备份和恢复数据
使用 COPY 命令 来备份和恢复数据。
备份表
将表 monitor 以 parquet 格式备份到文件 /home/backup/monitor/monitor.parquet：
sql
COPY monitor TO '/home/backup/monitor/monitor.parquet' WITH (FORMAT = 'parquet');COPY monitor TO '/home/backup/monitor/monitor.parquet' WITH (FORMAT = 'parquet');备份指定时间范围内的数据：
sql
COPY monitor TO '/home/backup/monitor/monitor_20240518.parquet' WITH (FORMAT = 'parquet', START_TIME='2024-05-18 00:00:00', END_TIME='2025-05-19 00:00:00');COPY monitor TO '/home/backup/monitor/monitor_20240518.parquet' WITH (FORMAT = 'parquet', START_TIME='2024-05-18 00:00:00', END_TIME='2025-05-19 00:00:00');上述命令将导出 2024-05-18 的数据。可以使用此命令实现增量备份。
恢复表
恢复 monitor 表：
sql
COPY monitor FROM '/home/backup/monitor/monitor.parquet' WITH (FORMAT = 'parquet');COPY monitor FROM '/home/backup/monitor/monitor.parquet' WITH (FORMAT = 'parquet');如果每次增量导出数据，所有文件在同一文件夹下但文件名不同，可以使用 PATTERN 选项选中并恢复它们：
sql
COPY monitor FROM '/home/backup/monitor/' WITH (FORMAT = 'parquet', PATTERN = '.*parquet');COPY monitor FROM '/home/backup/monitor/' WITH (FORMAT = 'parquet', PATTERN = '.*parquet');备份和恢复数据库
和表的命令类似：
sql
-- 备份数据库 public --
COPY DATABASE public TO '/home/backup/public/' WITH (FORMAT='parquet');
-- 恢复数据库 public --
COPY DATABASE public FROM '/home/backup/public/' WITH (FORMAT='parquet');-- 备份数据库 public --
COPY DATABASE public TO '/home/backup/public/' WITH (FORMAT='parquet');
-- 恢复数据库 public --
COPY DATABASE public FROM '/home/backup/public/' WITH (FORMAT='parquet');导出后，查看文件夹 /home/backup/public/，该命令将每个表导出为单独的文件。