sql server 学习笔记 ( backup 备份和复原方案, clear log file )

更新: 2020-11-15

log file 是会一直长大的, 直到你 backup log file, backup full database log file 还是会长大.

一般的做法是 full back -> log backup (通常需要 2 次, 才可以 shrink, 不知道原因) 然后 shrink log file. 

refer : 

https://stackoverflow.com/questions/56628/how-do-you-clear-the-sql-server-transaction-log

https://www.sqlshack.com/sql-server-transaction-log-backup-truncate-and-shrink-operations/

做个记入就好 

USE [master]

SELECT
bs.database_name AS 'Database Name',
bs.backup_start_date AS 'Backup Start',
bs.backup_finish_date AS 'Backup Finished',
DATEDIFF(MINUTE, bs.backup_start_date, bs.backup_finish_date) AS 'Duration (min)',
bmf.physical_device_name AS 'Backup File',
CASE 
    WHEN bs.[type] = 'D' THEN 'Full Backup' 
    WHEN bs.[type] = 'I' THEN 'Differential Database' 
    WHEN bs.[type] = 'L' THEN 'Log' 
    WHEN bs.[type] = 'F' THEN 'File/Filegroup' 
    WHEN bs.[type] = 'G' THEN 'Differential File'
    WHEN bs.[type] = 'P' THEN 'Partial'  
    WHEN bs.[type] = 'Q' THEN 'Differential partial' 
END
AS 'Backup Type'
FROM msdb.dbo.backupmediafamily bmf WITH(NOLOCK)
    INNER JOIN msdb..backupset bs WITH(NOLOCK)
    ON bmf.media_set_id = bs.media_set_id
WHERE bs.database_name = 'test-recovery'
ORDER BY bs.backup_start_date ASC;
 


-- note for 下次看 
-- backup 有 3 种, full, log, differential 
-- 通常是 full -> log -> log -> differential -> log -> log -> full 
-- 比如 1 天 1 个 full, 半天一个 differential, 每小时一个 log 
-- 备份的关键是, 1.恢复的时间(尽可能短) 2. 恢复的层度 (尽可能完整)
-- express, web edition 不支持 backup compression 
-- norecovery 意思是还有下一个 restore 要跑, 最后一个 restore 才 recovery 
-- refer http://mysql.taobao.org/monthly/2017/11/03/
-- refer http://mysql.taobao.org/monthly/2017/12/05/
-- stats 是显示 progress % stats 10 = 完成 10% 就显示一下 
-- init and replace 用于 full 的情况, 另外 2 个 用 noint 和不需要放 replace 
-- STOPAT 是只恢复到某事时间点停止


use [master];
use [test-recovery];
alter database [test-recovery] set recovery full with no_wait 

declare @now nvarchar(50) = REPLACE(convert(nvarchar(20),GetDate(),120),':','-');
set @now = '2018-09-02 18-16-27';
declare @type nvarchar(50) = 'full';
declare @path nvarchar(500) = 'C:Program FilesMicrosoft SQL ServerMSSQL14.SQLEXPRESSMSSQLBackup	est-recovery_'+ @now +'_' + @type +'.bak';
--backup log [test-recovery] to disk = @path with noinit,stats=10;
--backup database [test-recovery] to disk = @path with differential,init,stats=10;
--backup database [test-recovery] to disk = @path with init,stats=10;
restore database [test-recovery] from disk = @path with norecovery, replace;


INSERT INTO Products(name) VALUES ('dada');
INSERT INTO Products(name) VALUES ('yyyy');
INSERT INTO Products(name) VALUES ('zz'); 
INSERT INTO Products(name) VALUES ('gg');

 

RESTORE DATABASE [test-recovery]
FROM DISK =N'C:Program FilesMicrosoft SQL ServerMSSQL14.SQLEXPRESSMSSQLBackup	est-recovery_2018_09_02-16_17_differential.bak' WITH NORECOVERY;

RESTORE LOG [test-recovery]
FROM DISK =N'C:Program FilesMicrosoft SQL ServerMSSQL14.SQLEXPRESSMSSQLBackup	est-recovery_2018_09_02_16_18_log.bak' WITH RECOVERY;

RESTORE LOG [test-recovery]
FROM DISK = N'C:Program FilesMicrosoft SQL ServerMSSQL14.SQLEXPRESSMSSQLBackup	est-recovery_2018_09_02_16_18_log.bak' WITH STOPAT = '2017-12-17 23:04:46.130', RECOVERY