Cardinality Estimation
Everything on SkillVeris tagged Cardinality Estimation — collected across the glossary, study notes, blog, and cheat sheets.
3 resources across 1 library
Interview Questions(3)
What Role Do Statistics and Histograms Play in Query Planning?
Statistics and histograms are metadata the database keeps about the distribution of values in each column, and the query optimizer uses them to estimate how ma…
What are the Limitations of a Cost-Based Query Optimizer?
A cost-based optimizer’s limitations stem from the fact that it estimates a query’s cheapest plan using statistics and heuristics rather than executing anythin…
What is HyperLogLog and How Does It Count Distinct Elements?
HyperLogLog is a probabilistic algorithm that estimates the number of distinct elements (cardinality) in a massive dataset using only a few kilobytes of memory…