Sun Microsystems purchase of MySQL for $1 billion is not only the largest open-source deal yet, it's almost bigger than all previous open-source deals combined, including RedHat's $326 million buy of JBoss, Citrix's $500 million purchase of XenSource and Yahoo's $350 million acquisition of Zimbra.

But the deal raises a number of questions for Sun. Was that $1 billion well spent? What will Sun do with its new database? And will the purchase improve its standing in the enterprise? More important than the $1 billion price tag, however, is whether Sun can execute its strategy of taking a database that's popular in certain circles and successfully move it into the enterprise accounts, where they are a well-respected vendor.

Whatever technical issues Sun may face in integrating MySQL into its current stack pale in comparison with the marketing challenge.In the scheme of things, the most important IT issue for large businesses is reliability. For databases, companies need to know product is solid, can scale and won't go down if they make severe demands on it.