Re: PL/PGSQL: Dynamic Record Introspection - Mailing list pgsql-patches

Tom Lane schrieb:
> "Titus von Boxberg" <ut@bhi-hamburg.de> writes:
> It works for me if we want to have an "NFIELDS" construct.  Personally
> I'm still not convinced that we need one --- what's the use-case?
I have removed the NFIELDS construct
>
>
> I'd prefer arbitrary expression, but I suppose there's no harm in doing
> the simple case first and generalizing if there's demand.
I took the "no harm" way.

Attached please find the updated patch.
The patch is against HEAD of 050721.

I switched the syntax to your proposal, renamed the functions
in pl_comp.c and updated the sgml doc source and regression
test files accordingly.

Regards
Titus

*** ./doc/src/sgml/plpgsql.sgml.orig    Sat Jul  2 08:59:47 2005
--- ./doc/src/sgml/plpgsql.sgml    Sat Jul 23 17:24:54 2005
***************
*** 867,872 ****
--- 867,921 ----
     </para>

     <para>
+     To obtain the values of the fields the record is made up of,
+     the record variable can be qualified with the column or field
+     name. This can be done either by literally using the column name
+     or the column name for indexing the record can be taken out of a scalar
+     variable. The syntax for this notation is Record_variable.(IndexVariable).
+     To get information about the column field names of the record,
+     a
 special expression exists that returns all column names as an array:
+     RecordVariable.(*) .
+     Thus, the RECORD can be viewed
+     as an associative array that allows for introspection of it's contents.
+     This feature is especially useful for writing generic triggers that
+     operate on records with unknown structure.
+     Here is an example procedure that shows column names and values
+     of the predefined record NEW in a trigger procedure:
+ <programlisting>
+
+ CREATE OR REPLACE FUNCTION show_associative_records() RETURNS TRIGGER AS $$
+     DECLARE
+         colname        TEXT;
+         colcontent    TEXT;
+         colnames    TEXT[];
+         coln        INT4;
+         coli        INT4;
+     BEGIN
+ -- obtain an array with all field names of the record
+         colnames := NEW.(*);
+         RAISE NOTICE 'All column names of test record: %', colnames;
+ -- show field names and contents of record
+         coli := 1;
+         coln := array_upper(colnames,1);
+         RAISE NOTICE 'Number of columns in NEW: %', coln;
+         FOR coli IN 1 .. coln LOOP
+             colname := colnames[coli];
+             colcontent := NEW.(colname);
+             RAISE NOTICE 'column % of NEW: %', quote_ident(colname), quote_literal(colcontent);
+         END LOOP;
+ -- Do it with a fixed field name:
+ -- will have to know the column name
+         RAISE NOTICE 'column someint of NEW: %', quote_literal(NEW.someint);
+         RETURN NULL;
+     END;
+ $$ LANGUAGE plpgsql;
+ --CREATE TABLE test_records (someint INT8, somestring TEXT);
+ --CREATE TRIGGER tr_test_record BEFORE INSERT ON test_records FOR EACH ROW EXECUTE PROCEDURE
show_associative_records();
+
+ </programlisting>
+    </para>
+
+    <para>
      Note that <literal>RECORD</> is not a true data type, only a placeholder.
      One should also realize that when a <application>PL/pgSQL</application>
      function is declared to return type <type>record</>, this is not quite the
*** ./src/pl/plpgsql/src/pl_comp.c.orig    Wed Jul  6 16:42:10 2005
--- ./src/pl/plpgsql/src/pl_comp.c    Thu Jul 21 21:28:15 2005
***************
*** 995,1001 ****

                  new = palloc(sizeof(PLpgSQL_recfield));
                  new->dtype = PLPGSQL_DTYPE_RECFIELD;
!                 new->fieldname = pstrdup(cp[1]);
                  new->recparentno = ns->itemno;

                  plpgsql_adddatum((PLpgSQL_datum *) new);
--- 995,1002 ----

                  new = palloc(sizeof(PLpgSQL_recfield));
                  new->dtype = PLPGSQL_DTYPE_RECFIELD;
!                 new->fieldindex.fieldname = pstrdup(cp[1]);
!                 new->fieldindex_flag = RECFIELD_USE_FIELDNAME;
                  new->recparentno = ns->itemno;

                  plpgsql_adddatum((PLpgSQL_datum *) new);
***************
*** 1101,1107 ****

                  new = palloc(sizeof(PLpgSQL_recfield));
                  new->dtype = PLPGSQL_DTYPE_RECFIELD;
!                 new->fieldname = pstrdup(cp[2]);
                  new->recparentno = ns->itemno;

                  plpgsql_adddatum((PLpgSQL_datum *) new);
--- 1102,1109 ----

                  new = palloc(sizeof(PLpgSQL_recfield));
                  new->dtype = PLPGSQL_DTYPE_RECFIELD;
!                 new->fieldindex.fieldname = pstrdup(cp[2]);
!                 new->fieldindex_flag = RECFIELD_USE_FIELDNAME;
                  new->recparentno = ns->itemno;

                  plpgsql_adddatum((PLpgSQL_datum *) new);
***************
*** 1550,1555 ****
--- 1552,1683 ----
      MemoryContextSwitchTo(oldCxt);
      return T_DTYPE;
  }
+
+ /* ----------
+  * plpgsql_parse_recindex
+  * lookup associative index into record
+  * ----------
+  */
+ int
+ plpgsql_parse_recindex(char *word)
+ {
+     PLpgSQL_nsitem *ns1, *ns2;
+     char        *cp[2];
+     int        ret = T_ERROR;
+     char        *fieldvar;
+     int        fl;
+
+     /* Do case conversion and word separation */
+     plpgsql_convert_ident(word, cp, 2);
+     Assert(cp[1] != NULL);
+
+     /* cleanup the "(identifier)" string to "identifier" */
+     fieldvar = cp[1];
+     Assert(*fieldvar == '(');
+     ++fieldvar;    /* get rid of ( */
+
+     fl = strlen(fieldvar);
+     Assert(fieldvar[fl-1] == ')');
+     fieldvar[fl-1] = 0; /* get rid of ) */
+
+     /*
+      * Lookup the first word
+      */
+     ns1 = plpgsql_ns_lookup(cp[0], NULL);
+     if ( ns1 == NULL )
+     {
+         pfree(cp[0]);
+         pfree(cp[1]);
+         return T_ERROR;
+     }
+
+     ns2 = plpgsql_ns_lookup(fieldvar, NULL);
+     pfree(cp[0]);
+     pfree(cp[1]);
+     if ( ns2 == NULL )    /* name lookup failed */
+         return T_ERROR;
+
+     switch (ns1->itemtype)
+     {
+         case PLPGSQL_NSTYPE_REC:
+             {
+                 /*
+                  * First word is a record name, so second word must be an
+                  * variable holding the field name in this record.
+                  */
+                 if ( ns2->itemtype == PLPGSQL_NSTYPE_VAR ) {
+                     PLpgSQL_recfield *new;
+
+                     new = palloc(sizeof(PLpgSQL_recfield));
+                     new->dtype = PLPGSQL_DTYPE_RECFIELD;
+                     new->fieldindex.indexvar_no = ns2->itemno;
+                     new->fieldindex_flag = RECFIELD_USE_INDEX_VAR;
+                     new->recparentno = ns1->itemno;
+
+                     plpgsql_adddatum((PLpgSQL_datum *) new);
+
+                     plpgsql_yylval.scalar = (PLpgSQL_datum *) new;
+                     ret =  T_SCALAR;
+                 }
+                 break;
+             }
+         default:
+             break;
+     }
+     return ret;
+ }
+
+
+ /* ----------
+  * plpgsql_parse_recfieldnames
+  * create fieldnames of a record
+  * ----------
+  */
+ int
+ plpgsql_parse_recfieldnames(char *word)
+ {
+     PLpgSQL_nsitem    *ns1;
+     char        *cp[2];
+     int        ret = T_ERROR;
+
+     /* Do case conversion and word separation */
+     plpgsql_convert_ident(word, cp, 2);
+
+     /*
+      * Lookup the first word
+      */
+     ns1 = plpgsql_ns_lookup(cp[0], NULL);
+     if ( ns1 == NULL )
+     {
+         pfree(cp[0]);
+         pfree(cp[1]);
+         return T_ERROR;
+     }
+
+     pfree(cp[0]);
+     pfree(cp[1]);
+
+     switch (ns1->itemtype)
+     {
+         case PLPGSQL_NSTYPE_REC:
+             {
+                 PLpgSQL_recfieldproperties *new;
+
+                 new = palloc(sizeof(PLpgSQL_recfieldproperties));
+                 new->dtype = PLPGSQL_DTYPE_RECFIELDNAMES;
+                 new->recparentno = ns1->itemno;
+                 new->save_fieldnames = NULL;
+                 plpgsql_adddatum((PLpgSQL_datum *) new);
+                 plpgsql_yylval.scalar = (PLpgSQL_datum *) new;
+                 ret =  T_SCALAR;    /* ??? */
+                 break;
+             }
+         default:
+             break;
+     }
+     return ret;
+ }
+

  /*
   * plpgsql_build_variable - build a datum-array entry of a given
*** ./src/pl/plpgsql/src/pl_exec.c.orig    Sun Jun 26 22:05:42 2005
--- ./src/pl/plpgsql/src/pl_exec.c    Sat Jul 23 17:13:32 2005
***************
*** 716,721 ****
--- 716,722 ----
          case PLPGSQL_DTYPE_RECFIELD:
          case PLPGSQL_DTYPE_ARRAYELEM:
          case PLPGSQL_DTYPE_TRIGARG:
+         case PLPGSQL_DTYPE_RECFIELDNAMES:
              /*
               * These datum records are read-only at runtime, so no need
               * to copy them
***************
*** 825,830 ****
--- 826,832 ----

              case PLPGSQL_DTYPE_RECFIELD:
              case PLPGSQL_DTYPE_ARRAYELEM:
+             case PLPGSQL_DTYPE_RECFIELDNAMES:
                  break;

              default:
***************
*** 2146,2151 ****
--- 2148,2155 ----
  static void
  exec_eval_cleanup(PLpgSQL_execstate *estate)
  {
+     int        i;
+     ArrayType    *a;
      /* Clear result of a full SPI_execute */
      if (estate->eval_tuptable != NULL)
          SPI_freetuptable(estate->eval_tuptable);
***************
*** 2154,2159 ****
--- 2158,2171 ----
      /* Clear result of exec_eval_simple_expr (but keep the econtext) */
      if (estate->eval_econtext != NULL)
          ResetExprContext(estate->eval_econtext);
+     for ( i = 0; i < estate->ndatums; ++i ) {
+         if ( estate->datums[i]->dtype == PLPGSQL_DTYPE_RECFIELDNAMES ) {
+             a = ((PLpgSQL_recfieldproperties *)(estate->datums[i]))->save_fieldnames;
+             if ( a )
+                 pfree(a);
+             ((PLpgSQL_recfieldproperties *)(estate->datums[i]))->save_fieldnames = NULL;
+         }
+     }
  }


***************
*** 3154,3165 ****
                   * Get the number of the records field to change and the
                   * number of attributes in the tuple.
                   */
!                 fno = SPI_fnumber(rec->tupdesc, recfield->fieldname);
!                 if (fno == SPI_ERROR_NOATTRIBUTE)
!                     ereport(ERROR,
!                             (errcode(ERRCODE_UNDEFINED_COLUMN),
!                              errmsg("record \"%s\" has no field \"%s\"",
!                                     rec->refname, recfield->fieldname)));
                  fno--;
                  natts = rec->tupdesc->natts;

--- 3166,3200 ----
                   * Get the number of the records field to change and the
                   * number of attributes in the tuple.
                   */
!                 if ( recfield->fieldindex_flag == RECFIELD_USE_FIELDNAME ) {
!                     fno = SPI_fnumber(rec->tupdesc, recfield->fieldindex.fieldname);
!                     if (fno == SPI_ERROR_NOATTRIBUTE)
!                         ereport(ERROR,
!                                 (errcode(ERRCODE_UNDEFINED_COLUMN),
!                                  errmsg("record \"%s\" has no field \"%s\"",
!                                         rec->refname, recfield->fieldindex.fieldname)));
!                 }
!                 else if ( recfield->fieldindex_flag == RECFIELD_USE_INDEX_VAR ) {
!                     PLpgSQL_var * idxvar = (PLpgSQL_var *) (estate->datums[recfield->fieldindex.indexvar_no]);
!                     char * fname = convert_value_to_string(idxvar->value, idxvar->datatype->typoid);
!                     if ( fname == NULL )
!                         ereport(ERROR,
!                                 (errcode(ERRCODE_UNDEFINED_COLUMN),
!                                 errmsg("record \"%s\": cannot evaluate variable to record index string",
!                                         rec->refname)));
!                     fno = SPI_fnumber(rec->tupdesc, fname);
!                     pfree(fname);
!                     if (fno == SPI_ERROR_NOATTRIBUTE)
!                         ereport(ERROR,
!                                 (errcode(ERRCODE_UNDEFINED_COLUMN),
!                                  errmsg("record \"%s\" has no field \"%s\"",
!                                         rec->refname, fname)));
!                 }
!                 else
!                     ereport(ERROR,
!                         (errcode(ERRCODE_UNDEFINED_COLUMN),
!                         errmsg("record \"%s\": internal error",
!                                     rec->refname)));
                  fno--;
                  natts = rec->tupdesc->natts;

***************
*** 3497,3518 ****
                         errmsg("record \"%s\" is not assigned yet",
                                rec->refname),
                         errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
!                 fno = SPI_fnumber(rec->tupdesc, recfield->fieldname);
!                 if (fno == SPI_ERROR_NOATTRIBUTE)
!                     ereport(ERROR,
!                             (errcode(ERRCODE_UNDEFINED_COLUMN),
!                              errmsg("record \"%s\" has no field \"%s\"",
!                                     rec->refname, recfield->fieldname)));
!                 *typeid = SPI_gettypeid(rec->tupdesc, fno);
!                 *value = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull);
!                 if (expectedtypeid != InvalidOid && expectedtypeid != *typeid)
!                     ereport(ERROR,
!                             (errcode(ERRCODE_DATATYPE_MISMATCH),
!                              errmsg("type of \"%s.%s\" does not match that when preparing the plan",
!                                     rec->refname, recfield->fieldname)));
!                 break;
!             }
!
          case PLPGSQL_DTYPE_TRIGARG:
              {
                  PLpgSQL_trigarg *trigarg = (PLpgSQL_trigarg *) datum;
--- 3532,3656 ----
                         errmsg("record \"%s\" is not assigned yet",
                                rec->refname),
                         errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
!                 if ( recfield->fieldindex_flag == RECFIELD_USE_FIELDNAME ) {
!                     fno = SPI_fnumber(rec->tupdesc, recfield->fieldindex.fieldname);
!                     if (fno == SPI_ERROR_NOATTRIBUTE)
!                         ereport(ERROR,
!                                 (errcode(ERRCODE_UNDEFINED_COLUMN),
!                                  errmsg("record \"%s\" has no field \"%s\"",
!                                         rec->refname, recfield->fieldindex.fieldname)));
!                 }
!                 else if ( recfield->fieldindex_flag == RECFIELD_USE_INDEX_VAR ) {
!                     PLpgSQL_var * idxvar = (PLpgSQL_var *) (estate->datums[recfield->fieldindex.indexvar_no]);
!                     char * fname = convert_value_to_string(idxvar->value, idxvar->datatype->typoid);
!                     if ( fname == NULL )
!                         ereport(ERROR,
!                                 (errcode(ERRCODE_UNDEFINED_COLUMN),
!                                 errmsg("record \"%s\": cannot evaluate variable to record index string",
!                                         rec->refname)));
!                     fno = SPI_fnumber(rec->tupdesc, fname);
!                     pfree(fname);
!                     if (fno == SPI_ERROR_NOATTRIBUTE)
!                         ereport(ERROR,
!                                 (errcode(ERRCODE_UNDEFINED_COLUMN),
!                                  errmsg("record \"%s\" has no field \"%s\"",
!                                         rec->refname, fname)));
!                 }
!                 else
!                     ereport(ERROR,
!                         (errcode(ERRCODE_UNDEFINED_COLUMN),
!                         errmsg("record \"%s\": internal error",
!                                 rec->refname)));
!
!                 /* Do not allow typeids to become "narrowed" by InvalidOids
!                 causing specialized typeids from the tuple restricting the destination */
!                 if ( expectedtypeid != InvalidOid && expectedtypeid != SPI_gettypeid(rec->tupdesc, fno) ) {
!                     Datum cval = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull);
!                     cval =   exec_simple_cast_value(cval,
!                                     SPI_gettypeid(rec->tupdesc, fno),
!                                     expectedtypeid,
!                                     -1,
!                                     isnull);
!
!                     *value = cval;
!                     *typeid = expectedtypeid;
!                     /* ereport(ERROR,
!                             (errcode(ERRCODE_DATATYPE_MISMATCH),
!                              errmsg("type of \"%s\" does not match that when preparing the plan",
!                                     rec->refname)));
!                     */
!                 }
!                 else { /* expected typeid matches */
!                     *value = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull);
!                     *typeid = SPI_gettypeid(rec->tupdesc, fno);
!                 }
!                 break;
!             }
!
!         case PLPGSQL_DTYPE_RECFIELDNAMES:
!             /* Construct array datum from record field names */
!             {
!                 Oid            arraytypeid,
!                             arrayelemtypeid = TEXTOID;
!                 int16            arraytyplen,
!                             elemtyplen;
!                 bool            elemtypbyval;
!                 char            elemtypalign;
!                 ArrayType        *arrayval;
!                 PLpgSQL_recfieldproperties * recfp = (PLpgSQL_recfieldproperties *) datum;
!                 PLpgSQL_rec        *rec = (PLpgSQL_rec *) (estate->datums[recfp->recparentno]);
!                 int            fc, tfc = 0;
!                 Datum            *arrayelems;
!                 char            *fieldname;
!
!                 if (!HeapTupleIsValid(rec->tup))
!                     ereport(ERROR,
!                       (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
!                        errmsg("record \"%s\" is not assigned yet",
!                               rec->refname),
!                        errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
!                 arrayelems = palloc(sizeof(Datum) * rec->tupdesc->natts);
!                 arraytypeid = get_array_type(arrayelemtypeid);
!                 arraytyplen = get_typlen(arraytypeid);
!                 get_typlenbyvalalign(arrayelemtypeid,
!                              &elemtyplen,
!                              &elemtypbyval,
!                              &elemtypalign);
!
!                 if ( expectedtypeid != InvalidOid && expectedtypeid != arraytypeid )
!                     ereport(ERROR,
!                             (errcode(ERRCODE_DATATYPE_MISMATCH),
!                              errmsg("type of \"%s\" does not match array type when preparing the plan",
!                                     rec->refname)));
!                 for ( fc = 0; fc < rec->tupdesc->natts; ++fc ) {
!                     fieldname = SPI_fname(rec->tupdesc, fc+1);
!                     if ( fieldname ) {
!                         arrayelems[fc] = DirectFunctionCall1(textin, CStringGetDatum(fieldname));
!                         pfree(fieldname);
!                         ++tfc;
!                     }
!                 }
!                 arrayval = construct_array(arrayelems, tfc,
!                              arrayelemtypeid,
!                              elemtyplen,
!                              elemtypbyval,
!                              elemtypalign);
!
!
!                 /* construct_array copies data; free temp elem array */
!                 for ( fc = 0; fc < tfc; ++fc )
!                     pfree(DatumGetPointer(arrayelems[fc]));
!                 pfree(arrayelems);
!                 *value = PointerGetDatum(arrayval);
!                 *typeid = arraytypeid;
!                 *isnull = false;
!                 /* need to save the pointer because otherwise it does not get freed */
!                 if ( recfp->save_fieldnames )
!                     pfree(recfp->save_fieldnames);
!                 recfp->save_fieldnames = arrayval;
!                 break;
!             }
!
          case PLPGSQL_DTYPE_TRIGARG:
              {
                  PLpgSQL_trigarg *trigarg = (PLpgSQL_trigarg *) datum;
***************
*** 3610,3616 ****
--- 3748,3790 ----
       */
      if (expr->plan == NULL)
          exec_prepare_plan(estate, expr);
+     else {
+         /*
+          * check for any subexpressions with varying type in the expression
+          * currently (July 05), this is a record field of a record indexed by a variable
+          */
+         int            i;
+         PLpgSQL_datum        *d;
+         PLpgSQL_recfield    *rf;
+         for ( i = 0; i < expr->nparams; ++i ) {
+             d = estate->datums[expr->params[i]];
+             if ( d->dtype == PLPGSQL_DTYPE_RECFIELD ) {
+                 rf = (PLpgSQL_recfield *)d;
+                 if ( rf->fieldindex_flag == RECFIELD_USE_INDEX_VAR )
+                     break;
+             }
+         }
+         if ( i < expr->nparams ) { /* expr may change it's type */
+             /* Make sure expr is not in the list of active simple expressions
+                because exec_prepare_plan()/exec_simple_check_plan()...
+                will destroy the link to the next simple expression */
+             PLpgSQL_expr *e, *enext;
+             PLpgSQL_expr **eprevnext = &active_simple_exprs;
+             for (e = active_simple_exprs; e; e = enext)
+             {
+                 enext = e->expr_simple_next;
+                 if ( e == expr ) /* found us in the list */
+                     *eprevnext = enext; /* discard us */
+                 else
+                     eprevnext = &(e->expr_simple_next);
+             }

+             /* now discard the plan and get new one */
+             SPI_freeplan(expr->plan);
+             expr->plan = NULL;
+             exec_prepare_plan(estate, expr);
+         }
+     }
      /*
       * If this is a simple expression, bypass SPI and use the executor
       * directly
*** ./src/pl/plpgsql/src/pl_funcs.c.orig    Wed Jun 22 01:35:02 2005
--- ./src/pl/plpgsql/src/pl_funcs.c    Thu Jul 21 21:03:40 2005
***************
*** 1066,1074 ****
                  printf("REC %s\n", ((PLpgSQL_rec *) d)->refname);
                  break;
              case PLPGSQL_DTYPE_RECFIELD:
!                 printf("RECFIELD %-16s of REC %d\n",
!                        ((PLpgSQL_recfield *) d)->fieldname,
!                        ((PLpgSQL_recfield *) d)->recparentno);
                  break;
              case PLPGSQL_DTYPE_ARRAYELEM:
                  printf("ARRAYELEM of VAR %d subscript ",
--- 1066,1078 ----
                  printf("REC %s\n", ((PLpgSQL_rec *) d)->refname);
                  break;
              case PLPGSQL_DTYPE_RECFIELD:
!                 if ( ((PLpgSQL_recfield *) d)->fieldindex_flag == RECFIELD_USE_FIELDNAME )
!                     printf("RECFIELD %-16s of REC %d\n",
!                            ((PLpgSQL_recfield *) d)->fieldindex.fieldname,
!                            ((PLpgSQL_recfield *) d)->recparentno);
!                 else
!                     printf("RECFIELD Variable of REC %d\n",
!                            ((PLpgSQL_recfield *) d)->recparentno);
                  break;
              case PLPGSQL_DTYPE_ARRAYELEM:
                  printf("ARRAYELEM of VAR %d subscript ",
*** ./src/pl/plpgsql/src/plpgsql.h.orig    Thu Jul 21 21:00:57 2005
--- ./src/pl/plpgsql/src/plpgsql.h    Thu Jul 21 21:15:42 2005
***************
*** 73,79 ****
      PLPGSQL_DTYPE_RECFIELD,
      PLPGSQL_DTYPE_ARRAYELEM,
      PLPGSQL_DTYPE_EXPR,
!     PLPGSQL_DTYPE_TRIGARG
  };

  /* ----------
--- 73,80 ----
      PLPGSQL_DTYPE_RECFIELD,
      PLPGSQL_DTYPE_ARRAYELEM,
      PLPGSQL_DTYPE_EXPR,
!     PLPGSQL_DTYPE_TRIGARG,
!     PLPGSQL_DTYPE_RECFIELDNAMES
  };

  /* ----------
***************
*** 269,278 ****
  {                                /* Field in record */
      int            dtype;
      int            rfno;
!     char       *fieldname;
      int            recparentno;    /* dno of parent record */
  } PLpgSQL_recfield;


  typedef struct
  {                                /* Element of array variable */
--- 270,294 ----
  {                                /* Field in record */
      int            dtype;
      int            rfno;
!     union {
!         char    *fieldname;
!         int    indexvar_no;        /* dno of variable holding index string */
!     } fieldindex;
!     enum {
!         RECFIELD_USE_FIELDNAME,
!         RECFIELD_USE_INDEX_VAR,
!     }    fieldindex_flag;
      int            recparentno;    /* dno of parent record */
  } PLpgSQL_recfield;

+ typedef struct
+ {                                /* Field in record */
+     int            dtype;
+     int            rfno;
+     int            recparentno;            /* dno of parent record */
+     ArrayType *        save_fieldnames;
+ } PLpgSQL_recfieldproperties;
+

  typedef struct
  {                                /* Element of array variable */
***************
*** 678,683 ****
--- 694,701 ----
  extern int    plpgsql_parse_tripwordtype(char *word);
  extern int    plpgsql_parse_wordrowtype(char *word);
  extern int    plpgsql_parse_dblwordrowtype(char *word);
+ extern int    plpgsql_parse_recfieldnames(char *word);
+ extern int    plpgsql_parse_recindex(char *word);
  extern PLpgSQL_type *plpgsql_parse_datatype(const char *string);
  extern PLpgSQL_type *plpgsql_build_datatype(Oid typeOid, int32 typmod);
  extern PLpgSQL_variable *plpgsql_build_variable(const char *refname, int lineno,
*** ./src/pl/plpgsql/src/scan.l.orig    Sun Jun 26 19:16:07 2005
--- ./src/pl/plpgsql/src/scan.l    Thu Jul 21 21:28:20 2005
***************
*** 243,248 ****
--- 243,254 ----
  {param}{space}*\.{space}*{identifier}{space}*%ROWTYPE    {
      plpgsql_error_lineno = plpgsql_scanner_lineno();
      return plpgsql_parse_dblwordrowtype(yytext); }
+ {identifier}{space}*\.\(\*\)        {
+     plpgsql_error_lineno = plpgsql_scanner_lineno();
+     return plpgsql_parse_recfieldnames(yytext); }
+ {identifier}{space}*\.\({identifier}\)        {
+     plpgsql_error_lineno = plpgsql_scanner_lineno();
+     return plpgsql_parse_recindex(yytext); }

  {digit}+        { return T_NUMBER;            }

*** ./src/test/regress/expected/plpgsql.out.orig    Sat Jul  2 08:59:48 2005
--- ./src/test/regress/expected/plpgsql.out    Thu Jul 21 22:32:52 2005
***************
*** 2721,2723 ****
--- 2721,2761 ----
  $$ language plpgsql;
  ERROR:  end label "outer_label" specified for unlabelled block
  CONTEXT:  compile of PL/pgSQL function "end_label4" near line 5
+ -- check introspective records
+ create table ritest (i INT4, t TEXT);
+ insert into ritest (i, t) VALUES (1, 'sometext');
+ create function test_record() returns void as $$
+ declare
+   cname text;
+   tval  text;
+   ival  int4;
+   tval2 text;
+   ival2 int4;
+   columns text[];
+   r     RECORD;
+ begin
+   SELECT INTO r * FROM ritest WHERE i = 1;
+   ival := r.i;
+   tval := r.t;
+   RAISE NOTICE 'ival=%, tval=%', ival, tval;
+   cname := 'i';
+   ival2 := r.(cname);
+   cname :='t';
+   tval2 := r.(cname);
+   RAISE NOTICE 'ival2=%, tval2=%', ival2, tval2;
+   columns := r.(*);
+   RAISE NOTICE 'fieldnames=%', columns;
+   RETURN;
+ end;
+ $$ language plpgsql;
+ select test_record();
+ NOTICE:  ival=1, tval=sometext
+ NOTICE:  ival2=1, tval2=sometext
+ NOTICE:  fieldnames={i,t}
+  test_record
+ -------------
+
+  (1 row)
+
+ drop table ritest;
+ drop function test_record();
*** ./src/test/regress/sql/plpgsql.sql.orig    Thu Jul 21 21:04:43 2005
--- ./src/test/regress/sql/plpgsql.sql    Thu Jul 21 21:36:11 2005
***************
*** 2280,2282 ****
--- 2280,2314 ----
    end loop outer_label;
  end;
  $$ language plpgsql;
+
+ -- check introspective records
+ create table ritest (i INT4, t TEXT);
+ insert into ritest (i, t) VALUES (1, 'sometext');
+ create function test_record() returns void as $$
+ declare
+   cname text;
+   tval  text;
+   ival  int4;
+   tval2 text;
+   ival2 int4;
+   columns text[];
+   r     RECORD;
+ begin
+   SELECT INTO r * FROM ritest WHERE i = 1;
+   ival := r.i;
+   tval := r.t;
+   RAISE NOTICE 'ival=%, tval=%', ival, tval;
+   cname := 'i';
+   ival2 := r.(cname);
+   cname :='t';
+   tval2 := r.(cname);
+   RAISE NOTICE 'ival2=%, tval2=%', ival2, tval2;
+   columns := r.(*);
+   RAISE NOTICE 'fieldnames=%', columns;
+   RETURN;
+ end;
+ $$ language plpgsql;
+ select test_record();
+ drop table ritest;
+ drop function test_record();
+