nvl(expr1, expr2) – Returns `expr2` if `expr1` is null, or `expr1` otherwise.
Platforms: WhereOS, Spark, Hive
Class: org.apache.spark.sql.catalyst.expressions.Nvl
More functions can be added to WhereOS via Python or R bindings or as Java & Scala UDF (user-defined function), UDAF (user-defined aggregation function) and UDTF (user-defined table generating function) extensions. Custom libraries can be added on via Settings-page or installed from WhereOS Store.