CODEWITHSUNDEEP
node.jsamazon-dynamodbaws-lambdanosql
Rudresh
Rudresh

Reputation: 75

How to get last inserted data from DynamoDb in lambda function

I am having table in Dynam0Db with,
timestamp as Partition Key,
Status as normal column.

I am inserting the timestamp and status in DynamoDb when ever new data comes.

I want to retrieve the last added data to the table(here we can refer timestamp).

So how can i do this(I am using lambda function with NodeJs language).

If any queries in question comment below, Thanks.

Upvotes: 1

Views: 9248

Answers (2)

Tofig Hasanov
Tofig Hasanov

Reputation: 3709

Stream->Lambda approach suggested in previous answer is OK, however that will not work if you need to retrieve latest entry more than once. Alternatively, because you always have exactly one newest item, you can simply create another table with exactly one item with constant hash key and overwrite it every time you do update. That second table will always contain 1 record which will be your newest item. You can update that second table via stream from your main table and lambda, or directly from your application that performs original write.

[Update] As noted in the comments, using only 1 record will limit throughput to 1 partition limits (1000 WCU). If you need more, use sharding approach: on write store newest data randomly in one of N records, and on read scan all N records and pick the newest one.

Upvotes: 1

Sigma
Sigma

Reputation: 542

You can make a query on your table with these parameters :

Limit: 1,
ScanIndexForward : false

But it seems complicated to do the query because of the timestamp as a partition key.

The other way is to generate a stream at every new entry in your table that trigger a lambda function : enter image description here

Upvotes: 3

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