You have a table with the following rowkeys:
r1, r2, r3, r10, r15, r20, r25, r30, r35
In which order will these rows be retrieved from a scan?

A.
r35, r30, r3, r25, r20, r2, r15, r10, r1

B.
r1, r2, r3, r10, r15, r20, r25, r30, r35

C.
r1, r10, r15, r2, r20, r25, r3, r30, r35

D.
r35, r30, r25, r20, r15, r10, r3, r2, r1

Explanation:
If you can have the table receiving rows always in decreasing order of the row keys,
you then have easy access to the first and last rows. This is possible because HBase tables are
always sorted by row key.