A huge Amazon warehouse Prime Day outage may have been caused by moving off Oracle's databases

Amazon did not have a great Prime Day this year. 

The ecommerce giant's website crashed, and separately shipping slowed down at one of Amazon's warehouses in Ohio due to a technical problem. 

CNBC reported that the warehouse outage was caused by Amazon moving off Oracle's database software to its own technology. This delayed 15,000 package deliveries and wasted $90,000 in labor costs, not including the hours spent by engineers troubleshooting, according to CNBC's reporting. 

Amazon's CTO Werner Vogels responded to the CNBC story with a tweet, saying that an application issue at a single fulfillment center led to a slight delay in shipping of products from that facility. The tweet said that there was a temporary situation where "the database was very slow and the application experienced intermittent timeouts."

Previously, Amazon announced it would move completely off Oracle's database by 2020. Oracle cofounder, chief technology officer and executive chairman Larry Ellison has since scoffed at the idea, saying  "it's kind of embarrassing" that Amazon uses Oracle's databases to power its business.  

Oracle also responded saying that just a year ago, Amazon spent $60 million on Oracle software. And on Monday at the Oracle OpenWorld keynote, Ellison compared Amazon's database to a semi-autonomous car, saying, "You get in, you start driving, you die." 

The Ohio warehouse was the largest of the 13 warehouses that moved its database off of Oracle's before Prime Day, CNBC reported.

UPDATE: This story has been updated to reflect a response on Twitter from Amazon CTO Werner Vogels.