Re: django migrations on live database for large tables for postgresql

2018-10-29 Thread Aymeric Augustin
Hello Pavel, Sorry for the delay in my answer. Unfortunately I don't know django.db.migrations very well and I won't be able to help you with the details of a patch in this area. I still think improving support for zero downtime migrations would be worthwhile. Writing a proposition in a ticket

Re: django migrations on live database for large tables for postgresql

2018-10-07 Thread pavel . tyslacki
Hello, Aymeric Thanks for your reply. CREATE INDEX CONCURRENTLY is a big part for zero downtime migrations support, but there are too many additional questions as should ALTER TABLE ADD COLUMN UNIQUE splitted to CREATE INDEX and constraint creation or should be handled FOREGN KEY, CHECK and NO

Re: django migrations on live database for large tables for postgresql

2018-10-07 Thread Aymeric Augustin
Hello Pavel, There's an accepted ticket about CREATE INDEX CONCURRENTLY: https://code.djangoproject.com/ticket/21039. A concrete proposal for adding this feature to Django would be interesting. I'm not really sure about your two other suggestions. If you think they're improving the PostgreSQL

django migrations on live database for large tables for postgresql

2018-09-26 Thread pavel . tyslacki
Hi, I found that django migrations don't designed for live updates on large tables for postgres, eg. index creation doesn't use concurrently or alter table operation can take ACCESS EXCLUSIVE lock for long time. Before I mostly wrote custom migrations, but after one of downtime I decided to av