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_subselect *	item {nullptr}
	the scalar subquery More...
table_map	m_correlation_map {0}
Item *	m_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

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

• sql/item.h