I've just installed ObjectDB and done some tests. I'm inserting 22k of records like 10k iterations of 22 linked entites. I've got indexes on Long id on every entity and additionally one entity have index on String column. Entities are not enhanced and inserts are committed in a separate transactions. My hardware is Intel i7 2x3.3GHz with 8Gb RAM. At first results was really impressive: 8,5 seconds against 30 seconds with hibernate+mysql. Then I started the test again and got 9,5 seconds; then 11 seconds and so on. Should I change my config in some way to get more stable insertion time?