Oracle Indexing

See below for a good article on the various types of indexes available in Oracle.

Oracle Indexing

Extending Django CMS Page Model

A very useful article suggesting a method by which custom properties can be applied to a page:

Extending Django CMS Page Model

It just goes to show how easy it is to extend Django CMS :)

Please note, as advised in the follow-up article, the custom properties are not automatically available in the menu, since menu items are instances of NavigationNode not Page. The follow-up article suggests a solution for this, but there is a proviso - it is quite inefficient from an SQL perspective, although this could be mitigated somewhat through diligent caching.

Creating a custom 404 page in Django CMS

The default 404 (page not found) response outputs the 404.html file in your application templates directory. But what if you want something a bit more user-friendly? You can override the default 404 handler in urls.py:

handler404 = 'application.views.handler404'

Now simply create a views.py module in your application and define a handler404 method:

from cms.views import details

def handler404(request):
return details(request, 'page-not-found')

Finally, via the Django CMS interface create a page with the slug 'page-not-found'. The contents of this page now be displayed in place of the default. I use this page to display a message and the site map to the user.

Make sure you publish the page, otherwise you will get a server error instead!

I would recommend removing all but the necessary permissions on this CMS page, to stop pesky non-super-users from removing it...

Starting a new DJango CMS application, using South

This is actually very simple. Firstly, make sure that 'south' is listed in your INSTALLED_APPS. Next, simply give the following commands:

python manage.py syncdb --all

This will create all the tables required by the installed applications, as per the old method.

python manage.py migrate --fake

This will populate the south_migrationhistory table with migration info for all applications where South is setup. Finally, you can confirm the status of your application:

python manage.py syncdb
Syncing...
No fixtures found.

Synced:
+ django.contrib.admin
+ django.contrib.contenttypes
+ django.contrib.sessions
+ django.contrib.sitemaps
+ django.contrib.sites
+ mptt
+ publisher
+ sorl.thumbnail
+ sekizai

Not synced (use migrations):
- django.contrib.auth
- cms
- cms.plugins.text
- cms.plugins.picture
- cms.plugins.link
- cms.plugins.file
- cms.plugins.snippet
- menus
- south
(use ./manage.py migrate to migrate these)

You can also check what South migrations have been installed via the following:

python manage.py migrate --list

Thanks to Martin for his assistance with this.

Django CMS - Disabling MultilingualURLMiddleware

I have a Django CMS site, which is currently configured to display in multiple languages - I am in the process of converting this to a single-language site.

As such I need to disable the Django MultilingualURLMiddleware, but I want the old /en/ URLs to resolve and redirect to the new URLs, so that any cached/bookmarked links with behave sensibly and I don't lose the Google Page Rank for the existing pages.

How do we do this? Easy, via an Apache RewriteRule:

RewriteRule ^/en/(.*) /$1 [R=301,L]

Thanks to Benjamin Wohlwend for his solution.

Informix LIMIT Clause

Informix has a proprietary specification of LIMIT clauses, via the FIRST and SKIP keywords:

SELECT FIRST 5 SKIP 20 * FROM mytable WHERE a = 1 ORDER BY b;

In comparison MySQL uses the following syntax:

SELECT * FROM mytable WHERE a = 1 ORDER BY b LIMIT 5 OFFSET 20;

I don't know that one is better than the other, but this is for reference.