A space tile is defined by specifying a tile extent along each dimension. The domain of each dimension is partitioned into segments equal to the tile extent, and hyper-rectangular tiles are formed in the multi-dimensional array space. The space tile concept applies to both dense and sparse arrays (as well as real dimensions) and is independent of the actual data stored in the array.
TileDB allows the user to specify an order for the space tiles, as well as the cells inside each space tile. The order can be:
Row-major: Assuming each tile or cell can be identified by a set of coordinates in the multi-dimensional space, row-major means that the rightmost coordinate index “varies the fastest”.
Column-major: Assuming each tile or cell can be identified by a set of coordinates in the multi-dimensional space, column-major means that the leftmost coordinate index “varies the fastest”.
The tile and cell order collectively determine the global cell order. The global cell order is essentially a mapping from the multi-dimensional cell space to the 1-dimensional physical storage space for the non-empty cells, i.e., it is the order in which TileDB stores the cell values on disk.