MySQL 8.2.0
Source Code Documentation
estimate_selectivity.h
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22
23#ifndef SQL_JOIN_OPTIMIZER_ESTIMATE_SELECTIVITY
24#define SQL_JOIN_OPTIMIZER_ESTIMATE_SELECTIVITY
25
26#include <string>
27
28class CompanionSet;
29class THD;
30class Item;
31
32/**
33 For the given condition, to try estimate its filtering selectivity,
34 on a 0..1 scale (where 1.0 lets all records through).
35 */
36double EstimateSelectivity(THD *thd, Item *condition,
37 const CompanionSet &companion_set,
38 std::string *trace);
39
40#endif // SQL_JOIN_OPTIMIZER_ESTIMATE_SELECTIVITY
RelationalExpression objects in the same companion set are those that are inner-joined against each o...
Definition: relational_expression.h:77
Base class that is used to represent any kind of expression in a relational query.
Definition: item.h:932
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_lexer_thd.h:35
double EstimateSelectivity(THD *thd, Item *condition, const CompanionSet &companion_set, std::string *trace)
For the given condition, to try estimate its filtering selectivity, on a 0..1 scale (where 1....