Brilliant! Now we have the opt in/out process implemented.
There is a request from our mailing team to get the list of customers who subscribed to the e-mail newsletters.
Create a new function named extract_mailing_list() that returns a table with the following columns:
RETURNS TABLE ( title character varying(8), first_name character varying(255), last_name character varying(255), email_address character varying(255), newsletter_name character varying(256) )
When it starts, the function should log the following message with the 'INFO' level:
ETL process Extract Mailing List Started
The type of newsletter must equal 'E-mail', and the final result set should contain only distinct records ordered by the email_address column.
When the function finishes, it should log the following message with the 'INFO' level:
ETL process Extract Mailing List Finished
Remember to pass in 'extract_mailing_list()' as the process name when logging.
