sql-server - 表锁定建议

Question

我想执行以下操作:

TRUNCATE TABLE Table1;
TRUNCATE TABLE Table2;

-- I do not want to allow possibly the viewing and definitely the modification 
-- of Table1 or Table2 at this point, so that I can make changes to them atomically
-- possibly even regardless of the isolation level in other sessions (or this one).

-- So, I lock both tables. I want to remove any data that could have made its way into
-- the tables, due to the current isolation level, for example, and remove any rows.
-- Also, from this point on, I want the tables to be unviewable (all queries blocked)
-- and unmodifyable (all INSERTs, UPDATEs, DELETEs blocked)
DELETE FROM Table1 WITH(TABLOCKX, HOLDLOCK);
DELETE FROM Table2 WITH(TABLOCKX, HOLDLOCK);

-- This is a long running complex INSERT operation into Table1
INSERT INTO Table1... SELECT ... 

-- This is a long running complex INSERT operation into Table2, based on the 
-- data in Table1 and some other ancillary tables
INSERT INTO Table2... SELECT ... FROM Table1... 

COMMIT;

我想阻止对表 Table1 和 Table2 的所有访问，从 TRUNCATE 命令完成到它们已完全构建，并且使用 COMMIT 提交更改。最好，即使是使用 READ_UNCOMMITTED 隔离级别的客户端，甚至是执行 NOLOCK 查询的客户端(如果可能的话)。

如有任何建议，我们将不胜感激。

Answer 1

使用分区切换。尽管人们普遍认为，分区切换并不需要对表进行分区。在临时表中准备新数据，快速切换它们并替换旧数据:

create table users (
    id int identity(1,1) primary key, 
    name char(100));
go

insert into users (name) 
    values ('A'), ('B'), ('C'), ('D');
go

select * from users;

create table staging (
    id int identity(1,1) primary key, 
    name char(100));
create table staging_empty (
    id int identity(1,1) primary key, 
    name char(100));
go

insert into staging (name) 
    values ('Z'), ('Y'), ('X');
go

begin transaction;
alter table users switch partition 1 to staging_empty;
alter table staging switch partition 1 to users;
commit
go

select * from users;
go

参见Transferring Data Efficiently by Using Partition Switching .