Oracle Corporation is to buy Sun Microsystems Inc. for $9.50 a share in a deal valued at $7.4 billion, just a few weeks after a deal by IBM to buy Sun fell apart. It looks like Oracle will pay a premium of $2.81 a share, or 42%, over Sun Micro’s closing price of $6.69 a share on Friday. Oracle said the deal is valued at $5.6 billion excluding cash and debt. Oracle is calling Sun’s Java “the most important software” it has ever acquired. The deal has massive implications for the future openness of Java and MySQL.