Tips for write Spark ETL application
Avoid use withColumn in loop
withColumn is very useful when operate on a column, but you should avoid using it in a loop.
withColumn is indeed a very useful function in Apache Spark when you want to operate on a column and create a new DataFrame with the added or modified column.
However, you should avoid using withColumn inside a loop, as it can lead to performance issues due to the repeated creation of new DataFrames.
Instead, you can use withColumn to perform column operations efficiently on the entire DataFrame at once, without the need for loops.
This way, you can achieve the desired transformations in a more optimized and performant manner.