流数据的最佳和唯一主键

Newbie question.... In a project, capturing streaming market data onto an SQL server using JDBC, I am retrieving the data using Java from the broker's systems,... What's best and unique primary key possible to use on the SQL database .. and what's its java equivalent. The project is to capture forex market data continuously for the 6 trading days straight (144 hours). - Thank you.Newbie question.... In a project, capturing str