• SHOW [GLOBAL|SESSION] VARIABLES
    • 语法图
    • 示例
    • MySQL 兼容性
    • 另请参阅

    SHOW [GLOBAL|SESSION] VARIABLES

    SHOW [GLOBAL|SESSION] VARIABLES 语句用于显示 GLOBAL 或 SESSION 范围的变量列表。如果未指定范围，则应用默认范围 SESSION。

    语法图

    ShowStmt:

    ShowStmt

    ShowTargetFilterable:

    ShowTargetFilterable

    GlobalScope:

    GlobalScope

    示例

    1. mysql> SHOW GLOBAL VARIABLES LIKE 'tidb%';
    2. +------------------------------------+--------------+
    3. | Variable_name                      | Value        |
    4. +------------------------------------+--------------+
    5. | tidb_ddl_reorg_worker_cnt          | 16           |
    6. | tidb_check_mb4_value_in_utf8       | 1            |
    7. | tidb_opt_agg_push_down             | 0            |
    8. | tidb_retry_limit                   | 10           |
    9. | tidb_constraint_check_in_place     | 0            |
    10. | tidb_ddl_reorg_priority            | PRIORITY_LOW |
    11. | tidb_current_ts                    | 0            |
    12. | tidb_mem_quota_indexlookupjoin     | 34359738368  |
    13. | tidb_query_log_max_len             | 2048         |
    14. | tidb_enable_cascades_planner       | 0            |
    15. | tidb_mem_quota_topn                | 34359738368  |
    16. | tidb_index_lookup_join_concurrency | 4            |
    17. | tidb_auto_analyze_end_time         | 23:59 +0000  |
    18. | tidb_mem_quota_query               | 34359738368  |
    19. | tidb_optimizer_selectivity_level   | 0            |
    20. | tidb_index_serial_scan_concurrency | 1            |
    21. | tidb_dml_batch_size                | 20000        |
    22. | tidb_max_chunk_size                | 1024         |
    23. | tidb_enable_table_partition        | auto         |
    24. | tidb_mem_quota_indexlookupreader   | 34359738368  |
    25. | tidb_enable_window_function        | 0            |
    26. | tidb_opt_write_row_id              | 0            |
    27. | tidb_ddl_error_count_limit         | 512          |
    28. | tidb_batch_delete                  | 0            |
    29. | tidb_mem_quota_sort                | 34359738368  |
    30. | tidb_enable_streaming              | 0            |
    31. | tidb_opt_insubq_to_join_and_agg    | 1            |
    32. | tidb_build_stats_concurrency       | 4            |
    33. | tidb_projection_concurrency        | 4            |
    34. | tidb_mem_quota_mergejoin           | 34359738368  |
    35. | tidb_hashagg_final_concurrency     | 4            |
    36. | tidb_checksum_table_concurrency    | 4            |
    37. | tidb_batch_insert                  | 0            |
    38. | tidb_slow_query_file               |              |
    39. | tidb_index_join_batch_size         | 25000        |
    40. | tidb_ddl_reorg_batch_size          | 1024         |
    41. | tidb_enable_fast_analyze           | 0            |
    42. | tidb_config                        |              |
    43. | tidb_distsql_scan_concurrency      | 15           |
    44. | tidb_hashagg_partial_concurrency   | 4            |
    45. | tidb_init_chunk_size               | 32           |
    46. | tidb_backoff_lock_fast             | 100          |
    47. | tidb_skip_utf8_check               | 0            |
    48. | tidb_hash_join_concurrency         | 5            |
    49. | tidb_index_lookup_concurrency      | 4            |
    50. | tidb_slow_log_threshold            | 300          |
    51. | tidb_index_lookup_size             | 20000        |
    52. | tidb_force_priority                | NO_PRIORITY  |
    53. | tidb_auto_analyze_start_time       | 00:00 +0000  |
    54. | tidb_mem_quota_nestedloopapply     | 34359738368  |
    55. | tidb_snapshot                      |              |
    56. | tidb_general_log                   | 0            |
    57. | tidb_batch_commit                  | 0            |
    58. | tidb_enable_radix_join             | 0            |
    59. | tidb_skip_isolation_level_check    | 0            |
    60. | tidb_auto_analyze_ratio            | 0.5          |
    61. | tidb_disable_txn_auto_retry        | 0            |
    62. | tidb_mem_quota_hashjoin            | 34359738368  |
    63. +------------------------------------+--------------+
    64. 58 rows in set (0.01 sec)
    66. mysql> SHOW GLOBAL VARIABLES LIKE 'time_zone%';
    67. +---------------+--------+
    68. | Variable_name | Value  |
    69. +---------------+--------+
    70. | time_zone     | SYSTEM |
    71. +---------------+--------+
    72. 1 row in set (0.00 sec)

    MySQL 兼容性

    SHOW [GLOBAL|SESSION] VARIABLES 语句与 MySQL 完全兼容。如有任何兼容性差异，请在 GitHub 上提交 issue。

    另请参阅

    • SET