- requestType is scan
- numBlocks is the number of blocks to scan at the top of the blockchain (optional)
- height is the height above which blockchain is to be scanned (optional if numBlocks provided)
- validate is true if signatures are to be re-verified and blocks and transactions re-validated (optional)
Note: The derived object tables are rolled back and rebuilt by rescanning the existing blockchain. A request to rescan more than 1440 blocks when table trimming is enabled will do a full rescan starting from height 0. Rescan status is saved in the database, so that if a rescan is interrupted or fails it will resume on restart.