Poll migration is not idempotent (PR #7964)

The migration script is not idempotent due to database constrains on the poll related objects, namely:

polls: index_polls_on_post_id_and_name (post_id,name) UNIQUE poll_options: index_poll_options_on_poll_id_and_digest (poll_id,digest) UNIQUE poll_votes: index_poll_votes_on_poll_id_and_poll_option_id_and_user_id (poll_id,poll_option_id,user_id) UNIQUE

This change skips a particular poll migration if it’s already found on the db. We also wrap the poll migration in a transaction so that if the script happens to fail mid-way while migrating a poll we rollback the poll and all it’s related records, thus preventing undesirable partial states.


Thanks for contributing this pull request! Could you please sign our CLA so we can review it? http://www.discourse.org/cla

This is very confusing to me… all migrations run in a transaction so we should not need to layer more transactions here.

1 Like

Just updated. Thanks for looking into this.

Thanks :+1:

This pull request has been mentioned on Discourse Meta. There might be relevant details there: