The format of the SStables

BBoxDB uses two persistent data structures. SSTables and SStableIndex files. Each file begins with a ‘magic’ byte sequence which is currently ‘scalephant’. Files without this byte sequence are classified as invalid and not processed further.

SStable

Format of a data record:

+----------------------------------------------------------------------------------------------+
| Key-Length | BBox-Length | Data-Length |  Version  |  Insert   |   Key   |  BBox   |   Data  |
|            |             |             | Timestamp | Timestamp |         |         |         |
|   2 Byte   |   4 Byte    |   4 Byte    |  8 Byte   |  8 Byte   |  n Byte |  n Byte |  n Byte |
+----------------------------------------------------------------------------------------------+

SSTableIndex

Format of index records:

+----------------------------------------------------------------+
| Tuple-Position | Tuple-Position |  .........  | Tuple-Position |
|                |                |             |                |
|     4 Byte     |     4 Byte     |  .........  |     4 Byte     |
+----------------------------------------------------------------+

## SSTableIndex

R-Tree spatial index

Format of a index record:

+---------------------------------------------------------------------------------------------------+
| Node following | Node Id | BBox-Length |    BBox   |  n x entry nodes  |  n x index node pointer  |
|                |         |             |           |                   |                          |
|    1 Byte      | 4 Byte  |    4 Byte   |           |     n Bytes       |       n x 4 Bytes        |
+---------------------------------------------------------------------------------------------------+          