## errors.NotIncremental


The plan is outside the fragment with verified delta rules.


Usage

``` python
errors.NotIncremental()
```


Raised by [sverify.engines.delta_plans](engines.delta_plans.md#sverify.engines.delta_plans) for a plan with an operator without a delta rule (a left join, aggregate, window, `DISTINCT` or `LIMIT`). A node over such a plan is recomputed and diffed instead, so refreshing it does not raise this. (A view that ends in `COUNT` and `SUM` per group, or in `DISTINCT`, is maintained from a state per group, `sverify._linear`.) The message is the checker's reason.