Use Athena generated path extractors

By default, Athena searches for top level Amazon Ion values that match Hive column names and creates path extractors at runtime based on these matching values. If your Amazon Ion data format matches the Hive table schema, Athena dynamically generates the extractors for you, and you do not need to add any additional path extractors. These default path extractors are not stored in the table metadata.

The following example shows how Athena generates extractors based on column name.

-- Example Amazon Ion Document
{
    identification: {
        name: "John Smith",
        driver_license: "XXXX"
    },
    
    alias: "Johnny"    
}

-- Example DDL
CREATE EXTERNAL TABLE example_schema2 (
    identification MAP<STRING, STRING>,
    alias STRING
)
STORED AS ION
LOCATION 's3://amzn-s3-demo-bucket/path_extraction1/'

The following example extractors are generated by Athena. The first extracts the identification field to the identification column, and the second extracts the alias field to the alias column.

'ion.identification.path_extractor' = '(identification)'
'ion.alias.path_extractor' = '(alias)'

The following example shows the extracted table.

|                  identification                    |  alias   |
|----------------------------------------------------|----------|
|{["name", "driver_license"],["John Smith", "XXXX"]} | "Johnny" |