azure cosmosdb - Difference between Client.CreateDocumentAsync( ) and documents.AddAsync( );

Question

I have one Azure Function which is adding documents to cosmos db. One way of adding is by creating a cosmos client and then calling client.CreateDocumentAsync( ) and other is creating an Output binding to Azure Function with IAsyncCollector documents and then calling documents.AddAsync().

I would like to know what's the difference between these two and which one is more preferable.

Thanks

question from:https://stackoverflow.com/questions/65905273/difference-between-client-createdocumentasync-and-documents-addasync

Answer 1

Two main differences:

• Output binding maintains a single static instance of the client across executions. When you are calling client.CreateDocumentAsync you are in charge of maintaining the client instance, and the recommendation is to follow the singleton pattern to avoid opening multiple connections and not sharing them across executions.
• Output binding actually does a UpsertDocumentAsync when AddAsync is called on the IAsyncCollector, you can check the source code: https://github.com/Azure/azure-webjobs-sdk-extensions/blob/dev/src/WebJobs.Extensions.CosmosDB/Bindings/CosmosDBAsyncCollector.cs#L28