A list of tables that were processed by BatchWriteItem and, for each table, information about any item collections that were affected by individual DeleteItem or PutItem operations.
Each entry consists of the following subelements:
ItemCollectionKey - The partition key value of the item collection. This
is the same as the partition key value of the item.
SizeEstimateRange - An estimate of item collection size, expressed in
GB. This is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on the table. Use this estimate to measure whether a local secondary index is approaching its size limit.
The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.