Running this fills up the statistics for the columns.

ANALYZE TABLE <TABLE> COMPUTE STATISTICS FOR COLUMNS timestamp,aid,ContextProcessId

But I still get the error when I run OPTIMIZE:

Unsupported datatype 'TimestampNTZType'
com.databricks.backend.common.rpc.SparkDriverExceptions$SQLExecutionException: java.lang.IllegalArgumentException: Unsupported datatype 'TimestampNTZType'
	at com.databricks.sql.io.skipping.Classifier$.getStatsForCol(Classifier.scala:180)
	at com.databricks.sql.io.skipping.SimpleClassifier.applyActionToIntersectingBinaryNode(Classifier.scala:424)
	at com.databricks.sql.io.skipping.SimpleClassifier.applyActionToIntersectingNode(Classifier.scala:405)
	at com.databricks.sql.io.skipping.SimpleClassifier.$anonfun$classifyForOptimize$3(Classifier.scala:268)
	at com.databricks.sql.io.skipping.SimpleClassifier.$anonfun$classifyForOptimize$3$adapted(Classifier.scala:266)
	at scala.collection.Iterator.foreach(Iterator.scala:943)
	at scala.collection.Iterator.foreach$(Iterator.scala:943)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1431)