To identify the blocks of data you want to view, use offset and span. The values you assign to offset and span, together, define a contiguous string of blocks that you want to view:

• The value assigned to offset specifies the relative block at which to start the view. An offset of 0 means the first block; an offset of 1 means the second block; an offset of 2 means the third block, and so forth.
• The value assigned to span specifies the number of blocks to view. A span of 1 means one block; a span of 2 means two blocks, and so forth. A span of 0 has special meaning: it means the view is to start at the specified offset and extend until the currently defined end of the object.