Playing around with Dynamo DB in Java (choice of language because of $DAYJOB$) I run this as an Eclipse Project for now

• AWS Java SDK

• AwsCredentials.properties placed under src/ with your ACCESS and SECRET KEY

• Tables in DynamoDB - either created via Management Console or API

• AmazonDynamoDBSample contains code

I ran some naive tests to get an idea of performance.

Individual inserts -

Throughput - 10, 10 (R,W) 1000 records Done adding to DB : Took millis : 100231 => 100seconds

Increased throughput - 20, 20 (R,W) - MAX 1000 records Same index prefix as before Done adding to DB : Took millis : 50921 => 50seconds

Nice! And as expected.

The API supports batch operations as well that should yield much better results

Individual inserts for 10K records takes ~1000 seconds => ~16 mins

Table Scan is pretty fast till a limit. After that it's slow/expensive and its limited to 1 MB anyway.

Created a second table which has reverse mapping. Primary - isGoogleEnabled Range - Key

During a put, I insert in 2 tables. The second table has just 2 attributes per item.

Now I can query - simply if Google is Enabled And then use those keys to fetch the remaining data

For table containing about 20K records - A query takes about - 3.8s to get the keys. To get the actual items, there is one more step.

My JAVA skills are rusty (adding Strings in a loop is not a good idea :) )

There are several wrapper DynamoDB APIs in the wild. Might be better to use them. Also I saw an example on AWS where they used Java Annotations. http://docs.amazonwebservices.com/amazondynamodb/latest/developerguide/JavaCRUDHighLevelExample1.html

Another helpful example (much cleaner API) - http://openmymind.net/2012/2/6/Lets-Build-Something-Using-Amazons-DynamoDB/

@DAYJOB we use GoogleAppEngine. Classes are serialized easily because of DataNucleus and other JAVA mumbo jumbo. I used brute force here to flatten out a class.

The class in question is - com.agent8.data.ActiveUser