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

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"