Suppose I have a code:

val spark = SparkSession.builder().master("local").getOrCreate()

spark.conf.set("spark.sql.sources.partitionOverwriteMode", "dynamic")

val partitionMode1 = spark.conf.get("spark.sql.sources.partitionOverwriteMode")
print(s"Partitioning: $partitionMode1")

val partitionMode2 = spark.sparkContext.getConf.get("spark.sql.sources.partitionOverwriteMode")
print(s"Partitioning: $partitionMode2")

This code will fail with error

Exception in thread "main" java.util.NoSuchElementException: spark.sql.sources.partitionOverwriteMode
        at org.apache.spark.SparkConf.$anonfun$get$1(SparkConf.scala:245)
        at scala.Option.getOrElse(Option.scala:189)

My question is it safe to update such property in runtime using spark.conf.set?