Expand description
Cardinality estimation for query optimization.
Estimates the number of rows produced by each operator in a query plan.
§Equi-Depth Histograms
This module provides equi-depth histogram support for accurate selectivity estimation of range predicates. Unlike equi-width histograms that divide the value range into equal-sized buckets, equi-depth histograms divide the data into buckets with approximately equal numbers of rows.
Benefits:
- Better estimates for skewed data distributions
- More accurate range selectivity than assuming uniform distribution
- Adaptive to actual data characteristics
Structs§
- Cardinality
Estimator - Cardinality estimator.
- Column
Stats - Statistics for a column.
- Equi
Depth Histogram - An equi-depth histogram for selectivity estimation.
- Histogram
Bucket - A bucket in an equi-depth histogram.
- Table
Stats - Statistics for a table/label.