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. SHOW GLOBAL VARIABLES LIKE 'tidb%';
  1. +-------------------------------------+---------------+
  2. | Variable_name                       | Value         |
  3. +-------------------------------------+---------------+
  4. | tidb_retry_limit                    | 10            |
  5. | tidb_enable_streaming               | 0             |
  6. | tidb_hashagg_final_concurrency      | 4             |
  7. | tidb_disable_txn_auto_retry         | 1             |
  8. | tidb_mem_quota_query                | 34359738368   |
  9. | tidb_skip_isolation_level_check     | 0             |
  10. | tidb_ddl_reorg_batch_size           | 1024          |
  11. | tidb_constraint_check_in_place      | 0             |
  12. | tidb_current_ts                     | 0             |
  13. | tidb_opt_insubq_to_join_and_agg     | 1             |
  14. | tidb_enable_window_function         | 1             |
  15. | tidb_ddl_error_count_limit          | 512           |
  16. | tidb_checksum_table_concurrency     | 4             |
  17. | tidb_config                         |               |
  18. | tidb_batch_insert                   | 0             |
  19. | tidb_opt_join_reorder_threshold     | 0             |
  20. | tidb_auto_analyze_end_time          | 23:59 +0000   |
  21. | tidb_index_lookup_size              | 20000         |
  22. | tidb_projection_concurrency         | 4             |
  23. | tidb_opt_correlation_threshold      | 0.9           |
  24. | tidb_enable_table_partition         | auto          |
  25. | tidb_wait_split_region_timeout      | 300           |
  26. | tidb_skip_utf8_check                | 0             |
  27. | tidb_dml_batch_size                 | 20000         |
  28. | tidb_backoff_weight                 | 2             |
  29. | tidb_txn_mode                       |               |
  30. | tidb_mem_quota_indexlookupjoin      | 34359738368   |
  31. | tidb_hashagg_partial_concurrency    | 4             |
  32. | tidb_enable_radix_join              | 0             |
  33. | tidb_mem_quota_topn                 | 34359738368   |
  34. | tidb_hash_join_concurrency          | 5             |
  35. | tidb_max_chunk_size                 | 1024          |
  36. | tidb_mem_quota_indexlookupreader    | 34359738368   |
  37. | tidb_expensive_query_time_threshold | 60            |
  38. | tidb_enable_cascades_planner        | 0             |
  39. | tidb_mem_quota_mergejoin            | 34359738368   |
  40. | tidb_auto_analyze_ratio             | 0.5           |
  41. | tidb_index_lookup_concurrency       | 4             |
  42. | tidb_force_priority                 | NO_PRIORITY   |
  43. | tidb_ddl_reorg_priority             | PRIORITY_LOW  |
  44. | tidb_index_lookup_join_concurrency  | 4             |
  45. | tidb_index_join_batch_size          | 25000         |
  46. | tidb_index_serial_scan_concurrency  | 1             |
  47. | tidb_mem_quota_nestedloopapply      | 34359738368   |
  48. | tidb_auto_analyze_start_time        | 00:00 +0000   |
  49. | tidb_snapshot                       |               |
  50. | tidb_low_resolution_tso             | 0             |
  51. | tidb_batch_commit                   | 0             |
  52. | tidb_init_chunk_size                | 32            |
  53. | tidb_build_stats_concurrency        | 4             |
  54. | tidb_backoff_lock_fast              | 100           |
  55. | tidb_optimizer_selectivity_level    | 0             |
  56. | tidb_batch_delete                   | 0             |
  57. | tidb_distsql_scan_concurrency       | 15            |
  58. | tidb_scatter_region                 | 0             |
  59. | tidb_opt_correlation_exp_factor     | 1             |
  60. | tidb_ddl_reorg_worker_cnt           | 16            |
  61. | tidb_wait_split_region_finish       | 1             |
  62. | tidb_mem_quota_sort                 | 34359738368   |
  63. | tidb_general_log                    | 0             |
  64. | tidb_opt_write_row_id               | 0             |
  65. | tidb_check_mb4_value_in_utf8        | 1             |
  66. | tidb_enable_fast_analyze            | 0             |
  67. | tidb_slow_query_file                | tidb-slow.log |
  68. | tidb_slow_log_threshold             | 300           |
  69. | tidb_opt_agg_push_down              | 0             |
  70. | tidb_mem_quota_hashjoin             | 34359738368   |
  71. | tidb_query_log_max_len              | 2048          |
  72. +-------------------------------------+---------------+
  73. 68 rows in set (0.01 sec)
  1. SHOW GLOBAL VARIABLES LIKE 'time_zone%';
  1. +---------------+--------+
  2. | Variable_name | Value  |
  3. +---------------+--------+
  4. | time_zone     | SYSTEM |
  5. +---------------+--------+
  6. 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