MySQL 8.4.3
Source Code Documentation
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Base class for structured and hierarchical EXPLAIN output formatters. More...
#include <opt_explain_format.h>
Public Member Functions | |
virtual | ~Explain_format ()=default |
virtual bool | is_hierarchical () const =0 |
A hierarchical text or a plain table. More... | |
virtual bool | is_iterator_based () const |
Whether the format closely resembles the final plan to be executed by execution iterators (See RowIterator). More... | |
bool | is_explain_into () const |
Whether the output of an EXPLAIN statement should be stored in a user variable or sent to the client. More... | |
bool | is_explain_for_schema () const |
Whether the EXPLAIN statement should be run in another schema than the current active schema. More... | |
std::string_view | explain_into_variable_name () const |
Returns the name of the user variable the output of this EXPLAIN statement is to be stored in. More... | |
virtual bool | send_headers (Query_result *result) |
Send EXPLAIN header item(s) to output stream. More... | |
virtual bool | begin_context (enum_parsing_context context, Query_expression *subquery=nullptr, const Explain_format_flags *flags=nullptr)=0 |
Enter a specified context. More... | |
virtual bool | end_context (enum_parsing_context context)=0 |
Leave the current context. More... | |
virtual bool | flush_entry ()=0 |
Flush TABLE/JOIN_TAB property set. More... | |
virtual qep_row * | entry ()=0 |
Get a pointer to the current TABLE/JOIN_TAB property set. More... | |
virtual std::string | ExplainJsonToString (Json_object *json) |
Convert Json object to string. More... | |
Public Attributes | |
LEX_CSTRING | m_schema_name_for_explain |
Protected Member Functions | |
Explain_format () | |
Explain_format (std::optional< std::string_view > explain_into_variable_name) | |
Protected Attributes | |
Query_result * | output |
output resulting data there More... | |
Private Member Functions | |
Explain_format (Explain_format &) | |
Explain_format & | operator= (Explain_format &) |
Private Attributes | |
std::optional< std::string_view > | m_explain_into_variable_name |
Base class for structured and hierarchical EXPLAIN output formatters.
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private |
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inlineprotected |
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inlineexplicitprotected |
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virtualdefault |
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pure virtual |
Enter a specified context.
context | context type |
subquery | for CTX_WHERE: unit of the subquery |
flags | Format flags, see Explain_format_flags. |
Implemented in Explain_format_JSON, Explain_format_traditional, and Explain_format_tree.
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pure virtual |
Leave the current context.
context | current context type (for validation/debugging) |
Implemented in Explain_format_JSON, Explain_format_traditional, and Explain_format_tree.
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pure virtual |
Get a pointer to the current TABLE/JOIN_TAB property set.
Implemented in Explain_format_JSON, Explain_format_traditional, and Explain_format_tree.
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inline |
Returns the name of the user variable the output of this EXPLAIN statement is to be stored in.
Should only be called if this is an EXPLAIN INTO statement.
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inlinevirtual |
Convert Json object to string.
Should only be called for iterator-based formats.
Reimplemented in Explain_format_JSON, and Explain_format_tree.
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pure virtual |
Flush TABLE/JOIN_TAB property set.
For traditional EXPLAIN: output a single EXPLAIN row.
Implemented in Explain_format_JSON, Explain_format_traditional, and Explain_format_tree.
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inline |
Whether the EXPLAIN statement should be run in another schema than the current active schema.
If this returns true, m_schema_name_for_explain contains the name of the schema to use for EXPLAIN.
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inline |
Whether the output of an EXPLAIN statement should be stored in a user variable or sent to the client.
If this function returns true, explain_into_variable_name() returns the name of the variable.
true | EXPLAIN output should be stored in a user variable. |
false | EXPLAIN output should be sent to the client. |
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pure virtual |
A hierarchical text or a plain table.
true | Formatter produces hierarchical text |
false | Traditional explain |
Implemented in Explain_format_JSON, Explain_format_traditional, and Explain_format_tree.
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inlinevirtual |
Whether the format closely resembles the final plan to be executed by execution iterators (See RowIterator).
These formats share a common logic that uses AccessPath structure to generate the information, so they all display exactly the same information, even though the style of each format might be different.
true | Format is Iterator-based. |
false | Format is not Iterator-based. |
Reimplemented in Explain_format_JSON, and Explain_format_tree.
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private |
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inlinevirtual |
Send EXPLAIN header item(s) to output stream.
result | output result set |
false | OK |
true | Error |
Reimplemented in Explain_format_tree, Explain_format_JSON, and Explain_format_traditional.
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private |
LEX_CSTRING Explain_format::m_schema_name_for_explain |
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protected |
output resulting data there