Very interesting question. Oracle's expansion into cloud/AI systems is no doubt fueling amplified earnings growth. Continued momentum in artificial intelligence should no doubt be a tailwind for Oracle. The only difficulty here is whether or not projected earnings and revenue growth not just from Oracle but from the AI sector overall are a bit too bullish right now.
I do believe over the long run Shopify has a bit more runway. There are a lot fewer competitors in its space, particularly ones that can provide any sort of edge over Shopify's ecosystem. But, Oracle is a mega cap, profitable company with rock-solid margins. Strong returns on invested capital, free cash flow generation, etc.
Only thing that rubs me the wrong way a bit about Oracle is the extensive debt and the share issuances. After going through a long period of buybacks, the company seems to have flipped the switch and now moved on to share and debt issuances. This is likely in an effort to expand AI infrastructure. If the industry continues to grow at an outsized pace, I'd imagine these equity/debt issuances will prove to be fruitful. Just something to keep in mind.
I'd view Oracle as the more blue-chip, safer play with some reasonable upside whereas Shopify would be the higher risk/higher reward play. Main reason I say this is not because Shopify is some speculative stock or anything. It's just valuations are a bit richer at this point in time and it will need to continue to perform and need the overall economy to improve to vault more activity from small and medium sized businesses.