使用 GSI 时，DynamoDBmapper 不返回我的所有数据

Question

I'm actually using DynamoDBmapper to query my dynamo table. To do so i created two classes that are used by the mapper to convert the queries returns by the table. See below

TableName.java

@DynamoDBTable(tableName = "customer_table")
public class CustomerTable {

    @DynamoDBHashKey(attributeName = "customer_id")
    String customerId;

    @DynamoDBIndexHashKey(attributeName = "customer_id_bis", globalSecondaryIndexName = "customer_id_bis-index")
    String customerIdBis;

    @DynamoDBIndexHashKey(attributeName = "customer_id_tier", globalSecondaryIndexName = "customer_id_tier-index")
    String customerIdTier;

    @DynamoDBAttribute(attributeName = "salutations")
    List<Salutations> salutations;
}

Salutations.java

@DynamoDBDocument
public class Salutations {

    @DynamoDBAttribute(attributeName = "salutations_id")
    private String salutationsId;

    @DynamoDBAttribute(attributeName = "rank")
    private Integer rank;

    @DynamoDBAttribute(attributeName = "score")
    private String score;

    @DynamoDBAttribute(attributeName = "typos")
    private List<String> typos;
}

Then i'm querying my table as follow on my HashKey

Map<String, AttributeValue> keyToGet = Map.of(":column", new AttributeValue(value));
DynamoDBQueryExpression<CustomerTable> queryExpression = new DynamoDBQueryExpression<CustomerTable>()
                .withKeyConditionExpression("customer_id = :column")
                .withExpressionAttributeValues(keyToGet);
mapper.query(CustomerTable.class, queryExpression);

and for a GSI i do this

Map<String, AttributeValue> keyToGet = Map.of(":column", new AttributeValue(value));
DynamoDBQueryExpression<CustomerTable> queryExpression = new DynamoDBQueryExpression<CustomerTable>()
                .withIndexName("customer_id_bis-index")
                .withKeyConditionExpression("customer_id_bis = :column")
                .withConsistentRead(false)
                .withExpressionAttributeValues(keyToGet);
mapper.query(CustomerTable.class, queryExpression);

Everything is working fine but i got differences between the two queries for the field named typos. For customer_id i obtain the complete element as follow

{
    "customer_id":"jean",
    "customer_id_bis":"paul",
    "customer_id_tier":"sartre",
    "salutations": [{
        "salutations_id": "12345",
        "rank": 1,
        "score": "0.6796357154846191",
        "typos": [        
            "185",
            "198",
            "199"
        ]
    }]
}

but for the same user but using his GSI i got as follow

{
    "customer_id":"jean",
    "customer_id_bis":"paul",
    "customer_id_tier":"sartre",
    "salutations": [{
        "salutations_id": "12345",
        "rank": 1,
        "score": "0.6796357154846191",
        "typos": []
    }]
}

I dont understand why i obtain different results for a same user.

Answer 1

Seems like your DynamoDB GSI is defined with KEYS_ONLY .

You have to project any additional attributes you'd like to have in GSI from the table

Optionally, since the query using the GSI returns the PK of the record, you can use GetItem() on the table.