When a query with multicolumn inequality is issued on clustering columns
having mixed order (ASC and DESC together), if the ranges are not
broken to none overlapping lexicographically monotonic ones, the node
return incorrect rows. This is due to the search nature
(prefix comparison). The solution is to break the range imposed
by the restriction into several single column restrictions OR-ed
together that will be logically equivalent and preserve the
monotonicity assumption. This commit also fixes incorrect results
returned by a multicolumn query on an all descending columns.
A unit test have been added to account for both issues fixed.
Fixes#2050
Tests: Unit test, manual tests of the use case in the issue.
Signed-off-by: Eliran Sinvani <eliransin@scylladb.com>
Message-Id: <3b96620a3bd8b0614359a3b0757f324d45189dbb.1536478193.git.eliransin@scylladb.com>
83628f5881