Support deferrable uniqueness constraints.

The current implementation fires an AFTER ROW trigger for each tuple that
looks like it might be non-unique according to the index contents at the
time of insertion.  This works well as long as there aren't many conflicts,
but won't scale to massive unique-key reassignments.  Improving that case
is a TODO item.

Dean Rasheed

3 files changed, 17 insertions, 3 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 0752cbfc00e..d10a9eb6cc5 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 1.435 2009/07/26 23:34:17 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.436 2009/07/29 20:56:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2091,6 +2091,8 @@ _copyConstraint(Constraint *from)
 	COPY_NODE_FIELD(keys);
 	COPY_NODE_FIELD(options);
 	COPY_STRING_FIELD(indexspace);
+	COPY_SCALAR_FIELD(deferrable);
+	COPY_SCALAR_FIELD(initdeferred);
 
 	return newnode;
 }
@@ -2510,6 +2512,8 @@ _copyIndexStmt(IndexStmt *from)
 	COPY_SCALAR_FIELD(unique);
 	COPY_SCALAR_FIELD(primary);
 	COPY_SCALAR_FIELD(isconstraint);
+	COPY_SCALAR_FIELD(deferrable);
+	COPY_SCALAR_FIELD(initdeferred);
 	COPY_SCALAR_FIELD(concurrent);
 
 	return newnode;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 121fbd0d2ee..6fceab27855 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 1.358 2009/07/26 23:34:18 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.359 2009/07/29 20:56:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1160,6 +1160,8 @@ _equalIndexStmt(IndexStmt *a, IndexStmt *b)
 	COMPARE_SCALAR_FIELD(unique);
 	COMPARE_SCALAR_FIELD(primary);
 	COMPARE_SCALAR_FIELD(isconstraint);
+	COMPARE_SCALAR_FIELD(deferrable);
+	COMPARE_SCALAR_FIELD(initdeferred);
 	COMPARE_SCALAR_FIELD(concurrent);
 
 	return true;
@@ -2068,6 +2070,8 @@ _equalConstraint(Constraint *a, Constraint *b)
 	COMPARE_NODE_FIELD(keys);
 	COMPARE_NODE_FIELD(options);
 	COMPARE_STRING_FIELD(indexspace);
+	COMPARE_SCALAR_FIELD(deferrable);
+	COMPARE_SCALAR_FIELD(initdeferred);
 
 	return true;
 }
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 4e808a5868e..e4de1c5aee2 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 1.361 2009/07/16 06:33:42 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.362 2009/07/29 20:56:19 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -1734,6 +1734,8 @@ _outIndexStmt(StringInfo str, IndexStmt *node)
 	WRITE_BOOL_FIELD(unique);
 	WRITE_BOOL_FIELD(primary);
 	WRITE_BOOL_FIELD(isconstraint);
+	WRITE_BOOL_FIELD(deferrable);
+	WRITE_BOOL_FIELD(initdeferred);
 	WRITE_BOOL_FIELD(concurrent);
 }
 
@@ -2285,6 +2287,8 @@ _outConstraint(StringInfo str, Constraint *node)
 			WRITE_NODE_FIELD(keys);
 			WRITE_NODE_FIELD(options);
 			WRITE_STRING_FIELD(indexspace);
+			WRITE_BOOL_FIELD(deferrable);
+			WRITE_BOOL_FIELD(initdeferred);
 			break;
 
 		case CONSTR_UNIQUE:
@@ -2292,6 +2296,8 @@ _outConstraint(StringInfo str, Constraint *node)
 			WRITE_NODE_FIELD(keys);
 			WRITE_NODE_FIELD(options);
 			WRITE_STRING_FIELD(indexspace);
+			WRITE_BOOL_FIELD(deferrable);
+			WRITE_BOOL_FIELD(initdeferred);
 			break;
 
 		case CONSTR_CHECK: