querySome

  def scanSome[A: Schema](
    tableName: String,
    limit: Int
  ): DynamoDBQuery[A, (Chunk[A], LastEvaluatedKey)] = ???  

The scanSome operation is used page limit number of items in a table, and returns them in a tuple of Chunk[A] and LastEvaluatedKey. The LastEvaluatedKey can be used to continue scanning the table from where the last page left off using the startKey combinator.

This paging behavior is useful when you have a large number of items in a table and you want to process them in smaller chunks to avoid memory issues - eg a REST API for a paging front end.

for {
  _                          <- put(tableName, Equipment("1", 2020, "Widget1", 1.0)).execute
  _                          <- put(tableName, Equipment("1", 2021, "Widget1", 2.0)).execute
  _                          <- put(tableName, Equipment("1", 2022, "Widget1", 2.1)).execute
  t                          <- querySome[Equipment](tableName, limit = 2).execute
  (page1, lastEvaluatedKey1) =  t
  t2                         <- querySome[Equipment](tableName, limit = 1).startKey(lastEvaluatedKey1).execute
  (page2, lastEvaluatedKey2) =  t2
} yield ()

Combinators

<SCAN_SOME_QUERY>
  .consistency(<ConsistencyMode>)
  .whereKey(<KeyConditionExpr>)  // eg Equipment.id.partitionKey === "1" && Equipment.year.sortKey > 2020
  .startKey(<LastEvaluatedKey>)
  .filter(<ConditionExpression>) // eg Equipment.price > 1.0 - filtering is done server side AFTER the scan
  .sortOrder(ascending)          // ascending is a boolean flag
  .indexName(<IndexName>)        // use a secondary index