修改interval在PG兼容模式下的默认单位为秒

src/common/backend/utils/adt/datetime.cpp

@@ -2761,7 +2761,7 @@ int DecodeInterval(char** field, const int* ftype, int nf, int range, int* dtype
                             type = DTK_SECOND;
                             break;
                         default:
-                            type = DTK_DAY;
+                            type = DB_IS_CMPT(PG_FORMAT) ? DTK_SECOND : DTK_DAY;
                             break;
                     }
                 }

src/test/regress/expected/pg_compatibility.out

@@ -118,3 +118,9 @@ CONTEXT:  referenced column: int8mod
 select numeric_mod(1234.5678,0.0);
 ERROR:  division by zero
 CONTEXT:  referenced column: numeric_mod
+select '10'::interval;
+ interval  
+-----------
+ @ 10 secs
+(1 row)
+

src/test/regress/sql/pg_compatibility.sql

@@ -44,4 +44,5 @@ select int1mod(3, 0);
 select int2mod(3, 0);
 select int4mod(3, 0);
 select int8mod(3, 0);
-select numeric_mod(1234.5678,0.0);
+select numeric_mod(1234.5678,0.0);
+select '10'::interval;