database - How to have a version control in django? -

i have django webapp different content (e.g. posts, threads, comments) , want keep track of history. i'm trying create "version-control" "content". how i'm doing (skip end question):

i have model create_content represents action: has actor (editor), set of modifications (edition), timestamp, , content acts on:

class create_content(models.model):     editor = models.foreignkey('user')     edition = models.textfield() # pickled dictionary     date = models.datetimefield(auto_now_add=true)     content = models.foreignkey('content') 

which saved once because history cannot changed.

i define content has:

class content(models.model):     last_edit = models.foreignkey(create_content, related_name='content_last_id')     first_edit = models.foreignkey(create_content, related_name='content_first_id')      def author(self):         return self.first_edit.editor 

where last_edit last action performed it, , first_edition use initial author of content.

all actual content of webapp implemented derived models of content, created/edited derived models of create_content. instance,

class comment(content):     post = models.foreignkey(post, related_name="comment_set")     body = models.textfield() 

is created during save of create_comment(create_content) (in fact subclasses of create_content proxies).

for instance, user editions instances of subclass of create_content (e.g. edit_comment(create_content)) which, during save(), makes last_edit point onto self , updates actual content (e.g. edit_comment.body).

in end i'm doing simplified version of git database:

• create_content commits (which store complete state in self.edition).
• content specific branch+working directory (last_edit being pointer),
• a user edition moves branch forward , changes content's new content (e.g. body of comment).

brief ending

what realized every user action have entry in table of create_content.

my question are:

how bad happen? mean, table can pretty big, , actions hitting it.

i think approach "clean", i'm pretty sure i'm re-inventing wheel. specific wheel?

you can try: https://bitbucket.org/emacsway/django-versioning. django-versioning allows version data stored in django models, , stores diff, not content copy. supports field types excepts manytomany (currently).

maybe useful project: django built-in comments app , way of referring objects. think nice , clean approach.

the physical database size doesn't matter. number of records doesn't matter. see: how big can mysql database before performance starts degrade

but how useful keep full history? start delete history timemachine does. have daily (for week), weekly (for months) , monthly records. crontab or django-celery delete old history.