I wonder know if MonetDB uses SIMD (Single Instruction Multiple Data) and if not How I can implement it for filtering or aggregation.
Having some hands-on experience with SIMD instructions I can tell you: it's harder than you'd think. Aggregation is feasible for a compiler to auto-vectorize but I doubt GCC does it (it would need to keep one aggregate per SIMD-lane and reduce that in the end). I could imagine ICC does that.
Filtering is VERY HARD (even by hand). The problem is that applying a predicate is not enough - you have to compact the result (i.e., throw out the values which don't qualify) and there aren't yet SIMD instructions to do that (in AVX-2). There are a lot of really smart database people thinking about how to do it by hand, i.e., using intrinsics. Unfortunately the resulting code won't make it into the MonetDB codebase because they cause portability problems.
On a more general note: Could you briefly explain what problem you're trying to solve? This seems a bit like a (vaguely defined) class assignment of pure academic value.