Please provide the detailed answer for this:

Q1. Explain why primary index file might be smaller than the data file?

Q2. Give an example of a situation where hashing indexes might work better than a B tree index ?

Q3. Explain the main advantage(s) and disadvantage(s) of keeping the data le sorted?

Q4. Explain why writes to a log disk might be faster than writes to the disk containing the database?

Q5. Since indexes speed up searches, explain why the DBMS does not automatically create an index for every column of a table?