clickhouse 备份与还原

网上找了找备份还原的方法，实践如下

clickhouse-client -udefault --password netjoy1234 -h127.0.0.1 --query="select * from netjoytest1.tank1 FORMAT CSV" > /home/tidb/ck_bak/1.csv 

clickhouse-client -udefault --password netjoy1234 -h127.0.0.1 --query="insert into netjoytest1.tank2 FORMAT CSV" < /home/tidb/ck_bak/1.csv 

[tidb@testjian ck_bak]$ cat 1.csv
2,"tank",0,"2021-08-23 14:21:30"
3,"tank",0,"2021-08-23 14:21:30"
4,"tank",0,"2021-08-23 14:21:30"

clickhouse-client -udefault --password netjoy1234 -h127.0.0.1 --query="select * from netjoytest1.tank1 " > /home/tidb/ck_bak/1.txt
clickhouse-client -udefault --password netjoy1234 -h127.0.0.1 --query="insert into netjoytest1.tank2 FORMAT TabSeparated" < /home/tidb/ck_bak/1.txt

[tidb@testjian ck_bak]$ cat 1.txt
2	tank	0	2021-08-23 14:21:30
3	tank	0	2021-08-23 14:21:30
4	tank	0	2021-08-23 14:21:30

这二个方法是一样的。缺点如下：

1，备份，还原单一，不能到库只能到表

2，如果单表太大，例如4亿的数据量，导出50多个G，上面的方式估计实现不了。