白雪公主

1. 备份日志， 避免日志过快增长 no_log / trancate_only


BACKUP LOG realnew_DATA WITH NO_LOG
DBCC SHRINKDATABASE(realnew_DATA ,TRUNCATEONLY)
BACKUP LOG realnew_DATA WITH Truncate_ONLY

BACKUP LOG sjyh WITH NO_LOG
DBCC SHRINKDATABASE(sjyh,TRUNCATEONLY)
BACKUP LOG sjyh WITH Truncate_ONLY





2. 维持历史库数据表中的记录不超过5000条， 并将实时库中数据插入历史库

(1) 使用存储过程 －－作业


CREATE procedure insert_calHistory as

if ((select count(tag_id) from CalcOUT_1_HIS)>3000)
begin
delete from CalcOUT_1_HIS where tag_id in
(select top 500 tag_id from CalcOUT_1_HIS order by tag_id)
end
insert into CalcOUT_1_HIS select * from CalcOUT_1_REAL

go




然后，添加作业

调度：每天每隔3分钟执行一次


SQL: exec insert_calHistory




(2) 使用触发器－－针对表一级的


CREATE TRIGGER deleterecord ON [dbo].[testtrigger]
after INSERT
AS
IF
(SELECT COUNT(*) FROM testtrigger) >5000
BEGIN
DELETE FROM testtrigger where id not in
( select top 300 id from testtrigger order by id desc)
END