The previous query would cause problems on many different systems, regardless of whether you’re using Databricks or another data warehousing tool. Luckily, as an user of Databricks, this customer has a feature available that can help solve this problem called the Query Watchdog.
Note: Query Watchdog is available on clusters created with version 2.1-db3 and greater.
A Query Watchdog is a simple process that checks whether or not a given query is creating too many output rows for the number of input rows at a task level. We can set a property to control this and in this example we will use a ratio of 1000 (which is the default).
It looks like this is an all-or-nothing process, but a very interesting start.