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Various technologies and development platforms, vary in their power and cost. As opposed to the possible misconception of “If you want something good, you’ll have to pay more.”, often cheaper, or even gratis (or open-source) solutions are more powerful (not to mention more reliable and faster) than their more costly counterparts.
Often, however, the really good solutions will be an overkill. Most experts I’ve talked with agreed that the Oracle Database is the most powerful on the market and “years ahead of anything else out there”. However, most run-of-the-mill web applications won’t make use of even a small percentage of its advanced features, enough to justify using it instead of, say, the open-source and gratis PostgreSQL.
For many problem domains, Oracle would make the most sense, but it’s still not very useful in the general case.