Supply and optimise more OP_VALUE_ comparison operators
|Reported by:||Richard Boulton||Owned by:||visvesh|
Description (last modified by )
We currently supply OP_VALUE_GE and OP_VALUE_LE. It might be useful to also supply OP_VALUE_GT and OP_VALUE_LT, and possibly OP_VALUE_EQ.
Also, we currently supply a range operator which can be represented in terms of two comparison operators: ie, OP_VALUE_RANGE(1, a, b) is equivalent to: (OP_VALUE_GE(1, a) AND OP_VALUE_LE(1, b)). It would be nice to teach the query optimiser about this equivalence, so that a range specified as two comparison operators would be transformed into an efficient single ValueRangePostList internally, instead of the combination of two Value*Cmp*PostLists. Also, the ValueRangePostList could be made more flexible by adding flags to tell it whether each end of the range is inclusive or not, to allow other combinations of comparison operator to be represented as ranges.
Change History (11)
comment:4 by , 12 years ago
|Status:||assigned → new|