Status of glibc2 problems

From: "Oliver Elphick" <olly(at)lfix(dot)co(dot)uk>
To: pgsql-hackers(at)hub(dot)org
Subject: Status of glibc2 problems
Date: 1998-02-19 08:02:35
Message-ID: 199802190802.IAA21135@linda.lfix.co.uk
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I confirm that libc6 2.0.7pre1 cures all the time and date problems
that I was having with glibc2. So no patches are needed; just undefine
HAVE_INT_TIMEZONE for glibc2.

Int2, int4, oidint2, oidint4:
In the regression tests, for glibc2 we should expect to see 'Numerical
result out of range' rather than `Math result not representable'.

New with libc6 2.0.7:
Float4: some of the tests failed because glibc2 works _better_ than libc5!
One test involves inserting values of 10e-40. libc5 fails, but glibc2
says that 10e-40 is equivalent to 1e-39 and successfully inserts it.
It also stores larger numbers as Inf and -Inf and inserts these values rather
than failing. So many of the tests report 9 rows instead of 5.

Float8:
Again some tests work which didn't with libc5:
expected:
QUERY: UPDATE FLOAT8_TBL
SET f1 = FLOAT8_TBL.f1 * '-1'
WHERE FLOAT8_TBL.f1 > '0.0';
QUERY: SELECT '' AS bad, f.f1 * '1e200' from FLOAT8_TBL f;
ERROR: Bad float8 input format -- overflow

glibc2:
QUERY: SELECT '' AS bad, f.f1 * '1e200' from FLOAT8_TBL f;
bad|?column?
---+----------------
|0
|-3.484e+201
|-1.0043e+203
|Infinity
|-1.2345678901234
(5 rows)

On the other hand, this no longer works:
expected:
QUERY: SELECT '' AS bad, : (f.f1) from FLOAT8_TBL f;
bad| ?column?
---+--------------------
| 1
|7.39912306090513e-16
| 0
| 0
| 1
(5 rows)

glibc2:
QUERY: SELECT '' AS bad, : (f.f1) from FLOAT8_TBL f;
ERROR: exp() result is out of range

geometry:
results from converting circles to polygons are still different by about
3e-12 on some co-ordinates.

triggers:
I think the expected results are wrong:
I get (among other differences):
QUERY: insert into fkeys2 values (70, '5', 3);
ERROR: check_fkeys2_pkey_exist: tuple references non-existing key in pkeys

which is not in the expected results but looks right.

select-views:
many differences, but I believe these are also seen on other platforms.

--
Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight http://www.lfix.co.uk/oliver

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