Optimized attachments in vB2.X.X

Hi vB Troopers,

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* Hack Idea:
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This hack is designed to improve 2 things:
1. Prevent duplicate attachments altogether.
2. Speed up the query for duplicates and avoid errors.

What does vB do now?
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If you have "Allow Duplicate Images" set to "No" in your attachments options and your database has a very large amount of attachments, at worst, the server will timeout or the query to check for duplicate attachments takes an extreme amount of time. The duplicates query also checks only for duplicates from a particular user so actually it is possible to have duplicate attachments in the database.

What does vB do differently after the hack?
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With the hack installed, each attachment receives a hash which is stored in the attachment table. This hash is then used to find duplicate attachments regardless of whether or not the attachment is from the same user or not. So duplicate attachments are not possible.

Why vB works faster with this hack?
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Since the hash field and not the actual file content is being compared, then much less server resources are needed for MySql to run the query. Also the hash field is indexed. This in turn speeds up the saving of the attachments when checking for duplicates.

Please be aware that this hack alters the database and when carried out incorrectly, could cause data loss. Installation is at your own risk.

That said, enjoy!

Scott

This hack was written by pogo.

Also note, a system similiar to this will be part of vB3, so no need to ask if it will be added.

[s.molinari]

Hi,

Newest version is up. This time in english.

Scott

[TranceMaster]

Originally posted by Boofo
What was causing your problem? Just curious.

there seemed to be duplicate hash indexes in the database.
so i just removed them
and everything seemed to work.

[TheComputerGuy]

great hack.. will install tonight.

[gmarik]

I hope it works from 2.3 -> 3.0 RC2