performance.txt

# query

where = '{comparator_table}.{comparator} = (SELECT MAX({comparator}) FROM {table} as sub WHERE {table}.cid = sub.cid)'

# optimized query

where = '{comparator_table}.{pk} IN {comparator_table}_latest_revisions'

# in the code

    # optimize by default
    if not getattr(settings, 'OPTIMIZE_REVISIONS', True):
        where
    else:
        optimized_where

# post-syncdb

for model in versioned_models:
    base = model.get_base_model()
    table = base._meta.db_table + "_latest_revisions"
    pk = model().pk_name
    latest = str(model.latest.only(pk).query)
    sql = "CREATE OR REPLACE VIEW {table} AS {selection}".format(
        table=table,
        selection=latest
        )

# NOTE TO SELF: create a script that enters ~20k records into a DB and test performance before committing this
# If this still isn't fast enough, we could actually go for a real, indexed  table, but then we have to take care of keeping the _latest_revisions table in sync with the real table, which isn't rocket science but which I'd rather avoid.