用于显示当前配置变量的 MySQL 命令?
要显示当前配置变量,可以使用 show 命令。语法如下 -
show variables;
您可以使用 LIKE 运算符进一步重写以上语法。语法如下 -
show variables like ‘%anyStringValue%’;
查询如下,显示一个示例以获取某些配置变量 -
mysql> show variables like '%max%';
输出
+------------------------------------------------------+----------------------+ | Variable_name | Value | +------------------------------------------------------+----------------------+ | binlog_max_flush_queue_time | 0 | | cte_max_recursion_depth | 1000 | | ft_max_word_len | 84 | | group_concat_max_len | 1024 | | histogram_generation_max_mem_size | 20000000 | | innodb_adaptive_max_sleep_delay | 150000 | | innodb_change_buffer_max_size | 25 | | innodb_compression_pad_pct_max | 50 | | innodb_ft_max_token_size | 84 | | innodb_io_capacity_max | 2000 | | innodb_max_dirty_pages_pct | 90.000000 | | innodb_max_dirty_pages_pct_lwm | 10.000000 | | innodb_max_purge_lag | 0 | | innodb_max_purge_lag_delay | 0 | | innodb_max_undo_log_size | 1073741824 | | innodb_online_alter_log_max_size | 134217728 | | max_allowed_packet | 4194304 | | max_binlog_cache_size | 18446744073709547520 | | max_binlog_size | 1073741824 | | max_binlog_stmt_cache_size | 18446744073709547520 | | max_connect_errors | 100 | | max_connections | 151 | | max_delayed_threads | 20 | | max_digest_length | 1024 | | max_error_count | 1024 | | max_execution_time | 0 | | max_heap_table_size | 16777216 | | max_insert_delayed_threads | 20 | | max_join_size | 18446744073709551615 | | max_length_for_sort_data | 4096 | | max_points_in_geometry | 65536 | | max_prepared_stmt_count | 16382 | | max_relay_log_size | 0 | | max_seeks_for_key | 4294967295 | | max_sort_length | 1024 | | max_sp_recursion_depth | 0 | | max_user_connections | 0 | | max_write_lock_count | 4294967295 | | myisam_max_sort_file_size | 107374182400 | | mysqlx_max_allowed_packet | 67108864 | | mysqlx_max_connections | 100 | | optimizer_trace_max_mem_size | 1048576 | | parser_max_mem_size | 18446744073709551615 | | performance_schema_max_cond_classes | 80 | | performance_schema_max_cond_instances | -1 | | performance_schema_max_digest_length | 1024 | | performance_schema_max_digest_sample_age | 60 | | performance_schema_max_file_classes | 80 | | performance_schema_max_file_handles | 32768 | | performance_schema_max_file_instances | -1 | | performance_schema_max_index_stat | -1 | | performance_schema_max_memory_classes | 450 | | performance_schema_max_metadata_locks | -1 | | performance_schema_max_mutex_classes | 300 | | performance_schema_max_mutex_instances | -1 | | performance_schema_max_prepared_statements_instances | -1 | | performance_schema_max_program_instances | -1 | | performance_schema_max_rwlock_classes | 60 | | performance_schema_max_rwlock_instances | -1 | | performance_schema_max_socket_classes | 10 | | performance_schema_max_socket_instances | -1 | | performance_schema_max_sql_text_length | 1024 | | performance_schema_max_stage_classes | 150 | | performance_schema_max_statement_classes | 212 | | performance_schema_max_statement_stack | 10 | | performance_schema_max_table_handles | -1 | | performance_schema_max_table_instances | -1 | | performance_schema_max_table_lock_stat | -1 | | performance_schema_max_thread_classes | 100 | | performance_schema_max_thread_instances | -1 | | range_optimizer_max_mem_size | 8388608 | | slave_max_allowed_packet | 1073741824 | | slave_pending_jobs_size_max | 134217728 | | temptable_max_ram | 1073741824 | +------------------------------------------------------+----------------------+ 74 rows in set (0.01 sec)
广告