I am fascinated by what I call “equal SQL”: statements that are equivalent, in that they deliver the same result but may have hugely different performance characteristics. Here’s a little case study. Consider this example, working in the OE demonstration …
HCC is available only on Oracle supplied storage, such as a ZFS storage appliance or (as in this case) an Exadata engineered system. Furthermore, it occurs only for direct loads: in my examples, using CTAS. This is the script I’m …
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