是的,这会带来一些负面影响:
如果您脚本化一个被此标志阻止的更改,您将得到以下脚本(我只是将Contact表中的ID列转换为自动编号的IDENTITY列,但该表具有依赖关系)。
请注意以下可能发生的错误:
- 即使微软也警告这可能导致数据丢失(该注释是自动生成的)!
- 在一段时间内,外键不会被强制执行。
- 如果您在ssms中手动运行并且 ' EXEC('INSERT INTO '失败,然后让以下语句运行(它们默认情况下通过'go'分隔),则会插入0行,然后删除旧表。
- 如果这是一个大表,插入的运行时间可能很长,并且事务正在持有模式修改锁,因此会阻塞许多事情。
--
BEGIN TRANSACTION
GO
ALTER TABLE raw.Contact
DROP CONSTRAINT fk_Contact_AddressType
GO
ALTER TABLE ref.ContactpointType SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.Contact
DROP CONSTRAINT fk_contact_profile
GO
ALTER TABLE raw.Profile SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
CREATE TABLE raw.Tmp_Contact
(
ContactID int NOT NULL IDENTITY (1, 1),
ProfileID int NOT NULL,
AddressType char(2) NOT NULL,
ContactText varchar(250) NULL
) ON [PRIMARY]
GO
ALTER TABLE raw.Tmp_Contact SET (LOCK_ESCALATION = TABLE)
GO
SET IDENTITY_INSERT raw.Tmp_Contact ON
GO
IF EXISTS(SELECT * FROM raw.Contact)
EXEC('INSERT INTO raw.Tmp_Contact (ContactID, ProfileID, AddressType, ContactText)
SELECT ContactID, ProfileID, AddressType, ContactText FROM raw.Contact WITH (HOLDLOCK TABLOCKX)')
GO
SET IDENTITY_INSERT raw.Tmp_Contact OFF
GO
ALTER TABLE raw.PostalAddress
DROP CONSTRAINT fk_AddressProfile
GO
ALTER TABLE raw.MarketingFlag
DROP CONSTRAINT fk_marketingflag_contact
GO
ALTER TABLE raw.Phones
DROP CONSTRAINT fk_phones_contact
GO
DROP TABLE raw.Contact
GO
EXECUTE sp_rename N'raw.Tmp_Contact', N'Contact', 'OBJECT'
GO
ALTER TABLE raw.Contact ADD CONSTRAINT
Idx_Contact_1 PRIMARY KEY CLUSTERED
(
ProfileID,
ContactID
)
GO
ALTER TABLE raw.Contact ADD CONSTRAINT
Idx_Contact UNIQUE NONCLUSTERED
(
ProfileID,
ContactID
)
GO
CREATE NONCLUSTERED INDEX idx_Contact_0 ON raw.Contact
(
AddressType
)
GO
ALTER TABLE raw.Contact ADD CONSTRAINT
fk_contact_profile FOREIGN KEY
(
ProfileID
) REFERENCES raw.Profile
(
ProfileID
) ON UPDATE NO ACTION
ON DELETE NO ACTION
GO
ALTER TABLE raw.Contact ADD CONSTRAINT
fk_Contact_AddressType FOREIGN KEY
(
AddressType
) REFERENCES ref.ContactpointType
(
ContactPointTypeCode
) ON UPDATE NO ACTION
ON DELETE NO ACTION
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.Phones ADD CONSTRAINT
fk_phones_contact FOREIGN KEY
(
ProfileID,
PhoneID
) REFERENCES raw.Contact
(
ProfileID,
ContactID
) ON UPDATE NO ACTION
ON DELETE NO ACTION
GO
ALTER TABLE raw.Phones SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.MarketingFlag ADD CONSTRAINT
fk_marketingflag_contact FOREIGN KEY
(
ProfileID,
ContactID
) REFERENCES raw.Contact
(
ProfileID,
ContactID
) ON UPDATE NO ACTION
ON DELETE NO ACTION
GO
ALTER TABLE raw.MarketingFlag SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.PostalAddress ADD CONSTRAINT
fk_AddressProfile FOREIGN KEY
(
ProfileID,
AddressID
) REFERENCES raw.Contact
(
ProfileID,
ContactID
) ON UPDATE NO ACTION
ON DELETE NO ACTION
GO
ALTER TABLE raw.PostalAddress SET (LOCK_ESCALATION = TABLE)
GO
COMMIT