ComosDB 配置上的 ScalarDB

Question

I'd like to estimate the costs of Azure CosmosDB on Scalar DB. CosmosDB requires the following parameters. But these parameters are not ScalarDB parameters.

• API
• Number of Regions
• Multi-region writes
• Default consistency
• Indexing policy
• Total data stored in transactional store
• Use Analyltical Store
• Workload mode
• Item Size
• Number of properties
• Point reads/sec
• Creates/sec
• Updates/sec
• Deletes/sec
• Queries/sec
• Average RU charge per query

So, should we set which configuration and can we above parameters map to Scalar DB parameters?

I confirm the following questions. About Configuration

• API -> Cassandra
• Number of Regions -> If we need to write into multi-region, set over 2.
• Multi-region writes -> If the multi-regions is over 2, set to "Enabled"
• Default consistency -> Strong. But CosmosDB could satisfy transactions across multi-partitions. It is covered by Scalar DB.

About API calls Scalar DB APIs vs ComosDB APIs

• Put: Insert without condition => createItem()
• Put: Insert with condition => readItem() -> not exists -> createItem()
• Put: Update with condition => readItem() -> if conditions are satisfied -> merge columns -> replaceItem()
• Get -> readItem()
• Delete without condition => deleteItem()
• Delete with condition => readItem() -> if conditions are satisfied -> deleteItem()
• Scan => container.queryItems()

I think ScalarDB has some operations before the above operations which check the transaction state. So, Does Scalar DB require more ComosDB API Calls?

Answer 1

Please use the following settings.

• API: Core (SQL) (not Cassandra)
• Number of Regions: 1 (since Strong consistency doesn't support multi-region)
• Multi-region writes: Disabled (since Strong consistency doesn't support multi-region)
• Default consistency: Strong

For what Scalar DB API calls which Cosmos DB API, please check the code.