Amazon Redshift Spectrum enables you to run complex Amazon Redshift SQL queries on a large amount data of different formats stored in Amazon S3. With Amazon Redshift Spectrum, you can directly run queries to read Amazon S3 data files without the need to load or transform the data.
You can run queries for the large amount of Amazon S3 data files without the need to scale the specified Amazon Redshift cluster.
Amazon Redshift Spectrum resides on Amazon Redshift servers independent of the Amazon Redshift cluster. When you run queries using Amazon Redshift Spectrum, the queries run faster and uses less Amazon Redshift cluster processing capacity as Amazon Redshift Spectrum pushes all the compute-intensive tasks to the Amazon Redshift Spectrum layer.