I just wonder, in normal way, my MS Access is around 35MB. After it is crashed and created a backup in the same folder automatically, it is now around 18MB. Why?
Because you probably hadn't compacted the database previously and a new database file doesn't have all of the reserved space (from deleted objects and data) that will occur naturally over time.
That is why you must run the COMPACT AND REPAIR feature as a regular part of maintenance.
When you delete something, Access doesn't really delete it (it just marks it for deletion) until you run the compact and repair.
Yes during development you should regularly:
- Compact & Repair
- Backup your work
Also if your DB deletes data over time in production, you should (somehow) program in a compact and repair after the delete has been done. Which is one of the reasons a lot of DBs have a "backend" database which you can compact pretty easily.