meteor

High Level API

The actions API is considered low level because it is a 1-2-1 mapping to the Java AWS SDK calls. In contrast, high level API abstracts over DynamoDB tables which makes it simpler to work with. For example:

Low level API action:

import meteor._
import cats.effect.IO

val client: Client[IO] = ???
val booksTable = PartitionKeyTable[Int]("books-table", KeyDef[Int]("id", DynamoDbType.N))
val lotr = Book(1, "The Lord of the Rings")

val get =
  client.get[Int, Book](
    booksTable,
    1,
    consistentRead = false
  )

High level API table:

import meteor._
import meteor.api.hi._
import cats.effect.IO

val jClient: DynamoDbAsyncClient = ???
val booksTable = SimpleTable[IO, Int]("books-table", KeyDef[Int]("id", DynamoDbType.N), jClient)
val lotr = Book(1, "The Lord of the Rings")

val put = booksTable.get[Book](1, consistentRead = false)

The differences might not look like much, but there are several benefits that high level API provides.

When using low level API actions, it can get confusing sometimes when there are several overloaded methods for the same actions to cater use cases for a table with a partition key or for a table with composite keys. The high level API removes this confusion by only provide the methods that are actionable on the table. It also bounds the key’s type(s) to table’s definition to reduce the number of type parameters required. Context bound of F[_] is now also on the method’s level.

Supports

  • SimpleTable represent a DynamoDB table which only has partition key index.
  • CompositeTable represent a DynamoDB table which has both partition key and sort key indexes.
  • SimpleIndex represent a secondary index on a partition key.
  • SecondaryCompositeIndex represent a secondary index on composite keys.

Limitations

Table actions and scan actions are not supported in high level API to keep them flexible.

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