Oracle (s orcl) said it will pay $68 per share for Micros Systems, a company that makes cash register software for the retail and hospitality industry. The deal is valued at about $5.3 billion, or at $4.6 billion when taking into account Micros's cash. The deal gets Oracle deeper into the retail market where its rival SAP is fairly strong, and is the biggest acquisition for Oracle since buying Sun Microsystems in 2010 for $7.4 billion. The Micro deal is expected to close in the second half of this year.