Normal queries running slower than Redshift Spectrum queries

Question

I am using Redshift Spectrum for some queries & I have some queries running without Spectrum. I notice that some queries accessing data in my cluster are running slower than my Redshift Spectrum queries. Why is that?

Answer 1

Amazon Redshift queries are run on your cluster resources against local disk. Redshift Spectrum queries run using per-query scale-out resources against data in S3. For most queries, local disk will be faster, but for queries that scan a lot of data and do minimal compute processing, we can apply a lot of Redshift Spectrum workers and complete them quickly.

Hope this helped.