SQL Window Functions: The Tutorial Most Skip
Window functions don't collapse rows. They compute across them. That's the whole superpower.
Window functions, CTEs, indexing strategy — query patterns that scale.
Window functions don't collapse rows. They compute across them. That's the whole superpower.
CTEs are subqueries with a name. Sometimes the optimizer treats them differently. Know when that matters.
INNER, LEFT, RIGHT, FULL, CROSS, SELF. One of those you'll never type. The others map to real shapes of data.
N+1 is the bug that turns 50ms into 5 seconds. Three fixes cover almost every case.