以下示例展示了 Spark SQL 向 Teradata 目标连接器发起 EXPLAIN 请求的情况。
scala> ForeignServer.sql("explain select name from default.nn1 where number = 10")
+------------------------------------------------------------------------------------+
|plan +------------------------------------------------------------------------------------+
|== Physical Plan ==
*Project [name#25]
+- *Filter (isnotnull(number#24) && (number#24 = 10))
+- *Scan com.teradata.querygrid.qgc.spark.QGRelation@4ec78008 default.nn1[name#25,number#24] PushedFilters: [IsNotNull(number), EqualTo(number,10)], ReadSchema: struct<name:string>|
+------------------------------------------------------------------------------------+
scala> ForeignServer.sql("explain insert into default.nn1 select * from players2")
+------------------------------------------------------------------------------------+
|plan
+------------------------------------------------------------------------------------+
|== Physical Plan ==
ExecutedCommand
+- InsertIntoDataSourceCommand Relation[number#24,name#25] com.teradata.querygrid.qgc.spark.QGRelation@4ec78008, OverwriteOptions(false,Map())
+- MetastoreRelation default, players2
+------------------------------------------------------------------------------------+