Until recently Amazon Redshift was not supporting external tables. But, you can create external tables in Amazon Redshift using Redshift Spectrum. External tables allow you to access S3 flat files as a regular Redshift table. You can join the Redshift external table with a database tables such as permanent or temporary table to get required information. You can also perform a complex transformation involving various tables including external tables. The External tables are usually used to build the data lake where you access the raw data file which is stored…