rdblue commented on a change in pull request #28027:
URL: https://github.com/apache/spark/pull/28027#discussion_r525619188
##########
File path:
sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/SupportsMetadataColumns.java
##########
@@ -0,0 +1,29 @@
+package org.apache.spark.sql.connector.catalog;
+
+import org.apache.spark.annotation.Evolving;
+import org.apache.spark.sql.connector.read.SupportsPushDownRequiredColumns;
+import org.apache.spark.sql.types.StructField;
+import org.apache.spark.sql.types.StructType;
+
+/**
+ * An interface for exposing data columns for a table that are not in the
table schema. For example,
+ * a file source could expose a "file" column that contains the path of the
file that contained each
+ * row.
+ * <p>
Review comment:
I added this:
> If a table column and a metadata column have the same name, the metadata
column will never be requested and is ignored. It is recommended that Table
implementations reject data column names that conflict with metadata column
names.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
