A list of the project's measures
The Data Lake is a project's catalogue of measures: revenue, orders, collections. Each measure has its unit, its type and its status, and they all sit in the same list.
From a series you can start again with «Nuova query da qui», which prepares a query from that measure. The Data Lake comes with the Analisi module.
Rules on the values a query returns
Data Checks adds rules to a query on the values it returns. A rule can check a range, that a value is not null, that it is one of the allowed values, or a single expression written by whoever defines it.
For each rule you choose what happens to a row that fails it: flag it or exclude it. Excluded rows go to a quarantine table, kept for 90 days, so they can be looked at and understood.
A score at every run
Every run gives a quality score. When the score changes, the people who own the rules are told, so they do not have to find out from a report that no longer adds up.
A rule and an alarm answer different questions: the rule asks whether a value is possible, for example a negative amount, the alarm signals that something needs a look. They serve different purposes.
Where to start
A reasonable way in is to pick the query behind an important report, add two or three rules on the fields that make it add up and watch the score for a few runs. The rest can be added as you go.