A bit tricky result of Spark SQL query result (Tested with 2.3.0)

a-bit-tricky-spark-sql.scala

/////////////////////////////////////////////////////////////////////////////////////////////
// 1. select with swapping columns, and apply where
/////////////////////////////////////////////////////////////////////////////////////////////
import spark.implicits._

import org.apache.spark.sql.{DataFrame, Dataset}

case class Hello(id: Int, name1: String, name2: String)

val ds = List(Hello(1, "Alice", "Bob"), Hello(2, "Bob", "Alice")).toDS
val swapRenamedDF: DataFrame = ds.select($"id", $"name1".as("name2"), $"name2".as("name1"))

swapRenamedDF.explain

swapRenamedDF.where($"name1" === "Alice").show
swapRenamedDF.where($"name1" === "Alice").explain

swapRenamedDF.where($"name2" === "Alice").show
swapRenamedDF.where($"name2" === "Alice").explain

/*
> swapRenamedDF.explain
== Physical Plan ==
LocalTableScan [id#3, name2#7, name1#8]

> swapRenamedDF.where($"name1" === "Alice").show
+---+-----+-----+
| id|name2|name1|
+---+-----+-----+
|  2|  Bob|Alice|
+---+-----+-----+

> swapRenamedDF.where($"name1" === "Alice").explain
== Physical Plan ==
*(1) Project [id#3, name1#4 AS name2#7, name2#5 AS name1#8]
+- *(1) Filter (isnotnull(name2#5) && (name2#5 = Alice))
   +- LocalTableScan [id#3, name1#4, name2#5]
   
> swapRenamedDF.where($"name2" === "Alice").show
+---+-----+-----+
| id|name2|name1|
+---+-----+-----+
|  1|Alice|  Bob|
+---+-----+-----+

> swapRenamedDF.where($"name2" === "Alice").explain
== Physical Plan ==
*(1) Project [id#3, name1#4 AS name2#7, name2#5 AS name1#8]
+- *(1) Filter (isnotnull(name1#4) && (name1#4 = Alice))
   +- LocalTableScan [id#3, name1#4, name2#5]   
*/

/////////////////////////////////////////////////////////////////////////////////////////////
// 2. apply where, and select with swapping columns
/////////////////////////////////////////////////////////////////////////////////////////////

import spark.implicits._

import org.apache.spark.sql.{DataFrame, Dataset}

case class Hello(id: Int, name1: String, name2: String)

val ds = List(Hello(1, "Alice", "Bob"), Hello(2, "Bob", "Alice")).toDS

val applyWhereToName1ThenSelectDF = ds.where($"name1" === "Alice").select($"id", $"name1".as("name2"), $"name2".as("name1"))
applyWhereToName1ThenSelectDF.show
applyWhereToName1ThenSelectDF.explain

val applyWhereToName2ThenSelectDF = ds.where($"name2" === "Alice").select($"id", $"name1".as("name2"), $"name2".as("name1"))
applyWhereToName2ThenSelectDF.show
applyWhereToName2ThenSelectDF.explain

/*
> applyWhereToName1ThenSelectDF.show
+---+-----+-----+
| id|name2|name1|
+---+-----+-----+
|  1|Alice|  Bob|
+---+-----+-----+

> applyWhereToName1ThenSelectDF.explain
== Physical Plan ==
*(1) Project [id#3, name1#4 AS name2#8, name2#5 AS name1#9]
+- *(1) Filter (isnotnull(name1#4) && (name1#4 = Alice))
   +- LocalTableScan [id#3, name1#4, name2#5]

> applyWhereToName2ThenSelectDF.show
+---+-----+-----+
| id|name2|name1|
+---+-----+-----+
|  2|  Bob|Alice|
+---+-----+-----+

> applyWhereToName2ThenSelectDF.explain
== Physical Plan ==
*(1) Project [id#3, name1#4 AS name2#26, name2#5 AS name1#27]
+- *(1) Filter (isnotnull(name2#5) && (name2#5 = Alice))
   +- LocalTableScan [id#3, name1#4, name2#5]
*/