Currently working on a project that is centered around a medical vocabulary known as SNOMED. At the heart of snomed is a (relational) dataset that is 350,000 terms/records in length. We want to be able to quickly query this dataset for the data entry portion where we would like to have some shape or form of auto-completion/suggestion. 

Its currently in a MySQL MyISAM DB just for dev purposes but we want to start playing with some in memory options. It's currently 30MB including the indexes. The MEMORY MySQL Engine and MemCached were the obvious ones, so my question is which of these would you suggest or is there something better out there? We're working in Python primarily at the app level if that makes a difference.

*Side Note: The dataset has a separate relation that maps these concepts to common alias names and abbreviations that is about 1.3 million records... eventually we'll want to use a subset of this as well here.*