Example Accounts whose account-numberbegins with the digit 9 are special high- interest accounts with a minimum balance of 2500. ■General constraint:: If the first digit of t [account-number]is 9,then t [balance]>2500." DKNF design: Regular-acct-schema=(branch-name,account-number,balance) Special-acct-schema=(branch-name,account-number,balance) Domain constraints for {Special-acct-schema}require that for each account: The account number begins with 9. The balance is greater than 2500. Database System Concepts-7th Edition 28.12 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 28.12 ©Silberschatz, Korth and Sudarshan th Edition Example ▪ Accounts whose account-number begins with the digit 9 are special high￾interest accounts with a minimum balance of 2500. ▪ General constraint: ``If the first digit of t [account-number] is 9, then t [balance]  2500.'' ▪ DKNF design: Regular-acct-schema = (branch-name, account-number, balance) Special-acct-schema = (branch-name, account-number, balance) ▪ Domain constraints for {Special-acct-schema} require that for each account: • The account number begins with 9. • The balance is greater than 2500