Try inlining indexes with table args

- Update the Notification and NotificationHistory model to reflect the database.
- Updates to datatypes, removal of indexes and addition of indexes.

Why?
After running the `flask db migrate` command there are many deltas because we did some work to update the notification and notification_history tables, however, the SQLAlchemy models were not updated to reflect those changes. This PR cleans up all those deltas.
However, there are still some differences that can be done but we can look at that in another PR.

app/models.py

@@ -1412,16 +1412,16 @@ class Notification(db.Model):
     job_id = db.Column(UUID(as_uuid=True), db.ForeignKey('jobs.id'), index=True, unique=False)
     job = db.relationship('Job', backref=db.backref('notifications', lazy='dynamic'))
     job_row_number = db.Column(db.Integer, nullable=True)
-    service_id = db.Column(UUID(as_uuid=True), db.ForeignKey('services.id'), index=True, unique=False)
+    service_id = db.Column(UUID(as_uuid=True), db.ForeignKey('services.id'), unique=False)
     service = db.relationship('Service')
     template_id = db.Column(UUID(as_uuid=True), index=True, unique=False)
     template_version = db.Column(db.Integer, nullable=False)
     template = db.relationship('TemplateHistory')
-    api_key_id = db.Column(UUID(as_uuid=True), db.ForeignKey('api_keys.id'), index=True, unique=False)
+    api_key_id = db.Column(UUID(as_uuid=True), db.ForeignKey('api_keys.id'), unique=False)
     api_key = db.relationship('ApiKey')
-    key_type = db.Column(db.String, db.ForeignKey('key_types.name'), index=True, unique=False, nullable=False)
+    key_type = db.Column(db.String, db.ForeignKey('key_types.name'), unique=False, nullable=False)
     billable_units = db.Column(db.Integer, nullable=False, default=0)
-    notification_type = db.Column(notification_types, index=True, nullable=False)
+    notification_type = db.Column(notification_types, nullable=False)
     created_at = db.Column(
         db.DateTime,
         index=True,
@@ -1441,9 +1441,8 @@ class Notification(db.Model):
         onupdate=datetime.datetime.utcnow)
     status = db.Column(
         'notification_status',
-        db.String,
+        db.Text,
         db.ForeignKey('notification_status_types.name'),
-        index=True,
         nullable=True,
         default='created',
         key='status'  # http://docs.sqlalchemy.org/en/latest/core/metadata.html#sqlalchemy.schema.Column
@@ -1456,7 +1455,7 @@ class Notification(db.Model):
 
     international = db.Column(db.Boolean, nullable=False, default=False)
     phone_prefix = db.Column(db.String, nullable=True)
-    rate_multiplier = db.Column(db.Float(asdecimal=False), nullable=True)
+    rate_multiplier = db.Column(db.Numeric(asdecimal=False), nullable=True)
 
     created_by = db.relationship('User')
     created_by_id = db.Column(UUID(as_uuid=True), db.ForeignKey('users.id'), nullable=True)
@@ -1472,7 +1471,8 @@ class Notification(db.Model):
             ['template_id', 'template_version'],
             ['templates_history.id', 'templates_history.version'],
         ),
-        {}
+        UniqueConstraint('job_id', 'job_row_number', name='uq_notifications_job_row_number'),
+        Index('ix_notifications_service_created_at', 'service_id', 'created_at')
     )
 
     @property
@@ -1688,24 +1688,23 @@ class NotificationHistory(db.Model, HistoryModel):
     job_id = db.Column(UUID(as_uuid=True), db.ForeignKey('jobs.id'), index=True, unique=False)
     job = db.relationship('Job')
     job_row_number = db.Column(db.Integer, nullable=True)
-    service_id = db.Column(UUID(as_uuid=True), db.ForeignKey('services.id'), index=True, unique=False)
+    service_id = db.Column(UUID(as_uuid=True), db.ForeignKey('services.id'), unique=False)
     service = db.relationship('Service')
-    template_id = db.Column(UUID(as_uuid=True), index=True, unique=False)
+    template_id = db.Column(UUID(as_uuid=True), unique=False)
     template_version = db.Column(db.Integer, nullable=False)
-    api_key_id = db.Column(UUID(as_uuid=True), db.ForeignKey('api_keys.id'), index=True, unique=False)
+    api_key_id = db.Column(UUID(as_uuid=True), db.ForeignKey('api_keys.id'), unique=False)
     api_key = db.relationship('ApiKey')
-    key_type = db.Column(db.String, db.ForeignKey('key_types.name'), index=True, unique=False, nullable=False)
+    key_type = db.Column(db.String, db.ForeignKey('key_types.name'), unique=False, nullable=False)
     billable_units = db.Column(db.Integer, nullable=False, default=0)
-    notification_type = db.Column(notification_types, index=True, nullable=False)
-    created_at = db.Column(db.DateTime, index=True, unique=False, nullable=False)
+    notification_type = db.Column(notification_types, nullable=False)
+    created_at = db.Column(db.DateTime, unique=False, nullable=False)
     sent_at = db.Column(db.DateTime, index=False, unique=False, nullable=True)
     sent_by = db.Column(db.String, nullable=True)
     updated_at = db.Column(db.DateTime, index=False, unique=False, nullable=True, onupdate=datetime.datetime.utcnow)
     status = db.Column(
         'notification_status',
-        db.String,
+        db.Text,
         db.ForeignKey('notification_status_types.name'),
-        index=True,
         nullable=True,
         default='created',
         key='status'  # http://docs.sqlalchemy.org/en/latest/core/metadata.html#sqlalchemy.schema.Column
@@ -1713,9 +1712,9 @@ class NotificationHistory(db.Model, HistoryModel):
     reference = db.Column(db.String, nullable=True, index=True)
     client_reference = db.Column(db.String, nullable=True)
 
-    international = db.Column(db.Boolean, nullable=False, default=False)
+    international = db.Column(db.Boolean, nullable=True, default=False)
     phone_prefix = db.Column(db.String, nullable=True)
-    rate_multiplier = db.Column(db.Float(asdecimal=False), nullable=True)
+    rate_multiplier = db.Column(db.Numeric(asdecimal=False), nullable=True)
 
     created_by_id = db.Column(UUID(as_uuid=True), nullable=True)
 
@@ -1728,7 +1727,10 @@ class NotificationHistory(db.Model, HistoryModel):
             ['template_id', 'template_version'],
             ['templates_history.id', 'templates_history.version'],
         ),
-        {}
+        Index(
+            'ix_notification_history_service_id_composite',
+            'service_id', 'key_type', 'notification_type', 'created_at',
+        )
     )
 
     @classmethod
@@ -1742,6 +1744,22 @@ class NotificationHistory(db.Model, HistoryModel):
         self.status = original.status
 
 
+# Indexes for notification_history and notifications to improve performance of fetch queries.
+Index(
+    'ix_notifications_notification_type_composite',
+    Notification.notification_type,
+    Notification.status,
+    Notification.created_at
+)
+Index(
+    "ix_notifications_service_id_composite",
+    Notification.service_id,
+    Notification.notification_type,
+    Notification.status,
+    Notification.created_at
+)
+
+
 class ScheduledNotification(db.Model):
     __tablename__ = 'scheduled_notifications'