streamViewType

When an item in the table is modified, `StreamViewType` determines what information is written to the stream for this table. Valid values for `StreamViewType` are: + `KEYS_ONLY` - Only the key attributes of the modified item are written to the stream. + `NEW_IMAGE` - The entire item, as it appears after it was modified, is written to the stream. + `OLD_IMAGE` - The entire item, as it appeared before it was modified, is written to the stream. + `NEW_AND_OLD_IMAGES` - Both the new and the old item images of the item are written to the stream.