Cover DROP COLUMN commands dropping columns in the either side of fkeys

src/backend/distributed/commands/foreign_constraint.c

@@ -483,6 +483,21 @@ ForeignConstraintFindDistKeys(HeapTuple pgConstraintTuple,
 }
 
 
+/*
+ * ColumnAppearsInForeignKey returns true if there is a foreign key constraint
+ * from/to given column.
+ */
+bool
+ColumnAppearsInForeignKey(char *columnName, Oid relationId)
+{
+	int searchForeignKeyColumnFlags = SEARCH_REFERENCING_RELATION |
+									  SEARCH_REFERENCED_RELATION;
+	List *foreignKeyIdsColumnAppeared =
+		GetForeignKeyIdsForColumn(columnName, relationId, searchForeignKeyColumnFlags);
+	return list_length(foreignKeyIdsColumnAppeared) > 0;
+}
+
+
 /*
  * ColumnAppearsInForeignKeyToReferenceTable checks if there is a foreign key
  * constraint from/to any reference table on the given column.

src/backend/distributed/commands/table.c

@@ -1099,6 +1099,17 @@ AlterTableCmdDropsFkey(AlterTableCmd *command, Oid relationId)
 			}
 		}
 	}
+	else if (alterTableType == AT_DropColumn)
+	{
+		char *columnName = command->name;
+		if (ColumnAppearsInForeignKey(columnName, relationId))
+		{
+			return true;
+		}
+	}
+
+	return false;
+}
 
 
 /*

src/include/distributed/commands.h

@@ -159,7 +159,7 @@ extern void ErrorIfUnsupportedForeignConstraintExists(Relation relation,
 													  Var *distributionColumn,
 													  uint32 colocationId);
 extern void ErrorOutForFKeyBetweenPostgresAndCitusLocalTable(Oid localTableId);
-extern bool ColumnReferencedByAnyForeignKey(char *columnName, Oid relationId);
+extern bool ColumnAppearsInForeignKey(char *columnName, Oid relationId);
 extern bool ColumnAppearsInForeignKeyToReferenceTable(char *columnName, Oid
 													  relationId);
 extern List * GetReferencingForeignConstaintCommands(Oid relationOid);