Accumulator $push not implemented yet. In Cosmos MongoDB

Question

I am using Aggregation in AzureCosmosDB, my collection have many messages and I want to group it by user_id. This is my pipeline:

{"$group": {"_id": "$user_id", "messages": {"$push": "$$ROOT"}}}

But when I ran aggregate, I found an error :

Accumulator $push not implemented yet

I have found the document supported $push accumulator here https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/feature-support-42#accumulator-expressions

So do I use it wrong or I need to call it in another way to use this feature ?

Answer 1

From the screenshot you've shared, you're trying out Cosmos DB for MongoDB vCore, $push aggregation operator in $group stage is not supported with vCore yet. The above documentation is for Cosmos DB for MongoDB RU