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Amazon's emergence as a major provider of data center technology has turned many of its longtime suppliers, including Oracle, into heated rivals. Now Amazon is dealing yet another blow to Oracle. The e-commerce giant, having already moved much of its infrastructure internally to Amazon Web Services, plans to be completely off Oracle's proprietary database software by the first quarter of 2020, according to people familiar with the matter. The shift is another sign of Amazon's rapid ascent in enterprise computing and further shows how much Oracle is struggling to keep pace as businesses move workloads to the cloud and away from traditional data centers. Propelled in part by expansion at AWS, which reported 49 percent revenue growth for the second quarter, Amazon passed Alphabet earlier this year to become the second most valuable publicly traded company in the world. Meanwhile, Oracle is about the same size it was four years ago and the stock is just above where it was trading at the end of 2014. Oracle shares dropped by about 1 percent after the initial report Wednesday.

Amazon began moving off Oracle about four or five years ago, said one of the people, who asked not to be named because the project is confidential. Some parts of Amazon's core shopping business still rely on Oracle, the person said, and the full migration should wrap up in about 14 to 20 months. Another person said that Amazon had been considering a departure from Oracle for years before the transition began but decided at the time that it would require too much engineering work with perhaps too little payoff. The primary issue Amazon has faced on Oracle is the inability for the database technology to scale to meet Amazon's performance needs, a person familiar with the matter said. Another person, who said the move could be completed by mid-2019, added that there hasn't been any development of new technology relying on Oracle databases for quite a while. Amazon's infrastructure is certainly not foolproof. The company's constant need for capacity upgrades turned into a near crisis during Amazon's Prime Day shopping extravaganza last month, when the company's systems proved incapable of handling a sudden traffic surge. Shoppers reported numerous errors trying to access the site and CNBC learned the snafu was related to a breakdown in an internal program called Sable, which is used by Amazon to provide storage services to its retail and digital businesses.

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