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In our case the root cause was an implicit cast preventing pushdown.
Team is split on approach A vs B. Looking for experiences from similar scale.
Context: SQL window function question, top 3 orders per customer
Happy to share schema snippets or metrics if useful.
In our case the root cause was an implicit cast preventing pushdown.
ELI5: think of it like a phone book. If it's sorted by last name and you search by last name, that's fast. Search by first name instead and you're flipping through every page.
Plain English: the system prefers to guess a good-enough plan than the perfect plan, because figuring out the perfect plan would take longer than just running the good-enough one.
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