union regression test

I have finally resolved the differences in the union regression test.
The problem is that the test uses the float8 table as part of the
test, and this table turns out to be different among platforms because
of different behavior with small numbers. Since the float8 part of
testing unions seemed entirely irrelevant I have changed it to use
float4, which is not different among platforms. This will prevent the
proliferation of special case files, while still properly testing the
union code (correct me if there really is something about float8 that
is important).

This raises an issue I had never considered before concerning the
development of regression tests. Perhaps something along the lines of
the following can be added to the developers FAQ.

When developing regression tests there is often a choice about
what tables in the regression database to obtain data from. In
most cases which table is used does not matter. However, some
tables contain different data depending on the platform and must
be special-cased for verifying the regression tests. These
tables can be recognized by looking for the
test/regress/expected/*-PLATFORM.out files, where PLATFORM is a
particular supported platform. Whenever possible, other
regression tests should avoid using data from these tables, or
special cases will inevitably proliferate and the regression
tests will be unnecessarily difficult to verify.

Cheers,
Brook

===========================================================================
--- test/regress/sql/union.sql.orig Fri May 29 07:23:02 1998
+++ test/regress/sql/union.sql Wed Sep 16 08:26:01 1998
@@ -42,23 +42,23 @@
-- Try testing from tables...
--

-SELECT f1 AS five FROM FLOAT8_TBL
+SELECT f1 AS five FROM FLOAT4_TBL
UNION
-SELECT f1 FROM FLOAT8_TBL;
+SELECT f1 FROM FLOAT4_TBL;

-SELECT f1 AS ten FROM FLOAT8_TBL
+SELECT f1 AS ten FROM FLOAT4_TBL
UNION ALL
-SELECT f1 FROM FLOAT8_TBL;
+SELECT f1 FROM FLOAT4_TBL;

-SELECT f1 AS nine FROM FLOAT8_TBL
+SELECT f1 AS nine FROM FLOAT4_TBL
UNION
SELECT f1 FROM INT4_TBL;

-SELECT f1 AS ten FROM FLOAT8_TBL
+SELECT f1 AS ten FROM FLOAT4_TBL
UNION ALL
SELECT f1 FROM INT4_TBL;

-SELECT f1 AS five FROM FLOAT8_TBL
+SELECT f1 AS five FROM FLOAT4_TBL
WHERE f1 BETWEEN -1e6 AND 1e6
UNION
SELECT f1 FROM INT4_TBL
===========================================================================
--- test/regress/expected/union.out.orig Fri May 29 07:22:42 1998
+++ test/regress/expected/union.out Wed Sep 16 10:03:17 1998
@@ -112,80 +112,80 @@
2
(3 rows)

-QUERY: SELECT f1 AS five FROM FLOAT8_TBL
+QUERY: SELECT f1 AS five FROM FLOAT4_TBL
UNION
-SELECT f1 FROM FLOAT8_TBL;
-five
----------------------
--1.2345678901234e+200
--1004.3
--34.84
--1.2345678901234e-200
-0
+SELECT f1 FROM FLOAT4_TBL;
+five
+------------
+-1.23457e+20
+-1004.3
+-34.84
+-1.23457e-20
+0
(5 rows)

-QUERY: SELECT f1 AS ten FROM FLOAT8_TBL
+QUERY: SELECT f1 AS ten FROM FLOAT4_TBL
UNION ALL
-SELECT f1 FROM FLOAT8_TBL;
-ten
----------------------
-0
--34.84
--1004.3
--1.2345678901234e+200
--1.2345678901234e-200
-0
--34.84
--1004.3
--1.2345678901234e+200
--1.2345678901234e-200
+SELECT f1 FROM FLOAT4_TBL;
+ten
+------------
+0
+-34.84
+-1004.3
+-1.23457e+20
+-1.23457e-20
+0
+-34.84
+-1004.3
+-1.23457e+20
+-1.23457e-20
(10 rows)

-QUERY: SELECT f1 AS nine FROM FLOAT8_TBL
+QUERY: SELECT f1 AS nine FROM FLOAT4_TBL
UNION
SELECT f1 FROM INT4_TBL;
-nine
----------------------
--1.2345678901234e+200
--2147483647
--123456
--1004.3
--34.84
--1.2345678901234e-200
-0
-123456
-2147483647
+nine
+------------
+-1.23457e+20
+-2.14748e+09
+-123456
+-1004.3
+-34.84
+-1.23457e-20
+0
+123456
+2.14748e+09
(9 rows)

-QUERY: SELECT f1 AS ten FROM FLOAT8_TBL
+QUERY: SELECT f1 AS ten FROM FLOAT4_TBL
UNION ALL
SELECT f1 FROM INT4_TBL;
-ten
----------------------
-0
--34.84
--1004.3
--1.2345678901234e+200
--1.2345678901234e-200
-0
-123456
--123456
-2147483647
--2147483647
+ten
+------------
+0
+-34.84
+-1004.3
+-1.23457e+20
+-1.23457e-20
+0
+123456
+-123456
+2.14748e+09
+-2.14748e+09
(10 rows)

-QUERY: SELECT f1 AS five FROM FLOAT8_TBL
+QUERY: SELECT f1 AS five FROM FLOAT4_TBL
WHERE f1 BETWEEN -1e6 AND 1e6
UNION
SELECT f1 FROM INT4_TBL
WHERE f1 BETWEEN 0 AND 1000000;
- five
----------------------
- -1004.3
- -34.84
--1.2345678901234e-200
- 0
- 123456
+ five
+------------
+ -1004.3
+ -34.84
+-1.23457e-20
+ 0
+ 123456
(5 rows)

QUERY: SELECT f1 AS five FROM VARCHAR_TBL