Due to the architectural upgrade and refactoring in OceanBase Database V4.x, many parameters or variables are no longer effective. V4.x has deleted and modified invalid parameters and variables. For example, the parameter minor_freeze_times, which was used to trigger a major freeze, has been deleted. We have also 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 used to replace those in V3.x in V4.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 one business unit, V4.x splits cluster-level capabilities into tenant-level capabilities. For example, 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 scope has been changed from cluster-level to tenant-level. |
| balancer_idle_time | Starting from V4.2.0, the scope has been changed from cluster-level to tenant-level. |
| log_archive_concurrency | Starting from V4.1.0, it has been changed from a cluster-level setting to a tenant-level setting. |
| log_restore_concurrency | Starting from V4.1.0, it has been changed from a cluster-level setting to a tenant-level setting. |
| 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 effective mode
Parameters generally have two effective modes: dynamic effective and restart effective. Most parameters are dynamically effective, meaning they take effect without restarting the OBServer node.
The following table lists the parameters with changed effective 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 V4.4.2, starting from V4.4.2 BP1, 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 |
Description |
|---|---|
| compaction_schedule_tablet_batch_cnt | Starting from V4.4.0, the value range changes from [10000, 200000] to [10000, 500000]. |
| compaction_dag_cnt_limit | Starting from V4.4.0, the value range changes from [10000, 200000] to [10000, 500000]. |
| net_thread_count | Starting from V4.3.5 BP2, the value range changes from [0, 64] to [0, 128]. |
| 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 changes from [10, 90] to [10, 95]. |
| cpu_quota_concurrency | Starting from V4.2.0, the value range changes from [1,10] to [1,20]. |
| memory_limit | Starting from V4.1.0, the value range changes from [4G, +∞) to [1G, +∞). |
| server_cpu_quota_min |
|
New parameters
The following table lists the parameters added in V4.x.
Parameter |
Introduced in |
Description |
|---|---|---|
| enable_standby_semi_sync | For V4.4.2, this parameter was introduced in V4.4.2 BP2. | Specifies whether to enable semi-synchronous replication for the standby database (standby tenant). |
| schema_history_archive_expire_time | For V4.4.2, this parameter was introduced in V4.4.2 BP1. | Specifies the retention period of schema multi-version history archive data. |
| zone_disk_balance_tolerance_percentage | For V4.4.2, this parameter was introduced in V4.4.2 BP1. | Controls the tolerance of the table group disk balancing algorithm for disk imbalance between zones. |
| enable_ls_leader_balance |
|
Controls whether to enable automatic leader balancing for log streams. |
| enable_gts_standalone |
|
Specifies whether to enable the tenant GTS service to occupy a group of units. |
| zone_deploy_mode |
|
Sets the distribution mode of the tenant across zones. |
| mds_minor_compact_trigger | V4.4.1 | Controls the number of SSTables that triggers an MDS Minor Compaction. |
| mds_compaction_mid_thread_score | V4.4.1 | Sets the number of DAG (Direct Acyclic Graph) threads for MDS Compaction with medium priority. |
| mds_compaction_high_thread_score | V4.4.1 | Sets the number of DAG (Direct Acyclic Graph) threads for MDS Compaction with high priority. |
| ls_scale_out_factor |
|
The scaling-out factor for log streams, which controls the number of log streams 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 (in bytes) of a merge range. 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 on a single node. |
| ob_enable_java_udf | V4.4.0 | Enables or disables the Java UDF feature. |
| load_data_diagnosis_log_compression | V4.4.0 | Sets the compression algorithm for diagnostic logs. |
| load_data_diagnosis_log_max_size | V4.4.0 | Sets the size of a single diagnostic log file. |
| result_cache_max_size | V4.4.0 | Controls the maximum amount of memory that can be used by the result cache module. |
| result_cache_max_result | V4.4.0 | Controls the maximum proportion of result_cache_max_size that can be used by a single result cache object. |
| ob_result_cache_evict_percentage | V4.4.0 | Sets the memory evict water level for result cache. |
| ob_deterministic_udf_cache_max_size | V4.4.0 | Specifies the maximum amount of memory (in bytes) that can be used by the cache pool for all deterministic UDFs during statement execution. If this value is set to 0, the execution cache feature is disabled. |
| enable_lock_priority | V4.3.5 BP2 | Enables or disables table lock priority. |
| enable_adaptive_plan_cache | V4.3.5 BP2 | Controls whether to enable the adaptive plan cache feature for tenants. |
| global_index_auto_split_policy | V4.3.5 BP2 | Controls whether to enable automatic partitioning for new global indexes.
NoticeStarting from V4.4.1, in the open-source edition, the default value of this parameter is changed to |
| clog_io_isolation_mode | V4.3.5 BP2 | Determines whether to isolate I/O requests on the clog disk based on whether the clog disk and data disk are independent. You can adjust this parameter based on your system deployment 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 | Enables or disables the Java environment required for external table capabilities such as HDFS/MaxCompute (ODPS). |
| ob_java_home | V4.3.5 BP1 | Specifies the Java home path required for JNI operations. This parameter can be configured only when ob_enable_java_env is enabled. |
| ob_java_opts | V4.3.5 BP1 | Specifies the JVM startup parameters, such as memory size and garbage collection algorithm. You must enable the ob_enable_java_env parameter before you specify this parameter. |
| ob_java_connector_path | V4.3.5 BP1 | Specifies the path of the JAR package of the external table connector. You must enable the ob_enable_java_env parameter before you specify this parameter. |
| temporary_file_max_disk_size | V4.3.5 BP1 | Specifies the maximum disk space that can be occupied by a single node of a tenant for temporary files. |
| package_state_sync_max_size | V4.3.5 BP1 | Controls the maximum length of the package variable value in package state synchronization. If the length of the package variable value exceeds the specified value, the package variable is not synchronized. |
| unit_gc_wait_time |
|
Specifies the maximum wait time for Unit GC. If the wait time exceeds the maximum wait time, GC is forcibly performed. |
| recover_table_concurrency |
|
Specifies the maximum number of tables that can be restored in parallel during the cross-tenant table import phase of table-level restore. |
| recover_table_dop |
|
Specifies the maximum degree of parallelism (DOP) for restoring a single table during the cross-tenant table import phase of table-level restore. |
| query_memory_limit_percentage |
|
Specifies the percentage of the tenant memory that can be used by 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 strategy. |
| 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 by this parameter when no hint is specified for a load operation. |
| direct_load_allow_fallback | V4.3.4 | Controls whether to return an error when the direct load feature is not supported in a load operation. |
| enable_auto_split | V4.3.4 | Specifies whether to enable the automatic partitioning feature for a table.
NoticeStarting from V4.4.1, for clusters created by using the KV template, the default value of this parameter is set to true. |
| auto_split_tablet_size | V4.3.4 | Specifies the threshold for triggering a split after the automatic partitioning feature is enabled for a tenant.
NoticeStarting from V4.4.1, the default value of this parameter is set to 2 GB. |
| sync_io_thread_count | V4.3.4 | Configures the number of threads for synchronous I/O requests. |
| ob_encoding_granularity | V4.3.3 | Controls the upper limit of memory resources available to the vector index module as a percentage. |
| ob_storage_s3_url_encode_type | V4.3.3 | Specifies whether to enable URL encoding for S3 requests that is compatible with the RFC 3986 standard. |
| ob_vector_memory_limit_percentage | V4.3.3 | Configures the threshold for memory resource usage by the vector index module (unit: percentage). |
| storage_rowsets_size | V4.3.2 | Controls the number of rows to vectorize in a batch for the columnar engine. |
| alert_log_level |
|
Sets the level of warning logs. |
| enable_global_background_resource_isolation |
|
Controls whether to enable the global foreground and background resource isolation feature. |
| global_background_cpu_quota |
|
Controls the number of CPU cores for background tasks when global foreground and 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 LOB query caching in OUTROW storage. |
| spill_compression_codec | V4.3.1 | Specifies the compression algorithm type for data disk-offloading 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 clog storage compression. |
| syslog_compress_func |
|
Sets the compression algorithm for system logs. |
| syslog_disk_size |
|
Specifies the maximum disk space for system logs. |
| syslog_file_uncompressed_count |
|
Specifies the maximum number of system log files without compression. |
| log_storage_compress_func |
|
Specifies the compression algorithm for clog storage. |
| enable_dblink |
|
Specifies whether to enable the DBLink feature. |
| data_disk_write_limit_percentage |
|
Specifies the percentage of the maximum write limit for 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 storage format for user tenants. The supported formats include rowstore, columnstore, and hybrid rowstore/columnstore. |
| enable_rpc_authentication_bypass | V4.3.0 | In an OBServer cluster with RPC security authentication enabled, specifies whether to allow OMS migration services and OBKV services to bypass RPC security authentication and connect to the cluster. |
| sql_protocol_min_tls_version | V4.2.1 | Specifies the minimum SSL/TLS protocol version for SSL connections used to execute SQL statements. |
| 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 partitions to be scheduled in each batch during 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 | The IP address of the server where you deploy the OBServer node. |
| observer_id | V4.2.0 | The unique identifier assigned to the OBServer node by the RS. |
| standby_fetch_log_bandwidth_limit | V4.2.0 | Sets the maximum bandwidth that can be occupied by the total log synchronization traffic from all servers in the standby tenant's cluster 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 time for tenant log archiving delay. |
| log_disk_throttling_maximum_duration | V4.2.0 | Adjusts 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 | Configures the time for tenant log stream delay deletion. |
| partition_balance_schedule_interval | V4.2.0 | Sets 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 for standby database log fetching, to control the log transmission service to detect when a server in the primary database is unavailable and switch to another server. |
| standby_db_preferred_upstream_log_region | V4.1.0 | Configures the preferred region for upstream log synchronization in physical standby tenant scenarios. |
| log_storage_warning_tolerance_time | V4.1.0 | Sets the time from log disk I/O failure to disk being marked as bad. |
| ob_startup_mode | V4.1.0 | Sets the startup mode for OBServer nodes, which can only be modified during the first startup. |
| sql_net_thread_count | V4.1.0 | Sets the number of MySQL cluster I/O threads, i.e., the number of global_sql_nio_server threads. |
| arbitration_timeout | V4.1.0 | Sets the timeout for triggering automatic downgrade. |
| dump_data_dictionary_to_log_interval | V4.1.0 | Controls the tenant data dictionary persistence cycle. |
| enable_user_defined_rewrite_rules | V4.1.0 | Controls whether to enable user-defined rules. |
| log_transport_compress_all | V4.1.0 | Specifies whether to use compression for log transport. |
| log_transport_compress_func | V4.1.0 | Specifies the compression algorithm for log transmission. |
| rpc_memory_limit_percentage | V4.1.0 | Specifies the maximum percentage of memory allocated to RPC in a tenant. |
| tenant_sql_login_thread_count | V4.1.0 | Specifies the number of threads for MySQL tenant login, i.e., the number of mysql_queue threads. |
| tenant_sql_net_thread_count | V4.1.0 | Specifies the number of IO threads for MySQL tenants, i.e., 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. |
| log_disk_size | V4.0.0 | Specifies the size of the redo log disk, i.e., the total available space for logs on this OBServer node. |
| ha_high_thread_score | V4.0.0 | Specifies the current number of working threads for high-priority threads in high availability. |
| ha_low_thread_score | V4.0.0 | Specifies the current number of working threads for low-priority threads in high availability. |
| ha_mid_thread_score | V4.0.0 | Specifies 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 deprecated in V4.x.
Parameter name |
Description |
|---|---|
| schema_history_recycle_interval | Internal optimization and modification. For version V4.4.2, it has been removed since V4.4.2 BP1. |
| 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 | The architecture upgrade change has been removed since version V4.2.0. |
| system_trace_level | This parameter is no longer applicable for implementing logical changes and has been removed since V4.2.0. |
| token_reserved_percentage | This parameter is no longer applicable for implementing logical changes and has been removed since V4.2.0. |
| trace_log_sampling_interval | This parameter is no longer applicable for implementing logical changes and has been removed since V4.2.0. |
| io_category_config | This parameter is no longer applicable for implementing logical changes and has been removed since V4.2.0. |
| auto_broadcast_location_cache_rate_limit | Architecture upgrade changes have been removed since version V4.0.0. |
| auto_leader_switch_interval | Architecture upgrade changes have been removed since version V4.0.0. |
| auto_refresh_location_cache_rate_limit | Architecture upgrade changes have been removed since 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 have been removed since 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 have been removed since version V4.0.0. |
| backup_log_archive_option | Architecture upgrade changes have been removed since version V4.0.0. |
| backup_net_limit | Architecture upgrade changes have been removed since version V4.0.0. |
| backup_recovery_window | Architecture upgrade changes have been removed since version V4.0.0. |
| backup_region | Architecture upgrade changes have been removed since version V4.0.0. |
| backup_zone | Architecture upgrade changes have been removed since version V4.0.0. |
| balance_blacklist_failure_threshold | Architecture upgrade changes have been removed since version V4.0.0. |
| balance_blacklist_retry_interval | Architecture upgrade changes have been removed since version V4.0.0. |
| balancer_emergency_percentage | Architecture upgrade changes have been removed since version V4.0.0. |
| balancer_timeout_check_interval | Architecture upgrade changes have been removed since 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 have been removed since version V4.0.0. |
| clog_cache_priority | Architecture upgrade changes have been removed since version V4.0.0. |
| clog_disk_usage_limit_percentage | Architecture upgrade changes have been removed since version V4.0.0. |
| clog_transport_compress_func | This feature is not supported in 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 have been removed since 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 have been removed since version V4.0.0. |
| election_cpu_quota | Architecture upgrade changes have been removed since version V4.0.0. |
| election_blacklist_interval | Architecture upgrade changes have been removed since version V4.0.0. |
| enable_auto_refresh_location_cache | Architecture upgrade changes have been removed since version V4.0.0. |
| enable_auto_leader_switch | Architecture upgrade changes have been removed since 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 re-enabled 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 have been removed since version V4.0.0. |
| enable_log_archive | Architecture upgrade changes have been removed since version V4.0.0. |
| enable_election_group | Architecture upgrade changes have been removed since 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 have been removed since 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 have been removed since version V4.0.0. |
| enable_rootservice_standalone | Architecture upgrade changes have been removed since 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 method has a low utilization rate and has been deprecated since V4.0.0. |
| gc_wait_archive | Architecture upgrade changes have been removed since 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 method has a low utilization rate and has been deprecated since V4.0.0. |
| get_leader_candidate_rpc_timeout | Architecture upgrade changes have been removed since version V4.0.0. |
| ignore_replica_checksum_error | Not recommended. This feature has been deprecated since V4.0.0 and will be removed. |
| index_clog_cache_priority | Architecture upgrade changes have been removed since version V4.0.0. |
| index_info_block_cache_priority | Architecture upgrade changes have been removed since version V4.0.0. |
| index_cache_priority | Architecture upgrade changes have been removed since version V4.0.0. |
| ilog_index_expire_time | Architecture upgrade changes have been removed since version V4.0.0. |
| location_cache_priority | Architecture upgrade changes have been removed since version V4.0.0. |
| location_cache_expire_time | Architecture upgrade changes have been removed since version V4.0.0. |
| log_archive_batch_buffer_limit | Architecture upgrade changes have been removed since 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 method has a low utilization rate and has been deprecated since 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 method has a low utilization rate and has been deprecated since 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 have been removed since version V4.0.0. |
| migrate_concurrency | The implementation logic change feature has been removed since V4.0.0. Starting from V4.0.0, the parameter ha_mid_thread_score has been introduced to replace it. |
| minor_deferred_gc_time | Not recommended. This feature has been deprecated since V4.0.0 and will be removed. |
| 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 parameter compaction_mid_thread_score has been introduced to replace it. |
| minor_warm_up_duration_time | Not recommended. This feature has been deprecated since V4.0.0 and will be removed. |
| multiblock_read_gap_size | Architecture upgrade changes have been removed since version V4.0.0. |
| multiblock_read_size | Architecture upgrade changes have been removed since 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 have been removed since version V4.0.0. |
| rebuild_replica_data_lag_threshold | Architecture upgrade changes have been removed since version V4.0.0. |
| replica_safe_remove_time | Architecture upgrade changes have been removed since version V4.0.0. |
| resource_soft_limit | Architecture upgrade changes have been removed since 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 feature has been removed since V4.0.0. Starting from V4.0.0, the parameter ha_mid_thread_score has been introduced to replace it. |
| server_data_copy_in_concurrency | The implementation logic change feature has been removed since V4.0.0. Starting from V4.0.0, the parameter ha_mid_thread_score has been introduced to replace it. |
| 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 have been removed since version V4.0.0. |
| sys_bkgd_io_high_percentage | Architecture upgrade changes have been removed since version V4.0.0. |
| sys_bkgd_io_low_percentage | Architecture upgrade changes have been removed since version V4.0.0. |
| sys_cpu_limit_trigger | Architecture upgrade changes have been removed since version V4.0.0. |
| system_cpu_quota | Architecture upgrade changes have been removed since 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 have been removed since 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 have been removed since 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 in V4.x, 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 modified 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, this variable can only be modified via a local Unix socket connection. |
New system variables
The following table lists the new system variables 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 | It is used to control whether anonymous blocks and CALL statements are parameterized 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 the number of 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 |
|
Returns the pathname of the file on which the server writes its process ID. |
| port |
|
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 in case of compatibility conflicts with MySQL 5.7 and 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 is automatically granted the ALTER and EXECUTE privileges. |
| lc_time_names |
|
Controls the language for displaying date, 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 | Enables optimizer features for different OceanBase versions. |
| parallel_degree_limit | V4.2.0 | Sets the upper limit for the degree of parallelism (DOP) 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 by setting 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 the 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 terminates 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. |
Deprecated system variables
The following table lists the system variables deprecated in V4.x.
Variable name |
Description |
|---|---|
| ob_enable_trace_log | Architecture upgrade changes have been removed since version V4.1.0. |
| ob_create_table_strict_mode | Architecture upgrade changes have been removed since 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, removed starting from V4.0.0. |