database has also made a series of optimization adjustments to tenant variable default values and value ranges. Specifically, in previous versions, undo_retention was introduced as a system variable. Starting from V4.0.0, undo_retention has been adjusted to a tenant-level parameter.
System variables with changed default values
The following table lists the 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 is changed toNULLAdjusted to"". |
| max_allowed_packet | Starting from V4.2.1, the default value has been adjusted from 4194304 to 16777216. |
| ob_max_read_stale_time | Starting from V4.1.0, the default value has been adjusted from 5000000 to -1. |
| ob_trx_idle_timeout | Starting from V4.0.0, the default value has been adjusted from 120s to 1d. |
| ob_trx_timeout | Starting from V4.0.0, the default value has been adjusted from 100s to 1d. |
System variables with changed value ranges or meanings
The following table lists the system variables with changed value ranges or meanings.
Variable name |
Description |
|---|---|
| secure_file_priv | Starting from V4.2.0, the empty string ("") andNULLThe meaning has been adjusted from "Unrestricted" to "Import and export are 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 with changed permission requirements
The following table lists the variables with changed permission requirements.
Variable name |
Description |
|---|---|
| secure_file_priv | Starting from V4.2.0, modifying this variable is restricted to local Unix Socket connections only. |
New system variables
The following table lists the new system variables introduced in V4.x.
Variable name |
Import version |
Description |
|---|---|---|
| event_scheduler | V4.3.5 BP2 | Determines whether the event scheduler is enabled and running on the server. |
| ob_enable_ps_parameter_anonymous_block | V4.3.5 BP2 | This parameter specifies whether to enable or disable parameterization for anonymous blocks and CALL statements during parsing in PS mode. |
| 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 | This parameter specifies how many nearest cluster centers to search for in a vector index query. |
| mview_refresh_dop | V4.3.5 BP1 | Controls the default refresh parallelism for materialized views. |
| enable_optimizer_rowgoal | V4.3.5 BP1 | This option specifies whether the optimizer should consider the impact of row count targets (such as those specified by the LIMIT operator) during cardinality estimation. |
| pid_file |
|
Retrieves the path name of the file on which the server writes its process ID. |
| port |
|
This parameter specifies the port number on which the server listens for TCP/IP connections during OBServer node deployment. |
| socket |
|
Retrieves the name of the socket file used to connect local clients. |
| ob_hnsw_ef_search | V4.3.3 | Specifies the number of neighbor nodes to consider during HNSW vector index search. |
| ob_table_access_policy | V4.3.3 | Controls the optimizer to prefer specific storage formats when generating base table plans. |
| cardinality_estimation_model |
|
Controls the correlation model used by the optimizer for row estimation. |
| activate_all_roles_on_login |
|
Controls whether all roles are automatically enabled by default during login. |
| innodb_stats_persistent |
|
Controls whether to persist InnoDB index statistics to disk. |
| ob_compatibility_control |
|
It is used to control the behavior mode when there is a compatibility conflict with MySQL 5.7 or MySQL 8.0. |
| ob_compatibility_version |
|
Controls the version of OceanBase Database for which the feature that causes a behavior change is compatible. |
| ob_security_version |
|
Controls the OceanBase Database version compatible with security features. |
| automatic_sp_privileges |
|
Specifies whether the stored procedure will automatically grant the ALTER and EXECUTE privileges. |
| lc_time_names |
|
Controls the language for displaying date and month names and their abbreviations. |
| ob_enable_pl_cache |
|
Controls whether to enable the PL cache module. |
| optimizer_dynamic_sampling | V4.2.0 | Controls the level of dynamic sampling. |
| optimizer_features_enable | V4.2.0 | Optimization features of different OceanBase Database versions are enabled. |
| parallel_degree_limit | V4.2.0 | Sets the upper limit of parallelism selected by the optimizer when the auto-DOP strategy is used. |
| parallel_degree_policy | V4.2.0 | Sets the parallelism selection strategy. |
| parallel_min_scan_time_threshold | V4.2.0 | In the auto DOP strategy, this parameter is used to calculate the degree of parallelism. It sets the minimum estimated execution time for parallel processing of base table scans. |
| runtime_filter_type | V4.2.0 | Sets the runtime filter type at the tenant level. |
| runtime_filter_wait_time_ms | V4.2.0 | Sets the maximum wait time for a runtime filter. |
| runtime_filter_max_in_num | V4.2.0 | Set the NDV (the number of distinct values in a column) for Runtime In Filter. |
| runtime_bloom_filter_max_size | V4.2.0 | Sets the maximum memory for the Runtime Bloom Filter, in bytes. |
| cte_max_recursion_depth | V4.1.0 | Sets the maximum recursion depth for common table expressions (CTEs). The server will terminate operations that exceed this CTE value. |
| ob_max_read_stale_time | V4.1.0 | Sets the maximum latency threshold (in microseconds) for weak-consistency read queries. |
| regexp_stack_limit | V4.1.0 | Sets the maximum available memory for the internal stack of regular expression matching operations. The default unit is bytes. |
| ob_enable_show_trace | V4.1.0 | Specifies whether to use Show Trace logs. |
| cursor_sharing | V4.0.0 | Determines whether to parameterize SQL statements during processing. |
| innodb_strict_mode | V4.0.0 | Sets the SQL check mode for specific syntax. |
| log_row_value_options | V4.0.0 | Controls whether to use partial updates for LOB data. |
| ob_enable_rich_error_msg | V4.0.0 | Controls whether to display information such as svr_ip, time, and trace_id when an SQL execution error occurs. |
Deprecated system variables
The following table lists the deprecated system variables in V4.x.
Variable name |
Description |
|---|---|
| ob_enable_trace_log | The architecture upgrade change has been removed since version V4.1.0. |
| ob_create_table_strict_mode | Architecture upgrade changes, deleted starting from version V4.0.0. |
| ob_enable_blk_nestedloop_join | The implementation logic has changed, and the corresponding feature is no longer applicable. It has been removed since V4.0.0. |
| ob_enable_hash_group_by | The implementation method has changed and is removed starting from V4.0.0. |
| ob_timestamp_service | Architecture upgrade change. Deleted starting from V4.0.0. |