anchor.diff:              async { 
                   let! bc = Blob.Create(config, partitionKey, guid(), fun () -> value)
                   if overwrite then
  -                    let e = new BlobReferenceEntity(partitionKey, mkRowKey rowKey index, null, ETag = "*")
  +                    let e = new BlobReferenceEntity(partitionKey, BlobReferenceEntity.MakeRowKey(rowKey, index), null, ETag = "*")
                       e.Uri <- bc.Path
                       let! _ = Table.merge config config.RuntimeTable e
                       return! completed()
                   else
  -                    let entity = Table.read<BlobReferenceEntity> config 
  -                    let! _ = Table.transact<BlobReferenceEntity> config config.RuntimeTable partitionKey (mkRowKey rowKey index)
  +                    let! _ = Table.transact<BlobReferenceEntity> config config.RuntimeTable partitionKey (BlobReferenceEntity.MakeRowKey(rowKey, index))
                                   (fun e ->
                                       if e.Uri = null then e.Uri <- bc.Path)
                       return! completed()
  
positive.code: 
      let getEntities () = async {
          let pkFilter = TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, partitionKey)
          let lower = mkRowKey rowKey 0
          let upper = mkRowKey rowKey size
          let rkFilter = 
              TableQuery.CombineFilters(
                  TableQuery.GenerateFilterCondition("RowKey", QueryComparisons.LessThanOrEqual, upper),
  
negative.code: 
  open System
  open System.Runtime.Serialization
  open Microsoft.WindowsAzure.Storage.Table
  open MBrace.Core.Internals
  open MBrace.Azure
  open MBrace.Azure.Runtime.Utilities
  open MBrace.Runtime
  
  type BlobReferenceEntity(partitionKey, rowKey, uri : string) = 
      inherit TableEntity(partitionKey, rowKey)
      member val Uri = uri with get, set
      new() = BlobReferenceEntity(null, null, null)
      static member internal MakeRowKey(rowKey, index) = sprintf "%s:%010d" rowKey index
  
  
  [<DataContract; Sealed>]
  type ResultAggregator<'T> internal (config : ConfigurationId, partitionKey : string, rowKey : string, size : int) = 
  
      [<DataMember(Name = "config")>]
      let config = config
  