diff options
Diffstat (limited to 'src/mongo/db/query/ce/histogram_estimation.h')
| -rw-r--r-- | src/mongo/db/query/ce/histogram_estimation.h | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/src/mongo/db/query/ce/histogram_estimation.h b/src/mongo/db/query/ce/histogram_estimation.h index b949d0b752e..0e554993983 100644 --- a/src/mongo/db/query/ce/histogram_estimation.h +++ b/src/mongo/db/query/ce/histogram_estimation.h @@ -59,7 +59,8 @@ struct EstimationResult { EstimationResult getTotals(const ScalarHistogram& h); /** - * Estimates the cardinality of a predicate of the given type against the histogram. + * Compute an estimate for a given value and estimation type. Use linear interpolation for values + * that fall inside of histogram buckets. */ EstimationResult estimate(const ScalarHistogram& h, sbe::value::TypeTags tag, @@ -74,4 +75,26 @@ double estimateIntervalCardinality(const ArrayHistogram& estimator, const optimizer::IntervalRequirement& interval, optimizer::CEType inputCardinality); +/** + * Estimates the cardinality of an equality predicate given an ArrayHistogram and an SBE value and + * type tag pair. + */ +double estimateCardEq(const ArrayHistogram& ah, sbe::value::TypeTags tag, sbe::value::Value val); + +/** + * Estimates the cardinality of a range predicate given an ArrayHistogram and a range predicate. + * Set 'includeScalar' to true to indicate whether or not the provided range should include no-array + * values. The other fields define the range of the estimation. + */ +double estimateCardRange(const ArrayHistogram& ah, + bool includeScalar, + /* Define lower bound. */ + bool lowInclusive, + sbe::value::TypeTags tagLow, + sbe::value::Value valLow, + /* Define upper bound. */ + bool highInclusive, + sbe::value::TypeTags tagHigh, + sbe::value::Value valHigh); + } // namespace mongo::ce |