How to get the SUM of a Column from Dynamo DB using JAVA

Question

My table is in the below format:

|ID(primary)|date(String)|Result(number)|Accuracy(Number)|
|   edfca   |   20180101 |    12        |     59.99      |
|    yrdfa  |  20180109  |    72        |     91.49      |
| arfead    | 20180101   |    122       |     32.12      |
|  readssda | 20180112   |     12       |       33       |
| geeddar   | 20180123   |    3         |     81.11      | 
|  rogeasa  |  20180203  |     14       |       81       |
| swiwads   | 20180205   |     32       |      13.12     |

I want to get the sum of the Accuracy column. Do dynamoDB provide the Sum of the column similar to the SQL:

SQL query:

SELECT SUM(column_name)
FROM table_name
WHERE condition;

Is there any query similar to the Above.

From the below article: There is a reserved keyword 'SUM' https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html

But I'm Not able to find an example where the Keyword SUM is used in Java.

From the below link they have mentioned an example using HiveQL : https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/EMRforDynamoDB.Querying.html#w2ab1c33c13c17c11

Is there any option I can get the SUM of the column using Java.

I have an alternate option that is to get all the items using SCAN operation and then perform the addition of the column for all items. But this is a slow process takes a lot of time if there is a huge data.

Answer 1

IMHO the aggregate functions (or rather lack of them) is one of the pains when using DynamoDB. Hive SQL under the hood will scan/query anyway.

If you know what aggregates will be needed, you could keep them updated in other tables using dynamodb streams (and lambda and atomic counter).