Replicate Spark Row N-times

You can add a column with a literal value of an Array with size 100, and then use explode to make each of its elements create its own row; Then, just get rid of this "dummy" column:

import org.apache.spark.sql.functions._

val result = singleRowDF
  .withColumn("dummy", explode(array((1 until 100).map(lit): _*)))
  .selectExpr(singleRowDF.columns: _*)