Make a "normal" table as temporal table - sql-server

Question

I have a table created like this:
CREATE TABLE address_user
(
[username] VARCHAR(13) NOT NULL,
[address] CHAR(58) NOT NULL,
[id] BIGINT NOT NULL,
CONSTRAINT [PK_ address_user]
PRIMARY KEY CLUSTERED ([id] ASC)
);
Now I want to be able to keep the history modification of this table, so I want to make it as temporal table. I know the script to create a temporal table, the final result should be:
CREATE TABLE address_user
(
[username] VARCHAR(13) NOT NULL,
[address] CHAR(58) NOT NULL,
[id] BIGINT NOT NULL,
[sys_start_time] DATETIME2(7)
GENERATED ALWAYS AS ROW START HIDDEN NOT NULL,
[sys_end_time] DATETIME2 (7)
GENERATED ALWAYS AS ROW END HIDDEN NOT NULL,
PERIOD FOR SYSTEM_TIME ([sys_start_time], [sys_end_time]),
CONSTRAINT [PK_ address_user]
PRIMARY KEY CLUSTERED ([id] ASC)
)
WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE=[dbo].[address_user_history], DATA_CONSISTENCY_CHECK=ON));
The easy way to do that is just delete the previous table, and recreate the table with the good schema.
However, I have a lot of information in my table, save the data and delete the table, recreate it and re-insert the data make me uncomfortable.
So if you have a solution to transform the first table in temporal table without the need to delete everything and recreate it, it should be a great help!

Answer 1

Create the new table address_user_new, insert the data, then use sp_rename to rename address_user to address_user_old and address_user_new to address_user. This can all be done in a transaction to ensure ensure that the transition is atomic and apparently-instantaneous. eg
if object_id('address_user') is not null
ALTER TABLE address_user SET ( SYSTEM_VERSIONING = OFF)
go
if object_id('address_user_new') is not null
ALTER TABLE address_user_new SET ( SYSTEM_VERSIONING = OFF)
go
drop table if exists address_user
drop table if exists address_user_history
drop table if exists address_user_new
drop table if exists address_user_old
go
CREATE TABLE address_user
(
[username] VARCHAR(13) NOT NULL,
[address] CHAR(58) NOT NULL,
[id] BIGINT NOT NULL,
CONSTRAINT [PK_address_user]
PRIMARY KEY CLUSTERED ([id] ASC)
);
go
CREATE TABLE address_user_new
(
[username] VARCHAR(13) NOT NULL,
[address] CHAR(58) NOT NULL,
[id] BIGINT NOT NULL,
[sys_start_time] DATETIME2(7)
GENERATED ALWAYS AS ROW START HIDDEN NOT NULL,
[sys_end_time] DATETIME2 (7)
GENERATED ALWAYS AS ROW END HIDDEN NOT NULL,
PERIOD FOR SYSTEM_TIME ([sys_start_time], [sys_end_time]),
CONSTRAINT [PK_address_user_new]
PRIMARY KEY CLUSTERED ([id] ASC)
)
WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE=[dbo].[address_user_history], DATA_CONSISTENCY_CHECK=ON));
go
set xact_abort on
begin transaction
insert into address_user_new(username,address,id)
select username,address,id
from address_user with (tablockx)
exec sp_rename 'address_user', 'address_user_old', 'OBJECT'
exec sp_rename 'PK_address_user', 'PK_address_user_old', 'OBJECT'
exec sp_rename 'address_user_new', 'address_user', 'OBJECT'
exec sp_rename 'PK_address_user_new', 'PK_address_user', 'OBJECT'
commit transaction