Provide a wiki page explaining things to consider when making storage model changes.

[seanlip]

Currently, most contributors (probably) don't know how to update the index.yaml file when making changes to the datastore that involve querying on 2 or more fields. This can lead to errors when the PR is subsequently deployed to production.

We should have a wiki page that explains things to be aware of when making storage model changes, and that details how to make them safely. This page should detail common operations like updating the index.yaml file (see discussion at https://github.com/oppia/oppia/pull/17259/files#r1098564239).

[seanlip]

@vojtechjelinek @lkbhitesh07 Is there anything you would want to add to such a page re e.g. validation? E.g. deleting models safely, deleting fields safely, etc. -- this page seems like it would be a good place for such topics.

[vojtechjelinek]

I think that after we verify that @lkbhitesh07 approach for the deletion of model filed works we can put it there. Ditto with deleting models.

[U8NWXD]

@lkbhitesh07 have you confirmed that your approach for deleting a model works?

[lkbhitesh07]

@lkbhitesh07 have you confirmed that your approach for deleting a model works?

Hey @U8NWXD I have submitted the testing request for the same. I think @kevintab95 will be taking up the testing as @DubeySandeep is busy for the next 3 days. I'm currently in conversation with them via mail.
Thanks

EDIT - Just received the response from @kevintab95 and he will be running the job by Friday.
Thanks

[Shivkant-Chauhan]

Hi @lkbhitesh07 can you please update the project board with the expected merge date.. thanks!

[lkbhitesh07]

The job still needs to be tested so I would say that my PR would be merged by 6 April.
Thanks.

[lkbhitesh07]

Hey guys, just wanted to update the discussion that my PR has been tested successfully on the backup server. I can provide assistance to the wiki page where we are talking about deleting a field from the model.
Thanks

[U8NWXD]

That's great news @lkbhitesh07! When do you expect to update the wiki page (assuming you are okay with taking up this issue)?

[lkbhitesh07]

I think I will not be able to carve this wiki page due to a few other commitments I have. I will be providing my assistance in updating the part where we talk about removing some fields from the model because I have worked on that part.