Adding an array of an array at Amazon DynamoDB

Question

I know that AmazonDB supports number, string, number set and string set as item types. But, how about a set of an string set (array of array, or multidimensional array)?

In case it's possible, this is the only way I found to do that, which didn't work (using PHP):

$units_frequencies["id"][0] = "400";
$units_frequencies["id"][1] = "401";
$units_frequencies["id"][2] = "402";
$units_frequencies["frequency"][0] = "20";
$units_frequencies["frequency"][1] = "30";
$units_frequencies["frequency"][2] = "50";

// item that will be inserted
$item = array(
    'id' => array(AmazonDynamoDB::TYPE_STRING => $id), 
    'arrays_field' => array(
        AmazonDynamoDB::TYPE_ARRAY_OF_STRINGS => array(
            AmazonDynamoDB::TYPE_ARRAY_OF_STRINGS => $units_frequencies)));

I don't want to have two columns (one for $units_frequencies["id"] and $units_frequencies["frequency"]) because the second one can have two index with the same values, which is not allowed by Dynamo.

Thanks in advance.

Answer 1

It doesn't.
At least while looking at AttributeValue.class (AWS Java SDK)
I also couldn't find any hint on the documentation site except for those dealing with int, string, set of string or set of int

Answer 2

You can eventually serialize your object. More info at https://java.awsblog.com/post/Tx1K7U34AOZBLJ2/Using-Custom-Marshallers-to-Store-Complex-Objects-in-Amazon-DynamoDB