- No but the key point is you will be creating this index in small steps. Adding an index is a change in schema, schema updates are always executed "per actor".

- No but the key point is you will be creating this index in small steps. Adding an index is a change in schema, schema updates are always executed "per actor". This means actors who are currently not doing anything, will not perform this schema change. Once that actor is required to do something it will perform the schema update. This can be right after schema change, or it can be 10 days later. - We are limited to what SQLite supports. If you absolutely must drop a column, you can only do it by re-creating a table. Again the above point stands. You will not be doing this for the entire database at once. - There is a backup tool. It basically uses lmdb backup functionality. It will perform a database copy very quickly if you are copying to a second disk (at the performance limit of sequential writes).