MySQL 8.3.0
Source Code Documentation

See EstimateFilterCost. More...
#include <cost_model.h>
Public Attributes  
double  cost_if_not_materialized {0.0} 
Cost of evaluating the filter for all rows if subqueries are not materialized. More...  
double  init_cost_if_not_materialized {0.0} 
Initial cost before the filter can be applied for the first time. More...  
double  cost_if_materialized {0.0} 
Cost of evaluating the filter for all rows if all subqueries in it have been materialized beforehand. More...  
double  cost_to_materialize {0.0} 
Cost of materializing all subqueries present in the filter. More...  
See EstimateFilterCost.
double FilterCost::cost_if_materialized {0.0} 
Cost of evaluating the filter for all rows if all subqueries in it have been materialized beforehand.
If there are no subqueries in the condition, equals cost_if_not_materialized.
double FilterCost::cost_if_not_materialized {0.0} 
Cost of evaluating the filter for all rows if subqueries are not materialized.
(Note that this includes the contribution from init_cost_if_not_materialized.)
double FilterCost::cost_to_materialize {0.0} 
Cost of materializing all subqueries present in the filter.
If there are no subqueries in the condition, equals zero.
double FilterCost::init_cost_if_not_materialized {0.0} 
Initial cost before the filter can be applied for the first time.
Typically the cost of executing 'independent subquery' in queries like: "SELECT * FROM tab WHERE field = <independent subquery>". (That corresponds to the Item_singlerow_subselect class.)