What is the role of Catalyst Optimizer in PySpark?
Catalyst Optimizer plays a very important role in Apache Spark. It helps to improve structural queries in SQL or expressed through DataFrame or DataSet APIs by reducing the program execution time and cost. The Spark Catalyst Optimizer supports both cost-based and rule-based optimization. Rule-based optimization contains a set of rules that define how a query is executed. Cost-based optimization uses rules to create multiple plans and calculate their costs. Catalyst optimizer also manages various big data challenges like semi-structured data and advanced analytics.
