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Posted by NC on 01/09/08 03:55
On Jan 8, 8:56 am, missmoo <mor...@gmail.com> wrote:
>
> I would like to know what the differences are in terms of security,
> reliability and resources between storing user-uploaded images in a
> file or storing them in a mySQL database.
The only significant difference is the DB server load. Since <img
data="*"> tags are not (yet?) commonly supported by browsers, you need
a separate instance of an image display script (and a separate
connection to the DB server) to display each image. So if your Web
page has 100 images on it, it will require 101 nearly simultaneous
connections to display itself and the images, as opposed to one
connection if images were stored in the file system. Granted, image
retrieval connections would be very short, but at high loads, this
architecture would be patently inferior to disk-based alternative.
Also, if you use MyISAM tables, storing large images in them will
bring you to the limit of table file size much more quickly. If your
average image is 1 MB and your file system's maximum file size is 2 GB
(there are still some older Linux servers whose file systems have this
constraint), you will only be able to store about 2,000 images until
your table exceeds the maximum allowed file size.
Additionally, you'll need to make sure that your MySQL server is
configured with a packet size large enough to transmit the entire
record, including the image. Up to MySQL 3.23, this limit was 16MB
for MyISAM tables. As of MySQL 4.0, situation changed; the effective
maximum length of LONGBLOB is determined by maximum packet size and
available memory.
> Our company is starting an image-competition soon, and I am not sure
> if I should write the php script to insert the binary code into a
> mySQL database or if I should just store the files in a dedicated
> folder and the data about them in the mySQL database.
Large image sharing sites invariably stick to the second approach.
Moreover, images may be stored on separate servers, optimized for
serving static content.
I answered a similar question here a few months ago, take a look:
http://groups.google.com/group/comp.lang.php/msg/e44b33db1a37543b
> Which system should I use? Is there a real difference between the two?
Only at high loads...
Cheers,
NC
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