If you are referring to indices on expressions, MemSQL definitely supports them. In MemSQL you do it by creating a computed column (http://docs.memsql.com/v5.0/docs/persistent-computed-columns) and creating an index over one of those. Computed columns turn out to give you a significant perf boost since you only have to run the expression once (at INSERT time), and never while executing a SELECT query or seeking in the index.