时间：2021-07-01 10:21:17 帮助过：1人阅读
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概述：
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★查询日志：general_log
★慢查询日志：log_slow_queries
★错误日志：log_error， log_warnings
★二进制日志：binlog
★中继日志：relay_log
★事务日志：innodb_log
日志相关的参数：
MariaDB [(none)]> SHOW VARIABLES LIKE ‘%log%‘; +-------------------------------------------+--------------------------------------------------------------------------------------------------------------+ | Variable_name | Value | +-------------------------------------------+--------------------------------------------------------------------------------------------------------------+ | aria_checkpoint_log_activity | 1048576 | | aria_log_file_size | 1073741824 | | aria_log_purge_type | immediate | | aria_sync_log_dir | NEWFILE | | back_log | 50 | | binlog_annotate_row_events | OFF | | binlog_cache_size | 32768 | | binlog_checksum | NONE | | binlog_direct_non_transactional_updates | OFF | | binlog_format | STATEMENT | | binlog_optimize_thread_scheduling | ON | | binlog_stmt_cache_size | 32768 | | expire_logs_days | 0 | | general_log | OFF | | general_log_file | centos7.log | | innodb_flush_log_at_trx_commit | 1 | | innodb_locks_unsafe_for_binlog | OFF | | innodb_log_block_size | 512 | | innodb_log_buffer_size | 8388608 | | innodb_log_file_size | 5242880 | | innodb_log_files_in_group | 2 | | innodb_log_group_home_dir | ./ | | innodb_mirrored_log_groups | 1 | | innodb_recovery_update_relay_log | OFF | | innodb_use_global_flush_log_at_trx_commit | ON | | log | OFF | | log_bin | OFF | | log_bin_trust_function_creators | OFF | | log_error | /var/log/mariadb/mariadb.log | | log_output | FILE | | log_queries_not_using_indexes | OFF | | log_slave_updates | OFF | | log_slow_filter | admin,filesort,filesort_on_disk,full_join,full_scan,query_cache,query_cache_miss,tmp_table,tmp_table_on_disk | | log_slow_queries | OFF | | log_slow_rate_limit | 1 | | log_slow_verbosity | | | log_warnings | 1 | | max_binlog_cache_size | 18446744073709547520 | | max_binlog_size | 1073741824 | | max_binlog_stmt_cache_size | 18446744073709547520 | | max_relay_log_size | 0 | | relay_log | | | relay_log_index | | | relay_log_info_file | relay-log.info | | relay_log_purge | ON | | relay_log_recovery | OFF | | relay_log_space_limit | 0 | | slow_query_log | OFF | | slow_query_log_file | centos7-slow.log | | sql_log_bin | ON | | sql_log_off | OFF | | sync_binlog | 0 | | sync_relay_log | 0 | | sync_relay_log_info | 0 | +-------------------------------------------+--------------------------------------------------------------------------------------------------------------+ 54 rows in set (0.00 sec)
★作用：
记录查询语句；
★日志存储位置：
文件：file
·general_log_file=HOSTNAME.log （主机名加log的文件）
表：table
·mysql.general_log
★相关参数：
general_log={ON|OFF} 默认是OFF
★定义输出位置
log_output={FILE|TABLE|NONE}
注意：
想要永久有效，要写到配置文件当中，但实际工作中，没有特殊要求，一般不建议开启，因为数据库查询非常多，开启会对I/O造成严重的影响。
演示：
1.开启查询日志，设定输出位置为table和file；
MariaDB [hellodb]> SET GLOBAL general_log = ON; # 开启查询日志 MariaDB [mysql]> SET GLOBAL log_output = ‘TABLE,FILE‘; # 设定输出位置为TABLE和FILE MariaDB [mysql]> SHOW VARIABLES LIKE ‘log_output‘; # 查看输出位置 +---------------+------------+ | Variable_name | Value | +---------------+------------+ | log_output | FILE,TABLE | +---------------+------------+ 1 row in set (0.01 sec) MariaDB [mysql]> SELECT @@log_output; +--------------+ | @@log_output | +--------------+ | FILE,TABLE | +--------------+ 1 row in set (0.01 sec)
2.执行查询语句，并查看表和文件是否记录相关的数据
MariaDB [hellodb]> SELECT * FROM mysql.general_log; +----------------------------+---------------------------+-----------+-----------+--------------+----------------------------------+ | event_time | user_host | thread_id | server_id | command_type | argument | +----------------------------+---------------------------+-----------+-----------+--------------+----------------------------------+ | 2016-12-01 10:45:23.715603 | root[root] @ localhost [] | 3 | 0 | Query | SELECT * FROM mysql.general_log | | 2016-12-01 10:45:28.195891 | root[root] @ localhost [] | 3 | 0 | Query | select * from students | | 2016-12-01 10:45:36.486132 | root[root] @ localhost [] | 3 | 0 | Query | SELECT @@log_output | | 2016-12-01 10:45:44.909488 | root[root] @ localhost [] | 3 | &nb