Recognize functional dependency on primary keys. This allows a table's

other columns to be referenced without listing them in GROUP BY, so long as
the primary key column(s) are listed in GROUP BY.

Eventually we should also allow functional dependency on a UNIQUE constraint
when the columns are marked NOT NULL, but that has to wait until NOT NULL
constraints are represented in pg_constraint, because we need to have
pg_constraint OIDs for all the conditions needed to ensure functional
dependency.

Peter Eisentraut, reviewed by Alex Hunsaker and Tom Lane

4 files changed, 8 insertions, 4 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index a5862771a90..54af8b62cac 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.466 2010/07/25 23:21:21 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.467 2010/08/07 02:44:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2272,6 +2272,7 @@ _copyQuery(Query *from)
 	COPY_NODE_FIELD(limitCount);
 	COPY_NODE_FIELD(rowMarks);
 	COPY_NODE_FIELD(setOperations);
+	COPY_NODE_FIELD(constraintDeps);
 
 	return newnode;
 }
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 7056287c93b..0cb87015b6e 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -22,7 +22,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.386 2010/07/25 23:21:21 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.387 2010/08/07 02:44:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -877,6 +877,7 @@ _equalQuery(Query *a, Query *b)
 	COMPARE_NODE_FIELD(limitCount);
 	COMPARE_NODE_FIELD(rowMarks);
 	COMPARE_NODE_FIELD(setOperations);
+	COMPARE_NODE_FIELD(constraintDeps);
 
 	return true;
 }
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 6089ea3e3aa..8c694350950 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.387 2010/07/25 23:21:21 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.388 2010/08/07 02:44:06 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -2020,6 +2020,7 @@ _outQuery(StringInfo str, Query *node)
 	WRITE_NODE_FIELD(limitCount);
 	WRITE_NODE_FIELD(rowMarks);
 	WRITE_NODE_FIELD(setOperations);
+	WRITE_NODE_FIELD(constraintDeps);
 }
 
 static void
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index f28191d2d00..4d85d676979 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.232 2010/02/16 22:34:43 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.233 2010/08/07 02:44:07 tgl Exp $
  *
  * NOTES
  *	  Path and Plan nodes do not have any readfuncs support, because we
@@ -218,6 +218,7 @@ _readQuery(void)
 	READ_NODE_FIELD(limitCount);
 	READ_NODE_FIELD(rowMarks);
 	READ_NODE_FIELD(setOperations);
+	READ_NODE_FIELD(constraintDeps);
 
 	READ_DONE();
 }