1 files changed, 51 insertions, 7 deletions

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a7722052faa..fafd85db348 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8207,6 +8207,9 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	SysScanDesc scan;
 	HeapTuple	depTup;
 	ObjectAddress address;
+	ListCell   *lc;
+	ListCell   *prev;
+	ListCell   *next;
 
 	attrelation = heap_open(AttributeRelationId, RowExclusiveLock);
 
@@ -8320,14 +8323,20 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 
 					if (relKind == RELKIND_INDEX)
 					{
+						/*
+						 * Indexes that are directly dependent on the table
+						 * might be regular indexes or constraint indexes.
+						 * Constraint indexes typically have only indirect
+						 * dependencies; but there are exceptions, notably
+						 * partial exclusion constraints.  Hence we must check
+						 * whether the index depends on any constraint that's
+						 * due to be rebuilt, which we'll do below after we've
+						 * found all such constraints.
+						 */
 						Assert(foundObject.objectSubId == 0);
-						if (!list_member_oid(tab->changedIndexOids, foundObject.objectId))
-						{
-							tab->changedIndexOids = lappend_oid(tab->changedIndexOids,
-													   foundObject.objectId);
-							tab->changedIndexDefs = lappend(tab->changedIndexDefs,
-							   pg_get_indexdef_string(foundObject.objectId));
-						}
+						tab->changedIndexOids =
+							list_append_unique_oid(tab->changedIndexOids,
+												   foundObject.objectId);
 					}
 					else if (relKind == RELKIND_SEQUENCE)
 					{
@@ -8482,6 +8491,41 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 	systable_endscan(scan);
 
 	/*
+	 * Check the collected index OIDs to see which ones belong to the
+	 * constraint(s) of the table, and drop those from the list of indexes
+	 * that we need to process; rebuilding the constraints will handle them.
+	 */
+	prev = NULL;
+	for (lc = list_head(tab->changedIndexOids); lc; lc = next)
+	{
+		Oid			indexoid = lfirst_oid(lc);
+		Oid			conoid;
+
+		next = lnext(lc);
+
+		conoid = get_index_constraint(indexoid);
+		if (OidIsValid(conoid) &&
+			list_member_oid(tab->changedConstraintOids, conoid))
+			tab->changedIndexOids = list_delete_cell(tab->changedIndexOids,
+													 lc, prev);
+		else
+			prev = lc;
+	}
+
+	/*
+	 * Now collect the definitions of the indexes that must be rebuilt.  (We
+	 * could merge this into the previous loop, but it'd be more complicated
+	 * for little gain.)
+	 */
+	foreach(lc, tab->changedIndexOids)
+	{
+		Oid			indexoid = lfirst_oid(lc);
+
+		tab->changedIndexDefs = lappend(tab->changedIndexDefs,
+										pg_get_indexdef_string(indexoid));
+	}
+
+	/*
 	 * Now scan for dependencies of this column on other things.  The only
 	 * thing we should find is the dependency on the column datatype, which we
 	 * want to remove, and possibly a collation dependency.