CREATE TABLE web_client_accelerator (id NUMBER, name CLOB, operating_system CLOB, client CLOB, connection CLOB)
CREATE TABLE browser (id NUMBER, name CLOB, market_share NUMBER)
CREATE TABLE accelerator_compatible_browser (accelerator_id NUMBER, browser_id NUMBER, compatible_since_year NUMBER)

How many different kinds of clients are supported by the web clients accelerators?
SELECT COUNT(DISTINCT client) FROM web_client_accelerator
SELECT COUNT(DISTINCT "client") FROM "web_client_accelerator"