The cstring datatype can now be copied, passed around, etc. The typlen

value '-2' is used to indicate a variable-width type whose width is
computed as strlen(datum)+1.  Everything that looks at typlen is updated
except for array support, which Joe Conway is working on; at the moment
it wouldn't work to try to create an array of cstring.

3 files changed, 34 insertions, 11 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 5dafb1a42ad..c7dbe44f780 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.42 2002/08/11 00:08:48 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.43 2002/08/24 15:00:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -860,6 +860,8 @@ compute_minimal_stats(VacAttrStats *stats,
 	double		total_width = 0;
 	bool		is_varlena = (!stats->attr->attbyval &&
 							  stats->attr->attlen == -1);
+	bool		is_varwidth = (!stats->attr->attbyval &&
+							   stats->attr->attlen < 0);
 	FmgrInfo	f_cmpeq;
 	typedef struct
 	{
@@ -905,7 +907,7 @@ compute_minimal_stats(VacAttrStats *stats,
 		nonnull_cnt++;
 
 		/*
-		 * If it's a varlena field, add up widths for average width
+		 * If it's a variable-width field, add up widths for average width
 		 * calculation.  Note that if the value is toasted, we use the
 		 * toasted width.  We don't bother with this calculation if it's a
 		 * fixed-width type.
@@ -928,6 +930,11 @@ compute_minimal_stats(VacAttrStats *stats,
 			}
 			value = PointerGetDatum(PG_DETOAST_DATUM(value));
 		}
+		else if (is_varwidth)
+		{
+			/* must be cstring */
+			total_width += strlen(DatumGetCString(value)) + 1;
+		}
 
 		/*
 		 * See if the value matches anything we're already tracking.
@@ -984,7 +991,7 @@ compute_minimal_stats(VacAttrStats *stats,
 		stats->stats_valid = true;
 		/* Do the simple null-frac and width stats */
 		stats->stanullfrac = (double) null_cnt / (double) numrows;
-		if (is_varlena)
+		if (is_varwidth)
 			stats->stawidth = total_width / (double) nonnull_cnt;
 		else
 			stats->stawidth = stats->attrtype->typlen;
@@ -1157,6 +1164,8 @@ compute_scalar_stats(VacAttrStats *stats,
 	double		total_width = 0;
 	bool		is_varlena = (!stats->attr->attbyval &&
 							  stats->attr->attlen == -1);
+	bool		is_varwidth = (!stats->attr->attbyval &&
+							   stats->attr->attlen < 0);
 	double		corr_xysum;
 	RegProcedure cmpFn;
 	SortFunctionKind cmpFnKind;
@@ -1196,7 +1205,7 @@ compute_scalar_stats(VacAttrStats *stats,
 		nonnull_cnt++;
 
 		/*
-		 * If it's a varlena field, add up widths for average width
+		 * If it's a variable-width field, add up widths for average width
 		 * calculation.  Note that if the value is toasted, we use the
 		 * toasted width.  We don't bother with this calculation if it's a
 		 * fixed-width type.
@@ -1219,6 +1228,11 @@ compute_scalar_stats(VacAttrStats *stats,
 			}
 			value = PointerGetDatum(PG_DETOAST_DATUM(value));
 		}
+		else if (is_varwidth)
+		{
+			/* must be cstring */
+			total_width += strlen(DatumGetCString(value)) + 1;
+		}
 
 		/* Add it to the list to be sorted */
 		values[values_cnt].value = value;
@@ -1311,7 +1325,7 @@ compute_scalar_stats(VacAttrStats *stats,
 		stats->stats_valid = true;
 		/* Do the simple null-frac and width stats */
 		stats->stanullfrac = (double) null_cnt / (double) numrows;
-		if (is_varlena)
+		if (is_varwidth)
 			stats->stawidth = total_width / (double) nonnull_cnt;
 		else
 			stats->stawidth = stats->attrtype->typlen;
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index e0bbe7560bb..c0b40c6e143 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.166 2002/08/22 00:01:42 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.167 2002/08/24 15:00:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -567,6 +567,8 @@ CopyTo(Relation rel, List *attnumlist, bool binary, bool oids,
 			elog(ERROR, "COPY: couldn't lookup info for type %u",
 				 attr[attnum-1]->atttypid);
 		fmgr_info(out_func_oid, &out_functions[attnum-1]);
+		if (binary && attr[attnum-1]->attlen == -2)
+			elog(ERROR, "COPY BINARY: cstring not supported");
 	}
 
 	if (binary)
@@ -820,9 +822,16 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 		fmgr_info(in_func_oid, &in_functions[i]);
 		elements[i] = GetTypeElement(attr[i]->atttypid);
 
-		/* if column not specified, use default value if one exists */
-		if (!intMember(i + 1, attnumlist))
+		if (intMember(i + 1, attnumlist))
 		{
+			/* attribute is to be copied */
+			if (binary && attr[i]->attlen == -2)
+				elog(ERROR, "COPY BINARY: cstring not supported");
+		}
+		else
+		{
+			/* attribute is NOT to be copied */
+			/* use default value if one exists */
 			defexprs[num_defaults] = build_column_default(rel, i + 1);
 			if (defexprs[num_defaults] != NULL)
 			{
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ee2df73f21e..94c687721b0 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.32 2002/08/22 14:23:36 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.33 2002/08/24 15:00:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3504,8 +3504,8 @@ needs_toast_table(Relation rel)
 
 	for (i = 0; i < tupdesc->natts; i++)
 	{
-		data_length = att_align(data_length, att[i]->attlen, att[i]->attalign);
-		if (att[i]->attlen >= 0)
+		data_length = att_align(data_length, att[i]->attalign);
+		if (att[i]->attlen > 0)
 		{
 			/* Fixed-length types are never toastable */
 			data_length += att[i]->attlen;