Unverified50% confidenceFactExact time
Cardinality indicates the number of distinct values in a column and is closely related to selectivity; in composite indexes, it is usually more advantageous to place highly selective equality-predicate columns first.
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50%
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Long-term
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10/13/2026
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UnverifiedSelectivity refers to the ratio of the number of distinct values in a column to the total number of rows; indexes on highly selective columns (such as email or order number) can quickly filter out large numbers of rows, while indexes on low-selectivity columns (such as gender or status flags) yield limited benefit, and a sequential scan may be faster.71% similarUnverifiedThe core characteristics of multivariate ordinal data with covariates are that the scores are ordered (differences between scores are not necessarily equidistant), multi-dimensional, and influenced by external covariates.68% similarUnverifiedPlacing the most relevant chunks at the beginning or end of the prompt rather than arranging them in order of retrieval score often improves generation quality.68% similarUnverifiedThe column order of a composite index is crucial, as the leading column determines which query patterns the index can efficiently support; an index beginning with customer_id can support queries filtering only by customer, but may not efficiently support queries filtering only by status.66% similarUnverifiedThe author believes that optimizations targeting sequential access are very likely to become standard components in long-context reasoning stacks.64% similar
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