[lichtenberger]

Good catch :-) right, but still merging/compaction work has to be done. Maybe too much, if you just need to fetch a value by its key and thus just an equality scan is needed (no range scans or other comparisons). For the latter case I've implemented an AVL-tree, which is also versioned and stored in our record pages and best read fully in-memory (but doesn't have to). For sure there are plenty of optimizations and for instance also spatio-temporal indexes or full-text indexes possible, but I guess first looking into cost-based rewrite rules for the query compiler and replication/partitioning for horizontal scaling. Too many ideas I guess ;-) but the best would be to have a great open source community :-)