Amazon Athena query outputting all columns in the csv as VARCHARs

Question

A customer wants to join two AWS Glue generated tables via Athena. The Athena query CSV result is crawled, creating a new table in the data catalog. 
Whenever Athena is generating a CSV output that has all VARCHAR columns which have double quotes on the values, even the ones that are not supposed to be a VARCHAR. All of the columns have double quotes; how do you remove the double quotes so the Glue crawler can detect the proper data type?

Is there a way to fix this?

Accepted Answer

To have a Glue Crawler use OpenCSVSerDe you can use a [custom CSV classifier](https://docs.aws.amazon.com/glue/latest/dg/custom-classifier.html#custom-classifier-csv), specify Double-quote(") in the quote symbol and select Trim whitespace before identifying column names.

Amazon Athena query outputting all columns in the csv as VARCHARs

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