我需要在现有表格中增加一个汽车编号栏,该表在2005年有约1 500万个记录。
你们是否认为它需要多少时间? 如何更好地做到这一点?
为了尽量减少影响,我将制作一个新表格,添加身份栏,从旧表格中挑选,然后删除旧表格,重新命名。 我提出以下基本大纲。 可能需要采取额外步骤处理外国钥匙等。
create table NewTable (
NewID int identity(1,1),
Column1 ...
)
go
insert into NewTable
(Column1, ...)
select Column1, ...
from OldTable
go
drop table OldTable
go
exec sp_rename NewTable , OldTable
go
确实很难说它需要多长时间。
我认为,你的最好之点是,将生产数据库复制件退回,在发展环境中恢复数据库,并在那里进行改动,以了解其需要多长时间。
从那以后,你可以协调网站的故障时间,或者在用户有线时安排更新时间。
除非发生紧急情况:
找到你需要多少时间,恢复新的非行,改变那里。
时间太长:这不仅取决于多少行,而且取决于每行有多少数据。 (SQL服务器将复制整个表格。)
您是否可选择支持生产数据库、应用另一个服务器上的变动以及改变连接线体? 你们甚至可以把它恢复在原来的服务器上,改变连接线,并删除旧的数据库。
如果磁盘空间有限,则可能不可行。
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