SQL Server 2008 - 存储文件

Question

I am building a MVC3 web app against a SQL Server 2008 database. The web app will allow users to upload photos and documents.

Currently the files are stored in a column of type "image".

Is this an okay thing to do, or is it an outdated approach?

Is there any advantages in moving storage to another data type or start using FILESTREAM?

Stats - 500 (users) x 7 (avg documents each) x 2MB (avg doc size)

EDIT 1

Can anyone comment; is what I'm doing currently--storing as "image" data type--bad?

Answer 1

You should store the images on the filesystem. See this thread: Storing Images in DB - Yea or Nay?

As for the documents, are they just static files the user uploads/downloads, or will you search for content within the documents? Do you need to do anything special with the documents?

Answer 2

(Moving my comments to an answer)

From MSDN : ntext , text , and image data types will be removed in a future version of Microsoft SQL Server. Avoid using these data types in new development work, and plan to modify applications that currently use them. Use nvarchar(max), varchar(max), and varbinary(max) instead.

It's "bad" if you care about the data type's planned obsolescence. It sounds like varbinary(max) or even filestream are the preferred data types going forward.

Storing files in the database vs. file system is a separate debate that everyone else seems to be jumping on instead.

Answer 3

您可能想要在SQL SERVER 2008中查看新的FILESTREAM数据类型。阅读链接 - 它将为您提供一些指导，以确定这是否是适当的存储类型。

Answer 4

There's a really good paper by Microsoft Research called To Blob or Not To Blob .

Their conclusion after a large number of performance tests and analysis is this:

• if your pictures or document are typically below 256K in size, storing them in a database VARBINARY column is more efficient

• if your pictures or document are typically over 1 MB in size, storing them in the filesystem is more efficient (and with SQL Server 2008's FILESTREAM attribute, they're still under transactional control and part of the database)

• in between those two, it's a bit of a toss-up depending on your use

If you decide to put your pictures into a SQL Server table, I would strongly recommend using a separate table for storing those pictures - do not store the employee foto in the employee table - keep them in a separate table. That way, the Employee table can stay lean and mean and very efficient, assuming you don't always need to select the employee foto, too, as part of your queries.

For filegroups, check out Files and Filegroup Architecture for an intro. Basically, you would either create your database with a separate filegroup for large data structures right from the beginning, or add an additional filegroup later. Let's call it "LARGE_DATA".

Now, whenever you have a new table to create which needs to store VARCHAR(MAX) or VARBINARY(MAX) columns, you can specify this file group for the large data:

 CREATE TABLE dbo.YourTable
     (....... define the fields here ......)
     ON Data                   -- the basic "Data" filegroup for the regular data
     TEXTIMAGE_ON LARGE_DATA   -- the filegroup for large chunks of data

Check out the MSDN intro on filegroups, and play around with it!

Answer 5

In my experience it is better to store your files on disk and store a path to the file in your DB. This frees up your DB to focus on the stuff it should be doing rather than file storage.