Re: [GENERAL] Crosstab Problems

Tom Lane wrote:
> Joe Conway <mail@joeconway.com> writes:
>> Tom Lane wrote:
>>> 1. Treat NULL rowid as a category in its own right.  This would conform
>>> with the behavior of GROUP BY and DISTINCT, for instance.
>
>> In any case, the attached changes the behavior to #1 for both flavors of
>> crosstab (the original crosstab(text, int) and the usually more useful
>> crosstab(text, text)).
>
>> It is appropriate for 8.3 but not back-patching as it changes behavior
>> in a non-backward compatible way and is probably too invasive anyway.
>
> Um, if the previous code crashed in this case, why would you worry about
> being backward-compatible with it?  You're effectively changing the
> behavior anyway, so you might as well make it do what you've decided is
> the right thing.

Well, maybe the attached patches better explain what I mean.

In the case of the 8.2 patch, a very small code change allows new
regression data including NULL rowids to:

   1) not crash
   2) have no impact otherwise

The much bigger 8.3 patch shows that for the very same new regression
data, there is a significant impact on the output (i.e. NULL rowids get
their own output row as discussed).

I'm still leaning toward applying the 8.2 patch for back branches but
I'll bow to the general consensus.

Joe
Index: tablefunc.c
===================================================================
RCS file: /opt/src/cvs/pgsql/contrib/tablefunc/tablefunc.c,v
retrieving revision 1.47
diff -c -r1.47 tablefunc.c
*** tablefunc.c    3 Mar 2007 19:32:54 -0000    1.47
--- tablefunc.c    25 Oct 2007 02:11:06 -0000
***************
*** 355,360 ****
--- 355,361 ----
      crosstab_fctx *fctx;
      int            i;
      int            num_categories;
+     bool        firstpass = false;
      MemoryContext oldcontext;

      /* stuff done only on the first call of the function */
***************
*** 469,474 ****
--- 470,476 ----
          funcctx->max_calls = proc;

          MemoryContextSwitchTo(oldcontext);
+         firstpass = true;
      }

      /* stuff done on every call of the function */
***************
*** 500,506 ****
          HeapTuple    tuple;
          Datum        result;
          char      **values;
!         bool        allnulls = true;

          while (true)
          {
--- 502,508 ----
          HeapTuple    tuple;
          Datum        result;
          char      **values;
!         bool        skip_tuple = false;

          while (true)
          {
***************
*** 530,555 ****
                  rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

                  /*
!                  * If this is the first pass through the values for this rowid
!                  * set it, otherwise make sure it hasn't changed on us. Also
!                  * check to see if the rowid is the same as that of the last
!                  * tuple sent -- if so, skip this tuple entirely
                   */
                  if (i == 0)
-                     values[0] = pstrdup(rowid);
-
-                 if ((rowid != NULL) && (strcmp(rowid, values[0]) == 0))
                  {
!                     if ((lastrowid != NULL) && (strcmp(rowid, lastrowid) == 0))
                          break;
!                     else if (allnulls == true)
!                         allnulls = false;

                      /*
!                      * Get the next category item value, which is alway
                       * attribute number three.
                       *
!                      * Be careful to sssign the value to the array index based
                       * on which category we are presently processing.
                       */
                      values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3);
--- 532,574 ----
                  rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

                  /*
!                  * If this is the first pass through the values for this
!                  * rowid, set the first column to rowid
                   */
                  if (i == 0)
                  {
!                     if (rowid)
!                         values[0] = pstrdup(rowid);
!                     else
!                         values[0] = NULL;
!
!                     /*
!                      * Check to see if the rowid is the same as that of the last
!                      * tuple sent -- if so, skip this tuple entirely
!                      */
!                     if (!firstpass &&
!                         (((lastrowid == NULL) && (rowid == NULL)) ||
!                          ((lastrowid != NULL) &&
!                           (rowid != NULL) &&
!                           (strcmp(rowid, lastrowid) == 0))))
!                     {
!                         skip_tuple = true;
                          break;
!                     }
!                 }

+                 /*
+                  * If rowid hasn't changed on us, continue building the
+                  * ouput tuple.
+                  */
+                 if ((rowid && values[0] && (strcmp(rowid, values[0]) == 0)) ||
+                     ((rowid == NULL) && (values[0] == NULL)))
+                 {
                      /*
!                      * Get the next category item value, which is always
                       * attribute number three.
                       *
!                      * Be careful to assign the value to the array index based
                       * on which category we are presently processing.
                       */
                      values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3);
***************
*** 572,584 ****
                      call_cntr = --funcctx->call_cntr;
                      break;
                  }
!
!                 if (rowid != NULL)
!                     xpfree(rowid);
              }

              xpfree(fctx->lastrowid);
-
              if (values[0] != NULL)
              {
                  /*
--- 591,600 ----
                      call_cntr = --funcctx->call_cntr;
                      break;
                  }
!                 xpfree(rowid);
              }

              xpfree(fctx->lastrowid);
              if (values[0] != NULL)
              {
                  /*
***************
*** 586,597 ****
                   * calls
                   */
                  oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
                  lastrowid = fctx->lastrowid = pstrdup(values[0]);
                  MemoryContextSwitchTo(oldcontext);
              }

!             if (!allnulls)
              {
                  /* build the tuple */
                  tuple = BuildTupleFromCStrings(attinmeta, values);
--- 602,614 ----
                   * calls
                   */
                  oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
                  lastrowid = fctx->lastrowid = pstrdup(values[0]);
                  MemoryContextSwitchTo(oldcontext);
              }
+             else
+                 lastrowid = fctx->lastrowid = NULL;

!             if (!skip_tuple)
              {
                  /* build the tuple */
                  tuple = BuildTupleFromCStrings(attinmeta, values);
***************
*** 625,630 ****
--- 642,650 ----
                      SPI_finish();
                      SRF_RETURN_DONE(funcctx);
                  }
+
+                 /* need to reset this before the next tuple is started */
+                 skip_tuple = false;
              }
          }
      }
***************
*** 856,861 ****
--- 876,882 ----
          int            ncols = spi_tupdesc->natts;
          char       *rowid;
          char       *lastrowid = NULL;
+         bool        firstpass = true;
          int            i,
                      j;
          int            result_ncols;
***************
*** 918,938 ****
              /* get the rowid from the current sql result tuple */
              rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

-             /* if rowid is null, skip this tuple entirely */
-             if (rowid == NULL)
-                 continue;
-
              /*
               * if we're on a new output row, grab the column values up to
               * column N-2 now
               */
!             if ((lastrowid == NULL) || (strcmp(rowid, lastrowid) != 0))
              {
                  /*
                   * a new row means we need to flush the old one first, unless
                   * we're on the very first row
                   */
!                 if (lastrowid != NULL)
                  {
                      /* rowid changed, flush the previous output row */
                      tuple = BuildTupleFromCStrings(attinmeta, values);
--- 939,958 ----
              /* get the rowid from the current sql result tuple */
              rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

              /*
               * if we're on a new output row, grab the column values up to
               * column N-2 now
               */
!             if (firstpass ||
!                 (lastrowid == NULL && rowid != NULL) ||
!                 (lastrowid != NULL && rowid == NULL) ||
!                 (lastrowid != NULL && rowid != NULL && (strcmp(rowid, lastrowid) != 0)))
              {
                  /*
                   * a new row means we need to flush the old one first, unless
                   * we're on the very first row
                   */
!                 if (!firstpass)
                  {
                      /* rowid changed, flush the previous output row */
                      tuple = BuildTupleFromCStrings(attinmeta, values);
***************
*** 949,954 ****
--- 969,977 ----
                  values[0] = rowid;
                  for (j = 1; j < ncols - 2; j++)
                      values[j] = SPI_getvalue(spi_tuple, spi_tupdesc, j + 1);
+
+                 /* we're no longer on the first pass */
+                 firstpass = false;
              }

              /* look up the category and fill in the appropriate column */
***************
*** 964,970 ****
              }

              xpfree(lastrowid);
!             lastrowid = pstrdup(rowid);
          }

          /* flush the last output row */
--- 987,994 ----
              }

              xpfree(lastrowid);
!             if (rowid)
!                 lastrowid = pstrdup(rowid);
          }

          /* flush the last output row */
Index: data/ct.data
===================================================================
RCS file: /opt/src/cvs/pgsql/contrib/tablefunc/data/ct.data,v
retrieving revision 1.1
diff -c -r1.1 ct.data
*** data/ct.data    12 Sep 2002 00:14:40 -0000    1.1
--- data/ct.data    25 Oct 2007 21:45:49 -0000
***************
*** 12,14 ****
--- 12,18 ----
  12    group2    test4    att1    val4
  13    group2    test4    att2    val5
  14    group2    test4    att3    val6
+ 15    group1    \N    att1    val9
+ 16    group1    \N    att2    val10
+ 17    group1    \N    att3    val11
+ 18    group1    \N    att4    val12
Index: expected/tablefunc.out
===================================================================
RCS file: /opt/src/cvs/pgsql/contrib/tablefunc/expected/tablefunc.out,v
retrieving revision 1.13
diff -c -r1.13 tablefunc.out
*** expected/tablefunc.out    27 Feb 2006 16:09:49 -0000    1.13
--- expected/tablefunc.out    25 Oct 2007 22:24:01 -0000
***************
*** 23,64 ****
  ----------+------------+------------
   test1    | val2       | val3
   test2    | val6       | val7
! (2 rows)

  SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2''
orattribute = ''att3'') ORDER BY 1,2;'); 
   row_name | category_1 | category_2 | category_3
  ----------+------------+------------+------------
   test1    | val2       | val3       |
   test2    | val6       | val7       |
! (2 rows)

  SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2''
orattribute = ''att3'') ORDER BY 1,2;'); 
   row_name | category_1 | category_2 | category_3 | category_4
  ----------+------------+------------+------------+------------
   test1    | val2       | val3       |            |
   test2    | val6       | val7       |            |
! (2 rows)

  SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
   row_name | category_1 | category_2
  ----------+------------+------------
   test1    | val1       | val2
   test2    | val5       | val6
! (2 rows)

  SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
   row_name | category_1 | category_2 | category_3
  ----------+------------+------------+------------
   test1    | val1       | val2       | val3
   test2    | val5       | val6       | val7
! (2 rows)

  SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
   row_name | category_1 | category_2 | category_3 | category_4
  ----------+------------+------------+------------+------------
   test1    | val1       | val2       | val3       | val4
   test2    | val5       | val6       | val7       | val8
! (2 rows)

  SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1''
orattribute = ''att2'') ORDER BY 1,2;'); 
   row_name | category_1 | category_2
--- 23,70 ----
  ----------+------------+------------
   test1    | val2       | val3
   test2    | val6       | val7
!           | val10      | val11
! (3 rows)

  SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2''
orattribute = ''att3'') ORDER BY 1,2;'); 
   row_name | category_1 | category_2 | category_3
  ----------+------------+------------+------------
   test1    | val2       | val3       |
   test2    | val6       | val7       |
!           | val10      | val11      |
! (3 rows)

  SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' and (attribute = ''att2''
orattribute = ''att3'') ORDER BY 1,2;'); 
   row_name | category_1 | category_2 | category_3 | category_4
  ----------+------------+------------+------------+------------
   test1    | val2       | val3       |            |
   test2    | val6       | val7       |            |
!           | val10      | val11      |            |
! (3 rows)

  SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
   row_name | category_1 | category_2
  ----------+------------+------------
   test1    | val1       | val2
   test2    | val5       | val6
!           | val9       | val10
! (3 rows)

  SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
   row_name | category_1 | category_2 | category_3
  ----------+------------+------------+------------
   test1    | val1       | val2       | val3
   test2    | val5       | val6       | val7
!           | val9       | val10      | val11
! (3 rows)

  SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
   row_name | category_1 | category_2 | category_3 | category_4
  ----------+------------+------------+------------+------------
   test1    | val1       | val2       | val3       | val4
   test2    | val5       | val6       | val7       | val8
!           | val9       | val10      | val11      | val12
! (3 rows)

  SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' and (attribute = ''att1''
orattribute = ''att2'') ORDER BY 1,2;'); 
   row_name | category_1 | category_2
***************
*** 103,127 ****
  (2 rows)

  SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid
text,att1 text, att2 text); 
!  rowid | att1 | att2
! -------+------+------
   test1 | val1 | val2
   test2 | val5 | val6
! (2 rows)

  SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid
text,att1 text, att2 text, att3 text); 
!  rowid | att1 | att2 | att3
! -------+------+------+------
!  test1 | val1 | val2 | val3
!  test2 | val5 | val6 | val7
! (2 rows)

  SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid
text,att1 text, att2 text, att3 text, att4 text); 
!  rowid | att1 | att2 | att3 | att4
! -------+------+------+------+------
!  test1 | val1 | val2 | val3 | val4
!  test2 | val5 | val6 | val7 | val8
! (2 rows)

  -- check it works with OUT parameters, too
  CREATE FUNCTION crosstab_out(text,
--- 109,136 ----
  (2 rows)

  SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid
text,att1 text, att2 text); 
!  rowid | att1 | att2
! -------+------+-------
   test1 | val1 | val2
   test2 | val5 | val6
!        | val9 | val10
! (3 rows)

  SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid
text,att1 text, att2 text, att3 text); 
!  rowid | att1 | att2  | att3
! -------+------+-------+-------
!  test1 | val1 | val2  | val3
!  test2 | val5 | val6  | val7
!        | val9 | val10 | val11
! (3 rows)

  SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid
text,att1 text, att2 text, att3 text, att4 text); 
!  rowid | att1 | att2  | att3  | att4
! -------+------+-------+-------+-------
!  test1 | val1 | val2  | val3  | val4
!  test2 | val5 | val6  | val7  | val8
!        | val9 | val10 | val11 | val12
! (3 rows)

  -- check it works with OUT parameters, too
  CREATE FUNCTION crosstab_out(text,
***************
*** 130,140 ****
  AS '$libdir/tablefunc','crosstab'
  LANGUAGE C STABLE STRICT;
  SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
!  rowid | att1 | att2 | att3
! -------+------+------+------
!  test1 | val1 | val2 | val3
!  test2 | val5 | val6 | val7
! (2 rows)

  --
  -- hash based crosstab
--- 139,150 ----
  AS '$libdir/tablefunc','crosstab'
  LANGUAGE C STABLE STRICT;
  SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
!  rowid | att1 | att2  | att3
! -------+------+-------+-------
!  test1 | val1 | val2  | val3
!  test2 | val5 | val6  | val7
!        | val9 | val10 | val11
! (3 rows)

  --
  -- hash based crosstab
***************
*** 150,187 ****
  insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
  insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
  insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
  -- return attributes as plain text
  SELECT * FROM crosstab(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1')
  AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
!  rowid |          rowdt           | temperature | test_result | test_startdate | volts
! -------+--------------------------+-------------+-------------+----------------+--------
!  test1 | Sat Mar 01 00:00:00 2003 | 42          | PASS        |                | 2.6987
!  test2 | Sun Mar 02 00:00:00 2003 | 53          | FAIL        | 01 March 2003  | 3.1234
! (2 rows)

  -- this time without rowdt
  SELECT * FROM crosstab(
    'SELECT rowid, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1')
  AS c(rowid text, temperature text, test_result text, test_startdate text, volts text);
!  rowid | temperature | test_result | test_startdate | volts
! -------+-------------+-------------+----------------+--------
!  test1 | 42          | PASS        |                | 2.6987
!  test2 | 53          | FAIL        | 01 March 2003  | 3.1234
! (2 rows)

  -- convert attributes to specific datatypes
  SELECT * FROM crosstab(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1')
  AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
!  rowid |          rowdt           | temperature | test_result |      test_startdate      | volts
! -------+--------------------------+-------------+-------------+--------------------------+--------
!  test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          | 2.6987
!  test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 | 3.1234
! (2 rows)

  -- source query and category query out of sync
  SELECT * FROM crosstab(
--- 160,205 ----
  insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
  insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
  insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
+ -- next group tests for NULL rowids
+ insert into cth values(DEFAULT,NULL,'25 October 2007','temperature','57');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_result','PASS');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_startdate','24 October 2007');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','volts','1.41234');
  -- return attributes as plain text
  SELECT * FROM crosstab(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1')
  AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
!  rowid |          rowdt           | temperature | test_result | test_startdate  |  volts
! -------+--------------------------+-------------+-------------+-----------------+---------
!  test1 | Sat Mar 01 00:00:00 2003 | 42          | PASS        |                 | 2.6987
!  test2 | Sun Mar 02 00:00:00 2003 | 53          | FAIL        | 01 March 2003   | 3.1234
!        | Thu Oct 25 00:00:00 2007 | 57          | PASS        | 24 October 2007 | 1.41234
! (3 rows)

  -- this time without rowdt
  SELECT * FROM crosstab(
    'SELECT rowid, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1')
  AS c(rowid text, temperature text, test_result text, test_startdate text, volts text);
!  rowid | temperature | test_result | test_startdate  |  volts
! -------+-------------+-------------+-----------------+---------
!  test1 | 42          | PASS        |                 | 2.6987
!  test2 | 53          | FAIL        | 01 March 2003   | 3.1234
!        | 57          | PASS        | 24 October 2007 | 1.41234
! (3 rows)

  -- convert attributes to specific datatypes
  SELECT * FROM crosstab(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1')
  AS c(rowid text, rowdt timestamp, temperature int4, test_result text, test_startdate timestamp, volts float8);
!  rowid |          rowdt           | temperature | test_result |      test_startdate      |  volts
! -------+--------------------------+-------------+-------------+--------------------------+---------
!  test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          |  2.6987
!  test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 |  3.1234
!        | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007 | 1.41234
! (3 rows)

  -- source query and category query out of sync
  SELECT * FROM crosstab(
***************
*** 192,198 ****
  -------+--------------------------+-------------+-------------+--------------------------
   test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |
   test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003
! (2 rows)

  -- if category query generates no rows, get expected error
  SELECT * FROM crosstab(
--- 210,217 ----
  -------+--------------------------+-------------+-------------+--------------------------
   test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |
   test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003
!        | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007
! (3 rows)

  -- if category query generates no rows, get expected error
  SELECT * FROM crosstab(
***************
*** 235,245 ****
  SELECT * FROM crosstab_named(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1');
!  rowid |          rowdt           | temperature | test_result |      test_startdate      | volts
! -------+--------------------------+-------------+-------------+--------------------------+--------
!  test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          | 2.6987
!  test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 | 3.1234
! (2 rows)

  -- check it works with OUT parameters
  CREATE FUNCTION crosstab_out(text, text,
--- 254,265 ----
  SELECT * FROM crosstab_named(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1');
!  rowid |          rowdt           | temperature | test_result |      test_startdate      |  volts
! -------+--------------------------+-------------+-------------+--------------------------+---------
!  test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          |  2.6987
!  test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 |  3.1234
!        | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007 | 1.41234
! (3 rows)

  -- check it works with OUT parameters
  CREATE FUNCTION crosstab_out(text, text,
***************
*** 252,262 ****
  SELECT * FROM crosstab_out(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1');
!  rowid |          rowdt           | temperature | test_result |      test_startdate      | volts
! -------+--------------------------+-------------+-------------+--------------------------+--------
!  test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          | 2.6987
!  test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 | 3.1234
! (2 rows)

  --
  -- connectby
--- 272,283 ----
  SELECT * FROM crosstab_out(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
    'SELECT DISTINCT attribute FROM cth ORDER BY 1');
!  rowid |          rowdt           | temperature | test_result |      test_startdate      |  volts
! -------+--------------------------+-------------+-------------+--------------------------+---------
!  test1 | Sat Mar 01 00:00:00 2003 |          42 | PASS        |                          |  2.6987
!  test2 | Sun Mar 02 00:00:00 2003 |          53 | FAIL        | Sat Mar 01 00:00:00 2003 |  3.1234
!        | Thu Oct 25 00:00:00 2007 |          57 | PASS        | Wed Oct 24 00:00:00 2007 | 1.41234
! (3 rows)

  --
  -- connectby
Index: sql/tablefunc.sql
===================================================================
RCS file: /opt/src/cvs/pgsql/contrib/tablefunc/sql/tablefunc.sql,v
retrieving revision 1.12
diff -c -r1.12 tablefunc.sql
*** sql/tablefunc.sql    27 Feb 2006 16:09:49 -0000    1.12
--- sql/tablefunc.sql    25 Oct 2007 22:20:09 -0000
***************
*** 61,66 ****
--- 61,71 ----
  insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
  insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
  insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
+ -- next group tests for NULL rowids
+ insert into cth values(DEFAULT,NULL,'25 October 2007','temperature','57');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_result','PASS');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_startdate','24 October 2007');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','volts','1.41234');

  -- return attributes as plain text
  SELECT * FROM crosstab(
? tablefunc.8.2.diff
Index: tablefunc.c
===================================================================
RCS file: /cvsroot/pgsql/contrib/tablefunc/tablefunc.c,v
retrieving revision 1.45
diff -c -r1.45 tablefunc.c
*** tablefunc.c    4 Oct 2006 00:29:46 -0000    1.45
--- tablefunc.c    25 Oct 2007 22:24:40 -0000
***************
*** 535,542 ****
                   * check to see if the rowid is the same as that of the last
                   * tuple sent -- if so, skip this tuple entirely
                   */
!                 if (i == 0)
                      values[0] = pstrdup(rowid);

                  if ((rowid != NULL) && (strcmp(rowid, values[0]) == 0))
                  {
--- 535,544 ----
                   * check to see if the rowid is the same as that of the last
                   * tuple sent -- if so, skip this tuple entirely
                   */
!                 if (rowid && i == 0)
                      values[0] = pstrdup(rowid);
+                 else if (i == 0)
+                     break;

                  if ((rowid != NULL) && (strcmp(rowid, values[0]) == 0))
                  {
Index: data/ct.data
===================================================================
RCS file: /cvsroot/pgsql/contrib/tablefunc/data/ct.data,v
retrieving revision 1.1
diff -c -r1.1 ct.data
*** data/ct.data    12 Sep 2002 00:14:40 -0000    1.1
--- data/ct.data    25 Oct 2007 22:24:40 -0000
***************
*** 12,14 ****
--- 12,18 ----
  12    group2    test4    att1    val4
  13    group2    test4    att2    val5
  14    group2    test4    att3    val6
+ 15    group1    \N    att1    val9
+ 16    group1    \N    att2    val10
+ 17    group1    \N    att3    val11
+ 18    group1    \N    att4    val12
Index: expected/tablefunc.out
===================================================================
RCS file: /cvsroot/pgsql/contrib/tablefunc/expected/tablefunc.out,v
retrieving revision 1.13
diff -c -r1.13 tablefunc.out
*** expected/tablefunc.out    27 Feb 2006 16:09:49 -0000    1.13
--- expected/tablefunc.out    25 Oct 2007 22:24:40 -0000
***************
*** 150,155 ****
--- 150,160 ----
  insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
  insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
  insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
+ -- next group tests for NULL rowids
+ insert into cth values(DEFAULT,NULL,'25 October 2007','temperature','57');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_result','PASS');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_startdate','24 October 2007');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','volts','1.41234');
  -- return attributes as plain text
  SELECT * FROM crosstab(
    'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
Index: sql/tablefunc.sql
===================================================================
RCS file: /cvsroot/pgsql/contrib/tablefunc/sql/tablefunc.sql,v
retrieving revision 1.12
diff -c -r1.12 tablefunc.sql
*** sql/tablefunc.sql    27 Feb 2006 16:09:49 -0000    1.12
--- sql/tablefunc.sql    25 Oct 2007 22:24:40 -0000
***************
*** 61,66 ****
--- 61,71 ----
  insert into cth values(DEFAULT,'test2','02 March 2003','test_result','FAIL');
  insert into cth values(DEFAULT,'test2','02 March 2003','test_startdate','01 March 2003');
  insert into cth values(DEFAULT,'test2','02 March 2003','volts','3.1234');
+ -- next group tests for NULL rowids
+ insert into cth values(DEFAULT,NULL,'25 October 2007','temperature','57');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_result','PASS');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','test_startdate','24 October 2007');
+ insert into cth values(DEFAULT,NULL,'25 October 2007','volts','1.41234');

  -- return attributes as plain text
  SELECT * FROM crosstab(