Dynamodb updateitem only with global secondary index

Question

Can we update a dynamodb item only with global secondary index?

$response = $dynamodbClient->updateItem(array(
            'TableName' => 'feed',
            'Key' => array(
                'feed_guid'      => array('S' => 'ac1e9683832ad2923f0bd84b91f34381'),
                'created_date'   => array('N' => '1439295833'),
            ),
            "ExpressionAttributeValues" =>  array (
                    ":val1" => array('N' => '1')
                ) ,
            "UpdateExpression" => $updateExpression,  
            'ReturnValues' => 'ALL_NEW'
        ));

In the above code, I want to replace the key section and update the item using a global secondary index, that is user_id.

Titre

Answer 1

No, you cannot update items in a GSI. You make changes/updates to items in the table and those updates are propagated to the GSIs.

Friulian

Answer 2

A workaround I used for this was to first execute a query command using the document client, then extract the partition key from the result, and call the update method with my retrieved value as the key.

Extinction

Avoid using this solution if you worry about concurrency – Oversold

@Oversold Is there a better option? – Dupont

@Daniel yes, with versioning control of the row (act as a lock). Update a row by applying a unique version, process your stuff backend, then when writing back to the item use a transaction to apply a conditional check for the unique having to be unchanged – Oversold