PT_window Class Reference

Parse tree node for a window; just a shallow wrapper for class Window, q.v. More...

#include <parse_tree_window.h>

Inheritance diagram for PT_window:

Public Member Functions
	PT_window (PT_order_list *partition_by, PT_order_list *order_by, PT_frame *frame)
	PT_window (PT_order_list *partition_by, PT_order_list *order_by, PT_frame *frame, Item_string *inherit)
	PT_window (Item_string *name)
bool	contextualize (Parse_context *pc) override
Public Member Functions inherited from Parse_tree_node_tmpl< Context >
virtual	~Parse_tree_node_tmpl ()=default
bool	is_contextualized () const
virtual bool	contextualize (Context *pc)
	Do all context-sensitive things and mark the node as contextualized. More...
void	error (Context *pc, const POS &pos) const
	syntax_error() function replacement for deferred reporting of syntax errors More...
void	error (Context *pc, const POS &pos, const char *msg) const
	syntax_error() function replacement for deferred reporting of syntax errors More...
void	errorf (Context *pc, const POS &pos, const char *format,...) const
	syntax_error() function replacement for deferred reporting of syntax errors More...
Public Member Functions inherited from Window
void	save_pos (Window_retrieve_cached_row_reason reason)
	See m_tmp_pos. More...
void	restore_pos (Window_retrieve_cached_row_reason reason)
	See m_tmp_pos. More...
void	copy_pos (Window_retrieve_cached_row_reason from_reason, Window_retrieve_cached_row_reason to_reason)
	Copy frame buffer position hint from one to another. More...
	Window (Item_string *name)
	Reference to a named window. More...
	Window (PT_order_list *partition_by, PT_order_list *order_by, PT_frame *frame)
	Unnamed window. More...
	Window (PT_order_list *partition_by, PT_order_list *order_by, PT_frame *frame, Item_string *inherit)
	Unnamed window based on a named window. More...
void	set_name (Item_string *name)
	We have a named window. More...
void	set_ancestor (Window *a)
	After resolving an existing window name reference in a window definition, we set the ancestor pointer to easy access later. More...
Item_string *	name () const
	Get the name of a window. More...
uint	def_pos () const
void	set_def_pos (uint pos)
const PT_frame *	frame () const
	Get the frame, if any. More...
const PT_order_list *	effective_order_by () const
	Get the ORDER BY, if any. More...
ORDER *	first_order_by () const
	Get the first argument of the ORDER BY clause for this window if any. More...
const PT_order_list *	effective_partition_by () const
	Get partition, if any. More...
ORDER *	first_partition_by () const
	Get the first argument of the PARTITION clause for this window if any. More...
List< Item_sum > &	functions ()
	Get the list of functions invoked on this window. More...
ORDER *	sorting_order (THD *thd=nullptr, bool implicit_grouping=false)
	Concatenation of columns in PARTITION BY and ORDER BY. More...
bool	check_window_functions1 (THD *thd, Query_block *select)
	Check that the semantic requirements for window functions over this window are fulfilled, and accumulate evaluation requirements. More...
bool	check_window_functions2 (THD *thd)
	Like check_window_functions1() but contains checks which must wait until the start of the execution phase. More...
bool	setup_range_expressions (THD *thd)
	For RANGE frames we need to do computations involving add/subtract and less than, smaller than. More...
bool	is_reference () const
	Return if this window represents an unresolved window reference seen in a window function OVER clause. More...
void	check_partition_boundary ()
	Check if the just read input row marks the start of a new partition. More...
void	reset_order_by_peer_set ()
	Reset the current row's ORDER BY expressions when starting a new peer set. More...
bool	in_new_order_by_peer_set (bool compare_all_order_by_items=true)
	Determine if the current row is not in the same peer set as the previous row. More...
bool	before_frame ()
	While processing buffered rows in RANGE frame mode we, determine if the present row revisited from the buffer is before the row being processed; i.e. More...
bool	after_frame ()
bool	at_partition_border () const
	Check if we have read all the rows in a partition, possibly having buffered them for further processing. More...
void	save_special_row (uint64 special_rowno, TABLE *t)
	Save row special_rowno in table t->record[0] to an in-memory copy for later restoration. More...
void	restore_special_row (uint64 special_rowno, uchar *record)
	Restore row special_rowno into record from in-memory copy. More...
bool	resolve_window_ordering (THD *thd, Ref_item_array ref_item_array, Table_ref *tables, mem_root_deque< Item * > *fields, ORDER *o, bool partition_order)
	Resolve and set up the PARTITION BY or an ORDER BY list of a window. More...
bool	check_unique_name (const List< Window > &windows)
	Return true if this window's name is not unique in windows. More...
void	apply_temp_table (THD *thd, const Func_ptr_array &items_to_copy)
	Specify that this window is to be evaluated after a given temporary table. More...
bool	setup_ordering_cached_items (THD *thd, Query_block *select, const PT_order_list *o, bool partition_order)
	Set up cached items for an partition or an order by list updating m_partition_items or m_order_by_items respectively. More...
bool	needs_sorting () const
	Determine if the window had either a partition clause (inclusive) or a ORDER BY clause, either defined by itself or inherited from another window. More...
bool	needs_buffering () const
	If we cannot compute one of window functions without looking at succeeding rows, return true, else false. More...
bool	needs_peerset () const
	If we cannot compute one of window functions without looking at all rows in the peerset of the current row, return true, else false. More...
bool	needs_last_peer_in_frame () const
	If we cannot compute one of window functions without looking at all rows in the peerset of the current row in this frame, return true, else false. More...
bool	needs_partition_cardinality () const
	If we need to read the entire partition before we can evaluate some window function(s) on this window,. More...
bool	optimizable_row_aggregates () const
	Return true if the set of window functions are all ROW unit optimizable. More...
bool	optimizable_range_aggregates () const
	Return true if the set of window functions are all RANGE unit optimizable. More...
bool	static_aggregates () const
	Return true if the aggregates are static, i.e. More...
bool	opt_first_row () const
	See m_opt_first_row. More...
bool	opt_last_row () const
	See m_opt_last_row. More...
bool	is_last () const
	See m_last. More...
void	set_is_last (bool last)
	An override used by the hypergraph join optimizer only. More...
const st_nth &	opt_nth_row () const
	See m_opt_nth_row. More...
const st_lead_lag &	opt_lead_lag () const
	See m_opt_lead_lag. More...
Temp_table_param *	frame_buffer_param () const
	Getter for m_frame_buffer_param, q.v. More...
void	set_frame_buffer_param (Temp_table_param *p)
	Setter for m_frame_buffer_param, q.v. More...
TABLE *	frame_buffer () const
	Getter for m_frame_buffer, q.v. More...
void	set_frame_buffer (TABLE *tab)
	Setter for m_frame_buffer, q.v. More...
bool	short_circuit () const
void	set_short_circuit (bool short_circuit)
int64	partition_rowno () const
	Getter for m_part_row_number, q.v., the current row number within the partition. More...
bool	make_special_rows_cache (THD *thd, TABLE *out_tbl)
	Allocate the cache for special rows. More...
int64	last_row_output () const
	See m_last_row_output. More...
void	set_last_row_output (int64 rno)
	See m_last_row_output. More...
int64	rowno_being_visited () const
	See m_rowno_being_visited. More...
void	set_rowno_being_visited (int64 rno)
	See m_rowno_being_visited. More...
int64	last_rowno_in_cache () const
	See m_last_rowno_in_cache. More...
void	set_last_rowno_in_cache (uint64 rno)
	See m_last_rowno_in_cache. More...
int64	last_rowno_in_range_frame () const
	See m_last_rowno_in_range_frame. More...
void	set_last_rowno_in_range_frame (uint64 rno)
	See m_last_rowno_in_range_frame. More...
int64	last_rowno_in_peerset () const
	See m_last_rowno_in_peerset. More...
void	set_last_rowno_in_peerset (uint64 rno)
	See m_last_rowno_in_peerset. More...
int64	is_last_row_in_peerset_within_frame () const
	See m_is_last_row_in_peerset_within_frame. More...
void	set_is_last_row_in_peerset_within_frame (bool value)
	See m_is_last_row_in_peerset_within_frame. More...
bool	do_copy_null () const
	See m_do_copy_null. More...
void	set_do_copy_null (bool b)
	See m_do_copy_null. More...
bool	do_inverse () const
	See m_inverse_aggregation. More...
Window &	set_inverse (bool b)
	See m_inverse_aggregation. More...
bool	aggregates_primed () const
	See m_aggregates_primed. More...
void	set_aggregates_primed (bool b)
	See m_aggregates_primed. More...
bool	is_last_row_in_frame () const
	See m_is_last_row_in_frame. More...
void	set_is_last_row_in_frame (bool b)
	See m_is_last_row_in_frame. More...
int64	rowno_in_frame () const
	Return the size of the frame in number of rows. More...
Window &	set_rowno_in_frame (int64 rowno)
	See m_rowno_in_frame. More...
int64	rowno_in_partition () const
	See m_rowno_in_partition. More...
void	set_rowno_in_partition (int64 rowno)
	See m_rowno_in_partition. More...
void	set_first_rowno_in_rows_frame (int64 rowno)
	See m_first_rowno_in_rows_frame. More...
int64	first_rowno_in_rows_frame () const
void	set_first_rowno_in_range_frame (int64 rowno)
	See m_first_rowno_in_range_frame. More...
int64	first_rowno_in_range_frame () const
	See m_first_rowno_in_range_frame. More...
void	set_frame_buffer_total_rows (int64 rows)
	See m_frame_buffer_total_rows. More...
int64	frame_buffer_total_rows () const
	See m_frame_buffer_total_rows. More...
void	set_frame_buffer_partition_offset (int64 offset)
	See m_frame_buffer_partition_offset. More...
int64	frame_buffer_partition_offset () const
	See m_frame_buffer_partition_offset. More...
int64	row_has_fields_in_out_table () const
	See m_row_has_fields_in_out_table. More...
void	set_row_has_fields_in_out_table (int64 rowno)
	See m_row_has_fields_in_out_table. More...
void	cleanup ()
	Free up any resource used to process the window functions of this window, e.g. More...
void	destroy ()
	Free structures that were set up during preparation of window functions. More...
void	reset_partition_state ()
	Reset window state for a new partition. More...
void	reset_round ()
	Reset execution state for next call to JOIN::exec, cf. More...
void	reset_lead_lag ()
	Reset execution state for LEAD/LAG for the current row in partition. More...
void	reset_all_wf_state ()
	Reset the execution state for all window functions defined on this window. More...
const char *	printable_name () const
void	print (const THD *thd, String *str, enum_query_type qt, bool expand_definition) const
bool	has_windowing_steps () const

Private Types
typedef Parse_tree_node	super

Additional Inherited Members
Public Types inherited from Parse_tree_node_tmpl< Context >
typedef Context	context_t
Public Types inherited from Window
enum	Special_keys { FBC_FIRST_IN_NEXT_PARTITION = -1 , FBC_FIRST_KEY = FBC_FIRST_IN_NEXT_PARTITION , FBC_LAST_KEY = FBC_FIRST_IN_NEXT_PARTITION }
	Keys for m_special_rows_cache, for special rows (see the comment on m_special_row_cache). More...
Static Public Member Functions inherited from Parse_tree_node_tmpl< Context >
static void *	operator new (size_t size, MEM_ROOT *mem_root, const std::nothrow_t &arg=std::nothrow) noexcept
static void	operator delete (void *ptr, size_t size)
static void	operator delete (void *, MEM_ROOT *, const std::nothrow_t &) noexcept
Static Public Member Functions inherited from Window
static bool	resolve_reference (THD *thd, Item_sum *wf, PT_window **m_window)
	Resolve any named window to its definition and update m_window to point to the definition instead. More...
static bool	setup_windows1 (THD *thd, Query_block *select, Ref_item_array ref_item_array, Table_ref *tables, mem_root_deque< Item * > *fields, List< Window > *windows)
	Semantic checking of windows. More...
static bool	setup_windows2 (THD *thd, List< Window > *windows)
	Like setup_windows1() but contains operations which must wait until the start of the execution phase. More...
static void	eliminate_unused_objects (List< Window > *windows)
	Check window definitions to remove unused windows. More...
static double	compute_cost (double cost, const List< Window > &windows)
	Compute sorting costs for windowing. More...
Public Attributes inherited from Window
Mem_root_array_YY< Frame_buffer_position >	m_frame_buffer_positions
	Execution state: used iff m_needs_frame_buffering. More...
Frame_buffer_position	m_tmp_pos
	Sometimes we read one row too many, so that the saved position will be too far out because we subsequently need to read an earlier (previous) row of the same kind (reason). More...
Bounds_checked_array< Arg_comparator >	m_comparators [2]
int	m_ordering_idx
	The logical ordering index (into LogicalOrderings) needed by this window's PARTITION BY and ORDER BY clauses together (if any; else, 0). More...
bool	m_mark
	Used temporarily by the hypergraph join optimizer to mark which windows are referred to by a given ordering (so that one doesn't try to satisfy a window's ordering by an ordering referring to that window). More...
Static Public Attributes inherited from Window
static constexpr int	FRAME_BUFFER_POSITIONS_CARD
	Cardinality of m_frame_buffer_positions if no NTH_VALUE, LEAD/LAG. More...
Protected Member Functions inherited from Parse_tree_node_tmpl< Context >
	Parse_tree_node_tmpl ()
Protected Attributes inherited from Window
Query_block *	m_query_block
	The SELECT the window is on. More...
PT_order_list *const	m_partition_by
	<window partition clause> More...
PT_order_list *const	m_order_by
	<window order clause> More...
ORDER *	m_sorting_order
	merged partition/order by More...
PT_frame *const	m_frame
	<window frame clause> More...
Item_string *	m_name
	<window name> More...
uint	m_def_pos
	Position of definition in query's text, 1 for leftmost. More...
Item_string *const	m_inherit_from
	<existing window name> More...
const bool	m_is_reference
	If true, m_name is an unbound window reference, other fields are unused. More...
bool	m_needs_frame_buffering
	(At least) one window function needs to buffer frame rows for evaluation i.e. More...
bool	m_needs_peerset
	(At least) one window function needs the peer set of the current row to evaluate the wf for the current row More...
bool	m_needs_last_peer_in_frame
	(At least) one window function (currently JSON_OBJECTAGG) needs the last peer for the current row to evaluate the wf for the current row. More...
bool	m_needs_partition_cardinality
	(At least) one window function needs the cardinality of the partition of the current row to evaluate the wf for the current row More...
bool	m_row_optimizable
	The functions are optimizable with ROW unit. More...
bool	m_range_optimizable
	The functions are optimizable with RANGE unit. More...
bool	m_static_aggregates
	The aggregates (SUM, etc) can be evaluated once for a partition, since it is static, i.e. More...
bool	m_opt_first_row
	Window equires re-evaluation of the first row in optimized moving frame mode e.g. More...
bool	m_opt_last_row
	Window requires re-evaluation of the last row in optimized moving frame mode e.g. More...
bool	m_last
	The last window to be evaluated at execution time. More...
st_nth	m_opt_nth_row
	Window requires re-evaluation of the Nth row in optimized moving frame mode e.g. More...
st_lead_lag	m_opt_lead_lag
const Window *	m_ancestor
	resolved from existing window name More...
List< Item_sum >	m_functions
	window functions based on 'this' More...
Mem_root_array< Cached_item * >	m_partition_items
	items for the PARTITION BY columns More...
Mem_root_array< Cached_item * >	m_order_by_items
	items for the ORDER BY exprs. More...
Temp_table_param *	m_frame_buffer_param
	Execution state: used iff m_needs_frame_buffering. More...
bool	m_short_circuit = false
	Holds whether this window should be “short-circuit”, ie., goes directly to the query output instead of to a temporary table. More...
TABLE *	m_frame_buffer
	Execution state: used iff m_needs_frame_buffering. More...
int64	m_frame_buffer_total_rows
	Execution state: The frame buffer tmp file is not truncated for each new partition. More...
int64	m_frame_buffer_partition_offset
	Execution state: Snapshot of m_frame_buffer_total_rows when we start a new partition, i.e. More...
int64	m_row_has_fields_in_out_table
	If >=1: the row with this number (1-based, relative to start of partition) currently has its fields in the record buffer of the IN table and of the OUT table. More...
uchar *	m_special_rows_cache
	Holds a fixed number of copies of special rows; each copy can use up to m_special_rows_cache_max_length bytes. More...
size_t	m_special_rows_cache_length [FBC_FIRST_KEY - FBC_LAST_KEY+1]
	Length of each copy in m_special_rows_cache, in bytes. More...
size_t	m_special_rows_cache_max_length
	Maximum allocated size in m_special_rows_cache. More...
int64	m_last_rowno_in_cache
	Execution state: used iff m_needs_frame_buffering. More...
int64	m_last_rowno_in_peerset
	Execution state: used iff m_needs_peerset. More...
int64	m_is_last_row_in_peerset_within_frame
	Execution state: used iff m_needs_last_peer_in_frame. More...
int64	m_part_row_number
	Execution state: the current row number in the current partition. More...
bool	m_partition_border
	Execution state: the current row starts a new partition. More...
int64	m_last_row_output
	Execution state: The number, in the current partition, of the last output row, i.e. More...
int64	m_rowno_being_visited
	Execution state: The number of the row being visited for its contribution to a window function, relative to the start of the partition. More...
int64	m_rowno_in_frame
	Execution state: the row number of the row we are looking at for evaluating its contribution to some window function(s). More...
int64	m_rowno_in_partition
	Execution state: The row number of the current row being readied for output within the partition. More...
bool	m_aggregates_primed
	Execution state: for optimizable aggregates, cf. More...
int64	m_first_rowno_in_range_frame
	Execution state: the row number of the first row in a frame when evaluating RANGE based frame bounds. More...
int64	m_last_rowno_in_range_frame
	Execution state: used for RANGE bounds frame evaluation for the continued evaluation for current row > 2 in a partition. More...
int64	m_first_rowno_in_rows_frame
	Execution state. More...
bool	m_is_last_row_in_frame
	Execution state: the current row is the last row in a window frame For some aggregate functions, e.g AVG, we can save computation by not evaluating the entire function value before the last row has been read. More...
bool	m_do_copy_null
	Execution state: make frame wf produce a NULL (or 0 depending, e.g. More...
bool	m_inverse_aggregation
	Execution state: do inverse, e.g. More...

Detailed Description

Parse tree node for a window; just a shallow wrapper for class Window, q.v.

Member Typedef Documentation

super

typedef Parse_tree_node PT_window::super

private

Constructor & Destructor Documentation

PT_window() [1/3]

PT_window::PT_window ( PT_order_list *  partition_by, PT_order_list *  order_by, PT_frame *  frame  )

inline

PT_window() [2/3]

PT_window::PT_window ( PT_order_list *  partition_by, PT_order_list *  order_by, PT_frame *  frame, Item_string *  inherit  )

inline

PT_window() [3/3]

PT_window::PT_window ( Item_string *  name )

inline

Member Function Documentation

contextualize()

bool PT_window::contextualize ( Parse_context *  pc )

override

---

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

• sql/parse_tree_window.h
• sql/parse_tree_window.cc