I am saving my spark dataframe on azure databricks and create delta lake table.
It works fine, however I am getting this warning message while execution.
Question- Why I am still getting this message, even with my table is delta table. What is wrong with my approach, any inputs is greatly appreciated.
Warning Message
This query contains a highly selective filter. To improve the performance of queries, convert the table to Delta and run the OPTIMIZE ZORDER BY command on the table
Code
dfMerged.write\
.partitionBy("Date")\
.mode("append")\
.format("delta")\
.option("overwriteSchema", "true")\
.save("/mnt/path..")
spark.sql("CREATE TABLE DeltaUDTable USING DELTA LOCATION '/mnt/path..'")
Some more details
- I've mounted azure storage gen 2 to above mount location.
- databricks runtime - 6.4 (includes Apache Spark 2.4.5, Scala 2.11)