[Owncloud] Commiting Oracle support tomorrow, beware of SQL without escaped identifiers

[Frank Karlitschek]

On 26.08.2012, at 02:02, Thomas Müller <thomas.mueller at tmit.eu> wrote:

> Hi,
> 
> due to the big impact Oracle has on the ownCloud code and the pretty high risk
> to screw up the system (which is actually the case - git master is unusable).
> 
> I'd like to vote for a revert of the change in the current state of the release cycle.
> Last week MTGap and members of the community started to test 4.5 especially
> with the focus on the new sharing features. Putting another big change set on top
> will actually kill all the testing effort.
> 
> I simply think the risk is to high to introduce bug which will give us headaches.
> 
> In addition to that I'd like to ask the community's opinion on ownCloud supporting 
> Oracle database. My point of view is pretty clear - which is a non-business point of view:
>    I don't need it - I don't want it - I don't want to maintain it!
> 
> As soon as some more elaborate database layer is in place (e.g. doctrine) and 
> the impact of the database management systems on the code are minimal I don't 
> care which databases are supported, but until that point let us stick with our 3 
> databases for now - it's already a hell of testing!

I agree with you in general. I don´t like Oracle either.
The thing is that we have requests for supporting it from users and customers so we have to do it.
I don´t think it´s a good idea to try to keep this in a separate branch because this would
make the testing really difficult and longtime support close to impossible.

Oracle support is already working and we have 4 weeks left to fix remaining small problems.

What do you think?


Frank



> 
> 
> Take care,
> 
> Tom aka DeepDiver
> 
> 
> Am Freitag, dem 24.08.2012 um 19:31 schrieb Jörn Friedrich Dreyer:
>> I am currently merging master into my personal stable4-oracle branch and
>> will commit oracle support tomorrow. This will allow us to give the
>> implementation a lot of testing before owncloud customers will be using
>> it in production.
>> 
>> On the bad side I had to make changes to ALL SQL statements.
>> On the good side the changes are consistent and leave no room for
>> exceptions:
>> 1. Escape every identifier with backticks ('SELECT user' ... becomes
>> 'SELECT `user`)
>> 2. Move LIMIT & OFFSET SQL to a parameter for OC_DB::prepare()
>> 3. Disable using PDO for oracle.
>> 
>> Why:
>> 1. In contrast to mysql, postgrasql and sqlite oracle uppercases
>> unescaped identifiers. This leads to a ton of nameclashes with 'user',
>> 'uid', 'gid' and others, so escaping them is the right way.
>> 2. oracle does not know limit and offset, which is why mdb2 also
>> provides limit and offset parameters to add the necessary SQL or a
>> workaround for oracle.
>> 3. PDO for oracle is unstable and in general a PITA to set up.
>> 
>> If you want to help testing with oracle suport, there is an express
>> version free of charge limited to 18GB of data and one CPU:
>> http://www.oracle.com/technetwork/products/express-edition/downloads/index.html
>> 
>> +1 for introducing doctrine
>> 
>> so long
>> 
>> Jörn
>> 
>> -- 
>> Jörn Friedrich Dreyer (jfd at owncloud.com)
>> Software Developer
>> ownCloud GmbH
>> 
>> Your Data, Your Cloud, Your Way!
>> 
>> ownCloud GmbH, GF: Markus Rex, Holger Dyroff
>> Schloßäckerstrasse 26a, 90443 Nürnberg, HRB 28050 (AG Nürnberg)
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