Skip site navigation (1) Skip section navigation (2)

pgsql: Remove troublesome Asserts in cost_mergejoin().

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: pgsql-committers(at)postgresql(dot)org
Subject: pgsql: Remove troublesome Asserts in cost_mergejoin().
Date: 2011-12-05 20:50:15
Message-ID: E1RXfUN-0003Hq-6n@gemulon.postgresql.org (view raw or flat)
Thread:
Lists: pgsql-committers
Remove troublesome Asserts in cost_mergejoin().

While logically correct, these two Asserts could fail depending on the
vagaries of floating-point arithmetic.  In particular, on machines with
floating-point registers wider than standard "double" values, it was
possible for the compiler to compare a rounded-to-double value already
stored in memory with an unrounded long double value still in a register.
Given the preceding checks, these assertions aren't adding much, so let's
just get rid of them rather than try to find a compiler-proof fix.
Per report from Pavel Stehule.

Given the lack of previous complaints, and the fact that only developers
would be likely to trip over it, I'm only going to change this in HEAD,
even though the code has been like this for a long time.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/ff68b256a533b398e3420750f34d161aeee4e099

Modified Files
--------------
src/backend/optimizer/path/costsize.c |    3 ---
1 files changed, 0 insertions(+), 3 deletions(-)

pgsql-committers by date

Next:From: Bruce MomjianDate: 2011-12-05 21:45:52
Subject: pgsql: In pg_upgrade,allow tables using regclass to be upgraded becaus
Previous:From: Bruce MomjianDate: 2011-12-05 18:11:54
Subject: Re: pgsql: plpython: Add SPI cursor support

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group