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 ref_transaction_types (transaction_type_code CLOB, transaction_type_description 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 transactions_lots (transaction_id NUMBER, lot_id NUMBER)
CREATE TABLE purchases (purchase_transaction_id NUMBER, purchase_details CLOB)
CREATE TABLE investors (investor_id NUMBER, investor_details CLOB)

Show the average amount of transactions for different lots.
SELECT T2.lot_id, AVG(amount_of_transaction) FROM transactions AS T1 JOIN transactions_lots AS T2 ON T1.transaction_id = T2.transaction_id GROUP BY T2.lot_id
SELECT "T2"."lot_id", AVG("amount_of_transaction") FROM "transactions" "T1" JOIN "transactions_lots" "T2" ON "T1"."transaction_id" = "T2"."transaction_id" GROUP BY "T2"."lot_id"