4D stores records in contiguous blocks of 128 bytes. Therefore a record never occupies less than 128 bytes – the space occupied is therefore always a multiple of 128 bytes. When you create and then save a record 4D calculates the size of this record. It then looks for the first available blocks that have enough space to save the record. For example if your record is 280 bytes, 4D will need a block of 384 bytes (128 * 3). If you have any fat fields (text, BLOB or picture) these will be stored in a separate place. A pointer to this location will be stored with the original record.