If you attempt to export a DATETIME column directly to Avro, it might not be handled appropriately because BigQuery does not have a direct Avro logical type mapping for its DATETIME type and natively supports logical datetime type in Avro. BigQuery usually represents a DATETIME column as an Avro string when exporting it to Avro. Before exporting to Avro, change DATETIME to a supported type in BigQuery, like STRING or TIMESTAMP, to ensure compatibility. For more details you can refer to this documentation.