SQLServer理解copyonly备份操作

Always在添加数据库的过程中如果同步首选项选择的是“完整”，那么就会在主副本上执行copyonly的完整备份和日志备份在辅助副本上执行还原操作，也正是这个操作让我对copyonly有了新的理解。接下来详细介绍copyonly的操作

一、备份测试

CREATE DATABASE city;
GO
CREATE TABLE city.dbo.test(id INT);

---执行完整备份
BACKUP DATABASE [city] TO  DISK = N'D:\backup\city_full_20170613.bak' WITH NOFORMAT, NOINIT,  NAME = N'city-完整 数据库 备份', SKIP, NOREWIND, NOUNLOAD,  STATS = 10
GO

--插入1条记录
INSERT INTO city.dbo.test VALUES(1);

--执行日志备份1
BACKUP LOG [city] TO  DISK = N'D:\backup\city_log1_20170613.trn' WITH NOFORMAT, NOINIT,  NAME = N'city-日志备份1 备份', SKIP, NOREWIND, NOUNLOAD,  STATS = 10
GO

INSERT INTO city.dbo.test VALUES(2);
GO

--执行完整copy only备份
BACKUP DATABASE [city] TO  DISK = N'D:\backup\city_full_copyonly_20170613.bak' WITH  COPY_ONLY, NOFORMAT, NOINIT,  NAME = N'city-完整copyonly 数据库 备份', SKIP, NOREWIND, NOUNLOAD,  STATS = 10
GO

INSERT INTO city.dbo.test VALUES(3);

--执行差异备份
BACKUP DATABASE [city] TO  DISK = N'D:\backup\city_diff_20170613.bak' WITH  DIFFERENTIAL , NOFORMAT, NOINIT,  NAME = N'city-差异 数据库 备份', SKIP, NOREWIND, NOUNLOAD,  STATS = 10
GO

INSERT INTO city.dbo.test VALUES(4);

GO
--执行日志备份2
BACKUP LOG [city] TO  DISK = N'D:\backup\city_log2_20170613.trn' WITH NOFORMAT, NOINIT,  NAME = N'city-日志备份2 备份', SKIP, NOREWIND, NOUNLOAD,  STATS = 10
GO

二、查询备份

SELECT 
bs.database_name,
bs.name AS BackupName,
bs.first_lsn,--备份集中最早的一条日志记录的日志序列号
bs.last_lsn, --备份集下一条日志记录的日志序列号
bs.database_backup_lsn, --最近的数据库完整备份的日志序列号
bs.checkpoint_lsn,  --重做日志开始的日志序列号
bs.is_copy_only,
CASE bs.type WHEN 'D' THEN 'FullBack' WHEN 'L' THEN 'LogBack' WHEN 'I' THEN 'DiffBack' ELSE  bs.type END AS BackupType,
bs.backup_start_date,
bs.backup_finish_date,
bs.backup_size,
bs.recovery_model
FROM msdb.dbo.backupset bs 
--INNER JOIN msdb.dbo.backupfile bf ON bs.backup_set_id=bf.backup_set_id
WHERE bs.database_name='city'