If you have a large Postgres database, consider trying Google Cloud BigQuery for OLAP-style reporting queries.
database> COPY (<query_to_denomralize_report_data>) TO '<dest_filename>' DELIMITER ',' CSV HEADER;
Then upload it to GCS:
$ gsutil cp <dest_filename> gs://<dest_bucket>/<dest_filename>
Then, follow Loading Data into BigQuery (with Google Cloud Storage). For this to work, you’ll have to define the schema and skip the first leading row.
My most recent load job took 4 seconds, loading a very large CSV file. Query outputs can be saved to Google Sheets or other BigQuery tables.
For those of you who are looking for something similar on AWS, check out Amazon Athena.