Developers,

I'm finding an issue I thought was fixed with RC2, which is affecting my
ability to use arrays in RC5:

Summary: Fast repeated calls to INT[] = INT[] operator causes error
Severity: Query Failure
Version: 8.0.0rc5, previous builds of 8.0.0
Platform: Gentoo Linux
Description:

The following comparison works fine normally:
template1=# select '{}'::INT[] = '{}'::INT[];
?column?
----------
t
(1 row)


However, we're found that if you run thousands of empty array comparisons in a
few seconds/minutes, eventually the empty array comparison breaks, and you
get:
ERROR: cache lookup failed for function 0

Thereafter, *any* attempt to compare arrays gets:
dm=# select '{}'::INT[] = '{}'::INT[];
ERROR: cache lookup failed for function 0

I'm working on a repeatable test case and seeing whether vacuum and/or restart
affects this, but since we're 24 hours from wrap, I thought I should raise
this issue ASAP.

--
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco

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Folks,

Oh, this may be a bug specifically in INTARRAY; that module is installed.

--
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco

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Josh Berkus <josh (AT) agliodbs (DOT) com> writes:
I tried

while true; do echo "select '{}'::INT[] = '{}'::INT[];" ; done | psql regression >/dev/null

on a couple different platforms, with and without INTARRAY (which
isn't invoked by this query anyway, so I doubt it matters). I haven't
seen any misbehavior yet.

If you can reproduce this, please attach to the backend with gdb, set a
breakpoint at errfinish(), and get a stack traceback from the point of
the error.

regards, tom lane

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