Support MySQL FULLTEXT INDEX in the model DDL

[Ed Morley]

Whilst there is ticket #3254 filed for general full text search support, it's regarding multiple DB types and primarily about adding support for searching, rather than creating indexes. As such, I think it's easier to break this piece out to a new ticket.

In MySQL 5.6 support was added to InnoDB for full text indexes:
​https://dev.mysql.com/doc/refman/5.6/en/innodb-fulltext-index.html

Currently we have to create these via a migration like:

migrations.RunSQL(
    sql='CREATE FULLTEXT INDEX `idx_description` on foo(`description`);',
    reverse_sql='ALTER TABLE foo DROP INDEX idx_description',
),

It would be ideal to be able to define them via the model DDL instead, so the full DB state can be recreated from the model.

[Tim Graham]

This seems better suited for a possible contrib.mysql package, however, I don't think it makes sense to add such an index if this is the only feature. We might reopen this at some later time if such a package developers in Django. Meanwhile, you could propose it in an external package such as ​django-mysql. It likely needs to wait until more formal support for indexes is release in Django 1.11 (#26808).

[Ed Morley]

Thank you, I've filed:
​https://github.com/adamchainz/django-mysql/issues/314