Common base class for n-ary set operations, including unary. More...

#include <query_term.h>

Inheritance diagram for Query_term_set_op:

Public Member Functions
Query_block *	query_block () const override
	Getter for m_block, q.v. More...

bool	set_block (Query_block *b)
	Setter for m_block, q.v. More...

void	label_children () override
	Set the correct value of `Query_term::m_sibling_idx` recursively for set operations. More...

size_t	child_count () const override
	Get the number of children this node has. More...

bool	open_result_tables (THD *thd, int level) override
	Open tmp tables for the tree of set operation query results, by recursing. More...

void	cleanup (bool full) override
	Reset resources used. More...

void	destroy_tree () override
	Destroy the query term tree structure. More...

bool	has_mixed_distinct_operators ()
	Check if this set operation has a mix of DISTINCT and ALL. More...

bool	is_unary () const
	Check if this term is a unary set operation. More...

Mem_root_array< MaterializePathParameters::Operand >	setup_materialize_set_op (THD thd, TABLE dst_table, bool union_distinct_only, bool calc_found_rows)
	Sets up each() query block in this query expression for materialization into the given table by making a materialization parameter for each block () modulo union_distinct_only. More...

Public Member Functions inherited from Query_term
Query_term *	pushdown_limit_order_by (Query_term_set_op *parent=nullptr)
	Called after contextualization to simplify query, c.f. More...

bool	validate_structure (const Query_term *parent, int depth=0) const
	Return true if structure is too deep, i.e. More...

std::pair< bool, bool >	redundant_order_by (Query_block *block, int level)
	Determine if we have a redundant ORDER BY in block. More...

virtual Query_term_type	term_type () const =0
	Get the node tree type. More...

virtual const char *	operator_string () const =0
	Get the node type description. More...

virtual	~Query_term ()=default
	Node destructor. More...

Query_term_set_op *	parent () const
	Getter for m_parent, q.v. More...

void	set_sibling_idx (uint idx)
	Setter for `m_sibling_idx`, q.v. More...

uint	sibling_idx ()
	Getter for `m_sibling_idx`, q.v. More...

virtual void	debugPrint (int level, std::ostringstream &buf) const =0
	Print the tree rooted at this node to buf. More...

void	printPointers (std::ostringstream &buf) const
	Print the pointer of this node and its parent to buf. More...

void	set_setop_query_result (Query_result *rs)
	Setter for m_setop_query_result, q.v. More...

Query_result *	setop_query_result ()
	Getter for m_setop_query_result, q.v. More...

Query_result_union *	setop_query_result_union ()
	Getter for m_setop_query_result, q.v. Use only if we can down cast. More...

void	cleanup_query_result (bool full)
	Cleanup m_setop_query_result, q.v. More...

void	set_owning_operand ()
	Setter for m_owning_operand, q.v. More...

bool	owning_operand ()
	Getter for m_owning_operand, q.v. More...

void	set_result_table (Table_ref *tl)
	Setter for m_result_table, q.v. More...

Table_ref &	result_table ()
	Getter for m_result_table, q.v. More...

void	set_fields (mem_root_deque< Item * > *fields)

mem_root_deque< Item * > *	fields ()

Public Attributes
mem_root_deque< Query_term * >	m_children
	Tree structure. More...

int64_t	m_last_distinct
	Index of last query expression which has <set-op> DISTINCT on its left. More...

int64_t	m_first_distinct
	Presently only needed by EXCEPT set operator: the index of the first DISTINCT set operand: minimum legal value is 1. More...

bool	m_is_materialized {true}
	true if the result of this set operation is materialized. More...

Protected Member Functions
	Query_term_set_op (MEM_ROOT *mem_root)

void	print (int level, std::ostringstream &buf, const char *type) const
	Common printing minion for set operations. More...

Private Attributes
Query_block *	m_block {nullptr}
	Replaces the old "fake" query block for post processing result set with ORDER BY, LIMIT. More...

Additional Inherited Members
Static Public Member Functions inherited from Query_term
static void	indent (int level, std::ostringstream &buf)
	Print blank space indentation (unit: two) to buf according to level. More...

static void	print_order (const THD thd, String str, ORDER *ord, enum_query_type query_type)
	Print into str the order indicated in ord, using standard print_for_order Used by traditional explain. More...

Protected Attributes inherited from Query_term
Query_term_set_op *	m_parent {nullptr}
	Back pointer to the node whose child we are, or nullptr (root term). More...

uint	m_sibling_idx {0}
	If parent is non-null, this holds the index of the current sibling. More...

Query_result *	m_setop_query_result {nullptr}
	The query result for this term. More...

bool	m_owning_operand {false}
	The operand of a n-ary set operation (that owns the common query result) has this set to true. More...

Table_ref *	m_result_table {nullptr}
	Result temporary table for the set operation, if applicable. More...

mem_root_deque< Item * > *	m_fields {nullptr}
	Used only when streaming, i.e. More...

Detailed Description

Common base class for n-ary set operations, including unary.

Constructor & Destructor Documentation

◆ Query_term_set_op()

Query_term_set_op::Query_term_set_op ( MEM_ROOT * mem_root )

inlineprotected

Member Function Documentation

◆ child_count()

size_t Query_term_set_op::child_count ( ) const

inlineoverridevirtual

Get the number of children this node has.

Returns: the number

Reimplemented from Query_term.

◆ cleanup()

void Query_term_set_op::cleanup ( bool full )

overridevirtual

Reset resources used.

Parameters

full	do full cleanup. Same semantics as for Query_expression's cleanup

Reimplemented from Query_term.

◆ destroy_tree()

void Query_term_set_op::destroy_tree ( )

inlineoverridevirtual

Destroy the query term tree structure.

Implements Query_term.

◆ has_mixed_distinct_operators()

bool Query_term_set_op::has_mixed_distinct_operators ( )

Check if this set operation has a mix of DISTINCT and ALL.

Returns: true if so. Always false for unary

◆ is_unary()

bool Query_term_set_op::is_unary ( ) const

inline

Check if this term is a unary set operation.

Returns: true if so

◆ label_children()

void Query_term_set_op::label_children ( )

inlineoverridevirtual

Set the correct value of Query_term::m_sibling_idx recursively for set operations.

For Query_term_unary, this is done in its constructor. A no-op for Query_block. See also set_sibling_idx.

Implements Query_term.

◆ open_result_tables()

bool Query_term_set_op::open_result_tables	(	THD *	thd,
		int	level
	)

overridevirtual

Open tmp tables for the tree of set operation query results, by recursing.

Parameters

thd	session context
level	level in the tree, top should be called with 0.

Returns: true on error

Reimplemented from Query_term.

◆ print()

void Query_term_set_op::print	(	int	level,
		std::ostringstream &	buf,
		const char *	type
	)		const

protected

Common printing minion for set operations.

Parameters

level	level in tree
buf	the buffer to format output into
type	descriptive string of set operation to use for printing

◆ query_block()

Query_block * Query_term_set_op::query_block ( ) const

inlineoverridevirtual

Getter for m_block, q.v.

Implements Query_term.

◆ set_block()

bool Query_term_set_op::set_block ( Query_block * b )

inline

Setter for m_block, q.v.

◆ setup_materialize_set_op()

Mem_root_array< MaterializePathParameters::Operand > Query_term_set_op::setup_materialize_set_op	(	THD *	thd,
		TABLE *	dst_table,
		bool	union_distinct_only,
		bool	calc_found_rows
	)

Sets up each(*) query block in this query expression for materialization into the given table by making a materialization parameter for each block (*) modulo union_distinct_only.

Parameters

thd	session context
dst_table	the table to materialize into
union_distinct_only	if true, materialize only UNION DISTINCT query blocks (any UNION ALL blocks are presumed handled higher up, by AppendIterator)
calc_found_rows	if true, calculate rows found

Returns: array of materialization parameters

Member Data Documentation

◆ m_block

Query_block* Query_term_set_op::m_block {nullptr}

private

Replaces the old "fake" query block for post processing result set with ORDER BY, LIMIT.

The query block(s) of the query specifications can be found via m_children.

◆ m_children

mem_root_deque<Query_term *> Query_term_set_op::m_children

Tree structure.

Cardinality is one for unary, two or more for UNION, EXCEPT, INTERSECT

◆ m_first_distinct

int64_t Query_term_set_op::m_first_distinct

Presently only needed by EXCEPT set operator: the index of the first DISTINCT set operand: minimum legal value is 1.

If not DISTINCT, it should have the value std::numeric_limits<int64_t>::max(). The value is set in PT_set_operation::merge_descendants.

◆ m_is_materialized

bool Query_term_set_op::m_is_materialized {true}

true if the result of this set operation is materialized.

A priori true unless we have a pure UNION ALL.

◆ m_last_distinct

int64_t Query_term_set_op::m_last_distinct

Index of last query expression which has <set-op> DISTINCT on its left.

In a list of <set-op>ed blocks, UNION is left-associative; so UNION DISTINCT eliminates duplicates in all blocks up to the first one on its right included. Which is why we only need to remember that query block. Is -1 for Unary.

The documentation for this class was generated from the following files:

Public Member Functions

Public Attributes

Protected Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Query_term_set_op()

Member Function Documentation

◆ child_count()

◆ cleanup()

◆ destroy_tree()

◆ has_mixed_distinct_operators()

◆ is_unary()

◆ label_children()

◆ open_result_tables()

◆ print()

◆ query_block()

◆ set_block()

◆ setup_materialize_set_op()

Member Data Documentation

◆ m_block

◆ m_children

◆ m_first_distinct

◆ m_is_materialized

◆ m_last_distinct