Amazon SimpleDB Limitations

Write Limitation

In the Write to DB stage, the write mode Update is not available when writing to an Amazon SimpleDB table. The Insert option handles both insert and update operations. It differentiates between an insert and an update using the unique value of the ItemName column which is present in all Amazon SimpleDB tables.

Reason: An update query requires a Primary Key for each record of the table to be updated, which is not supported by Amazon SimpleDB databases.

Read Limitation

The aggregate functions SUM and AVG are not supported while executing queries on Model Store.