Write a quarterly SQL report and a bash max-file script

## Part A — SQL (conditional aggregation) You have two tables: - `coins(coin_id, name)` - `transactions(id, coin_id, dt, amount)` Write a query that returns **one row per coin** with the following columns: - `name` - `q1_amount`, `q2_amount`, `q3_amount`, `q4_amount` (sum of `amount` for transactions whose `dt` falls in quarter 1/2/3/4) - `total_transactions` (count of transactions for that coin) - `total_amount` (sum of `amount` for that coin) Assume all transactions are within the same calendar year; if multiple years exist, state how you would filter to a target year. ## Part B — Bash (filesystem) Given a directory path, implement a shell function that returns the **maximum file size (bytes)** among all regular files under that directory. Clarify whether the search is recursive; if not specified, assume **recursive** (include subdirectories). Handle the empty-directory case sensibly (e.g., return `0` or no output) and avoid counting directories.