CREATE TABLE Investors (investor_id NUMBER, Investor_details VARCHAR2)
CREATE TABLE Transactions_Lots (transaction_id NUMBER, lot_id NUMBER)
CREATE TABLE Transactions (transaction_id NUMBER, investor_id NUMBER, transaction_type_code VARCHAR2, date_of_transaction DATETIME, amount_of_transaction NUMBER, share_count VARCHAR2, other_details VARCHAR2)
CREATE TABLE Lots (lot_id NUMBER, investor_id NUMBER, lot_details VARCHAR2)
CREATE TABLE Ref_Transaction_Types (transaction_type_code VARCHAR2, transaction_type_description VARCHAR2)
CREATE TABLE Sales (sales_transaction_id NUMBER, sales_details VARCHAR2)
CREATE TABLE Purchases (purchase_transaction_id NUMBER, purchase_details VARCHAR2)

Show the number of transactions for different investors with a scatter chart.
SELECT investor_id, COUNT(*) FROM Transactions GROUP BY investor_id
SELECT "investor_id", COUNT(*) FROM "Transactions" GROUP BY "investor_id"