Attribute is the Catalyst name for an input column from a child operator.
An AttributeReference has been resolved, meaning we know which input column
in particular it is referring too. An AttributeReference also has a known
DataType. In contrast, before analysis there might still exist
Thank you Michael for the detail explanation, it makes clear to me. Thanks!
At 2015-08-25 15:37:54, Michael Armbrust mich...@databricks.com wrote:
Attribute is the Catalyst name for an input column from a child operator. An
AttributeReference has been resolved, meaning we know which input
There are many such kind of case class or concept such as
Attribute/AttributeReference/Expression in Spark SQL
I would ask what Attribute/AttributeReference/Expression mean， given a sql
query like select a,b from c, it a, b are two Attributes? a + b is an
expression?
Looks I misunderstand it
