- The following table describes the common development-related parameters.
| Parameter | Value | Description | Scope |
|---|---|---|---|
| minor_freeze_times | 0 | Specifies the number of minor freezes before a major freeze is triggered. | Cluster |
| enable_major_freeze | True | Specifies whether to enable an automatic major freeze in a cluster. | Cluster |
| major_freeze_duty_time | 02:00 | Specifies the time that a cluster starts an automatic major freeze. | Cluster |
| enable_rebalance | True | Specifies whether to enable partition load balancing. Valid values: True and False, where True means to enable partition load balancing and False means to disable it. | Cluster |
| enable_auto_leader_switch | True | Specifies whether to enable automatic leader switch. | Cluster |
| large_query_threshold | 100 ms | Specifies the execution time threshold to identify a large query. | Cluster |
| large_query_worker_percentage | 30 | Specifies the percentage of CPU worker threads used by a large query. | Cluster |
| data_copy_concurrency | 20 | Specifies the maximum number of migration tasks in a cluster during a partition migration. | Cluster |
| server_data_copy_out_concurrency | 2 | Specifies the maximum number of outbound migration tasks of each node during a partition migration. | Cluster |
| server_data_copy_in_concurrency | 2 | Specifies the maximum number of inbound migration tasks of each node during a partition migration. | Cluster |
| freeze_trigger_percentage | 70 | Specifies the threshold of incremental memory usage at which a minor freeze is triggered. | Cluster |
| enable_perf_event | True | Specifies whether to enable the collection of performance event information. Default value: False. | Cluster |
| enable_sql_audit | True | Specifies whether to enable SQL logging. Default value: True. | Cluster |
| sql_work_area | 1G | Specifies the SQL working memory in a tenant. | Tenant |
| writing_throttling_maximum_duration | 1h | Specifies the estimated maximum time for incremental memory usage when tenant throttling is triggered. | Tenant |
| writing_throttling_trigger_percentage | 100 | Specifies the threshold of the percentage of incremental memory usage when tenant throttling is triggered. | Tenant |
| max_stale_time_for_weak_consistency | ≥ 5s | Specifies the maximum allowed latency between the follower and the leader for weak consistency reads. | Tenant |
- The following table describes some general tenant variables.
| Variable | Value | Meaning |
|---|---|---|
| auto_increment_increment | 1 | Specifies the step size of an auto-increment column in a MySQL tenant. |
| auto_increment_offset | 1 | Specifies the starting value of an auto-increment column in a MySQL tenant. |
| auto_increment_cache_size | 1,000,000 | Specifies the cache size of an auto-increment column in a MySQL tenant. |
| autocommit | ON | Specifies whether to enable autocommit in a tenant. |
| ob_compatibility_mode | ORACLE/MYSQL | Displays the compatibility mode of the current tenant. ORACLE/MYSQL Read-only variable. |
| ob_tcp_invited_nodes | % | Specifies a comma-separated list of IP addresses that are allowed to access the tenant. For example, 127.1,192.168.0.0/16 |
| ob_timestamp_service | GTS | Specifies whether a tenant uses the Global Timestamp Service (GTS) or Local Timestamp Service (LTS). |
| ob_query_timeout | 10,000,000 | Specifies the default SQL execution timeout value in microseconds (µs). |
| ob_trx_idle_timeout | 120,000,000 | Specifies the idle transaction timeout value in a tenant in microseconds (µs). |
| ob_trx_timeout | 100,000,000 | Specifies the maximum transaction timeout in microseconds (µs) in a tenant. |
| ob_read_consistency | STRONG | Specifies the default data read consistency for SQL statements in a tenant. STRONG means strong consistency read, WEAK means weak consistency read, and FROZEN means to read data from the last major freeze. |
| ob_sql_audit_percentage | 3 | Specifies the maximum allowed percentage of memory used by SQL logs in a tenant. |
| ob_sql_work_area_percentage | 5 | Specifies the maximum allowed percentage of memory used by SQL execution in a tenant. |
| recyclebin | ON | Specifies whether to enable the recycle bin. Valid values: ON and OFF, where ON means to enable the recycle bin and OFF means to disable it. |
| sql_mode | STRICT_TRANS_TABLES,STRICT_ALL_TABLES,PAD_CHAR_TO_FULL_LENGTH | Specifies the SQL mode. |
| tx_isolation | READ-COMMITTED | Specifies the default transaction isolation level for a tenant. |
| time_zone | +8:00 | Specifies the default time zone for a tenant. |
| system_time_zone | +08:00 | Displays the default time zone of the system. |
| version_comment | Displays the OceanBase version, which is a read-only variable. |