mysql information_schema tables update_time

2023-07-24

mysql information_schema tables update_time  阅读全文...

discovery.seed_hosts

2023-07-18

java.lang.IllegalArgumentException: unknown setting [discovery.zen.ping.unicast.hosts] please check that any required plugins are installed, or check the breaking changes documentation for removed settings  阅读全文...

purge_relay_logs

2023-07-12

1 [root@localhost ~]# yum -y install epel-release
[root@localhost ~]#yum install -y perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-ExtUtils-CBuilder perl-ExtUtils-MakeMaker perl-CPAN  阅读全文...

mariadb vs mysql

2023-04-24

Mariadb的10.6, 10.7, 10.8, 10.9, 10.10对应MySQL 8  阅读全文...

mongo查询某列

2022-07-06

DBQuery.shellBatchSize = 300  阅读全文...

mongodb 6.0 增加密码认证

2022-06-19

在启动认证前,先创建管理员用户,以防切换开启认证后无法登录;admin数据库创建需要的角色权限以方便对数据库进行管理,第一个创建的用户必须在admin库中创建。  阅读全文...

flashback table t1 to before drop;

2022-05-26

1、select 'drop table '||tname||';' from tab;
drop table t1;
2、flashback table t1 to before drop;  阅读全文...

mysql批量drop table

2021-12-07

SELECT concat('DROP TABLE IF EXISTS ', table_name, ';') FROM information_schema.tables WHERE table_schema = 'dbdb';  阅读全文...

阿里云oss云存储ossutil工具

2021-11-23

ossfs挂载当磁盘rsync时候非常卡,替换ossutil工具  阅读全文...

alter index rebuild online

2021-11-06

rebuild index online不阻塞DML操作,这是相对于rebuild index来说的,加上了online,只是在rebuild的期间不阻塞DML,但是在开始和结束阶段还是可能阻塞其他进程的DML的,系统负载飙升,甚至宕机。10G rebuild index online 会锁表  阅读全文...

oracle ALTER INDEX RENAME TO

2021-11-06

ALTER INDEX [schema.]index RENAME TO ;   阅读全文...

oracle出现错误提示:ORA-28000: the account is locked。

2021-11-01

出现错误提示:ORA-28000: the account is locked。  阅读全文...

mysql从ibd文件恢复数据

2021-10-30

数据库冷备份无法启动,但是有无数个idb表文件  阅读全文...

fuser查询文件被哪个进程占用

2021-10-29

1、linux umount分区时候:
umount: /data4: target is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))  阅读全文...

zabbix MEMORY.UTIL.MAX

2021-10-28

MEMORY.UTIL.MAX 90% 修改为95%  阅读全文...