Using the Athena data source, I created three SPICE datasets (a, b, and c). I created a new dataset that joins all SPICE datasets (left joins) as follows:
dataset_a left join dataset_b on date and unique_key
dataset_a left join dataset_c on date and unique_key
The result shows all records from dataset_a and dataset_b and only some from dataset_c.
I verified against Athena using the same datasets and joins, and all records from dataset_c returned as expected.
Joining multiple SPICE datasets is flaky. Anyone running into similar issues, please share your experience or workaround. I greatly appreciated it.