MySQL 8.4.3
Source Code Documentation
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Common base class for n-ary set operations, including unary. More...
#include <query_term.h>
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... | |
Common base class for n-ary set operations, including unary.
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inlineprotected |
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inlineoverridevirtual |
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overridevirtual |
Reset resources used.
full | do full cleanup. Same semantics as for Query_expression's cleanup |
Reimplemented from Query_term.
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inlineoverridevirtual |
Destroy the query term tree structure.
Implements Query_term.
bool Query_term_set_op::has_mixed_distinct_operators | ( | ) |
Check if this set operation has a mix of DISTINCT and ALL.
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inline |
Check if this term is a unary set operation.
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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.
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overridevirtual |
Open tmp tables for the tree of set operation query results, by recursing.
thd | session context |
level | level in the tree, top should be called with 0. |
Reimplemented from Query_term.
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protected |
Common printing minion for set operations.
level | level in tree |
buf | the buffer to format output into |
type | descriptive string of set operation to use for printing |
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inlineoverridevirtual |
Getter for m_block, q.v.
Implements Query_term.
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inline |
Setter for m_block, q.v.
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.
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 |
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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.
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
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.
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.
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.