CREATE TABLE transactions (transaction_id NUMBER, investor_id NUMBER, transaction_type_code CLOB, date_of_transaction TIME, amount_of_transaction NUMBER, share_count CLOB, other_details CLOB)
CREATE TABLE transactions_lots (transaction_id NUMBER, lot_id NUMBER)
CREATE TABLE ref_transaction_types (transaction_type_code CLOB, transaction_type_description CLOB)
CREATE TABLE investors (investor_id NUMBER, investor_details CLOB)
CREATE TABLE sales (sales_transaction_id NUMBER, sales_details CLOB)
CREATE TABLE lots (lot_id NUMBER, investor_id NUMBER, lot_details CLOB)
CREATE TABLE purchases (purchase_transaction_id NUMBER, purchase_details CLOB)

Show the id and details of the investor that has the largest number of transactions.
SELECT T2.investor_id, T1.investor_details FROM investors AS T1 JOIN transactions AS T2 ON T1.investor_id = T2.investor_id GROUP BY T2.investor_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."investor_id", "T1"."investor_details" FROM "investors" "T1" JOIN "transactions" "T2" ON "T1"."investor_id" = "T2"."investor_id" GROUP BY "T2"."investor_id" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY