PostgreSQL Source Code  git master
geqo.h File Reference
#include "common/pg_prng.h"
#include "nodes/pathnodes.h"
#include "optimizer/geqo_gene.h"
Include dependency graph for geqo.h:
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Data Structures

struct  GeqoPrivateData
 

Macros

#define ERX
 
#define DEFAULT_GEQO_EFFORT   5
 
#define MIN_GEQO_EFFORT   1
 
#define MAX_GEQO_EFFORT   10
 
#define DEFAULT_GEQO_SELECTION_BIAS   2.0
 
#define MIN_GEQO_SELECTION_BIAS   1.5
 
#define MAX_GEQO_SELECTION_BIAS   2.0
 

Functions

RelOptInfogeqo (PlannerInfo *root, int number_of_rels, List *initial_rels)
 
Cost geqo_eval (PlannerInfo *root, Gene *tour, int num_gene)
 
RelOptInfogimme_tree (PlannerInfo *root, Gene *tour, int num_gene)
 

Variables

PGDLLIMPORT int Geqo_effort
 
PGDLLIMPORT int Geqo_pool_size
 
PGDLLIMPORT int Geqo_generations
 
PGDLLIMPORT double Geqo_selection_bias
 
PGDLLIMPORT double Geqo_seed
 

Macro Definition Documentation

◆ DEFAULT_GEQO_EFFORT

#define DEFAULT_GEQO_EFFORT   5

Definition at line 55 of file geqo.h.

◆ DEFAULT_GEQO_SELECTION_BIAS

#define DEFAULT_GEQO_SELECTION_BIAS   2.0

Definition at line 65 of file geqo.h.

◆ ERX

#define ERX

Definition at line 44 of file geqo.h.

◆ MAX_GEQO_EFFORT

#define MAX_GEQO_EFFORT   10

Definition at line 57 of file geqo.h.

◆ MAX_GEQO_SELECTION_BIAS

#define MAX_GEQO_SELECTION_BIAS   2.0

Definition at line 67 of file geqo.h.

◆ MIN_GEQO_EFFORT

#define MIN_GEQO_EFFORT   1

Definition at line 56 of file geqo.h.

◆ MIN_GEQO_SELECTION_BIAS

#define MIN_GEQO_SELECTION_BIAS   1.5

Definition at line 66 of file geqo.h.

Function Documentation

◆ geqo()

RelOptInfo* geqo ( PlannerInfo root,
int  number_of_rels,
List initial_rels 
)

Definition at line 72 of file geqo_main.c.

73 {
74  GeqoPrivateData private;
75  int generation;
76  Chromosome *momma;
77  Chromosome *daddy;
78  Chromosome *kid;
79  Pool *pool;
80  int pool_size,
81  number_generations;
82 
83 #ifdef GEQO_DEBUG
84  int status_interval;
85 #endif
86  Gene *best_tour;
87  RelOptInfo *best_rel;
88 
89 #if defined(ERX)
90  Edge *edge_table; /* list of edges */
91  int edge_failures = 0;
92 #endif
93 #if defined(CX) || defined(PX) || defined(OX1) || defined(OX2)
94  City *city_table; /* list of cities */
95 #endif
96 #if defined(CX)
97  int cycle_diffs = 0;
98  int mutations = 0;
99 #endif
100 
101 /* set up private information */
102  root->join_search_private = (void *) &private;
103  private.initial_rels = initial_rels;
104 
105 /* initialize private number generator */
107 
108 /* set GA parameters */
109  pool_size = gimme_pool_size(number_of_rels);
110  number_generations = gimme_number_generations(pool_size);
111 #ifdef GEQO_DEBUG
112  status_interval = 10;
113 #endif
114 
115 /* allocate genetic pool memory */
116  pool = alloc_pool(root, pool_size, number_of_rels);
117 
118 /* random initialization of the pool */
119  random_init_pool(root, pool);
120 
121 /* sort the pool according to cheapest path as fitness */
122  sort_pool(root, pool); /* we have to do it only one time, since all
123  * kids replace the worst individuals in
124  * future (-> geqo_pool.c:spread_chromo ) */
125 
126 #ifdef GEQO_DEBUG
127  elog(DEBUG1, "GEQO selected %d pool entries, best %.2f, worst %.2f",
128  pool_size,
129  pool->data[0].worth,
130  pool->data[pool_size - 1].worth);
131 #endif
132 
133 /* allocate chromosome momma and daddy memory */
134  momma = alloc_chromo(root, pool->string_length);
135  daddy = alloc_chromo(root, pool->string_length);
136 
137 #if defined (ERX)
138 #ifdef GEQO_DEBUG
139  elog(DEBUG2, "using edge recombination crossover [ERX]");
140 #endif
141 /* allocate edge table memory */
142  edge_table = alloc_edge_table(root, pool->string_length);
143 #elif defined(PMX)
144 #ifdef GEQO_DEBUG
145  elog(DEBUG2, "using partially matched crossover [PMX]");
146 #endif
147 /* allocate chromosome kid memory */
148  kid = alloc_chromo(root, pool->string_length);
149 #elif defined(CX)
150 #ifdef GEQO_DEBUG
151  elog(DEBUG2, "using cycle crossover [CX]");
152 #endif
153 /* allocate city table memory */
154  kid = alloc_chromo(root, pool->string_length);
155  city_table = alloc_city_table(root, pool->string_length);
156 #elif defined(PX)
157 #ifdef GEQO_DEBUG
158  elog(DEBUG2, "using position crossover [PX]");
159 #endif
160 /* allocate city table memory */
161  kid = alloc_chromo(root, pool->string_length);
162  city_table = alloc_city_table(root, pool->string_length);
163 #elif defined(OX1)
164 #ifdef GEQO_DEBUG
165  elog(DEBUG2, "using order crossover [OX1]");
166 #endif
167 /* allocate city table memory */
168  kid = alloc_chromo(root, pool->string_length);
169  city_table = alloc_city_table(root, pool->string_length);
170 #elif defined(OX2)
171 #ifdef GEQO_DEBUG
172  elog(DEBUG2, "using order crossover [OX2]");
173 #endif
174 /* allocate city table memory */
175  kid = alloc_chromo(root, pool->string_length);
176  city_table = alloc_city_table(root, pool->string_length);
177 #endif
178 
179 
180 /* my pain main part: */
181 /* iterative optimization */
182 
183  for (generation = 0; generation < number_generations; generation++)
184  {
185  /* SELECTION: using linear bias function */
186  geqo_selection(root, momma, daddy, pool, Geqo_selection_bias);
187 
188 #if defined (ERX)
189  /* EDGE RECOMBINATION CROSSOVER */
190  gimme_edge_table(root, momma->string, daddy->string, pool->string_length, edge_table);
191 
192  kid = momma;
193 
194  /* are there any edge failures ? */
195  edge_failures += gimme_tour(root, edge_table, kid->string, pool->string_length);
196 #elif defined(PMX)
197  /* PARTIALLY MATCHED CROSSOVER */
198  pmx(root, momma->string, daddy->string, kid->string, pool->string_length);
199 #elif defined(CX)
200  /* CYCLE CROSSOVER */
201  cycle_diffs = cx(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
202  /* mutate the child */
203  if (cycle_diffs == 0)
204  {
205  mutations++;
206  geqo_mutation(root, kid->string, pool->string_length);
207  }
208 #elif defined(PX)
209  /* POSITION CROSSOVER */
210  px(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
211 #elif defined(OX1)
212  /* ORDER CROSSOVER */
213  ox1(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
214 #elif defined(OX2)
215  /* ORDER CROSSOVER */
216  ox2(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
217 #endif
218 
219 
220  /* EVALUATE FITNESS */
221  kid->worth = geqo_eval(root, kid->string, pool->string_length);
222 
223  /* push the kid into the wilderness of life according to its worth */
224  spread_chromo(root, kid, pool);
225 
226 
227 #ifdef GEQO_DEBUG
228  if (status_interval && !(generation % status_interval))
229  print_gen(stdout, pool, generation);
230 #endif
231 
232  }
233 
234 
235 #if defined(ERX)
236 #if defined(GEQO_DEBUG)
237  if (edge_failures != 0)
238  elog(LOG, "[GEQO] failures: %d, average: %d",
239  edge_failures, (int) number_generations / edge_failures);
240  else
241  elog(LOG, "[GEQO] no edge failures detected");
242 #else
243  /* suppress variable-set-but-not-used warnings from some compilers */
244  (void) edge_failures;
245 #endif
246 #endif
247 
248 #if defined(CX) && defined(GEQO_DEBUG)
249  if (mutations != 0)
250  elog(LOG, "[GEQO] mutations: %d, generations: %d",
251  mutations, number_generations);
252  else
253  elog(LOG, "[GEQO] no mutations processed");
254 #endif
255 
256 #ifdef GEQO_DEBUG
257  print_pool(stdout, pool, 0, pool_size - 1);
258 #endif
259 
260 #ifdef GEQO_DEBUG
261  elog(DEBUG1, "GEQO best is %.2f after %d generations",
262  pool->data[0].worth, number_generations);
263 #endif
264 
265 
266  /*
267  * got the cheapest query tree processed by geqo; first element of the
268  * population indicates the best query tree
269  */
270  best_tour = (Gene *) pool->data[0].string;
271 
272  best_rel = gimme_tree(root, best_tour, pool->string_length);
273 
274  if (best_rel == NULL)
275  elog(ERROR, "geqo failed to make a valid plan");
276 
277  /* DBG: show the query plan */
278 #ifdef NOT_USED
279  print_plan(best_plan, root);
280 #endif
281 
282  /* ... free memory stuff */
283  free_chromo(root, momma);
284  free_chromo(root, daddy);
285 
286 #if defined (ERX)
287  free_edge_table(root, edge_table);
288 #elif defined(PMX)
289  free_chromo(root, kid);
290 #elif defined(CX)
291  free_chromo(root, kid);
292  free_city_table(root, city_table);
293 #elif defined(PX)
294  free_chromo(root, kid);
295  free_city_table(root, city_table);
296 #elif defined(OX1)
297  free_chromo(root, kid);
298  free_city_table(root, city_table);
299 #elif defined(OX2)
300  free_chromo(root, kid);
301  free_city_table(root, city_table);
302 #endif
303 
304  free_pool(root, pool);
305 
306  /* ... clear root pointer to our private storage */
307  root->join_search_private = NULL;
308 
309  return best_rel;
310 }
#define LOG
Definition: elog.h:31
#define DEBUG2
Definition: elog.h:29
#define DEBUG1
Definition: elog.h:30
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:224
float gimme_edge_table(PlannerInfo *root, Gene *tour1, Gene *tour2, int num_gene, Edge *edge_table)
Definition: geqo_erx.c:95
void free_edge_table(PlannerInfo *root, Edge *edge_table)
Definition: geqo_erx.c:76
int gimme_tour(PlannerInfo *root, Edge *edge_table, Gene *new_gene, int num_gene)
Definition: geqo_erx.c:196
Edge * alloc_edge_table(PlannerInfo *root, int num_gene)
Definition: geqo_erx.c:56
Cost geqo_eval(PlannerInfo *root, Gene *tour, int num_gene)
Definition: geqo_eval.c:57
RelOptInfo * gimme_tree(PlannerInfo *root, Gene *tour, int num_gene)
Definition: geqo_eval.c:163
int Gene
Definition: geqo_gene.h:30
double Geqo_seed
Definition: geqo_main.c:48
static int gimme_number_generations(int pool_size)
Definition: geqo_main.c:352
static int gimme_pool_size(int nr_rel)
Definition: geqo_main.c:320
double Geqo_selection_bias
Definition: geqo_main.c:47
void geqo_mutation(PlannerInfo *root, Gene *tour, int num_gene)
void sort_pool(PlannerInfo *root, Pool *pool)
Definition: geqo_pool.c:135
void free_chromo(PlannerInfo *root, Chromosome *chromo)
Definition: geqo_pool.c:176
void free_pool(PlannerInfo *root, Pool *pool)
Definition: geqo_pool.c:69
void random_init_pool(PlannerInfo *root, Pool *pool)
Definition: geqo_pool.c:91
Chromosome * alloc_chromo(PlannerInfo *root, int string_length)
Definition: geqo_pool.c:162
void spread_chromo(PlannerInfo *root, Chromosome *chromo, Pool *pool)
Definition: geqo_pool.c:187
Pool * alloc_pool(PlannerInfo *root, int pool_size, int string_length)
Definition: geqo_pool.c:42
void geqo_set_seed(PlannerInfo *root, double seed)
Definition: geqo_random.c:20
void free_city_table(PlannerInfo *root, City *city_table)
void pmx(PlannerInfo *root, Gene *tour1, Gene *tour2, Gene *offspring, int num_gene)
void ox1(PlannerInfo *root, Gene *mom, Gene *dad, Gene *offspring, int num_gene, City *city_table)
int cx(PlannerInfo *root, Gene *tour1, Gene *tour2, Gene *offspring, int num_gene, City *city_table)
void ox2(PlannerInfo *root, Gene *mom, Gene *dad, Gene *offspring, int num_gene, City *city_table)
void px(PlannerInfo *root, Gene *tour1, Gene *tour2, Gene *offspring, int num_gene, City *city_table)
City * alloc_city_table(PlannerInfo *root, int num_gene)
void geqo_selection(PlannerInfo *root, Chromosome *momma, Chromosome *daddy, Pool *pool, double bias)
tree ctl root
Definition: radixtree.h:1840
Cost worth
Definition: geqo_gene.h:35
Gene * string
Definition: geqo_gene.h:34
Definition: geqo_gene.h:39
int string_length
Definition: geqo_gene.h:42
Chromosome * data
Definition: geqo_gene.h:40

References alloc_chromo(), alloc_city_table(), alloc_edge_table(), alloc_pool(), cx(), Pool::data, DEBUG1, DEBUG2, elog, ERROR, free_chromo(), free_city_table(), free_edge_table(), free_pool(), geqo_eval(), geqo_mutation(), Geqo_seed, geqo_selection(), Geqo_selection_bias, geqo_set_seed(), gimme_edge_table(), gimme_number_generations(), gimme_pool_size(), gimme_tour(), gimme_tree(), LOG, ox1(), ox2(), pmx(), px(), random_init_pool(), root, sort_pool(), spread_chromo(), generate_unaccent_rules::stdout, Chromosome::string, Pool::string_length, and Chromosome::worth.

Referenced by make_rel_from_joinlist().

◆ geqo_eval()

Cost geqo_eval ( PlannerInfo root,
Gene tour,
int  num_gene 
)

Definition at line 57 of file geqo_eval.c.

58 {
59  MemoryContext mycontext;
60  MemoryContext oldcxt;
61  RelOptInfo *joinrel;
62  Cost fitness;
63  int savelength;
64  struct HTAB *savehash;
65 
66  /*
67  * Create a private memory context that will hold all temp storage
68  * allocated inside gimme_tree().
69  *
70  * Since geqo_eval() will be called many times, we can't afford to let all
71  * that memory go unreclaimed until end of statement. Note we make the
72  * temp context a child of the planner's normal context, so that it will
73  * be freed even if we abort via ereport(ERROR).
74  */
76  "GEQO",
78  oldcxt = MemoryContextSwitchTo(mycontext);
79 
80  /*
81  * gimme_tree will add entries to root->join_rel_list, which may or may
82  * not already contain some entries. The newly added entries will be
83  * recycled by the MemoryContextDelete below, so we must ensure that the
84  * list is restored to its former state before exiting. We can do this by
85  * truncating the list to its original length. NOTE this assumes that any
86  * added entries are appended at the end!
87  *
88  * We also must take care not to mess up the outer join_rel_hash, if there
89  * is one. We can do this by just temporarily setting the link to NULL.
90  * (If we are dealing with enough join rels, which we very likely are, a
91  * new hash table will get built and used locally.)
92  *
93  * join_rel_level[] shouldn't be in use, so just Assert it isn't.
94  */
95  savelength = list_length(root->join_rel_list);
96  savehash = root->join_rel_hash;
97  Assert(root->join_rel_level == NULL);
98 
99  root->join_rel_hash = NULL;
100 
101  /* construct the best path for the given combination of relations */
102  joinrel = gimme_tree(root, tour, num_gene);
103 
104  /*
105  * compute fitness, if we found a valid join
106  *
107  * XXX geqo does not currently support optimization for partial result
108  * retrieval, nor do we take any cognizance of possible use of
109  * parameterized paths --- how to fix?
110  */
111  if (joinrel)
112  {
113  Path *best_path = joinrel->cheapest_total_path;
114 
115  fitness = best_path->total_cost;
116  }
117  else
118  fitness = DBL_MAX;
119 
120  /*
121  * Restore join_rel_list to its former state, and put back original
122  * hashtable if any.
123  */
124  root->join_rel_list = list_truncate(root->join_rel_list,
125  savelength);
126  root->join_rel_hash = savehash;
127 
128  /* release all the memory acquired within gimme_tree */
129  MemoryContextSwitchTo(oldcxt);
130  MemoryContextDelete(mycontext);
131 
132  return fitness;
133 }
Assert(fmt[strlen(fmt) - 1] !='\n')
List * list_truncate(List *list, int new_size)
Definition: list.c:631
MemoryContext CurrentMemoryContext
Definition: mcxt.c:131
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:442
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:153
double Cost
Definition: nodes.h:251
static int list_length(const List *l)
Definition: pg_list.h:152
MemoryContextSwitchTo(old_ctx)
Definition: dynahash.c:220
Cost total_cost
Definition: pathnodes.h:1647
struct Path * cheapest_total_path
Definition: pathnodes.h:892

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert(), RelOptInfo::cheapest_total_path, CurrentMemoryContext, gimme_tree(), list_length(), list_truncate(), MemoryContextDelete(), MemoryContextSwitchTo(), root, and Path::total_cost.

Referenced by geqo(), and random_init_pool().

◆ gimme_tree()

RelOptInfo* gimme_tree ( PlannerInfo root,
Gene tour,
int  num_gene 
)

Definition at line 163 of file geqo_eval.c.

164 {
165  GeqoPrivateData *private = (GeqoPrivateData *) root->join_search_private;
166  List *clumps;
167  int rel_count;
168 
169  /*
170  * Sometimes, a relation can't yet be joined to others due to heuristics
171  * or actual semantic restrictions. We maintain a list of "clumps" of
172  * successfully joined relations, with larger clumps at the front. Each
173  * new relation from the tour is added to the first clump it can be joined
174  * to; if there is none then it becomes a new clump of its own. When we
175  * enlarge an existing clump we check to see if it can now be merged with
176  * any other clumps. After the tour is all scanned, we forget about the
177  * heuristics and try to forcibly join any remaining clumps. If we are
178  * unable to merge all the clumps into one, fail.
179  */
180  clumps = NIL;
181 
182  for (rel_count = 0; rel_count < num_gene; rel_count++)
183  {
184  int cur_rel_index;
185  RelOptInfo *cur_rel;
186  Clump *cur_clump;
187 
188  /* Get the next input relation */
189  cur_rel_index = (int) tour[rel_count];
190  cur_rel = (RelOptInfo *) list_nth(private->initial_rels,
191  cur_rel_index - 1);
192 
193  /* Make it into a single-rel clump */
194  cur_clump = (Clump *) palloc(sizeof(Clump));
195  cur_clump->joinrel = cur_rel;
196  cur_clump->size = 1;
197 
198  /* Merge it into the clumps list, using only desirable joins */
199  clumps = merge_clump(root, clumps, cur_clump, num_gene, false);
200  }
201 
202  if (list_length(clumps) > 1)
203  {
204  /* Force-join the remaining clumps in some legal order */
205  List *fclumps;
206  ListCell *lc;
207 
208  fclumps = NIL;
209  foreach(lc, clumps)
210  {
211  Clump *clump = (Clump *) lfirst(lc);
212 
213  fclumps = merge_clump(root, fclumps, clump, num_gene, true);
214  }
215  clumps = fclumps;
216  }
217 
218  /* Did we succeed in forming a single join relation? */
219  if (list_length(clumps) != 1)
220  return NULL;
221 
222  return ((Clump *) linitial(clumps))->joinrel;
223 }
static List * merge_clump(PlannerInfo *root, List *clumps, Clump *new_clump, int num_gene, bool force)
Definition: geqo_eval.c:238
void * palloc(Size size)
Definition: mcxt.c:1304
#define lfirst(lc)
Definition: pg_list.h:172
#define NIL
Definition: pg_list.h:68
#define linitial(l)
Definition: pg_list.h:178
static void * list_nth(const List *list, int n)
Definition: pg_list.h:299
for(int i=0;i< RT_NUM_SIZE_CLASSES;i++)
Definition: radixtree.h:1810
int size
Definition: geqo_eval.c:39
RelOptInfo * joinrel
Definition: geqo_eval.c:38
Definition: pg_list.h:54

References for(), Clump::joinrel, lfirst, linitial, list_length(), list_nth(), merge_clump(), NIL, palloc(), root, and Clump::size.

Referenced by geqo(), and geqo_eval().

Variable Documentation

◆ Geqo_effort

PGDLLIMPORT int Geqo_effort
extern

Definition at line 44 of file geqo_main.c.

Referenced by gimme_pool_size().

◆ Geqo_generations

PGDLLIMPORT int Geqo_generations
extern

Definition at line 46 of file geqo_main.c.

Referenced by gimme_number_generations().

◆ Geqo_pool_size

PGDLLIMPORT int Geqo_pool_size
extern

Definition at line 45 of file geqo_main.c.

Referenced by gimme_pool_size().

◆ Geqo_seed

PGDLLIMPORT double Geqo_seed
extern

Definition at line 48 of file geqo_main.c.

Referenced by geqo().

◆ Geqo_selection_bias

PGDLLIMPORT double Geqo_selection_bias
extern

Definition at line 47 of file geqo_main.c.

Referenced by geqo().