Yes, it is possible to add fields to an existing AWS Athena table. This can be done either through an ALTER TABLE command or by creating a new table with the desired properties and then inserting the contents of the original table into it.
Here are the steps to add fields to an existing Athena table:
Determine the fields you want to add to the table, including data types, lengths, and other relevant attributes.
Write an ALTER TABLE statement to add the fields to the table. Alternatively, you can create a new table with the fields already included, and then use an INSERT statement to insert the contents of the original table into the new table.
Once the fields have been added to the table, query the table to ensure that the fields were added properly.
Refresh the table in Athena using the REFRESH TABLE command.
You can find comprehensive information about modifying tables in AWS Athena in the AWS documentation here: https://docs.aws.amazon.com/athena/latest/ug/alter-table.html