这里是一个完整的脚本,显示100万只需要10万次,只要10万次。你的情况可能略有不同,但这表明基本面不是问题。
结果显示100,000条记录需要146毫秒,1,000,000条记录需要1315毫秒。
这些结果来自我的电脑桌面。如果其他人可以运行该脚本并发布其结果,那将非常有用。
罗布
USE master;
GO
-- Drop database SourceDB
IF EXISTS (SELECT * FROM sys.databases WHERE name = 'SourceDB') ALTER DATABASE SourceDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
IF EXISTS (SELECT * FROM sys.databases WHERE name = 'SourceDB') DROP DATABASE SourceDB;
GO
-- Create database SourceDB
CREATE DATABASE SourceDB;
ALTER DATABASE SourceDB SET RECOVERY SIMPLE;
GO
USE SourceDB;
GO
-- Create table SourceDB.dbo.SourceTable
CREATE TABLE dbo.SourceTable (
ColID int PRIMARY KEY
);
GO
-- Populate table SourceDB.dbo.SourceTable
DECLARE @i int = 0;
WHILE @i < 1300000
BEGIN
SET @i += 1;
INSERT INTO dbo.SourceTable (ColID) VALUES (@i);
END;
GO
-- Drop database Test1
IF EXISTS (SELECT * FROM sys.databases WHERE name = 'Test1') ALTER DATABASE Test1 SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
IF EXISTS (SELECT * FROM sys.databases WHERE name = 'Test1') DROP DATABASE Test1;
GO
-- Create database Test1
CREATE DATABASE Test1;
ALTER DATABASE Test1 SET RECOVERY SIMPLE;
ALTER DATABASE Test1 MODIFY FILE (NAME = Test1, SIZE = 3000MB, MAXSIZE = 8TB);
ALTER DATABASE Test1 MODIFY FILE (NAME = Test1_log, SIZE = 3000MB, MAXSIZE = 2TB);
GO
USE Test1;
GO
IF EXISTS (SELECT * FROM sys.tables WHERE [OBJECT_ID] = OBJECT_ID('dbo.DestinationTable1')) DROP TABLE dbo.DestinationTable1;
IF EXISTS (SELECT * FROM sys.tables WHERE [OBJECT_ID] = OBJECT_ID('dbo.DestinationTable2')) DROP TABLE dbo.DestinationTable2;
GO
DECLARE @n int = 100000;
DECLARE @t1 datetime2 = SYSDATETIME();
SELECT TOP (@n) db_id = IDENTITY(int, 1, 1), *
INTO dbo.DestinationTable1
FROM SourceDB.dbo.SourceTable;
SELECT DATEDIFF(ms, @t1, SYSDATETIME()) AS ElapsedMs;
GO
DECLARE @n int = 1000000;
DECLARE @t1 datetime2 = SYSDATETIME();
SELECT TOP (@n) db_id = IDENTITY(int, 1, 1), *
INTO dbo.DestinationTable2
FROM SourceDB.dbo.SourceTable;
SELECT DATEDIFF(ms, @t1, SYSDATETIME()) AS ElapsedMs;
GO
您确定SQL Server不只是忙于扩展.mdf或.ldf吗? – Filburt 2012-03-23 10:15:21
嗯,那么为什么(例如)从.bak文件中恢复GB级备份的速度要快于此时的全部磁盘空间分配? – cdbeelala89 2012-03-23 10:22:30
因为如果您将自动展开设置为百分比而不是固定数量,它将不断地忙于分配更多空间。在恢复(通过现有的)数据库时,所需的大小已知,可以一次分配。 – Filburt 2012-03-23 10:25:50