Answer:
A flat file database stores data in a single table structure. A relational database uses multiple table structures, cross-referencing records between tables. Tables in both organize records in rows, with each column containing a single piece of data in the record.
You cannot select it because it is either not able to be done at the time or there was an error.
Answer: Its not appropriate to call the same day, probably the next day you can call, if they don't respond because that person could have been working the whole day and have not got a chance to read or see your email.
Explanation:
