granicus.if.org Git - postgresql/blob - contrib/tablefunc/tablefunc.c

   1 /*
   2  * $PostgreSQL: pgsql/contrib/tablefunc/tablefunc.c,v 1.62 2010/01/02 16:57:32 momjian Exp $
   3  *
   4  *
   5  * tablefunc
   6  *
   7  * Sample to demonstrate C functions which return setof scalar
   8  * and setof composite.
   9  * Joe Conway <mail@joeconway.com>
  10  * And contributors:
  11  * Nabil Sayegh <postgresql@e-trolley.de>
  12  *
  13  * Copyright (c) 2002-2010, PostgreSQL Global Development Group
  14  *
  15  * Permission to use, copy, modify, and distribute this software and its
  16  * documentation for any purpose, without fee, and without a written agreement
  17  * is hereby granted, provided that the above copyright notice and this
  18  * paragraph and the following two paragraphs appear in all copies.
  19  *
  20  * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
  21  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
  22  * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
  23  * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
  27  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  28  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  29  * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
  30  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  31  *
  32  */
  33 #include "postgres.h"
  34
  35 #include <math.h>
  36
  37 #include "catalog/pg_type.h"
  38 #include "fmgr.h"
  39 #include "funcapi.h"
  40 #include "executor/spi.h"
  41 #include "lib/stringinfo.h"
  42 #include "miscadmin.h"
  43 #include "utils/builtins.h"
  44 #include "utils/guc.h"
  45 #include "utils/lsyscache.h"
  46
  47 #include "tablefunc.h"
  48
  49 PG_MODULE_MAGIC;
  50
  51 static HTAB *load_categories_hash(char *cats_sql, MemoryContext per_query_ctx);
  52 static Tuplestorestate *get_crosstab_tuplestore(char *sql,
  53                                                 HTAB *crosstab_hash,
  54                                                 TupleDesc tupdesc,
  55                                                 MemoryContext per_query_ctx,
  56                                                 bool randomAccess);
  57 static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial);
  58 static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
  59 static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
  60 static void get_normal_pair(float8 *x1, float8 *x2);
  61 static Tuplestorestate *connectby(char *relname,
  62                   char *key_fld,
  63                   char *parent_key_fld,
  64                   char *orderby_fld,
  65                   char *branch_delim,
  66                   char *start_with,
  67                   int max_depth,
  68                   bool show_branch,
  69                   bool show_serial,
  70                   MemoryContext per_query_ctx,
  71                   bool randomAccess,
  72                   AttInMetadata *attinmeta);
  73 static Tuplestorestate *build_tuplestore_recursively(char *key_fld,
  74                                                          char *parent_key_fld,
  75                                                          char *relname,
  76                                                          char *orderby_fld,
  77                                                          char *branch_delim,
  78                                                          char *start_with,
  79                                                          char *branch,
  80                                                          int level,
  81                                                          int *serial,
  82                                                          int max_depth,
  83                                                          bool show_branch,
  84                                                          bool show_serial,
  85                                                          MemoryContext per_query_ctx,
  86                                                          AttInMetadata *attinmeta,
  87                                                          Tuplestorestate *tupstore);
  88 static char *quote_literal_cstr(char *rawstr);
  89
  90 typedef struct
  91 {
  92         float8          mean;                   /* mean of the distribution */
  93         float8          stddev;                 /* stddev of the distribution */
  94         float8          carry_val;              /* hold second generated value */
  95         bool            use_carry;              /* use second generated value */
  96 } normal_rand_fctx;
  97
  98 #define xpfree(var_) \
  99         do { \
 100                 if (var_ != NULL) \
 101                 { \
 102                         pfree(var_); \
 103                         var_ = NULL; \
 104                 } \
 105         } while (0)
 106
 107 #define xpstrdup(tgtvar_, srcvar_) \
 108         do { \
 109                 if (srcvar_) \
 110                         tgtvar_ = pstrdup(srcvar_); \
 111                 else \
 112                         tgtvar_ = NULL; \
 113         } while (0)
 114
 115 #define xstreq(tgtvar_, srcvar_) \
 116         (((tgtvar_ == NULL) && (srcvar_ == NULL)) || \
 117          ((tgtvar_ != NULL) && (srcvar_ != NULL) && (strcmp(tgtvar_, srcvar_) == 0)))
 118
 119 /* sign, 10 digits, '\0' */
 120 #define INT32_STRLEN    12
 121
 122 /* stored info for a crosstab category */
 123 typedef struct crosstab_cat_desc
 124 {
 125         char       *catname;            /* full category name */
 126         int                     attidx;                 /* zero based */
 127 } crosstab_cat_desc;
 128
 129 #define MAX_CATNAME_LEN                 NAMEDATALEN
 130 #define INIT_CATS                               64
 131
 132 #define crosstab_HashTableLookup(HASHTAB, CATNAME, CATDESC) \
 133 do { \
 134         crosstab_HashEnt *hentry; char key[MAX_CATNAME_LEN]; \
 135         \
 136         MemSet(key, 0, MAX_CATNAME_LEN); \
 137         snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATNAME); \
 138         hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \
 139                                                                                  key, HASH_FIND, NULL); \
 140         if (hentry) \
 141                 CATDESC = hentry->catdesc; \
 142         else \
 143                 CATDESC = NULL; \
 144 } while(0)
 145
 146 #define crosstab_HashTableInsert(HASHTAB, CATDESC) \
 147 do { \
 148         crosstab_HashEnt *hentry; bool found; char key[MAX_CATNAME_LEN]; \
 149         \
 150         MemSet(key, 0, MAX_CATNAME_LEN); \
 151         snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATDESC->catname); \
 152         hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \
 153                                                                                  key, HASH_ENTER, &found); \
 154         if (found) \
 155                 ereport(ERROR, \
 156                                 (errcode(ERRCODE_DUPLICATE_OBJECT), \
 157                                  errmsg("duplicate category name"))); \
 158         hentry->catdesc = CATDESC; \
 159 } while(0)
 160
 161 /* hash table */
 162 typedef struct crosstab_hashent
 163 {
 164         char            internal_catname[MAX_CATNAME_LEN];
 165         crosstab_cat_desc *catdesc;
 166 } crosstab_HashEnt;
 167
 168 /*
 169  * normal_rand - return requested number of random values
 170  * with a Gaussian (Normal) distribution.
 171  *
 172  * inputs are int numvals, float8 mean, and float8 stddev
 173  * returns setof float8
 174  */
 175 PG_FUNCTION_INFO_V1(normal_rand);
 176 Datum
 177 normal_rand(PG_FUNCTION_ARGS)
 178 {
 179         FuncCallContext *funcctx;
 180         int                     call_cntr;
 181         int                     max_calls;
 182         normal_rand_fctx *fctx;
 183         float8          mean;
 184         float8          stddev;
 185         float8          carry_val;
 186         bool            use_carry;
 187         MemoryContext oldcontext;
 188
 189         /* stuff done only on the first call of the function */
 190         if (SRF_IS_FIRSTCALL())
 191         {
 192                 /* create a function context for cross-call persistence */
 193                 funcctx = SRF_FIRSTCALL_INIT();
 194
 195                 /*
 196                  * switch to memory context appropriate for multiple function calls
 197                  */
 198                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 199
 200                 /* total number of tuples to be returned */
 201                 funcctx->max_calls = PG_GETARG_UINT32(0);
 202
 203                 /* allocate memory for user context */
 204                 fctx = (normal_rand_fctx *) palloc(sizeof(normal_rand_fctx));
 205
 206                 /*
 207                  * Use fctx to keep track of upper and lower bounds from call to call.
 208                  * It will also be used to carry over the spare value we get from the
 209                  * Box-Muller algorithm so that we only actually calculate a new value
 210                  * every other call.
 211                  */
 212                 fctx->mean = PG_GETARG_FLOAT8(1);
 213                 fctx->stddev = PG_GETARG_FLOAT8(2);
 214                 fctx->carry_val = 0;
 215                 fctx->use_carry = false;
 216
 217                 funcctx->user_fctx = fctx;
 218
 219                 MemoryContextSwitchTo(oldcontext);
 220         }
 221
 222         /* stuff done on every call of the function */
 223         funcctx = SRF_PERCALL_SETUP();
 224
 225         call_cntr = funcctx->call_cntr;
 226         max_calls = funcctx->max_calls;
 227         fctx = funcctx->user_fctx;
 228         mean = fctx->mean;
 229         stddev = fctx->stddev;
 230         carry_val = fctx->carry_val;
 231         use_carry = fctx->use_carry;
 232
 233         if (call_cntr < max_calls)      /* do when there is more left to send */
 234         {
 235                 float8          result;
 236
 237                 if (use_carry)
 238                 {
 239                         /*
 240                          * reset use_carry and use second value obtained on last pass
 241                          */
 242                         fctx->use_carry = false;
 243                         result = carry_val;
 244                 }
 245                 else
 246                 {
 247                         float8          normval_1;
 248                         float8          normval_2;
 249
 250                         /* Get the next two normal values */
 251                         get_normal_pair(&normval_1, &normval_2);
 252
 253                         /* use the first */
 254                         result = mean + (stddev * normval_1);
 255
 256                         /* and save the second */
 257                         fctx->carry_val = mean + (stddev * normval_2);
 258                         fctx->use_carry = true;
 259                 }
 260
 261                 /* send the result */
 262                 SRF_RETURN_NEXT(funcctx, Float8GetDatum(result));
 263         }
 264         else
 265                 /* do when there is no more left */
 266                 SRF_RETURN_DONE(funcctx);
 267 }
 268
 269 /*
 270  * get_normal_pair()
 271  * Assigns normally distributed (Gaussian) values to a pair of provided
 272  * parameters, with mean 0, standard deviation 1.
 273  *
 274  * This routine implements Algorithm P (Polar method for normal deviates)
 275  * from Knuth's _The_Art_of_Computer_Programming_, Volume 2, 3rd ed., pages
 276  * 122-126. Knuth cites his source as "The polar method", G. E. P. Box, M. E.
 277  * Muller, and G. Marsaglia, _Annals_Math,_Stat._ 29 (1958), 610-611.
 278  *
 279  */
 280 static void
 281 get_normal_pair(float8 *x1, float8 *x2)
 282 {
 283         float8          u1,
 284                                 u2,
 285                                 v1,
 286                                 v2,
 287                                 s;
 288
 289         do
 290         {
 291                 u1 = (float8) random() / (float8) MAX_RANDOM_VALUE;
 292                 u2 = (float8) random() / (float8) MAX_RANDOM_VALUE;
 293
 294                 v1 = (2.0 * u1) - 1.0;
 295                 v2 = (2.0 * u2) - 1.0;
 296
 297                 s = v1 * v1 + v2 * v2;
 298         } while (s >= 1.0);
 299
 300         if (s == 0)
 301         {
 302                 *x1 = 0;
 303                 *x2 = 0;
 304         }
 305         else
 306         {
 307                 s = sqrt((-2.0 * log(s)) / s);
 308                 *x1 = v1 * s;
 309                 *x2 = v2 * s;
 310         }
 311 }
 312
 313 /*
 314  * crosstab - create a crosstab of rowids and values columns from a
 315  * SQL statement returning one rowid column, one category column,
 316  * and one value column.
 317  *
 318  * e.g. given sql which produces:
 319  *
 320  *                      rowid   cat             value
 321  *                      ------+-------+-------
 322  *                      row1    cat1    val1
 323  *                      row1    cat2    val2
 324  *                      row1    cat3    val3
 325  *                      row1    cat4    val4
 326  *                      row2    cat1    val5
 327  *                      row2    cat2    val6
 328  *                      row2    cat3    val7
 329  *                      row2    cat4    val8
 330  *
 331  * crosstab returns:
 332  *                                      <===== values columns =====>
 333  *                      rowid   cat1    cat2    cat3    cat4
 334  *                      ------+-------+-------+-------+-------
 335  *                      row1    val1    val2    val3    val4
 336  *                      row2    val5    val6    val7    val8
 337  *
 338  * NOTES:
 339  * 1. SQL result must be ordered by 1,2.
 340  * 2. The number of values columns depends on the tuple description
 341  *        of the function's declared return type.  The return type's columns
 342  *        must match the datatypes of the SQL query's result.  The datatype
 343  *        of the category column can be anything, however.
 344  * 3. Missing values (i.e. not enough adjacent rows of same rowid to
 345  *        fill the number of result values columns) are filled in with nulls.
 346  * 4. Extra values (i.e. too many adjacent rows of same rowid to fill
 347  *        the number of result values columns) are skipped.
 348  * 5. Rows with all nulls in the values columns are skipped.
 349  */
 350 PG_FUNCTION_INFO_V1(crosstab);
 351 Datum
 352 crosstab(PG_FUNCTION_ARGS)
 353 {
 354         char       *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
 355         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 356         Tuplestorestate *tupstore;
 357         TupleDesc       tupdesc;
 358         int                     call_cntr;
 359         int                     max_calls;
 360         AttInMetadata *attinmeta;
 361         SPITupleTable *spi_tuptable;
 362         TupleDesc       spi_tupdesc;
 363         bool            firstpass;
 364         char       *lastrowid;
 365         int                     i;
 366         int                     num_categories;
 367         MemoryContext per_query_ctx;
 368         MemoryContext oldcontext;
 369         int                     ret;
 370         int                     proc;
 371
 372         /* check to see if caller supports us returning a tuplestore */
 373         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
 374                 ereport(ERROR,
 375                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 376                                  errmsg("set-valued function called in context that cannot accept a set")));
 377         if (!(rsinfo->allowedModes & SFRM_Materialize))
 378                 ereport(ERROR,
 379                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 380                                  errmsg("materialize mode required, but it is not " \
 381                                                 "allowed in this context")));
 382
 383         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
 384
 385         /* Connect to SPI manager */
 386         if ((ret = SPI_connect()) < 0)
 387                 /* internal error */
 388                 elog(ERROR, "crosstab: SPI_connect returned %d", ret);
 389
 390         /* Retrieve the desired rows */
 391         ret = SPI_execute(sql, true, 0);
 392         proc = SPI_processed;
 393
 394         /* If no qualifying tuples, fall out early */
 395         if (ret != SPI_OK_SELECT || proc <= 0)
 396         {
 397                 SPI_finish();
 398                 rsinfo->isDone = ExprEndResult;
 399                 PG_RETURN_NULL();
 400         }
 401
 402         spi_tuptable = SPI_tuptable;
 403         spi_tupdesc = spi_tuptable->tupdesc;
 404
 405         /*----------
 406          * The provided SQL query must always return three columns.
 407          *
 408          * 1. rowname
 409          *      the label or identifier for each row in the final result
 410          * 2. category
 411          *      the label or identifier for each column in the final result
 412          * 3. values
 413          *      the value for each column in the final result
 414          *----------
 415          */
 416         if (spi_tupdesc->natts != 3)
 417                 ereport(ERROR,
 418                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 419                                  errmsg("invalid source data SQL statement"),
 420                                  errdetail("The provided SQL must return 3 "
 421                                                    "columns: rowid, category, and values.")));
 422
 423         /* get a tuple descriptor for our result type */
 424         switch (get_call_result_type(fcinfo, NULL, &tupdesc))
 425         {
 426                 case TYPEFUNC_COMPOSITE:
 427                         /* success */
 428                         break;
 429                 case TYPEFUNC_RECORD:
 430                         /* failed to determine actual type of RECORD */
 431                         ereport(ERROR,
 432                                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 433                                          errmsg("function returning record called in context "
 434                                                         "that cannot accept type record")));
 435                         break;
 436                 default:
 437                         /* result type isn't composite */
 438                         elog(ERROR, "return type must be a row type");
 439                         break;
 440         }
 441
 442         /*
 443          * Check that return tupdesc is compatible with the data we got from SPI,
 444          * at least based on number and type of attributes
 445          */
 446         if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
 447                 ereport(ERROR,
 448                                 (errcode(ERRCODE_SYNTAX_ERROR),
 449                                  errmsg("return and sql tuple descriptions are " \
 450                                                 "incompatible")));
 451
 452         /*
 453          * switch to long-lived memory context
 454          */
 455         oldcontext = MemoryContextSwitchTo(per_query_ctx);
 456
 457         /* make sure we have a persistent copy of the result tupdesc */
 458         tupdesc = CreateTupleDescCopy(tupdesc);
 459
 460         /* initialize our tuplestore in long-lived context */
 461         tupstore =
 462                 tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
 463                                                           false, work_mem);
 464
 465         MemoryContextSwitchTo(oldcontext);
 466
 467         /*
 468          * Generate attribute metadata needed later to produce tuples from raw C
 469          * strings
 470          */
 471         attinmeta = TupleDescGetAttInMetadata(tupdesc);
 472
 473         /* total number of tuples to be examined */
 474         max_calls = proc;
 475
 476         /* the return tuple always must have 1 rowid + num_categories columns */
 477         num_categories = tupdesc->natts - 1;
 478
 479         firstpass = true;
 480         lastrowid = NULL;
 481
 482         for (call_cntr = 0; call_cntr < max_calls; call_cntr++)
 483         {
 484                 bool            skip_tuple = false;
 485                 char      **values;
 486
 487                 /* allocate and zero space */
 488                 values = (char **) palloc0((1 + num_categories) * sizeof(char *));
 489
 490                 /*
 491                  * now loop through the sql results and assign each value in sequence
 492                  * to the next category
 493                  */
 494                 for (i = 0; i < num_categories; i++)
 495                 {
 496                         HeapTuple       spi_tuple;
 497                         char       *rowid;
 498
 499                         /* see if we've gone too far already */
 500                         if (call_cntr >= max_calls)
 501                                 break;
 502
 503                         /* get the next sql result tuple */
 504                         spi_tuple = spi_tuptable->vals[call_cntr];
 505
 506                         /* get the rowid from the current sql result tuple */
 507                         rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
 508
 509                         /*
 510                          * If this is the first pass through the values for this rowid,
 511                          * set the first column to rowid
 512                          */
 513                         if (i == 0)
 514                         {
 515                                 xpstrdup(values[0], rowid);
 516
 517                                 /*
 518                                  * Check to see if the rowid is the same as that of the last
 519                                  * tuple sent -- if so, skip this tuple entirely
 520                                  */
 521                                 if (!firstpass && xstreq(lastrowid, rowid))
 522                                 {
 523                                         xpfree(rowid);
 524                                         skip_tuple = true;
 525                                         break;
 526                                 }
 527                         }
 528
 529                         /*
 530                          * If rowid hasn't changed on us, continue building the output
 531                          * tuple.
 532                          */
 533                         if (xstreq(rowid, values[0]))
 534                         {
 535                                 /*
 536                                  * Get the next category item value, which is always attribute
 537                                  * number three.
 538                                  *
 539                                  * Be careful to assign the value to the array index based on
 540                                  * which category we are presently processing.
 541                                  */
 542                                 values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3);
 543
 544                                 /*
 545                                  * increment the counter since we consume a row for each
 546                                  * category, but not for last pass because the outer loop will
 547                                  * do that for us
 548                                  */
 549                                 if (i < (num_categories - 1))
 550                                         call_cntr++;
 551                                 xpfree(rowid);
 552                         }
 553                         else
 554                         {
 555                                 /*
 556                                  * We'll fill in NULLs for the missing values, but we need to
 557                                  * decrement the counter since this sql result row doesn't
 558                                  * belong to the current output tuple.
 559                                  */
 560                                 call_cntr--;
 561                                 xpfree(rowid);
 562                                 break;
 563                         }
 564                 }
 565
 566                 if (!skip_tuple)
 567                 {
 568                         HeapTuple       tuple;
 569
 570                         /* build the tuple and store it */
 571                         tuple = BuildTupleFromCStrings(attinmeta, values);
 572                         tuplestore_puttuple(tupstore, tuple);
 573                         heap_freetuple(tuple);
 574                 }
 575
 576                 /* Remember current rowid */
 577                 xpfree(lastrowid);
 578                 xpstrdup(lastrowid, values[0]);
 579                 firstpass = false;
 580
 581                 /* Clean up */
 582                 for (i = 0; i < num_categories + 1; i++)
 583                         if (values[i] != NULL)
 584                                 pfree(values[i]);
 585                 pfree(values);
 586         }
 587
 588         /* let the caller know we're sending back a tuplestore */
 589         rsinfo->returnMode = SFRM_Materialize;
 590         rsinfo->setResult = tupstore;
 591         rsinfo->setDesc = tupdesc;
 592
 593         /* release SPI related resources (and return to caller's context) */
 594         SPI_finish();
 595
 596         return (Datum) 0;
 597 }
 598
 599 /*
 600  * crosstab_hash - reimplement crosstab as materialized function and
 601  * properly deal with missing values (i.e. don't pack remaining
 602  * values to the left)
 603  *
 604  * crosstab - create a crosstab of rowids and values columns from a
 605  * SQL statement returning one rowid column, one category column,
 606  * and one value column.
 607  *
 608  * e.g. given sql which produces:
 609  *
 610  *                      rowid   cat             value
 611  *                      ------+-------+-------
 612  *                      row1    cat1    val1
 613  *                      row1    cat2    val2
 614  *                      row1    cat4    val4
 615  *                      row2    cat1    val5
 616  *                      row2    cat2    val6
 617  *                      row2    cat3    val7
 618  *                      row2    cat4    val8
 619  *
 620  * crosstab returns:
 621  *                                      <===== values columns =====>
 622  *                      rowid   cat1    cat2    cat3    cat4
 623  *                      ------+-------+-------+-------+-------
 624  *                      row1    val1    val2    null    val4
 625  *                      row2    val5    val6    val7    val8
 626  *
 627  * NOTES:
 628  * 1. SQL result must be ordered by 1.
 629  * 2. The number of values columns depends on the tuple description
 630  *        of the function's declared return type.
 631  * 3. Missing values (i.e. missing category) are filled in with nulls.
 632  * 4. Extra values (i.e. not in category results) are skipped.
 633  */
 634 PG_FUNCTION_INFO_V1(crosstab_hash);
 635 Datum
 636 crosstab_hash(PG_FUNCTION_ARGS)
 637 {
 638         char       *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
 639         char       *cats_sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
 640         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 641         TupleDesc       tupdesc;
 642         MemoryContext per_query_ctx;
 643         MemoryContext oldcontext;
 644         HTAB       *crosstab_hash;
 645
 646         /* check to see if caller supports us returning a tuplestore */
 647         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
 648                 ereport(ERROR,
 649                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 650                                  errmsg("set-valued function called in context that cannot accept a set")));
 651         if (!(rsinfo->allowedModes & SFRM_Materialize) ||
 652                 rsinfo->expectedDesc == NULL)
 653                 ereport(ERROR,
 654                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 655                                  errmsg("materialize mode required, but it is not " \
 656                                                 "allowed in this context")));
 657
 658         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
 659         oldcontext = MemoryContextSwitchTo(per_query_ctx);
 660
 661         /* get the requested return tuple description */
 662         tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
 663
 664         /*
 665          * Check to make sure we have a reasonable tuple descriptor
 666          *
 667          * Note we will attempt to coerce the values into whatever the return
 668          * attribute type is and depend on the "in" function to complain if
 669          * needed.
 670          */
 671         if (tupdesc->natts < 2)
 672                 ereport(ERROR,
 673                                 (errcode(ERRCODE_SYNTAX_ERROR),
 674                                  errmsg("query-specified return tuple and " \
 675                                                 "crosstab function are not compatible")));
 676
 677         /* load up the categories hash table */
 678         crosstab_hash = load_categories_hash(cats_sql, per_query_ctx);
 679
 680         /* let the caller know we're sending back a tuplestore */
 681         rsinfo->returnMode = SFRM_Materialize;
 682
 683         /* now go build it */
 684         rsinfo->setResult = get_crosstab_tuplestore(sql,
 685                                                                                                 crosstab_hash,
 686                                                                                                 tupdesc,
 687                                                                                                 per_query_ctx,
 688                                                          rsinfo->allowedModes & SFRM_Materialize_Random);
 689
 690         /*
 691          * SFRM_Materialize mode expects us to return a NULL Datum. The actual
 692          * tuples are in our tuplestore and passed back through rsinfo->setResult.
 693          * rsinfo->setDesc is set to the tuple description that we actually used
 694          * to build our tuples with, so the caller can verify we did what it was
 695          * expecting.
 696          */
 697         rsinfo->setDesc = tupdesc;
 698         MemoryContextSwitchTo(oldcontext);
 699
 700         return (Datum) 0;
 701 }
 702
 703 /*
 704  * load up the categories hash table
 705  */
 706 static HTAB *
 707 load_categories_hash(char *cats_sql, MemoryContext per_query_ctx)
 708 {
 709         HTAB       *crosstab_hash;
 710         HASHCTL         ctl;
 711         int                     ret;
 712         int                     proc;
 713         MemoryContext SPIcontext;
 714
 715         /* initialize the category hash table */
 716         MemSet(&ctl, 0, sizeof(ctl));
 717         ctl.keysize = MAX_CATNAME_LEN;
 718         ctl.entrysize = sizeof(crosstab_HashEnt);
 719         ctl.hcxt = per_query_ctx;
 720
 721         /*
 722          * use INIT_CATS, defined above as a guess of how many hash table entries
 723          * to create, initially
 724          */
 725         crosstab_hash = hash_create("crosstab hash",
 726                                                                 INIT_CATS,
 727                                                                 &ctl,
 728                                                                 HASH_ELEM | HASH_CONTEXT);
 729
 730         /* Connect to SPI manager */
 731         if ((ret = SPI_connect()) < 0)
 732                 /* internal error */
 733                 elog(ERROR, "load_categories_hash: SPI_connect returned %d", ret);
 734
 735         /* Retrieve the category name rows */
 736         ret = SPI_execute(cats_sql, true, 0);
 737         proc = SPI_processed;
 738
 739         /* Check for qualifying tuples */
 740         if ((ret == SPI_OK_SELECT) && (proc > 0))
 741         {
 742                 SPITupleTable *spi_tuptable = SPI_tuptable;
 743                 TupleDesc       spi_tupdesc = spi_tuptable->tupdesc;
 744                 int                     i;
 745
 746                 /*
 747                  * The provided categories SQL query must always return one column:
 748                  * category - the label or identifier for each column
 749                  */
 750                 if (spi_tupdesc->natts != 1)
 751                         ereport(ERROR,
 752                                         (errcode(ERRCODE_SYNTAX_ERROR),
 753                                          errmsg("provided \"categories\" SQL must " \
 754                                                         "return 1 column of at least one row")));
 755
 756                 for (i = 0; i < proc; i++)
 757                 {
 758                         crosstab_cat_desc *catdesc;
 759                         char       *catname;
 760                         HeapTuple       spi_tuple;
 761
 762                         /* get the next sql result tuple */
 763                         spi_tuple = spi_tuptable->vals[i];
 764
 765                         /* get the category from the current sql result tuple */
 766                         catname = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
 767
 768                         SPIcontext = MemoryContextSwitchTo(per_query_ctx);
 769
 770                         catdesc = (crosstab_cat_desc *) palloc(sizeof(crosstab_cat_desc));
 771                         catdesc->catname = catname;
 772                         catdesc->attidx = i;
 773
 774                         /* Add the proc description block to the hashtable */
 775                         crosstab_HashTableInsert(crosstab_hash, catdesc);
 776
 777                         MemoryContextSwitchTo(SPIcontext);
 778                 }
 779         }
 780
 781         if (SPI_finish() != SPI_OK_FINISH)
 782                 /* internal error */
 783                 elog(ERROR, "load_categories_hash: SPI_finish() failed");
 784
 785         return crosstab_hash;
 786 }
 787
 788 /*
 789  * create and populate the crosstab tuplestore using the provided source query
 790  */
 791 static Tuplestorestate *
 792 get_crosstab_tuplestore(char *sql,
 793                                                 HTAB *crosstab_hash,
 794                                                 TupleDesc tupdesc,
 795                                                 MemoryContext per_query_ctx,
 796                                                 bool randomAccess)
 797 {
 798         Tuplestorestate *tupstore;
 799         int                     num_categories = hash_get_num_entries(crosstab_hash);
 800         AttInMetadata *attinmeta = TupleDescGetAttInMetadata(tupdesc);
 801         char      **values;
 802         HeapTuple       tuple;
 803         int                     ret;
 804         int                     proc;
 805
 806         /* initialize our tuplestore (while still in query context!) */
 807         tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
 808
 809         /* Connect to SPI manager */
 810         if ((ret = SPI_connect()) < 0)
 811                 /* internal error */
 812                 elog(ERROR, "get_crosstab_tuplestore: SPI_connect returned %d", ret);
 813
 814         /* Now retrieve the crosstab source rows */
 815         ret = SPI_execute(sql, true, 0);
 816         proc = SPI_processed;
 817
 818         /* Check for qualifying tuples */
 819         if ((ret == SPI_OK_SELECT) && (proc > 0))
 820         {
 821                 SPITupleTable *spi_tuptable = SPI_tuptable;
 822                 TupleDesc       spi_tupdesc = spi_tuptable->tupdesc;
 823                 int                     ncols = spi_tupdesc->natts;
 824                 char       *rowid;
 825                 char       *lastrowid = NULL;
 826                 bool            firstpass = true;
 827                 int                     i,
 828                                         j;
 829                 int                     result_ncols;
 830
 831                 if (num_categories == 0)
 832                 {
 833                         /* no qualifying category tuples */
 834                         ereport(ERROR,
 835                                         (errcode(ERRCODE_SYNTAX_ERROR),
 836                                          errmsg("provided \"categories\" SQL must " \
 837                                                         "return 1 column of at least one row")));
 838                 }
 839
 840                 /*
 841                  * The provided SQL query must always return at least three columns:
 842                  *
 843                  * 1. rowname   the label for each row - column 1 in the final result
 844                  * 2. category  the label for each value-column in the final result 3.
 845                  * value         the values used to populate the value-columns
 846                  *
 847                  * If there are more than three columns, the last two are taken as
 848                  * "category" and "values". The first column is taken as "rowname".
 849                  * Additional columns (2 thru N-2) are assumed the same for the same
 850                  * "rowname", and are copied into the result tuple from the first time
 851                  * we encounter a particular rowname.
 852                  */
 853                 if (ncols < 3)
 854                         ereport(ERROR,
 855                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 856                                          errmsg("invalid source data SQL statement"),
 857                                          errdetail("The provided SQL must return 3 " \
 858                                                            " columns; rowid, category, and values.")));
 859
 860                 result_ncols = (ncols - 2) + num_categories;
 861
 862                 /* Recheck to make sure we tuple descriptor still looks reasonable */
 863                 if (tupdesc->natts != result_ncols)
 864                         ereport(ERROR,
 865                                         (errcode(ERRCODE_SYNTAX_ERROR),
 866                                          errmsg("invalid return type"),
 867                                          errdetail("Query-specified return " \
 868                                                            "tuple has %d columns but crosstab " \
 869                                                            "returns %d.", tupdesc->natts, result_ncols)));
 870
 871                 /* allocate space */
 872                 values = (char **) palloc(result_ncols * sizeof(char *));
 873
 874                 /* and make sure it's clear */
 875                 memset(values, '\0', result_ncols * sizeof(char *));
 876
 877                 for (i = 0; i < proc; i++)
 878                 {
 879                         HeapTuple       spi_tuple;
 880                         crosstab_cat_desc *catdesc;
 881                         char       *catname;
 882
 883                         /* get the next sql result tuple */
 884                         spi_tuple = spi_tuptable->vals[i];
 885
 886                         /* get the rowid from the current sql result tuple */
 887                         rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
 888
 889                         /*
 890                          * if we're on a new output row, grab the column values up to
 891                          * column N-2 now
 892                          */
 893                         if (firstpass || !xstreq(lastrowid, rowid))
 894                         {
 895                                 /*
 896                                  * a new row means we need to flush the old one first, unless
 897                                  * we're on the very first row
 898                                  */
 899                                 if (!firstpass)
 900                                 {
 901                                         /* rowid changed, flush the previous output row */
 902                                         tuple = BuildTupleFromCStrings(attinmeta, values);
 903
 904                                         tuplestore_puttuple(tupstore, tuple);
 905
 906                                         for (j = 0; j < result_ncols; j++)
 907                                                 xpfree(values[j]);
 908                                 }
 909
 910                                 values[0] = rowid;
 911                                 for (j = 1; j < ncols - 2; j++)
 912                                         values[j] = SPI_getvalue(spi_tuple, spi_tupdesc, j + 1);
 913
 914                                 /* we're no longer on the first pass */
 915                                 firstpass = false;
 916                         }
 917
 918                         /* look up the category and fill in the appropriate column */
 919                         catname = SPI_getvalue(spi_tuple, spi_tupdesc, ncols - 1);
 920
 921                         if (catname != NULL)
 922                         {
 923                                 crosstab_HashTableLookup(crosstab_hash, catname, catdesc);
 924
 925                                 if (catdesc)
 926                                         values[catdesc->attidx + ncols - 2] =
 927                                                 SPI_getvalue(spi_tuple, spi_tupdesc, ncols);
 928                         }
 929
 930                         xpfree(lastrowid);
 931                         xpstrdup(lastrowid, rowid);
 932                 }
 933
 934                 /* flush the last output row */
 935                 tuple = BuildTupleFromCStrings(attinmeta, values);
 936
 937                 tuplestore_puttuple(tupstore, tuple);
 938         }
 939
 940         if (SPI_finish() != SPI_OK_FINISH)
 941                 /* internal error */
 942                 elog(ERROR, "get_crosstab_tuplestore: SPI_finish() failed");
 943
 944         tuplestore_donestoring(tupstore);
 945
 946         return tupstore;
 947 }
 948
 949 /*
 950  * connectby_text - produce a result set from a hierarchical (parent/child)
 951  * table.
 952  *
 953  * e.g. given table foo:
 954  *
 955  *                      keyid   parent_keyid pos
 956  *                      ------+------------+--
 957  *                      row1    NULL             0
 958  *                      row2    row1             0
 959  *                      row3    row1             0
 960  *                      row4    row2             1
 961  *                      row5    row2             0
 962  *                      row6    row4             0
 963  *                      row7    row3             0
 964  *                      row8    row6             0
 965  *                      row9    row5             0
 966  *
 967  *
 968  * connectby(text relname, text keyid_fld, text parent_keyid_fld
 969  *                        [, text orderby_fld], text start_with, int max_depth
 970  *                        [, text branch_delim])
 971  * connectby('foo', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') returns:
 972  *
 973  *              keyid   parent_id       level    branch                         serial
 974  *              ------+-----------+--------+-----------------------
 975  *              row2    NULL              0               row2                            1
 976  *              row5    row2              1               row2~row5                       2
 977  *              row9    row5              2               row2~row5~row9          3
 978  *              row4    row2              1               row2~row4                       4
 979  *              row6    row4              2               row2~row4~row6          5
 980  *              row8    row6              3               row2~row4~row6~row8 6
 981  *
 982  */
 983 PG_FUNCTION_INFO_V1(connectby_text);
 984
 985 #define CONNECTBY_NCOLS                                 4
 986 #define CONNECTBY_NCOLS_NOBRANCH                3
 987
 988 Datum
 989 connectby_text(PG_FUNCTION_ARGS)
 990 {
 991         char       *relname = text_to_cstring(PG_GETARG_TEXT_PP(0));
 992         char       *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1));
 993         char       *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2));
 994         char       *start_with = text_to_cstring(PG_GETARG_TEXT_PP(3));
 995         int                     max_depth = PG_GETARG_INT32(4);
 996         char       *branch_delim = NULL;
 997         bool            show_branch = false;
 998         bool            show_serial = false;
 999         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1000         TupleDesc       tupdesc;
1001         AttInMetadata *attinmeta;
1002         MemoryContext per_query_ctx;
1003         MemoryContext oldcontext;
1004
1005         /* check to see if caller supports us returning a tuplestore */
1006         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
1007                 ereport(ERROR,
1008                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1009                                  errmsg("set-valued function called in context that cannot accept a set")));
1010         if (!(rsinfo->allowedModes & SFRM_Materialize) ||
1011                 rsinfo->expectedDesc == NULL)
1012                 ereport(ERROR,
1013                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1014                                  errmsg("materialize mode required, but it is not " \
1015                                                 "allowed in this context")));
1016
1017         if (fcinfo->nargs == 6)
1018         {
1019                 branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(5));
1020                 show_branch = true;
1021         }
1022         else
1023                 /* default is no show, tilde for the delimiter */
1024                 branch_delim = pstrdup("~");
1025
1026         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
1027         oldcontext = MemoryContextSwitchTo(per_query_ctx);
1028
1029         /* get the requested return tuple description */
1030         tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
1031
1032         /* does it meet our needs */
1033         validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
1034
1035         /* OK, use it then */
1036         attinmeta = TupleDescGetAttInMetadata(tupdesc);
1037
1038         /* OK, go to work */
1039         rsinfo->returnMode = SFRM_Materialize;
1040         rsinfo->setResult = connectby(relname,
1041                                                                   key_fld,
1042                                                                   parent_key_fld,
1043                                                                   NULL,
1044                                                                   branch_delim,
1045                                                                   start_with,
1046                                                                   max_depth,
1047                                                                   show_branch,
1048                                                                   show_serial,
1049                                                                   per_query_ctx,
1050                                                           rsinfo->allowedModes & SFRM_Materialize_Random,
1051                                                                   attinmeta);
1052         rsinfo->setDesc = tupdesc;
1053
1054         MemoryContextSwitchTo(oldcontext);
1055
1056         /*
1057          * SFRM_Materialize mode expects us to return a NULL Datum. The actual
1058          * tuples are in our tuplestore and passed back through rsinfo->setResult.
1059          * rsinfo->setDesc is set to the tuple description that we actually used
1060          * to build our tuples with, so the caller can verify we did what it was
1061          * expecting.
1062          */
1063         return (Datum) 0;
1064 }
1065
1066 PG_FUNCTION_INFO_V1(connectby_text_serial);
1067 Datum
1068 connectby_text_serial(PG_FUNCTION_ARGS)
1069 {
1070         char       *relname = text_to_cstring(PG_GETARG_TEXT_PP(0));
1071         char       *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1));
1072         char       *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2));
1073         char       *orderby_fld = text_to_cstring(PG_GETARG_TEXT_PP(3));
1074         char       *start_with = text_to_cstring(PG_GETARG_TEXT_PP(4));
1075         int                     max_depth = PG_GETARG_INT32(5);
1076         char       *branch_delim = NULL;
1077         bool            show_branch = false;
1078         bool            show_serial = true;
1079         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1080         TupleDesc       tupdesc;
1081         AttInMetadata *attinmeta;
1082         MemoryContext per_query_ctx;
1083         MemoryContext oldcontext;
1084
1085         /* check to see if caller supports us returning a tuplestore */
1086         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
1087                 ereport(ERROR,
1088                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1089                                  errmsg("set-valued function called in context that cannot accept a set")));
1090         if (!(rsinfo->allowedModes & SFRM_Materialize) ||
1091                 rsinfo->expectedDesc == NULL)
1092                 ereport(ERROR,
1093                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1094                                  errmsg("materialize mode required, but it is not " \
1095                                                 "allowed in this context")));
1096
1097         if (fcinfo->nargs == 7)
1098         {
1099                 branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(6));
1100                 show_branch = true;
1101         }
1102         else
1103                 /* default is no show, tilde for the delimiter */
1104                 branch_delim = pstrdup("~");
1105
1106         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
1107         oldcontext = MemoryContextSwitchTo(per_query_ctx);
1108
1109         /* get the requested return tuple description */
1110         tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
1111
1112         /* does it meet our needs */
1113         validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
1114
1115         /* OK, use it then */
1116         attinmeta = TupleDescGetAttInMetadata(tupdesc);
1117
1118         /* OK, go to work */
1119         rsinfo->returnMode = SFRM_Materialize;
1120         rsinfo->setResult = connectby(relname,
1121                                                                   key_fld,
1122                                                                   parent_key_fld,
1123                                                                   orderby_fld,
1124                                                                   branch_delim,
1125                                                                   start_with,
1126                                                                   max_depth,
1127                                                                   show_branch,
1128                                                                   show_serial,
1129                                                                   per_query_ctx,
1130                                                           rsinfo->allowedModes & SFRM_Materialize_Random,
1131                                                                   attinmeta);
1132         rsinfo->setDesc = tupdesc;
1133
1134         MemoryContextSwitchTo(oldcontext);
1135
1136         /*
1137          * SFRM_Materialize mode expects us to return a NULL Datum. The actual
1138          * tuples are in our tuplestore and passed back through rsinfo->setResult.
1139          * rsinfo->setDesc is set to the tuple description that we actually used
1140          * to build our tuples with, so the caller can verify we did what it was
1141          * expecting.
1142          */
1143         return (Datum) 0;
1144 }
1145
1146
1147 /*
1148  * connectby - does the real work for connectby_text()
1149  */
1150 static Tuplestorestate *
1151 connectby(char *relname,
1152                   char *key_fld,
1153                   char *parent_key_fld,
1154                   char *orderby_fld,
1155                   char *branch_delim,
1156                   char *start_with,
1157                   int max_depth,
1158                   bool show_branch,
1159                   bool show_serial,
1160                   MemoryContext per_query_ctx,
1161                   bool randomAccess,
1162                   AttInMetadata *attinmeta)
1163 {
1164         Tuplestorestate *tupstore = NULL;
1165         int                     ret;
1166         MemoryContext oldcontext;
1167
1168         int                     serial = 1;
1169
1170         /* Connect to SPI manager */
1171         if ((ret = SPI_connect()) < 0)
1172                 /* internal error */
1173                 elog(ERROR, "connectby: SPI_connect returned %d", ret);
1174
1175         /* switch to longer term context to create the tuple store */
1176         oldcontext = MemoryContextSwitchTo(per_query_ctx);
1177
1178         /* initialize our tuplestore */
1179         tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
1180
1181         MemoryContextSwitchTo(oldcontext);
1182
1183         /* now go get the whole tree */
1184         tupstore = build_tuplestore_recursively(key_fld,
1185                                                                                         parent_key_fld,
1186                                                                                         relname,
1187                                                                                         orderby_fld,
1188                                                                                         branch_delim,
1189                                                                                         start_with,
1190                                                                                         start_with, /* current_branch */
1191                                                                                         0,      /* initial level is 0 */
1192                                                                                         &serial,        /* initial serial is 1 */
1193                                                                                         max_depth,
1194                                                                                         show_branch,
1195                                                                                         show_serial,
1196                                                                                         per_query_ctx,
1197                                                                                         attinmeta,
1198                                                                                         tupstore);
1199
1200         SPI_finish();
1201
1202         return tupstore;
1203 }
1204
1205 static Tuplestorestate *
1206 build_tuplestore_recursively(char *key_fld,
1207                                                          char *parent_key_fld,
1208                                                          char *relname,
1209                                                          char *orderby_fld,
1210                                                          char *branch_delim,
1211                                                          char *start_with,
1212                                                          char *branch,
1213                                                          int level,
1214                                                          int *serial,
1215                                                          int max_depth,
1216                                                          bool show_branch,
1217                                                          bool show_serial,
1218                                                          MemoryContext per_query_ctx,
1219                                                          AttInMetadata *attinmeta,
1220                                                          Tuplestorestate *tupstore)
1221 {
1222         TupleDesc       tupdesc = attinmeta->tupdesc;
1223         int                     ret;
1224         int                     proc;
1225         int                     serial_column;
1226         StringInfoData sql;
1227         char      **values;
1228         char       *current_key;
1229         char       *current_key_parent;
1230         char            current_level[INT32_STRLEN];
1231         char            serial_str[INT32_STRLEN];
1232         char       *current_branch;
1233         HeapTuple       tuple;
1234
1235         if (max_depth > 0 && level > max_depth)
1236                 return tupstore;
1237
1238         initStringInfo(&sql);
1239
1240         /* Build initial sql statement */
1241         if (!show_serial)
1242         {
1243                 appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s",
1244                                                  key_fld,
1245                                                  parent_key_fld,
1246                                                  relname,
1247                                                  parent_key_fld,
1248                                                  quote_literal_cstr(start_with),
1249                                                  key_fld, key_fld, parent_key_fld);
1250                 serial_column = 0;
1251         }
1252         else
1253         {
1254                 appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s ORDER BY %s",
1255                                                  key_fld,
1256                                                  parent_key_fld,
1257                                                  relname,
1258                                                  parent_key_fld,
1259                                                  quote_literal_cstr(start_with),
1260                                                  key_fld, key_fld, parent_key_fld,
1261                                                  orderby_fld);
1262                 serial_column = 1;
1263         }
1264
1265         if (show_branch)
1266                 values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *));
1267         else
1268                 values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *));
1269
1270         /* First time through, do a little setup */
1271         if (level == 0)
1272         {
1273                 /* root value is the one we initially start with */
1274                 values[0] = start_with;
1275
1276                 /* root value has no parent */
1277                 values[1] = NULL;
1278
1279                 /* root level is 0 */
1280                 sprintf(current_level, "%d", level);
1281                 values[2] = current_level;
1282
1283                 /* root branch is just starting root value */
1284                 if (show_branch)
1285                         values[3] = start_with;
1286
1287                 /* root starts the serial with 1 */
1288                 if (show_serial)
1289                 {
1290                         sprintf(serial_str, "%d", (*serial)++);
1291                         if (show_branch)
1292                                 values[4] = serial_str;
1293                         else
1294                                 values[3] = serial_str;
1295                 }
1296
1297                 /* construct the tuple */
1298                 tuple = BuildTupleFromCStrings(attinmeta, values);
1299
1300                 /* now store it */
1301                 tuplestore_puttuple(tupstore, tuple);
1302
1303                 /* increment level */
1304                 level++;
1305         }
1306
1307         /* Retrieve the desired rows */
1308         ret = SPI_execute(sql.data, true, 0);
1309         proc = SPI_processed;
1310
1311         /* Check for qualifying tuples */
1312         if ((ret == SPI_OK_SELECT) && (proc > 0))
1313         {
1314                 HeapTuple       spi_tuple;
1315                 SPITupleTable *tuptable = SPI_tuptable;
1316                 TupleDesc       spi_tupdesc = tuptable->tupdesc;
1317                 int                     i;
1318                 StringInfoData branchstr;
1319                 StringInfoData chk_branchstr;
1320                 StringInfoData chk_current_key;
1321
1322                 /* First time through, do a little more setup */
1323                 if (level == 0)
1324                 {
1325                         /*
1326                          * Check that return tupdesc is compatible with the one we got
1327                          * from the query, but only at level 0 -- no need to check more
1328                          * than once
1329                          */
1330
1331                         if (!compatConnectbyTupleDescs(tupdesc, spi_tupdesc))
1332                                 ereport(ERROR,
1333                                                 (errcode(ERRCODE_SYNTAX_ERROR),
1334                                                  errmsg("invalid return type"),
1335                                                  errdetail("Return and SQL tuple descriptions are " \
1336                                                                    "incompatible.")));
1337                 }
1338
1339                 initStringInfo(&branchstr);
1340                 initStringInfo(&chk_branchstr);
1341                 initStringInfo(&chk_current_key);
1342
1343                 for (i = 0; i < proc; i++)
1344                 {
1345                         /* initialize branch for this pass */
1346                         appendStringInfo(&branchstr, "%s", branch);
1347                         appendStringInfo(&chk_branchstr, "%s%s%s", branch_delim, branch, branch_delim);
1348
1349                         /* get the next sql result tuple */
1350                         spi_tuple = tuptable->vals[i];
1351
1352                         /* get the current key and parent */
1353                         current_key = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
1354                         appendStringInfo(&chk_current_key, "%s%s%s", branch_delim, current_key, branch_delim);
1355                         current_key_parent = pstrdup(SPI_getvalue(spi_tuple, spi_tupdesc, 2));
1356
1357                         /* get the current level */
1358                         sprintf(current_level, "%d", level);
1359
1360                         /* check to see if this key is also an ancestor */
1361                         if (strstr(chk_branchstr.data, chk_current_key.data))
1362                                 elog(ERROR, "infinite recursion detected");
1363
1364                         /* OK, extend the branch */
1365                         appendStringInfo(&branchstr, "%s%s", branch_delim, current_key);
1366                         current_branch = branchstr.data;
1367
1368                         /* build a tuple */
1369                         values[0] = pstrdup(current_key);
1370                         values[1] = current_key_parent;
1371                         values[2] = current_level;
1372                         if (show_branch)
1373                                 values[3] = current_branch;
1374                         if (show_serial)
1375                         {
1376                                 sprintf(serial_str, "%d", (*serial)++);
1377                                 if (show_branch)
1378                                         values[4] = serial_str;
1379                                 else
1380                                         values[3] = serial_str;
1381                         }
1382
1383                         tuple = BuildTupleFromCStrings(attinmeta, values);
1384
1385                         xpfree(current_key);
1386                         xpfree(current_key_parent);
1387
1388                         /* store the tuple for later use */
1389                         tuplestore_puttuple(tupstore, tuple);
1390
1391                         heap_freetuple(tuple);
1392
1393                         /* recurse using current_key_parent as the new start_with */
1394                         tupstore = build_tuplestore_recursively(key_fld,
1395                                                                                                         parent_key_fld,
1396                                                                                                         relname,
1397                                                                                                         orderby_fld,
1398                                                                                                         branch_delim,
1399                                                                                                         values[0],
1400                                                                                                         current_branch,
1401                                                                                                         level + 1,
1402                                                                                                         serial,
1403                                                                                                         max_depth,
1404                                                                                                         show_branch,
1405                                                                                                         show_serial,
1406                                                                                                         per_query_ctx,
1407                                                                                                         attinmeta,
1408                                                                                                         tupstore);
1409
1410                         /* reset branch for next pass */
1411                         resetStringInfo(&branchstr);
1412                         resetStringInfo(&chk_branchstr);
1413                         resetStringInfo(&chk_current_key);
1414                 }
1415
1416                 xpfree(branchstr.data);
1417                 xpfree(chk_branchstr.data);
1418                 xpfree(chk_current_key.data);
1419         }
1420
1421         return tupstore;
1422 }
1423
1424 /*
1425  * Check expected (query runtime) tupdesc suitable for Connectby
1426  */
1427 static void
1428 validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial)
1429 {
1430         int                     serial_column = 0;
1431
1432         if (show_serial)
1433                 serial_column = 1;
1434
1435         /* are there the correct number of columns */
1436         if (show_branch)
1437         {
1438                 if (tupdesc->natts != (CONNECTBY_NCOLS + serial_column))
1439                         ereport(ERROR,
1440                                         (errcode(ERRCODE_SYNTAX_ERROR),
1441                                          errmsg("invalid return type"),
1442                                          errdetail("Query-specified return tuple has " \
1443                                                            "wrong number of columns.")));
1444         }
1445         else
1446         {
1447                 if (tupdesc->natts != CONNECTBY_NCOLS_NOBRANCH + serial_column)
1448                         ereport(ERROR,
1449                                         (errcode(ERRCODE_SYNTAX_ERROR),
1450                                          errmsg("invalid return type"),
1451                                          errdetail("Query-specified return tuple has " \
1452                                                            "wrong number of columns.")));
1453         }
1454
1455         /* check that the types of the first two columns match */
1456         if (tupdesc->attrs[0]->atttypid != tupdesc->attrs[1]->atttypid)
1457                 ereport(ERROR,
1458                                 (errcode(ERRCODE_SYNTAX_ERROR),
1459                                  errmsg("invalid return type"),
1460                                  errdetail("First two columns must be the same type.")));
1461
1462         /* check that the type of the third column is INT4 */
1463         if (tupdesc->attrs[2]->atttypid != INT4OID)
1464                 ereport(ERROR,
1465                                 (errcode(ERRCODE_SYNTAX_ERROR),
1466                                  errmsg("invalid return type"),
1467                                  errdetail("Third column must be type %s.",
1468                                                    format_type_be(INT4OID))));
1469
1470         /* check that the type of the fourth column is TEXT if applicable */
1471         if (show_branch && tupdesc->attrs[3]->atttypid != TEXTOID)
1472                 ereport(ERROR,
1473                                 (errcode(ERRCODE_SYNTAX_ERROR),
1474                                  errmsg("invalid return type"),
1475                                  errdetail("Fourth column must be type %s.",
1476                                                    format_type_be(TEXTOID))));
1477
1478         /* check that the type of the fifth column is INT4 */
1479         if (show_branch && show_serial && tupdesc->attrs[4]->atttypid != INT4OID)
1480                 elog(ERROR, "query-specified return tuple not valid for Connectby: "
1481                          "fifth column must be type %s", format_type_be(INT4OID));
1482
1483         /* check that the type of the fifth column is INT4 */
1484         if (!show_branch && show_serial && tupdesc->attrs[3]->atttypid != INT4OID)
1485                 elog(ERROR, "query-specified return tuple not valid for Connectby: "
1486                          "fourth column must be type %s", format_type_be(INT4OID));
1487
1488         /* OK, the tupdesc is valid for our purposes */
1489 }
1490
1491 /*
1492  * Check if spi sql tupdesc and return tupdesc are compatible
1493  */
1494 static bool
1495 compatConnectbyTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
1496 {
1497         Oid                     ret_atttypid;
1498         Oid                     sql_atttypid;
1499
1500         /* check the key_fld types match */
1501         ret_atttypid = ret_tupdesc->attrs[0]->atttypid;
1502         sql_atttypid = sql_tupdesc->attrs[0]->atttypid;
1503         if (ret_atttypid != sql_atttypid)
1504                 ereport(ERROR,
1505                                 (errcode(ERRCODE_SYNTAX_ERROR),
1506                                  errmsg("invalid return type"),
1507                                  errdetail("SQL key field datatype does " \
1508                                                    "not match return key field datatype.")));
1509
1510         /* check the parent_key_fld types match */
1511         ret_atttypid = ret_tupdesc->attrs[1]->atttypid;
1512         sql_atttypid = sql_tupdesc->attrs[1]->atttypid;
1513         if (ret_atttypid != sql_atttypid)
1514                 ereport(ERROR,
1515                                 (errcode(ERRCODE_SYNTAX_ERROR),
1516                                  errmsg("invalid return type"),
1517                                  errdetail("SQL parent key field datatype does " \
1518                                                    "not match return parent key field datatype.")));
1519
1520         /* OK, the two tupdescs are compatible for our purposes */
1521         return true;
1522 }
1523
1524 /*
1525  * Check if two tupdescs match in type of attributes
1526  */
1527 static bool
1528 compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
1529 {
1530         int                     i;
1531         Form_pg_attribute ret_attr;
1532         Oid                     ret_atttypid;
1533         Form_pg_attribute sql_attr;
1534         Oid                     sql_atttypid;
1535
1536         if (ret_tupdesc->natts < 2 ||
1537                 sql_tupdesc->natts < 3)
1538                 return false;
1539
1540         /* check the rowid types match */
1541         ret_atttypid = ret_tupdesc->attrs[0]->atttypid;
1542         sql_atttypid = sql_tupdesc->attrs[0]->atttypid;
1543         if (ret_atttypid != sql_atttypid)
1544                 ereport(ERROR,
1545                                 (errcode(ERRCODE_SYNTAX_ERROR),
1546                                  errmsg("invalid return type"),
1547                                  errdetail("SQL rowid datatype does not match " \
1548                                                    "return rowid datatype.")));
1549
1550         /*
1551          * - attribute [1] of the sql tuple is the category; no need to check it -
1552          * attribute [2] of the sql tuple should match attributes [1] to [natts]
1553          * of the return tuple
1554          */
1555         sql_attr = sql_tupdesc->attrs[2];
1556         for (i = 1; i < ret_tupdesc->natts; i++)
1557         {
1558                 ret_attr = ret_tupdesc->attrs[i];
1559
1560                 if (ret_attr->atttypid != sql_attr->atttypid)
1561                         return false;
1562         }
1563
1564         /* OK, the two tupdescs are compatible for our purposes */
1565         return true;
1566 }
1567
1568 /*
1569  * Return a properly quoted literal value.
1570  * Uses quote_literal in quote.c
1571  */
1572 static char *
1573 quote_literal_cstr(char *rawstr)
1574 {
1575         text       *rawstr_text;
1576         text       *result_text;
1577         char       *result;
1578
1579         rawstr_text = cstring_to_text(rawstr);
1580         result_text = DatumGetTextP(DirectFunctionCall1(quote_literal,
1581                                                                                           PointerGetDatum(rawstr_text)));
1582         result = text_to_cstring(result_text);
1583
1584         return result;
1585 }