MySQL 9.0.0
Source Code Documentation
Item::Css_info Struct Reference

Minion class under Collect_scalar_subquery_info ("Css"). More...

#include <item.h>

Public Attributes

int8 m_locations {0}
 set of locations More...
 
Item_singlerow_subselectitem {nullptr}
 the scalar subquery More...
 
table_map m_correlation_map {0}
 
Itemm_join_condition {nullptr}
 Where did we find item above? Used when m_location == L_JOIN_COND, nullptr for other locations. More...
 
bool m_implicitly_grouped_and_no_union {false}
 If true, we can forego cardinality checking of the derived table. More...
 
bool m_add_coalesce {false}
 If true, add a COALESCE around replaced subquery: used for implicitly grouped COUNT() in subquery select list when subquery is correlated. More...
 
bool m_add_having_compensation {false}
 Set iff m_add_coalesce is true: we may get a NULL anyway even for COUNT if a HAVING clause is false in the subquery. More...
 
uint m_having_idx {0}
 Index of the having expression copied to select list. More...
 

Detailed Description

Minion class under Collect_scalar_subquery_info ("Css").

Information about one scalar subquery being considered for transformation

Member Data Documentation

◆ item

Item_singlerow_subselect* Item::Css_info::item {nullptr}

the scalar subquery

◆ m_add_coalesce

bool Item::Css_info::m_add_coalesce {false}

If true, add a COALESCE around replaced subquery: used for implicitly grouped COUNT() in subquery select list when subquery is correlated.

◆ m_add_having_compensation

bool Item::Css_info::m_add_having_compensation {false}

Set iff m_add_coalesce is true: we may get a NULL anyway even for COUNT if a HAVING clause is false in the subquery.

◆ m_correlation_map

table_map Item::Css_info::m_correlation_map {0}

◆ m_having_idx

uint Item::Css_info::m_having_idx {0}

Index of the having expression copied to select list.

◆ m_implicitly_grouped_and_no_union

bool Item::Css_info::m_implicitly_grouped_and_no_union {false}

If true, we can forego cardinality checking of the derived table.

◆ m_join_condition

Item* Item::Css_info::m_join_condition {nullptr}

Where did we find item above? Used when m_location == L_JOIN_COND, nullptr for other locations.

◆ m_locations

int8 Item::Css_info::m_locations {0}

set of locations


The documentation for this struct was generated from the following file: