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diff --git a/src/backend/optimizer/geqo/geqo_ox2.c b/src/backend/optimizer/geqo/geqo_ox2.c
new file mode 100644
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+++ b/src/backend/optimizer/geqo/geqo_ox2.c
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+/*------------------------------------------------------------------------
+*
+* geqo_ox2.c--
+*
+*    order crossover [OX] routines;
+*    OX2 operator according to Syswerda
+*    (The Genetic Algorithms Handbook, ed L Davis)
+*
+* $Id: geqo_ox2.c,v 1.1 1997/03/14 16:03:02 scrappy Exp $
+*
+*-------------------------------------------------------------------------
+*/
+
+/* contributed by:
+   =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
+   *  Martin Utesch              * Institute of Automatic Control      *
+   =                             = University of Mining and Technology =
+   *  utesch@aut.tu-freiberg.de  * Freiberg, Germany                   *
+   =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
+ */
+
+/* the ox algorithm is adopted from Genitor : */
+/*************************************************************/
+/*                                                           */
+/*  Copyright (c) 1990                                       */
+/*  Darrell L. Whitley                                       */
+/*  Computer Science Department                              */
+/*  Colorado State University                                */
+/*                                                           */
+/*  Permission is hereby granted to copy all or any part of  */
+/*  this program for free distribution.   The author's name  */
+/*  and this copyright notice must be included in any copy.  */
+/*                                                           */
+/*************************************************************/
+
+#include "postgres.h"
+
+#include "nodes/pg_list.h"
+#include "nodes/relation.h"
+#include "nodes/primnodes.h"
+
+#include "utils/palloc.h"
+#include "utils/elog.h"
+
+#include "optimizer/internal.h"
+#include "optimizer/paths.h"
+#include "optimizer/pathnode.h"
+#include "optimizer/clauses.h"
+#include "optimizer/cost.h"
+
+#include "optimizer/geqo_gene.h"
+#include "optimizer/geqo.h"
+#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo_random.h"
+
+
+/* ox2--
+ *
+ *   position crossover
+ */
+void
+ox2(Gene *tour1, Gene *tour2, Gene *offspring, int num_gene, City *city_table)
+{
+   int k, j, count, pos, select, num_positions;
+
+   /* initialize city table */
+   for (k = 1; k <= num_gene; k++) {
+     city_table[k].used = 0;
+     city_table[k-1].select_list = -1;
+   }
+
+   /* determine the number of positions to be inherited from tour1  */
+   num_positions = geqo_randint (2*num_gene/3, num_gene/3);   
+
+   /* make a list of selected cities */
+   for (k=0; k<num_positions; k++) {
+      pos = geqo_randint (num_gene - 1, 0);
+      city_table[pos].select_list = (int) tour1[pos];
+      city_table[(int) tour1[pos]].used = 1; /* mark used */
+   }
+
+
+   count = 0;
+   k = 0;
+
+   /* consolidate the select list to adjacent positions */
+   while (count < num_positions) {
+      if (city_table[k].select_list == -1) {
+	 j = k + 1;
+	 while ((city_table[j].select_list == -1) && (j < num_gene))
+	    j++;
+
+	 city_table[k].select_list = city_table[j].select_list;
+	 city_table[j].select_list = -1;
+	 count ++;
+      }
+      else
+	 count ++;
+      k++;
+   }
+
+   select = 0;
+
+   for (k=0; k<num_gene; k++) {
+      if (city_table[(int) tour2[k]].used) {
+	 offspring[k] = (Gene) city_table[select].select_list;
+	 select ++; /* next city in  the select list   */
+      }
+      else /* city isn't used yet, so inherit from tour2 */
+	 offspring[k] = tour2[k];
+   }
+
+}