notifications-api/migrations/versions/0320_optimise_notifications.py

"""

Revision ID: 0320_optimise_notifications
Revises: 0319_contact_list_archived
Create Date: 2020-03-26 11:16:12.389524

"""

import os

from alembic import op

revision = "0320_optimise_notifications"
down_revision = "0319_contact_list_archived"
environment = os.environ["NOTIFY_ENVIRONMENT"]


def upgrade():
    # We like to run this operation on live via the command prompt, to watch the progress and stop if necessary
    if environment not in ["live", "production"]:
        # Drop indexes notifications - no need to recreate these indexes
        op.execute("DROP INDEX IF EXISTS ix_notifications_key_type")
        op.execute("DROP INDEX IF EXISTS ix_notifications_api_key_id")
        op.execute("DROP INDEX IF EXISTS ix_notifications_notification_status")
        op.execute("DROP INDEX IF EXISTS ix_notifications_notification_type")
        op.execute("DROP INDEX IF EXISTS ix_notifications_service_id")

        # Create new composite indexes
        # PLEASE NOTE: that if you create index on production you need to add concurrently to the create statement,
        # however we are unable to do that inside a transaction like this upgrade method
        ix_notifications_service_id_composite = """
        CREATE INDEX ix_notifications_service_id_composite
            on notifications (service_id, notification_type, notification_status, created_at)
        """
        op.execute(ix_notifications_service_id_composite)

        ix_notifications_notification_type_composite = """
            CREATE INDEX ix_notifications_notification_type_composite
            on notifications (notification_type, notification_status, created_at)
        """
        op.execute(ix_notifications_notification_type_composite)
        # DROP and CREATE all other indexes
        op.execute("DROP INDEX IF EXISTS ix_notifications_client_reference")
        op.execute(
            "CREATE INDEX ix_notifications_client_reference ON notifications (client_reference)"
        )

        op.execute("DROP INDEX IF EXISTS ix_notifications_created_at")
        op.execute(
            "CREATE INDEX ix_notifications_created_at ON notifications (created_at)"
        )

        op.execute("DROP INDEX IF EXISTS ix_notifications_job_id")
        op.execute("CREATE INDEX ix_notifications_job_id ON notifications (job_id)")

        op.execute("DROP INDEX IF EXISTS ix_notifications_reference")
        op.execute(
            "CREATE INDEX ix_notifications_reference ON notifications (reference)"
        )

        op.execute("DROP INDEX IF EXISTS ix_notifications_service_created_at")
        op.execute(
            "CREATE INDEX ix_notifications_service_created_at ON notifications (service_id, created_at)"
        )

        op.execute("DROP INDEX IF EXISTS ix_notifications_template_id")
        op.execute(
            "CREATE INDEX ix_notifications_template_id ON notifications (template_id)"
        )

        # Drop indexes notification_history
        op.execute("DROP INDEX IF EXISTS ix_notification_history_key_type")
        op.execute("DROP INDEX IF EXISTS ix_notification_history_api_key_id")
        op.execute("DROP INDEX IF EXISTS ix_notification_history_notification_status")
        op.execute("DROP INDEX IF EXISTS ix_notification_history_notification_type")
        op.execute("DROP INDEX IF EXISTS ix_notification_history_service_id")
        op.execute("DROP INDEX IF EXISTS ix_notification_history_week_created")


def downgrade():
    pass