为什么.mdb的大小会在小图像的情况下增长三倍？ [英] Why size of .mdb growing three times with small image?

问题描述

我在Access 2010中创建了几个表单，并在标题表单中添加了公司徽标。这张照片是.jpg，大小是70KB。我不知道为什么.mdb的大小会立即从4MB增加到12MB？ （几种形式和相同的标识）也许有一些图像压缩选项？

I made few forms in Access 2010 and I add logo of company to the header form. This picture is .jpg and size of it is 70KB. I don't know why size of .mdb immediately increased from 4MB to 12MB? (few forms and the same logo) Maybe there is some options of image compression ?

推荐答案

取自 http://office.microsoft.com/en-us /access-help/store-images-in-a-database-HP005280225.aspx

...但是，嵌入图像会迅速膨胀你的
数据库的大小并导致它运行缓慢。如果
存储GIF和JPEG文件，尤其如此，因为OLE会创建包含显示的额外位图文件
每个图像文件的信息，以及
这些附加文件可能比原始图像大。在
另外，此方法仅支持Windows位图（.bmp）和
设备独立位图（.dib）图形文件格式。如果你想要
显示其他常见类型的图像文件，比如GIF和JPEG
图像，你要哈哈我要安装其他软件。...

..."However, embedding images can rapidly inflate the size of your database and cause it to run slowly. This is especially true if you store GIF and JPEG files, because OLE creates additional bitmap files that contain display information for each of your image files, and those additional files can be larger than your original images. In addition, this method only supports the Windows Bitmap (.bmp) and Device Independent Bitmap (.dib) graphic file formats. If you want to display other common types of image files, such as GIF and JPEG images, you have to install additional software."...

为了解释这些位图文件的存储方式，下面的链接提供了比微软网站：

To explain how these bitmap files are stored, the link below offers more explanation than the microsoft site:

取自 http ：//www.ammara.com/support/kb/showkbe5cc.html

...OLE Linking&嵌入是Microsoft Access在数据库表中使用
存储'对象'的技术。该技术依赖于
关联的外部应用程序来存储，显示和编辑数据。
在某些情况下，表中还会保存额外的未压缩预览图像
（即使在链接时）。此预览图像用于
更快地显示数据，或者当服务器应用程序不是
可用时。这可能会导致巨大的开销。如果您正在存储jpeg
图像，则未压缩的预览可能是实际
图像大小的十倍或二十倍，导致数据库的大小发生火箭。...

..."OLE Linking & Embedding is a technique used by Microsoft Access to store 'Objects' in database tables.The technique relies on the associated external application to store, present and edit the data. In some cases an additional uncompressed 'preview' image is also saved in the table (even when linking). This preview image is used for faster display of the data, or when the server application isn't available. This can cause a massive overhead. If you're storing jpeg images the uncompressed preview can be ten or twenty times the actual image size, causing the size of the database to rocket."...

因此，当您将图像拖放到MS Access中的表单上时，未压缩的图像数据将保存到系统表中。这是实际的未压缩表数据，因此是紧凑的修复可能提供的帮助很少。

So, when you drop an image onto a form in MS Access, uncompressed image data is saved to the system tables. This is actual uncompressed table data, so a compact and repair may offer little help.

常见的解决方法似乎是在数据库表中存储图像的路径，并使用该路径调用表单上的图像。

The common workaround seems to be store the path to the image in a database table, and use that path to invoke the image on the form.

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