Add interval division/multiplication regression tests.

Michael Glaesemann

src/test/regress/expected/interval.out

@@ -208,6 +208,72 @@ SELECT '' AS fortyfive, r1.*, r2.*
            | 34 years        | 6 years
 (45 rows)
 
+-- Test multiplication and division with intervals.
+-- Floating point arithmetic rounding errors can lead to unexpected results, 
+-- though the code attempts to do the right thing and round up to days and 
+-- minutes to avoid results such as '3 days 24:00 hours' or '14:20:60'. 
+-- Note that it is expected for some day components to be greater than 29 and 
+-- some time components be greater than 23:59:59 due to how intervals are 
+-- stored internally.
+CREATE TABLE INTERVAL_MULDIV_TBL (span interval);
+COPY INTERVAL_MULDIV_TBL FROM STDIN;
+SELECT span * 0.3 AS product
+FROM INTERVAL_MULDIV_TBL;
+              product               
+------------------------------------
+ 1 year 12 days 122:24:00
+ -1 years -12 days +93:36:00
+ -3 days -14:24:00
+ 2 mons 13 days 01:22:28.80
+ -10 mons +120 days 37:28:21.6567
+ 1 mon 6 days
+ 4 mons 6 days
+ 24 years 11 mons 320 days 16:48:00
+(8 rows)
+
+SELECT span * 8.2 AS product
+FROM INTERVAL_MULDIV_TBL;
+                   product                   
+---------------------------------------------
+ 28 years 104 days 2961:36:00
+ -28 years -104 days +2942:24:00
+ -98 days -09:36:00
+ 6 years 1 mon -197 days +93:34:27.20
+ -24 years -7 mons +3946 days 640:15:11.9498
+ 2 years 8 mons 24 days
+ 9 years 6 mons 24 days
+ 682 years 7 mons 8215 days 19:12:00
+(8 rows)
+
+SELECT span / 10 AS quotient
+FROM INTERVAL_MULDIV_TBL;
+             quotient             
+----------------------------------
+ 4 mons 4 days 40:48:00
+ -4 mons -4 days +31:12:00
+ -1 days -04:48:00
+ 25 days -15:32:30.40
+ -3 mons +30 days 12:29:27.2189
+ 12 days
+ 1 mon 12 days
+ 8 years 3 mons 126 days 21:36:00
+(8 rows)
+
+SELECT span / 100 AS quotient
+FROM INTERVAL_MULDIV_TBL;
+        quotient         
+-------------------------
+ 12 days 13:40:48
+ -12 days -06:28:48
+ -02:52:48
+ 2 days 10:26:44.96
+ -6 days +01:14:56.72189
+ 1 day 04:48:00
+ 4 days 04:48:00
+ 9 mons 39 days 16:33:36
+(8 rows)
+
+DROP TABLE INTERVAL_MULDIV_TBL;
 SET DATESTYLE = 'postgres';
 SELECT '' AS ten, * FROM INTERVAL_TBL;
  ten |              f1               

src/test/regress/sql/interval.sql

@@ -59,6 +59,41 @@ SELECT '' AS fortyfive, r1.*, r2.*
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
 
+
+-- Test multiplication and division with intervals.
+-- Floating point arithmetic rounding errors can lead to unexpected results, 
+-- though the code attempts to do the right thing and round up to days and 
+-- minutes to avoid results such as '3 days 24:00 hours' or '14:20:60'. 
+-- Note that it is expected for some day components to be greater than 29 and 
+-- some time components be greater than 23:59:59 due to how intervals are 
+-- stored internally.
+
+CREATE TABLE INTERVAL_MULDIV_TBL (span interval);
+COPY INTERVAL_MULDIV_TBL FROM STDIN;
+41 mon 12 days 360:00
+-41 mon -12 days +360:00
+-12 days
+9 mon -27 days 12:34:56
+-3 years 482 days 76:54:32.189
+4 mon
+14 mon
+999 mon 999 days
+\.
+
+SELECT span * 0.3 AS product
+FROM INTERVAL_MULDIV_TBL;
+
+SELECT span * 8.2 AS product
+FROM INTERVAL_MULDIV_TBL;
+
+SELECT span / 10 AS quotient
+FROM INTERVAL_MULDIV_TBL;
+
+SELECT span / 100 AS quotient
+FROM INTERVAL_MULDIV_TBL;
+
+DROP TABLE INTERVAL_MULDIV_TBL;
+
 SET DATESTYLE = 'postgres';
 
 SELECT '' AS ten, * FROM INTERVAL_TBL;