Oracle Corp. has pushed back the completion dates for some of the data centers it’s developing for the artificial intelligence model developer OpenAI to 2028 from 2027, according to people familiar with the work. The delays are largely due to labor and material shortages, said the people, asking not to be identified discussing private schedules. Oracle has been working to deliver on a $300 billion contract to supply the computing power necessary to train and run OpenAI’s models since it was