Node class for CTX_SIMPLE_ORDER_BY, CTX_SIMPLE_GROUP_BY and CTX_SIMPLE_DISTINCT. More...

Inheritance diagram for opt_explain_json_namespace::sort_ctx:

Public Member Functions
	sort_ctx (enum_parsing_context type_arg, const char name_arg, context parent_arg, const Explain_format_flags *flags, Explain_sort_clause clause)

Public Member Functions inherited from opt_explain_json_namespace::join_ctx
	join_ctx (enum_parsing_context type_arg, const char name_arg, context parent_arg)

bool	add_join_tab (joinable_ctx *ctx) override
	Add a CTX_QEP_TAB node to a CTX_JOIN node. More...

void	set_sort (sort_ctx *ctx) override
	Set nested ORDER BY/GROUP BY/DISTINCT node to `ctx`. More...

void	set_window (window_ctx *ctx) override
	Set nested WINDOW node to `ctx`. More...

qep_row *	entry () override

bool	find_and_set_derived (context *subquery) override
	Associate a CTX_DERIVED node with its CTX_QEP_TAB node. More...

bool	add_subquery (subquery_list_enum subquery_type, subquery_ctx *ctx) override
	Append a subquery node to the specified list of the unit node. More...

bool	format_nested_loop (Opt_trace_context *json) override
	Format nested loop join subtree (if any) to JSON formatter. More...

size_t	id (bool hide) override
	Analogue of the "id" column in the traditional EXPLAIN output. More...

bool	cacheable () override

bool	dependent () override

int	add_where_subquery (subquery_ctx ctx, Query_expression subquery) override
	Associate WHERE subqueries of given context and unit with this object. More...

Public Member Functions inherited from opt_explain_json_namespace::unit_ctx
	unit_ctx (enum_parsing_context type_arg, const char name_arg, context parent_arg)

bool	has_no_subqueries () const
	Helper function to distinguish subquery-less nodes. More...

bool	format_query_expression (Opt_trace_context *json) override
	Helper function to format output for HAVING, ORDER/GROUP BY subqueries. More...

Public Member Functions inherited from opt_explain_json_namespace::context
	context (enum_parsing_context type_arg, const char name_arg, context parent_arg)

virtual	~context ()=default

virtual bool	format (Opt_trace_context *json)
	Pass the node with its child nodes to a JSON formatter. More...

bool	is_query_block () const

virtual enum_mod_type	get_mod_type ()

virtual void	set_child (context *)
	Associate a child node with this node. More...

virtual void	set_setop_result (setop_result_ctx *)
	associate CTX_UNION_RESULT node with CTX_UNION node More...

virtual bool	add_query_spec (context *ctx)
	Add a query specification node to the CTX_UNION node. More...

virtual bool	format_derived (Opt_trace_context *)
	Helper function to format output for derived subquery if any. More...

virtual bool	format_where (Opt_trace_context *)
	Helper function to format output for associated WHERE subqueries if any. More...

Public Member Functions inherited from Explain_context
	Explain_context (enum_parsing_context type_arg)

Public Member Functions inherited from qep_row
	qep_row ()

virtual	~qep_row ()=default

void	cleanup ()

virtual void	register_where_subquery (Query_expression *subquery)
	Remember a subquery's unit. More...

void	format_extra (Opt_trace_object *obj)

Protected Member Functions
bool	format_body (Opt_trace_context json, Opt_trace_object obj) override
	Format JSON object body. More...

const char *	get_cost_tag () override

Protected Member Functions inherited from opt_explain_json_namespace::join_ctx
bool	format_body_inner (Opt_trace_context json, Opt_trace_object obj)

Private Attributes
const bool	using_tmptable
	The clause creates temporary table. More...

const bool	using_filesort
	The clause uses filesort. More...

Additional Inherited Members
Public Attributes inherited from opt_explain_json_namespace::context
context *	parent
	link to parent node or NULL More...

Public Attributes inherited from Explain_context
enum_parsing_context	type
	type tag More...

Public Attributes inherited from qep_row
column< uint >	col_id
	"id" column: seq. number of SELECT within the query More...

column< enum_explain_type >	col_select_type
	"select_type" column More...

mem_root_str	col_table_name
	"table" to which the row of output refers More...

List< const char >	col_partitions
	"partitions" column More...

mem_root_str	col_join_type
	"type" column, see join_type_str array More...

List< const char >	col_possible_keys
	"possible_keys": comma-separated list More...

mem_root_str	col_key
	"key" column: index that is actually decided to use More...

mem_root_str	col_key_len
	"key_length" column: length of the "key" above More...

List< const char >	col_ref
	"ref":columns/constants which are compared to "key" More...

column< float >	col_filtered
	"filtered": % of rows filtered by condition More...

List< extra >	col_extra
	"extra" column (traditional) or property list More...

mem_root_str	col_message
	replaces "Extra" column if not empty More...

mem_root_str	col_attached_condition
	former "Using where" More...

column< ulonglong >	col_rows
	"rows": estimated number of examined table rows per single scan More...

column< ulonglong >	col_prefix_rows
	"rows": estimated number of examined table rows per query More...

column< double >	col_read_cost
	Time to read the table. More...

column< double >	col_prefix_cost
	Cost of the partial join including this table. More...

column< double >	col_cond_cost
	Cost of evaluating conditions on this table per query. More...

mem_root_str	col_data_size_query
	Size of data expected to be read per query. More...

List< const char >	col_used_columns
	List of used columns. More...

List< const char >	col_partial_update_columns
	List of columns that can be updated using partial update. More...

uint	query_block_id
	query block id for materialized subqueries More...

List< opt_explain_json_namespace::context >	derived_from
	List of "derived" subquery trees. More...

List< const char >	col_key_parts
	used parts of the key More...

bool	is_dependent

bool	is_cacheable

bool	using_temporary

enum_mod_type	mod_type

bool	is_materialized_from_subquery

uint	derived_clone_id
	If a clone of a materialized derived table, this is the ID of the first underlying query block of the first materialized derived table. More...

List< Window > *	m_windows
	Windows to describe in this node. More...

Protected Attributes inherited from opt_explain_json_namespace::join_ctx
List< joinable_ctx >	join_tabs
	hosted JOIN_TAB nodes More...

sort_ctx *	sort

window_ctx *	window

Protected Attributes inherited from opt_explain_json_namespace::context
const char *	name

Detailed Description

Node class for CTX_SIMPLE_ORDER_BY, CTX_SIMPLE_GROUP_BY and CTX_SIMPLE_DISTINCT.

CTX_JOIN context (see join_ctx class) may contain nested loop join node or ORDER BY/GROUP BY/DISTINCT node that is represented by this class:

join: { nested_loop: [ ... ] } or join: { order_by|group_by|distinct : { ... } }

CTX_ORDER_BY may contain nested loop join tree or GROUP BY/DISTINCT node:

order_by: { nested_loop|group_by|distinct: ... }

CTX_DISTINCT context structure:

distinct: { nested_loop|group_by: ... }

CTX_GROUP_BY:

group_by: { nested_loop: [ ... ] }

I.e. the most complex CTX_JOIN may have such a structure of JSON output as:

join: { order_by: { distinct: { group_by: { nested_loop: [ ... ] } } } } TODO

Constructor & Destructor Documentation

◆ sort_ctx()

opt_explain_json_namespace::sort_ctx::sort_ctx	(	enum_parsing_context	type_arg,
		const char *	name_arg,
		context *	parent_arg,
		const Explain_format_flags *	flags,
		Explain_sort_clause	clause
	)

inline

Member Function Documentation

◆ format_body()

bool opt_explain_json_namespace::sort_ctx::format_body	(	Opt_trace_context *	json,
		Opt_trace_object *	obj
	)

inlineoverrideprotectedvirtual

Format JSON object body.

Parameters

json	Formatter
obj	Object of this body

Return values

false	Ok
true	Error

Reimplemented from opt_explain_json_namespace::join_ctx.

Reimplemented in opt_explain_json_namespace::sort_with_subqueries_ctx.

◆ get_cost_tag()

const char * opt_explain_json_namespace::sort_ctx::get_cost_tag ( )

inlineoverrideprotectedvirtual

Reimplemented from opt_explain_json_namespace::join_ctx.

Member Data Documentation

◆ using_filesort

const bool opt_explain_json_namespace::sort_ctx::using_filesort

private

The clause uses filesort.

◆ using_tmptable

const bool opt_explain_json_namespace::sort_ctx::using_tmptable

private

The clause creates temporary table.

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

sql/opt_explain_json.cc

Public Member Functions

Protected Member Functions

Private Attributes

Additional Inherited Members