MySQL 8.0.29
Source Code Documentation
opt_hints.h
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2
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20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22
23/*
24 Parse tree node classes for optimizer hint syntax
25*/
26
27#ifndef OPT_HINTS_INCLUDED
28#define OPT_HINTS_INCLUDED
29
30#include <assert.h>
31#include <stddef.h>
32#include <sys/types.h>
33
34#include "lex_string.h"
35#include "m_ctype.h"
36#include "m_string.h"
37#include "my_compiler.h"
38
39#include "my_inttypes.h"
40#include "sql/enum_query_type.h"
41#include "sql/mem_root_array.h" // Mem_root_array
42#include "sql/sql_bitmap.h" // Bitmap
43#include "sql/sql_show.h" // append_identifier
44#include "sql_string.h" // String
45
46enum class Subquery_strategy : int;
47class Item;
48class JOIN;
49class Opt_hints_table;
50class Sys_var_hint;
51class THD;
52class set_var;
53class sys_var;
54struct MEM_ROOT;
55struct TABLE;
56struct TABLE_LIST;
57
58/**
59 Hint types, MAX_HINT_ENUM should be always last.
60 This enum should be synchronized with opt_hint_info
61 array(see opt_hints.cc).
62*/
88};
89
91 const char *hint_name; // Hint name.
92 bool check_upper_lvl; // true if upper level hint check is needed (for hints
93 // which can be specified on more than one level).
94 bool switch_hint; // true if hint is not complex.
95 bool irregular_hint; ///< true if hint requires some special handling.
96 ///< Currently it's used only for join order hints
97 ///< since they need special printing procedure.
98};
99
100/**
101 Opt_hints_map contains information
102 about hint state(specified or not, hint value).
103*/
104
106 Bitmap<64> hints; // hint state
107 Bitmap<64> hints_specified; // true if hint is specified
108 public:
109 /**
110 Check if hint is specified.
111
112 @param type_arg hint type
113
114 @return true if hint is specified
115 */
116 bool is_specified(opt_hints_enum type_arg) const {
117 return hints_specified.is_set(type_arg);
118 }
119 /**
120 Set switch value and set hint into specified state.
121
122 @param type_arg hint type
123 @param switch_state_arg switch value
124 */
125 void set_switch(opt_hints_enum type_arg, bool switch_state_arg) {
126 if (switch_state_arg)
127 hints.set_bit(type_arg);
128 else
129 hints.clear_bit(type_arg);
130 hints_specified.set_bit(type_arg);
131 }
132 /**
133 Get switch value.
134
135 @param type_arg hint type
136
137 @return switch value.
138 */
139 bool switch_on(opt_hints_enum type_arg) const {
140 return hints.is_set(type_arg);
141 }
142};
143
144class Opt_hints_key;
145class PT_hint;
147
148/**
149 Opt_hints class is used as ancestor for Opt_hints_global,
150 Opt_hints_qb, Opt_hints_table, Opt_hints_key classes.
151
152 Opt_hints_global class is hierarchical structure.
153 It contains information about global hints and also
154 conains array of QUERY BLOCK level objects (Opt_hints_qb class).
155 Each QUERY BLOCK level object contains array of TABLE level hints
156 (class Opt_hints_table). Each TABLE level hint contains array of
157 KEY lelev hints (Opt_hints_key class).
158 Hint information(specified, on|off state) is stored in hints_map object.
159*/
160
162 /*
163 Name of object referred by the hint.
164 This name is empty for global level,
165 query block name for query block level,
166 table name for table level and key name
167 for key level.
168 */
170 /*
171 Parent object. There is no parent for global level,
172 for query block level parent is Opt_hints_global object,
173 for table level parent is Opt_hints_qb object,
174 for key level parent is Opt_hints_key object.
175 */
177
179
180 /* Array of child objects. i.e. array of the lower level objects */
182 /* true if hint is connected to the real object */
184 /* Number of resolved children */
186
187 public:
188 Opt_hints(const LEX_CSTRING *name_arg, Opt_hints *parent_arg,
189 MEM_ROOT *mem_root_arg)
190 : name(name_arg),
191 parent(parent_arg),
192 child_array(mem_root_arg),
193 resolved(false),
195
196 virtual ~Opt_hints() = default;
197
198 bool is_specified(opt_hints_enum type_arg) const {
199 return hints_map.is_specified(type_arg);
200 }
201
202 /**
203 Function sets switch hint state.
204
205 @param switch_state_arg switch hint state
206 @param type_arg hint type
207 @param check_parent true if hint can be on parent level
208
209 @return true if hint is already specified,
210 false otherwise
211 */
212 bool set_switch(bool switch_state_arg, opt_hints_enum type_arg,
213 bool check_parent) {
214 if (is_specified(type_arg) ||
215 (check_parent && parent->is_specified(type_arg)))
216 return true;
217
218 hints_map.set_switch(type_arg, switch_state_arg);
219 return false;
220 }
221
222 /**
223 Function returns switch hint state.
224
225 @param type_arg hint type
226
227 @return hint value if hint is specified,
228 false otherwise
229 */
230 bool get_switch(opt_hints_enum type_arg) const;
231
232 virtual const LEX_CSTRING *get_name() const { return name; }
233 virtual const LEX_CSTRING *get_print_name() { return name; }
234 void set_name(const LEX_CSTRING *name_arg) { name = name_arg; }
235 Opt_hints *get_parent() const { return parent; }
236 virtual void set_resolved() { resolved = true; }
237 /**
238 Returns 'resolved' flag value for depending on hint type.
239
240 @param type_arg hint type
241
242 @return true if all hint objects are resolved, false otherwise.
243 */
244 virtual bool is_resolved(opt_hints_enum type_arg [[maybe_unused]]) {
245 return resolved;
246 }
247 /**
248 Set hint to unresolved state.
249
250 @param type_arg hint type
251 */
252 virtual void set_unresolved(opt_hints_enum type_arg [[maybe_unused]]) {}
253 /**
254 If ignore_print() returns true, hint is not printed
255 in Opt_hints::print() function. Atm used for
256 INDEX_MERGE, SKIP_SCAN, INDEX, JOIN_INDEX, GROUP_INDEX
257 ORDER_INDEX hints.
258
259 @param type_arg hint type
260
261 @return true if the hint should not be printed
262 in Opt_hints::print() function, false otherwise.
263 */
264 virtual bool ignore_print(opt_hints_enum type_arg [[maybe_unused]]) const {
265 return false;
266 }
269
270 bool is_all_resolved() const {
271 return child_array.size() == resolved_children;
272 }
273
274 void register_child(Opt_hints *hint_arg) { child_array.push_back(hint_arg); }
275
276 /**
277 Returns pointer to complex hint for a given type.
278
279 A complex hint is a hint that has arguments.
280 (It is not just an on/off switch.)
281
282 @param type hint type
283
284 @return pointer to complex hint for a given type.
285 */
286 virtual PT_hint *get_complex_hints(opt_hints_enum type [[maybe_unused]]) {
287 assert(0);
288 return nullptr; /* error C4716: must return a value */
289 }
290
291 /**
292 Find hint among lower-level hint objects.
293
294 @param name_arg hint name
295 @param cs Pointer to character set
296
297 @return hint if found,
298 NULL otherwise
299 */
300 Opt_hints *find_by_name(const LEX_CSTRING *name_arg,
301 const CHARSET_INFO *cs) const;
302 /**
303 Print all hints except of QB_NAME hint.
304
305 @param thd Pointer to THD object
306 @param str Pointer to String object
307 @param query_type If query type is QT_NORMALIZED_FORMAT,
308 un-resolved hints will also be printed
309 */
310 void print(const THD *thd, String *str, enum_query_type query_type);
311 /**
312 Check if there are any unresolved hint objects and
313 print warnings for them.
314
315 @param thd Pointer to THD object
316 */
317 void check_unresolved(THD *thd);
318 virtual void append_name(const THD *thd, String *str) = 0;
319
320 private:
321 /**
322 Append hint type.
323
324 @param str Pointer to String object
325 @param type Hint type
326 */
328 /**
329 Print warning for unresolved hint name.
330
331 @param thd Pointer to THD object
332 */
333 void print_warn_unresolved(THD *thd);
334 /**
335 Function prints hints which are non-standard and don't
336 fit into existing hint infrastructure.
337
338 @param thd pointer to THD object
339 @param str pointer to String object
340 */
341 virtual void print_irregular_hints(const THD *thd [[maybe_unused]],
342 String *str [[maybe_unused]]) {}
343};
344
345/**
346 Global level hints.
347*/
348
350 public:
353
355 : Opt_hints(nullptr, nullptr, mem_root_arg) {
356 max_exec_time = nullptr;
357 sys_var_hint = nullptr;
358 }
359
360 void append_name(const THD *, String *) override {}
362 void print_irregular_hints(const THD *thd, String *str) override;
363};
364
365class PT_qb_level_hint;
366
367/**
368 Query block level hints.
369*/
370
371class Opt_hints_qb : public Opt_hints {
372 uint select_number; // Query_block number
373 LEX_CSTRING sys_name; // System QB name
374 char buff[32]; // Buffer to hold sys name
375
377
378 /// Array of join order hints
380 /// Bit map of which hints are ignored.
382
383 /*
384 PT_qb_level_hint::contextualize sets subquery/semijoin_hint during parsing.
385 it also registers join order hints during parsing.
386 */
387 friend class PT_qb_level_hint;
388
389 public:
390 Opt_hints_qb(Opt_hints *opt_hints_arg, MEM_ROOT *mem_root_arg,
391 uint select_number_arg);
392
393 const LEX_CSTRING *get_print_name() override {
395 return str ? str : &sys_name;
396 }
397
398 /**
399 Append query block hint.
400
401 @param thd pointer to THD object
402 @param str pointer to String object
403 */
404 void append_qb_hint(const THD *thd, String *str) {
405 if (get_name()) {
406 str->append(STRING_WITH_LEN("QB_NAME("));
408 str->append(STRING_WITH_LEN(") "));
409 }
410 }
411 /**
412 Append query block name.
413
414 @param thd pointer to THD object
415 @param str pointer to String object
416 */
417 void append_name(const THD *thd, String *str) override {
418 str->append(STRING_WITH_LEN("@"));
421 }
422
424
425 /**
426 Function finds Opt_hints_table object corresponding to
427 table alias in the query block and attaches corresponding
428 key hint objects to appropriate KEY structures.
429
430 @param table Table reference
431
432 @return pointer Opt_hints_table object if this object is found,
433 NULL otherwise.
434 */
436
437 /**
438 Returns whether semi-join is enabled for this query block
439
440 A SEMIJOIN hint will force semi-join regardless of optimizer_switch
441 settings. A NO_SEMIJOIN hint will only turn off semi-join if the variant
442 with no strategies is used. A SUBQUERY hint will turn off semi-join. If
443 there is no SEMIJOIN/SUBQUERY hint, optimizer_switch setting determines
444 whether SEMIJOIN is used.
445
446 @param thd Pointer to THD object for session.
447 Used to access optimizer_switch
448
449 @return true if semijoin is enabled
450 */
451 bool semijoin_enabled(const THD *thd) const;
452
453 /**
454 Returns bit mask of which semi-join strategies are enabled for this query
455 block.
456
457 @param opt_switches Bit map of strategies enabled by optimizer_switch
458
459 @return Bit mask of strategies that are enabled
460 */
461 uint sj_enabled_strategies(uint opt_switches) const;
462
463 /**
464 Returns which subquery execution strategy has been specified by hints
465 for this query block.
466
467 @retval SUBQ_MATERIALIZATION Subquery Materialization should be used
468 @retval SUBQ_EXISTS In-to-exists execution should be used
469 @retval UNSPECIFIED No SUBQUERY hint for this query block
470 */
472
473 void print_irregular_hints(const THD *thd, String *str) override;
474
475 /**
476 Checks if join order hints are applicable and
477 applies table dependencies if possible.
478
479 @param join JOIN object
480 */
482
483 private:
485 join_order_hints.push_back(hint_arg);
486 }
487};
488
490
491/**
492 Auxiluary class for compound key objects.
493*/
495 PT_key_level_hint *pt_hint; // Pointer to PT_key_level_hint object.
496 Key_map key_map; // Indexes, specified in the hint.
497 bool resolved; // true if hint does not have unresolved index.
498
499 public:
501 key_map.init();
502 resolved = false;
503 pt_hint = nullptr;
504 }
505
506 virtual ~Compound_key_hint() = default;
507
508 void set_pt_hint(PT_key_level_hint *pt_hint_arg) { pt_hint = pt_hint_arg; }
510
511 void set_resolved(bool arg) { resolved = arg; }
512 bool is_resolved() { return resolved; }
513
515 bool is_set_key_map(uint i) { return key_map.is_set(i); }
518 virtual bool is_hint_conflicting(Opt_hints_table *table_hint [[maybe_unused]],
519 Opt_hints_key *key_hint [[maybe_unused]]) {
520 return false;
521 }
522};
523
524/**
525 Auxiliary class for JOIN_INDEX, GROUP_INDEX, ORDER_INDEX hints.
526*/
528 public:
529 bool is_hint_conflicting(Opt_hints_table *table_hint,
530 Opt_hints_key *key_hint) override;
531};
532
533/**
534 Auxiliary class for INDEX hint.
535*/
537 public:
538 bool is_hint_conflicting(Opt_hints_table *table_hint,
539 Opt_hints_key *key_hint) override;
540};
541
542bool is_compound_hint(opt_hints_enum type_arg);
543
544/**
545 Table level hints.
546*/
547
549 public:
557
558 Opt_hints_table(const LEX_CSTRING *table_name_arg, Opt_hints_qb *qb_hints_arg,
559 MEM_ROOT *mem_root_arg)
560 : Opt_hints(table_name_arg, qb_hints_arg, mem_root_arg),
561 keyinfo_array(mem_root_arg) {}
562
563 /**
564 Append table name.
565
566 @param thd pointer to THD object
567 @param str pointer to String object
568 */
569 void append_name(const THD *thd, String *str) override {
571 get_parent()->append_name(thd, str);
572 }
573 /**
574 Function sets correlation between key hint objects and
575 appropriate KEY structures.
576
577 @param table Pointer to TABLE_LIST object
578 */
579 void adjust_key_hints(TABLE_LIST *table);
581
582 void set_resolved() override {
590 }
591
592 void set_unresolved(opt_hints_enum type_arg) override {
593 if (is_specified(type_arg) && is_compound_hint(type_arg))
594 get_compound_key_hint(type_arg)->set_resolved(false);
595 }
596
597 bool is_resolved(opt_hints_enum type_arg) override {
598 if (is_compound_hint(type_arg))
599 return Opt_hints::is_resolved(type_arg) &&
601 return Opt_hints::is_resolved(type_arg);
602 }
603
611 }
612
614 if (type_arg == INDEX_MERGE_HINT_ENUM) return &index_merge;
615 if (type_arg == SKIP_SCAN_HINT_ENUM) return &skip_scan;
616 if (type_arg == INDEX_HINT_ENUM) return &index;
617 if (type_arg == JOIN_INDEX_HINT_ENUM) return &join_index;
618 if (type_arg == GROUP_INDEX_HINT_ENUM) return &group_index;
619 if (type_arg == ORDER_INDEX_HINT_ENUM) return &order_index;
620 assert(0);
621 return nullptr;
622 }
623
625 return (get_compound_key_hint(type_arg)->is_resolved() &&
626 get_switch(type_arg));
627 }
628
630 void update_index_hint_map(Key_map *keys_to_use,
631 Key_map *available_keys_to_use,
632 opt_hints_enum type_arg);
633 bool update_index_hint_maps(THD *thd, TABLE *tbl);
634};
635
636/**
637 Key level hints.
638*/
639
640class Opt_hints_key : public Opt_hints {
641 public:
642 Opt_hints_key(const LEX_CSTRING *key_name_arg,
643 Opt_hints_table *table_hints_arg, MEM_ROOT *mem_root_arg)
644 : Opt_hints(key_name_arg, table_hints_arg, mem_root_arg) {}
645
646 /**
647 Append key name.
648
649 @param thd pointer to THD object
650 @param str pointer to String object
651 */
652 void append_name(const THD *thd, String *str) override {
653 get_parent()->append_name(thd, str);
654 str->append(' ');
656 }
657 /**
658 Ignore printing of the object since parent complex hint has
659 its own printing method.
660 */
661 bool ignore_print(opt_hints_enum type_arg) const override {
662 return is_compound_hint(type_arg);
663 }
664};
665
666/**
667 Container for set_var object and original variable value.
668*/
669
671 public:
672 Hint_set_var(set_var *var_arg) : var(var_arg), save_value(nullptr) {}
673 set_var *var; // Pointer to set_var object
674 Item *save_value; // Original variable value
675};
676
677/**
678 SET_VAR hints.
679*/
680
682 // List of str_var variables which need to be updated.
684
685 public:
686 Sys_var_hint(MEM_ROOT *mem_root_arg) : var_list(mem_root_arg) {}
687 /**
688 Add variable to hint list.
689
690 @param thd pointer to THD object
691 @param var_tracker pointer to System_variable_tracker object
692 @param sys_var_value variable value
693
694 @return true if variable is added,
695 false otherwise
696 */
697 bool add_var(THD *thd, const System_variable_tracker &var_tracker,
698 Item *sys_var_value);
699 /**
700 Find variable in hint list.
701
702 @param thd Pointer to thread object
703 */
704 void update_vars(THD *thd);
705 /**
706 Restore system variables with original values.
707
708 @param thd Pointer to thread object
709 */
710 void restore_vars(THD *thd);
711 /**
712 Print applicable hints.
713
714 @param thd Thread handle
715 @param str Pointer to string object
716 */
717 void print(const THD *thd, String *str);
718};
719
720/**
721 Returns key hint value if hint is specified, returns
722 optimizer switch value if hint is not specified.
723
724 @param thd Pointer to THD object
725 @param table Pointer to TABLE_LIST object
726 @param keyno Key number
727 @param type_arg Hint type
728 @param optimizer_switch Optimizer switch flag
729
730 @return key hint value if hint is specified,
731 otherwise optimizer switch value.
732*/
733bool hint_key_state(const THD *thd, const TABLE_LIST *table, uint keyno,
734 opt_hints_enum type_arg, uint optimizer_switch);
735
736/**
737 Returns table hint value if hint is specified, returns
738 optimizer switch value if hint is not specified.
739
740 @param thd Pointer to THD object
741 @param table Pointer to TABLE_LIST object
742 @param type_arg Hint type
743 @param optimizer_switch Optimizer switch flag
744
745 @return table hint value if hint is specified,
746 otherwise optimizer switch value.
747*/
748bool hint_table_state(const THD *thd, const TABLE_LIST *table,
749 opt_hints_enum type_arg, uint optimizer_switch);
750/**
751 Append table and query block name.
752
753 @param thd pointer to THD object
754 @param str pointer to String object
755 @param qb_name pointer to query block name, may be null
756 @param table_name pointer to table name
757*/
758void append_table_name(const THD *thd, String *str, const LEX_CSTRING *qb_name,
759 const LEX_CSTRING *table_name);
760
761/**
762 Returns true if compound hint state is on with or without
763 specified keys, otherwise returns false.
764 If compound hint state is on and hint is specified without indexes,
765 function returns 'true' for any 'keyno' argument. If hint specified
766 with indexes, function returns true only for appropriate 'keyno' index.
767
768
769 @param table Pointer to TABLE object
770 @param keyno Key number
771 @param type_arg Hint type
772
773 @return true if compound hint state is on with or without
774 specified keys, otherwise returns false.
775*/
776
777bool compound_hint_key_enabled(const TABLE *table, uint keyno,
778 opt_hints_enum type_arg);
779
780/**
781 Returns true if index merge hint state is on otherwise returns false.
782
783 @param thd Thread handler
784 @param table Pointer to TABLE object
785 @param use_cheapest_index_merge IN/OUT Returns true if INDEX_MERGE hint is
786 used without any specified key.
787
788 @return true if index merge hint state is on otherwise returns false.
789*/
790
791bool idx_merge_hint_state(THD *thd, const TABLE *table,
792 bool *use_cheapest_index_merge);
793
794int cmp_lex_string(const LEX_CSTRING &s, const LEX_CSTRING &t,
795 const CHARSET_INFO *cs);
796
797#endif /* OPT_HINTS_INCLUDED */
void append_identifier(String *packet, const char *name, size_t length)
Convert and quote the given identifier if needed and append it to the target string.
Definition: sql_show.cc:1451
Definition: sql_bitmap.h:137
bool is_set(uint n) const
Definition: sql_bitmap.h:169
void set_bit(uint n)
Definition: sql_bitmap.h:148
bool is_clear_all() const
Definition: sql_bitmap.h:180
void init()
Definition: sql_bitmap.h:145
void clear_bit(uint n)
Definition: sql_bitmap.h:152
Auxiluary class for compound key objects.
Definition: opt_hints.h:494
void set_key_map(uint i)
Definition: opt_hints.h:514
PT_key_level_hint * pt_hint
Definition: opt_hints.h:495
void set_pt_hint(PT_key_level_hint *pt_hint_arg)
Definition: opt_hints.h:508
Key_map key_map
Definition: opt_hints.h:496
virtual ~Compound_key_hint()=default
void set_resolved(bool arg)
Definition: opt_hints.h:511
Compound_key_hint()
Definition: opt_hints.h:500
bool resolved
Definition: opt_hints.h:497
bool is_resolved()
Definition: opt_hints.h:512
bool is_set_key_map(uint i)
Definition: opt_hints.h:515
Key_map * get_key_map()
Definition: opt_hints.h:517
bool is_key_map_clear_all()
Definition: opt_hints.h:516
virtual bool is_hint_conflicting(Opt_hints_table *table_hint, Opt_hints_key *key_hint)
Definition: opt_hints.h:518
PT_key_level_hint * get_pt_hint()
Definition: opt_hints.h:509
Auxiliary class for INDEX hint.
Definition: opt_hints.h:536
bool is_hint_conflicting(Opt_hints_table *table_hint, Opt_hints_key *key_hint) override
Function checks if INDEX hint is conflicting with already specified JOIN_INDEX, GROUP_INDEX,...
Definition: opt_hints.cc:695
Container for set_var object and original variable value.
Definition: opt_hints.h:670
Item * save_value
Definition: opt_hints.h:674
Hint_set_var(set_var *var_arg)
Definition: opt_hints.h:672
set_var * var
Definition: opt_hints.h:673
Auxiliary class for JOIN_INDEX, GROUP_INDEX, ORDER_INDEX hints.
Definition: opt_hints.h:527
bool is_hint_conflicting(Opt_hints_table *table_hint, Opt_hints_key *key_hint) override
Function checks if JOIN_INDEX|GROUP_INDEX|ORDER_INDEX hint is conflicting with already specified INDE...
Definition: opt_hints.cc:712
Base class that is used to represent any kind of expression in a relational query.
Definition: item.h:802
Definition: sql_optimizer.h:125
A typesafe replacement for DYNAMIC_ARRAY.
Definition: mem_root_array.h:421
Global level hints.
Definition: opt_hints.h:349
void append_name(const THD *, String *) override
Definition: opt_hints.h:360
PT_hint * get_complex_hints(opt_hints_enum type) override
Returns pointer to complex hint for a given type.
Definition: opt_hints.cc:191
Opt_hints_global(MEM_ROOT *mem_root_arg)
Definition: opt_hints.h:354
Sys_var_hint * sys_var_hint
Definition: opt_hints.h:352
void print_irregular_hints(const THD *thd, String *str) override
Function prints hints which are non-standard and don't fit into existing hint infrastructure.
Definition: opt_hints.cc:198
PT_hint_max_execution_time * max_exec_time
Definition: opt_hints.h:351
Key level hints.
Definition: opt_hints.h:640
void append_name(const THD *thd, String *str) override
Append key name.
Definition: opt_hints.h:652
bool ignore_print(opt_hints_enum type_arg) const override
Ignore printing of the object since parent complex hint has its own printing method.
Definition: opt_hints.h:661
Opt_hints_key(const LEX_CSTRING *key_name_arg, Opt_hints_table *table_hints_arg, MEM_ROOT *mem_root_arg)
Definition: opt_hints.h:642
Opt_hints_map contains information about hint state(specified or not, hint value).
Definition: opt_hints.h:105
bool switch_on(opt_hints_enum type_arg) const
Get switch value.
Definition: opt_hints.h:139
bool is_specified(opt_hints_enum type_arg) const
Check if hint is specified.
Definition: opt_hints.h:116
void set_switch(opt_hints_enum type_arg, bool switch_state_arg)
Set switch value and set hint into specified state.
Definition: opt_hints.h:125
Bitmap< 64 > hints_specified
Definition: opt_hints.h:107
Bitmap< 64 > hints
Definition: opt_hints.h:106
Query block level hints.
Definition: opt_hints.h:371
void print_irregular_hints(const THD *thd, String *str) override
Function prints hints which are non-standard and don't fit into existing hint infrastructure.
Definition: opt_hints.cc:276
void register_join_order_hint(PT_qb_level_hint *hint_arg)
Definition: opt_hints.h:484
PT_qb_level_hint * semijoin_hint
Definition: opt_hints.h:376
uint select_number
Definition: opt_hints.h:372
Subquery_strategy subquery_strategy() const
Returns which subquery execution strategy has been specified by hints for this query block.
Definition: opt_hints.cc:269
ulonglong join_order_hints_ignored
Bit map of which hints are ignored.
Definition: opt_hints.h:381
void apply_join_order_hints(JOIN *join)
Checks if join order hints are applicable and applies table dependencies if possible.
Definition: opt_hints.cc:519
PT_qb_level_hint * subquery_hint
Definition: opt_hints.h:376
Opt_hints_qb(Opt_hints *opt_hints_arg, MEM_ROOT *mem_root_arg, uint select_number_arg)
Definition: opt_hints.cc:202
LEX_CSTRING sys_name
Definition: opt_hints.h:373
uint sj_enabled_strategies(uint opt_switches) const
Returns bit mask of which semi-join strategies are enabled for this query block.
Definition: opt_hints.cc:255
void append_name(const THD *thd, String *str) override
Append query block name.
Definition: opt_hints.h:417
PT_hint * get_complex_hints(opt_hints_enum type) override
Returns pointer to complex hint for a given type.
Definition: opt_hints.cc:215
char buff[32]
Definition: opt_hints.h:374
bool semijoin_enabled(const THD *thd) const
Returns whether semi-join is enabled for this query block.
Definition: opt_hints.cc:238
Opt_hints_table * adjust_table_hints(TABLE_LIST *table)
Function finds Opt_hints_table object corresponding to table alias in the query block and attaches co...
Definition: opt_hints.cc:224
const LEX_CSTRING * get_print_name() override
Definition: opt_hints.h:393
void append_qb_hint(const THD *thd, String *str)
Append query block hint.
Definition: opt_hints.h:404
Mem_root_array< PT_qb_level_hint * > join_order_hints
Array of join order hints.
Definition: opt_hints.h:379
Table level hints.
Definition: opt_hints.h:548
void adjust_key_hints(TABLE_LIST *table)
Function sets correlation between key hint objects and appropriate KEY structures.
Definition: opt_hints.cc:529
Compound_key_hint skip_scan
Definition: opt_hints.h:552
Index_key_hint group_index
Definition: opt_hints.h:555
void set_resolved() override
Definition: opt_hints.h:582
Index_key_hint join_index
Definition: opt_hints.h:554
bool is_hint_conflicting(Opt_hints_key *key_hint, opt_hints_enum type)
Definition: opt_hints.cc:585
void append_name(const THD *thd, String *str) override
Append table name.
Definition: opt_hints.h:569
Glob_index_key_hint index
Definition: opt_hints.h:553
void update_index_hint_map(Key_map *keys_to_use, Key_map *available_keys_to_use, opt_hints_enum type_arg)
Function updates key_to_use key map depending on index hint state.
Definition: opt_hints.cc:599
bool is_resolved(opt_hints_enum type_arg) override
Returns 'resolved' flag value for depending on hint type.
Definition: opt_hints.h:597
void set_unresolved(opt_hints_enum type_arg) override
Set hint to unresolved state.
Definition: opt_hints.h:592
bool update_index_hint_maps(THD *thd, TABLE *tbl)
Function updates keys_in_use_for_query, keys_in_use_for_group_by, keys_in_use_for_order_by depending ...
Definition: opt_hints.cc:641
Compound_key_hint * get_compound_key_hint(opt_hints_enum type_arg)
Definition: opt_hints.h:613
void set_compound_key_hint_map(Opt_hints *hint, uint arg)
Definition: opt_hints.h:604
Mem_root_array< Opt_hints_key * > keyinfo_array
Definition: opt_hints.h:550
Opt_hints_table(const LEX_CSTRING *table_name_arg, Opt_hints_qb *qb_hints_arg, MEM_ROOT *mem_root_arg)
Definition: opt_hints.h:558
PT_hint * get_complex_hints(opt_hints_enum type) override
Returns pointer to complex hint for a given type.
Definition: opt_hints.cc:580
Compound_key_hint index_merge
Definition: opt_hints.h:551
bool is_force_index_hint(opt_hints_enum type_arg)
Definition: opt_hints.h:624
Index_key_hint order_index
Definition: opt_hints.h:556
Opt_hints class is used as ancestor for Opt_hints_global, Opt_hints_qb, Opt_hints_table,...
Definition: opt_hints.h:161
bool get_switch(opt_hints_enum type_arg) const
Function returns switch hint state.
Definition: opt_hints.cc:115
virtual ~Opt_hints()=default
void append_hint_type(String *str, opt_hints_enum type)
Append hint type.
Definition: opt_hints.cc:159
Mem_root_array< Opt_hints * > * child_array_ptr()
Definition: opt_hints.h:268
Opt_hints_map hints_map
Definition: opt_hints.h:178
bool is_all_resolved() const
Definition: opt_hints.h:270
virtual void set_resolved()
Definition: opt_hints.h:236
virtual void append_name(const THD *thd, String *str)=0
virtual void set_unresolved(opt_hints_enum type_arg)
Set hint to unresolved state.
Definition: opt_hints.h:252
virtual const LEX_CSTRING * get_name() const
Definition: opt_hints.h:232
virtual bool is_resolved(opt_hints_enum type_arg)
Returns 'resolved' flag value for depending on hint type.
Definition: opt_hints.h:244
Opt_hints(const LEX_CSTRING *name_arg, Opt_hints *parent_arg, MEM_ROOT *mem_root_arg)
Definition: opt_hints.h:188
bool resolved
Definition: opt_hints.h:183
virtual const LEX_CSTRING * get_print_name()
Definition: opt_hints.h:233
virtual PT_hint * get_complex_hints(opt_hints_enum type)
Returns pointer to complex hint for a given type.
Definition: opt_hints.h:286
void print(const THD *thd, String *str, enum_query_type query_type)
Print all hints except of QB_NAME hint.
Definition: opt_hints.cc:133
void incr_resolved_children()
Definition: opt_hints.h:267
Opt_hints * parent
Definition: opt_hints.h:176
bool set_switch(bool switch_state_arg, opt_hints_enum type_arg, bool check_parent)
Function sets switch hint state.
Definition: opt_hints.h:212
void register_child(Opt_hints *hint_arg)
Definition: opt_hints.h:274
uint resolved_children
Definition: opt_hints.h:185
void print_warn_unresolved(THD *thd)
Print warning for unresolved hint name.
Definition: opt_hints.cc:165
const LEX_CSTRING * name
Definition: opt_hints.h:169
Opt_hints * find_by_name(const LEX_CSTRING *name_arg, const CHARSET_INFO *cs) const
Find hint among lower-level hint objects.
Definition: opt_hints.cc:124
virtual void print_irregular_hints(const THD *thd, String *str)
Function prints hints which are non-standard and don't fit into existing hint infrastructure.
Definition: opt_hints.h:341
bool is_specified(opt_hints_enum type_arg) const
Definition: opt_hints.h:198
void check_unresolved(THD *thd)
Check if there are any unresolved hint objects and print warnings for them.
Definition: opt_hints.cc:182
Mem_root_array< Opt_hints * > child_array
Definition: opt_hints.h:181
void set_name(const LEX_CSTRING *name_arg)
Definition: opt_hints.h:234
virtual bool ignore_print(opt_hints_enum type_arg) const
If ignore_print() returns true, hint is not printed in Opt_hints::print() function.
Definition: opt_hints.h:264
Opt_hints * get_parent() const
Definition: opt_hints.h:235
Parse tree hint object for MAX_EXECUTION_TIME hint.
Definition: parse_tree_hints.h:266
The class is a base class for representation of the different types of the hints.
Definition: parse_tree_hints.h:57
Parse tree hint object for key level hints.
Definition: parse_tree_hints.h:206
Parse tree hint object for query block level hints.
Definition: parse_tree_hints.h:123
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:166
SET_VAR hints.
Definition: opt_hints.h:681
Mem_root_array< Hint_set_var * > var_list
Definition: opt_hints.h:683
bool add_var(THD *thd, const System_variable_tracker &var_tracker, Item *sys_var_value)
Add variable to hint list.
Definition: opt_hints.cc:756
void restore_vars(THD *thd)
Restore system variables with original values.
Definition: opt_hints.cc:812
void print(const THD *thd, String *str)
Print applicable hints.
Definition: opt_hints.cc:838
void update_vars(THD *thd)
Find variable in hint list.
Definition: opt_hints.cc:789
Sys_var_hint(MEM_ROOT *mem_root_arg)
Definition: opt_hints.h:686
Wrapper interface for all kinds of system variables.
Definition: set_var.h:573
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:945
set_var_base descendant for assignments to the system variables.
Definition: set_var.h:970
A class representing one system variable - that is something that can be accessed as @global....
Definition: set_var.h:104
enum_query_type
Query type constants (usable as bitmap flags).
Definition: enum_query_type.h:30
Fido Client Authentication nullptr
Definition: fido_client_plugin.cc:221
Subquery_strategy
Strategy which will be used to handle this subquery: flattening to a semi-join, conversion to a deriv...
Definition: item_subselect.h:390
A better implementation of the UNIX ctype(3) library.
#define STRING_WITH_LEN(X)
Definition: m_string.h:314
Header for compiler-dependent features.
Some integer typedefs for easier portability.
unsigned long long int ulonglong
Definition: my_inttypes.h:55
std::string str(const mysqlrouter::ConfigGenerator::Options::Endpoint &ep)
Definition: config_generator.cc:1055
Definition: commit_order_queue.h:33
bool length(const dd::Spatial_reference_system *srs, const Geometry *g1, double *length, bool *null) noexcept
Computes the length of linestrings and multilinestrings.
Definition: length.cc:75
std::string join(Container cont, const std::string &delim)
join elements of an container into a string separated by a delimiter.
Definition: string.h:150
const char * table_name
Definition: rules_table_service.cc:55
bool hint_table_state(const THD *thd, const TABLE_LIST *table, opt_hints_enum type_arg, uint optimizer_switch)
Returns table hint value if hint is specified, returns optimizer switch value if hint is not specifie...
Definition: opt_hints.cc:907
bool is_compound_hint(opt_hints_enum type_arg)
Definition: opt_hints.cc:573
bool compound_hint_key_enabled(const TABLE *table, uint keyno, opt_hints_enum type_arg)
Returns true if compound hint state is on with or without specified keys, otherwise returns false.
Definition: opt_hints.cc:931
bool idx_merge_hint_state(THD *thd, const TABLE *table, bool *use_cheapest_index_merge)
Returns true if index merge hint state is on otherwise returns false.
Definition: opt_hints.cc:949
opt_hints_enum
Hint types, MAX_HINT_ENUM should be always last.
Definition: opt_hints.h:63
@ JOIN_PREFIX_HINT_ENUM
Definition: opt_hints.h:74
@ INDEX_MERGE_HINT_ENUM
Definition: opt_hints.h:78
@ DERIVED_MERGE_HINT_ENUM
Definition: opt_hints.h:73
@ MAX_HINT_ENUM
Definition: opt_hints.h:87
@ BNL_HINT_ENUM
Definition: opt_hints.h:65
@ ORDER_INDEX_HINT_ENUM
Definition: opt_hints.h:85
@ JOIN_SUFFIX_HINT_ENUM
Definition: opt_hints.h:75
@ DERIVED_CONDITION_PUSHDOWN_HINT_ENUM
Definition: opt_hints.h:86
@ RESOURCE_GROUP_HINT_ENUM
Definition: opt_hints.h:79
@ GROUP_INDEX_HINT_ENUM
Definition: opt_hints.h:84
@ JOIN_ORDER_HINT_ENUM
Definition: opt_hints.h:76
@ SUBQUERY_HINT_ENUM
Definition: opt_hints.h:72
@ SKIP_SCAN_HINT_ENUM
Definition: opt_hints.h:80
@ QB_NAME_HINT_ENUM
Definition: opt_hints.h:70
@ ICP_HINT_ENUM
Definition: opt_hints.h:66
@ JOIN_INDEX_HINT_ENUM
Definition: opt_hints.h:83
@ MAX_EXEC_TIME_HINT_ENUM
Definition: opt_hints.h:69
@ HASH_JOIN_HINT_ENUM
Definition: opt_hints.h:81
@ MRR_HINT_ENUM
Definition: opt_hints.h:67
@ JOIN_FIXED_ORDER_HINT_ENUM
Definition: opt_hints.h:77
@ INDEX_HINT_ENUM
Definition: opt_hints.h:82
@ BKA_HINT_ENUM
Definition: opt_hints.h:64
@ NO_RANGE_HINT_ENUM
Definition: opt_hints.h:68
@ SEMIJOIN_HINT_ENUM
Definition: opt_hints.h:71
void append_table_name(const THD *thd, String *str, const LEX_CSTRING *qb_name, const LEX_CSTRING *table_name)
Append table and query block name.
Definition: opt_hints.cc:919
bool hint_key_state(const THD *thd, const TABLE_LIST *table, uint keyno, opt_hints_enum type_arg, uint optimizer_switch)
Returns key hint value if hint is specified, returns optimizer switch value if hint is not specified.
Definition: opt_hints.cc:890
int cmp_lex_string(const LEX_CSTRING &s, const LEX_CSTRING &t, const CHARSET_INFO *cs)
Definition: opt_hints.cc:109
required string type
Definition: replication_group_member_actions.proto:33
Our own string classes, used pervasively throughout the executor.
Definition: m_ctype.h:354
The MEM_ROOT is a simple arena, where allocations are carved out of larger blocks.
Definition: my_alloc.h:82
Definition: mysql_lex_string.h:39
Definition: table.h:2684
Definition: table.h:1394
Definition: opt_hints.h:90
bool switch_hint
Definition: opt_hints.h:94
bool irregular_hint
true if hint requires some special handling.
Definition: opt_hints.h:95
bool check_upper_lvl
Definition: opt_hints.h:92
const char * hint_name
Definition: opt_hints.h:91
unsigned int uint
Definition: uca-dump.cc:29