geqo_main.c File Reference

#include "postgres.h"
#include <math.h>
#include "optimizer/geqo.h"
#include "optimizer/geqo_misc.h"
#include "optimizer/geqo_pool.h"
#include "optimizer/geqo_random.h"
#include "optimizer/geqo_recombination.h"
#include "optimizer/geqo_selection.h"

Include dependency graph for geqo_main.c:

Go to the source code of this file.

Functions
static int	gimme_pool_size (int nr_rel)
static int	gimme_number_generations (int pool_size)
RelOptInfo *	geqo (PlannerInfo *root, int number_of_rels, List *initial_rels)

Variables
int	Geqo_effort
int	Geqo_pool_size
int	Geqo_generations
double	Geqo_selection_bias
double	Geqo_seed

Function Documentation

geqo()

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

Definition at line 72 of file geqo_main.c.

{
    GeqoPrivateData private;
    int         generation;
    Chromosome *momma;
    Chromosome *daddy;
    Chromosome *kid;
    Pool       *pool;
    int         pool_size,
                number_generations;
 
#ifdef GEQO_DEBUG
    int         status_interval;
#endif
    Gene       *best_tour;
    RelOptInfo *best_rel;
 
#if defined(ERX)
    Edge       *edge_table;     /* list of edges */
    int         edge_failures = 0;
#endif
#if defined(CX) || defined(PX) || defined(OX1) || defined(OX2)
    City       *city_table;     /* list of cities */
#endif
#if defined(CX)
    int         cycle_diffs = 0;
    int         mutations = 0;
#endif
 
/* set up private information */
    root->join_search_private = (void *) &private;
    private.initial_rels = initial_rels;
 
/* initialize private number generator */
    geqo_set_seed(root, Geqo_seed);
 
/* set GA parameters */
    pool_size = gimme_pool_size(number_of_rels);
    number_generations = gimme_number_generations(pool_size);
#ifdef GEQO_DEBUG
    status_interval = 10;
#endif
 
/* allocate genetic pool memory */
    pool = alloc_pool(root, pool_size, number_of_rels);
 
/* random initialization of the pool */
    random_init_pool(root, pool);
 
/* sort the pool according to cheapest path as fitness */
    sort_pool(root, pool);      /* we have to do it only one time, since all
                                 * kids replace the worst individuals in
                                 * future (-> geqo_pool.c:spread_chromo ) */
 
#ifdef GEQO_DEBUG
    elog(DEBUG1, "GEQO selected %d pool entries, best %.2f, worst %.2f",
         pool_size,
         pool->data[0].worth,
         pool->data[pool_size - 1].worth);
#endif
 
/* allocate chromosome momma and daddy memory */
    momma = alloc_chromo(root, pool->string_length);
    daddy = alloc_chromo(root, pool->string_length);
 
#if defined (ERX)
#ifdef GEQO_DEBUG
    elog(DEBUG2, "using edge recombination crossover [ERX]");
#endif
/* allocate edge table memory */
    edge_table = alloc_edge_table(root, pool->string_length);
#elif defined(PMX)
#ifdef GEQO_DEBUG
    elog(DEBUG2, "using partially matched crossover [PMX]");
#endif
/* allocate chromosome kid memory */
    kid = alloc_chromo(root, pool->string_length);
#elif defined(CX)
#ifdef GEQO_DEBUG
    elog(DEBUG2, "using cycle crossover [CX]");
#endif
/* allocate city table memory */
    kid = alloc_chromo(root, pool->string_length);
    city_table = alloc_city_table(root, pool->string_length);
#elif defined(PX)
#ifdef GEQO_DEBUG
    elog(DEBUG2, "using position crossover [PX]");
#endif
/* allocate city table memory */
    kid = alloc_chromo(root, pool->string_length);
    city_table = alloc_city_table(root, pool->string_length);
#elif defined(OX1)
#ifdef GEQO_DEBUG
    elog(DEBUG2, "using order crossover [OX1]");
#endif
/* allocate city table memory */
    kid = alloc_chromo(root, pool->string_length);
    city_table = alloc_city_table(root, pool->string_length);
#elif defined(OX2)
#ifdef GEQO_DEBUG
    elog(DEBUG2, "using order crossover [OX2]");
#endif
/* allocate city table memory */
    kid = alloc_chromo(root, pool->string_length);
    city_table = alloc_city_table(root, pool->string_length);
#endif
 
 
/* my pain main part: */
/* iterative optimization */
 
    for (generation = 0; generation < number_generations; generation++)
    {
        /* SELECTION: using linear bias function */
        geqo_selection(root, momma, daddy, pool, Geqo_selection_bias);
 
#if defined (ERX)
        /* EDGE RECOMBINATION CROSSOVER */
        gimme_edge_table(root, momma->string, daddy->string, pool->string_length, edge_table);
 
        kid = momma;
 
        /* are there any edge failures ? */
        edge_failures += gimme_tour(root, edge_table, kid->string, pool->string_length);
#elif defined(PMX)
        /* PARTIALLY MATCHED CROSSOVER */
        pmx(root, momma->string, daddy->string, kid->string, pool->string_length);
#elif defined(CX)
        /* CYCLE CROSSOVER */
        cycle_diffs = cx(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
        /* mutate the child */
        if (cycle_diffs == 0)
        {
            mutations++;
            geqo_mutation(root, kid->string, pool->string_length);
        }
#elif defined(PX)
        /* POSITION CROSSOVER */
        px(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
#elif defined(OX1)
        /* ORDER CROSSOVER */
        ox1(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
#elif defined(OX2)
        /* ORDER CROSSOVER */
        ox2(root, momma->string, daddy->string, kid->string, pool->string_length, city_table);
#endif
 
 
        /* EVALUATE FITNESS */
        kid->worth = geqo_eval(root, kid->string, pool->string_length);
 
        /* push the kid into the wilderness of life according to its worth */
        spread_chromo(root, kid, pool);
 
 
#ifdef GEQO_DEBUG
        if (status_interval && !(generation % status_interval))
            print_gen(stdout, pool, generation);
#endif
 
    }
 
 
#if defined(ERX)
#if defined(GEQO_DEBUG)
    if (edge_failures != 0)
        elog(LOG, "[GEQO] failures: %d, average: %d",
             edge_failures, (int) number_generations / edge_failures);
    else
        elog(LOG, "[GEQO] no edge failures detected");
#else
    /* suppress variable-set-but-not-used warnings from some compilers */
    (void) edge_failures;
#endif
#endif
 
#if defined(CX) && defined(GEQO_DEBUG)
    if (mutations != 0)
        elog(LOG, "[GEQO] mutations: %d, generations: %d",
             mutations, number_generations);
    else
        elog(LOG, "[GEQO] no mutations processed");
#endif
 
#ifdef GEQO_DEBUG
    print_pool(stdout, pool, 0, pool_size - 1);
#endif
 
#ifdef GEQO_DEBUG
    elog(DEBUG1, "GEQO best is %.2f after %d generations",
         pool->data[0].worth, number_generations);
#endif
 
 
    /*
     * got the cheapest query tree processed by geqo; first element of the
     * population indicates the best query tree
     */
    best_tour = (Gene *) pool->data[0].string;
 
    best_rel = gimme_tree(root, best_tour, pool->string_length);
 
    if (best_rel == NULL)
        elog(ERROR, "geqo failed to make a valid plan");
 
    /* DBG: show the query plan */
#ifdef NOT_USED
    print_plan(best_plan, root);
#endif
 
    /* ... free memory stuff */
    free_chromo(root, momma);
    free_chromo(root, daddy);
 
#if defined (ERX)
    free_edge_table(root, edge_table);
#elif defined(PMX)
    free_chromo(root, kid);
#elif defined(CX)
    free_chromo(root, kid);
    free_city_table(root, city_table);
#elif defined(PX)
    free_chromo(root, kid);
    free_city_table(root, city_table);
#elif defined(OX1)
    free_chromo(root, kid);
    free_city_table(root, city_table);
#elif defined(OX2)
    free_chromo(root, kid);
    free_city_table(root, city_table);
#endif
 
    free_pool(root, pool);
 
    /* ... clear root pointer to our private storage */
    root->join_search_private = NULL;
 
    return best_rel;
}

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().

gimme_number_generations()

static int gimme_number_generations ( int  pool_size )

static

Definition at line 352 of file geqo_main.c.

{
    if (Geqo_generations > 0)
        return Geqo_generations;
 
    return pool_size;
}

References Geqo_generations.

Referenced by geqo().

gimme_pool_size()

static int gimme_pool_size ( int  nr_rel )

static

Definition at line 320 of file geqo_main.c.

{
    double      size;
    int         minsize;
    int         maxsize;
 
    /* Legal pool size *must* be at least 2, so ignore attempt to select 1 */
    if (Geqo_pool_size >= 2)
        return Geqo_pool_size;
 
    size = pow(2.0, nr_rel + 1.0);
 
    maxsize = 50 * Geqo_effort; /* 50 to 500 individuals */
    if (size > maxsize)
        return maxsize;
 
    minsize = 10 * Geqo_effort; /* 10 to 100 individuals */
    if (size < minsize)
        return minsize;
 
    return (int) ceil(size);
}

References Geqo_effort, Geqo_pool_size, and size.

Referenced by geqo().

Variable Documentation

Geqo_effort

int Geqo_effort

Definition at line 44 of file geqo_main.c.

Referenced by gimme_pool_size().

Geqo_generations

int Geqo_generations

Definition at line 46 of file geqo_main.c.

Referenced by gimme_number_generations().

Geqo_pool_size

int Geqo_pool_size

Definition at line 45 of file geqo_main.c.

Referenced by gimme_pool_size().

Geqo_seed

double Geqo_seed

Definition at line 48 of file geqo_main.c.

Referenced by geqo().

Geqo_selection_bias

double Geqo_selection_bias

Definition at line 47 of file geqo_main.c.

Referenced by geqo().