The two methods don't cooperate, so set_config_option("search_path",
...) has been ineffective under non-empty overrideStack. This defect
enabled an attacker having database-level CREATE privilege to execute
arbitrary code as the bootstrap superuser. While that particular attack
requires v13+ for the trusted extension attribute, other attacks are
feasible in all supported versions.
Standardize on the combination of NewGUCNestLevel() and
set_config_option("search_path", ...). It is newer than
PushOverrideSearchPath(), more-prevalent, and has no known
disadvantages. The "override" mechanism remains for now, for
compatibility with out-of-tree code. Users should update such code,
which likely suffers from the same sort of vulnerability closed here.
Back-patch to v11 (all supported versions).
Alexander Lakhin. Reported by Alexander Lakhin.
Security: CVE-2023-2454
pg_input_error_info() is now a SQL function able to return a row with
more than just the error message generated for incorrect data type
inputs when these are able to handle soft failures, returning more
contents of ErrorData, as of:
- The error message (same as before).
- The error detail, if set.
- The error hint, if set.
- SQL error code.
All the regression tests that relied on pg_input_error_message() are
updated to reflect the effects of the rename.
Per discussion with Tom Lane and Andrew Dunstan.
Author: Nathan Bossart
Discussion: https://postgr.es/m/139a68e1-bd1f-a9a7-b5fe-0be9845c6311@dunslane.net
seg stores the number of significant digits in an input number
in a "char" field. If char is signed, and the input is more than
127 digits long, the count can read out as negative causing
seg_out() to print garbage (or, if you're really unlucky,
even crash).
To fix, clamp the digit count to be not more than FLT_DIG.
(In theory this loses some information about what the original
input was, but it doesn't seem like useful information; it would
not survive dump/restore in any case.)
Also, in case there are stored values of the seg type containing
bad data, add a clamp in seg_out's restore() subroutine.
Per bug #17725 from Robins Tharakan. It's been like this
forever, so back-patch to all supported branches.
Discussion: https://postgr.es/m/17725-0a09313b67fbe86e@postgresql.org
If autovacuum comes along just after we fill table test_seg with
some data, it will update the stats to the point where we prefer
a plain indexscan over a bitmap scan, breaking the expected
output (as well as the point of the test case). To fix, just
force a bitmap scan to be chosen here.
This has evidently been wrong since commit de1d042f5. It's not
clear why we just recently saw any buildfarm failures due to it;
but prairiedog has failed twice on this test in the past week.
Hence, backpatch to v11 where this test case came in.
Previously, floating-point output was done by rounding to a specific
decimal precision; by default, to 6 or 15 decimal digits (losing
information) or as requested using extra_float_digits. Drivers that
wanted exact float values, and applications like pg_dump that must
preserve values exactly, set extra_float_digits=3 (or sometimes 2 for
historical reasons, though this isn't enough for float4).
Unfortunately, decimal rounded output is slow enough to become a
noticable bottleneck when dealing with large result sets or COPY of
large tables when many floating-point values are involved.
Floating-point output can be done much faster when the output is not
rounded to a specific decimal length, but rather is chosen as the
shortest decimal representation that is closer to the original float
value than to any other value representable in the same precision. The
recently published Ryu algorithm by Ulf Adams is both relatively
simple and remarkably fast.
Accordingly, change float4out/float8out to output shortest decimal
representations if extra_float_digits is greater than 0, and make that
the new default. Applications that need rounded output can set
extra_float_digits back to 0 or below, and take the resulting
performance hit.
We make one concession to portability for systems with buggy
floating-point input: we do not output decimal values that fall
exactly halfway between adjacent representable binary values (which
would rely on the reader doing round-to-nearest-even correctly). This
is known to be a problem at least for VS2013 on Windows.
Our version of the Ryu code originates from
https://github.com/ulfjack/ryu/ at commit c9c3fb1979, but with the
following (significant) modifications:
- Output format is changed to use fixed-point notation for small
exponents, as printf would, and also to use lowercase 'e', a
minimum of 2 exponent digits, and a mandatory sign on the exponent,
to keep the formatting as close as possible to previous output.
- The output of exact midpoint values is disabled as noted above.
- The integer fast-path code is changed somewhat (since we have
fixed-point output and the upstream did not).
- Our project style has been largely applied to the code with the
exception of C99 declaration-after-statement, which has been
retained as an exception to our present policy.
- Most of upstream's debugging and conditionals are removed, and we
use our own configure tests to determine things like uint128
availability.
Changing the float output format obviously affects a number of
regression tests. This patch uses an explicit setting of
extra_float_digits=0 for test output that is not expected to be
exactly reproducible (e.g. due to numerical instability or differing
algorithms for transcendental functions).
Conversions from floats to numeric are unchanged by this patch. These
may appear in index expressions and it is not yet clear whether any
change should be made, so that can be left for another day.
This patch assumes that the only supported floating point format is
now IEEE format, and the documentation is updated to reflect that.
Code by me, adapting the work of Ulf Adams and other contributors.
References:
https://dl.acm.org/citation.cfm?id=3192369
Reviewed-by: Tom Lane, Andres Freund, Donald Dong
Discussion: https://postgr.es/m/87r2el1bx6.fsf@news-spur.riddles.org.uk
Windows, alone among our supported platforms, likes to emit three-digit
exponent fields even when two digits would do. Adjust such results to
look like the way everyone else does it. Eliminate a bunch of variant
expected-output files that were needed only because of this quirk.
Discussion: https://postgr.es/m/2934.1539122454@sss.pgh.pa.us
To do this, we only have to remove the compress and decompress support
functions, which have never done anything more than detoasting.
In the wake of commit d3a4f89d8, this results in automatically enabling
index-only scans, since the core code will now know that the stored
representation is the same as the original data (up to detoasting).
The only exciting part of this is that ALTER OPERATOR FAMILY lacks
a way to drop a support function that was declared as being part of
an opclass rather than being loose in the family. For the moment,
we'll hack our way to a solution with a manual update of the pg_depend
entry type, which is what distinguishes the two cases. Perhaps
someday it'll be worth providing a cleaner way to do that, but for
now it seems like a very niche problem.
Note that the underlying C functions remain, to support use of the shared
libraries with older versions of the modules' SQL declarations. Someday
we may be able to remove them, but not soon.
Andrey Borodin, reviewed by me
Discussion: https://postgr.es/m/D0F53A05-4F4A-4DEC-8339-3C069FA0EE11@yandex-team.ru
I'd supposed that people would do this manually when creating new operator
classes, but the folly of that was exposed today. The tests seem fast
enough that we can just apply them during the normal regression tests.
contrib/isn fails the checks for lack of complete sets of cross-type
operators. That's a nice-to-have policy rather than a functional
requirement, so leave it as-is, but insert ORDER BY in the query to
ensure consistent cross-platform output.
Discussion: https://postgr.es/m/7076.1480446837@sss.pgh.pa.us
This isn't fully tested as yet, in particular I'm not sure that the
"foo--unpackaged--1.0.sql" scripts are OK. But it's time to get some
buildfarm cycles on it.
sepgsql is not converted to an extension, mainly because it seems to
require a very nonstandard installation process.
Dimitri Fontaine and Tom Lane
uses of the long-deprecated float32 in contrib/seg; the definitions themselves
are still there, but no longer used. fmgr/README updated to match.
I added a CREATE FUNCTION to account for existing seg_center() code in seg.c
too, and some tests for it and the neighbor functions. At the same time,
remove checks for NULL which are not needed (because the functions are declared
STRICT).
I had to do some adjustments to contrib's btree_gist too. The choices for
representation there are not ideal for changing the underlying types :-(
Original patch by Zoltan Boszormenyi, with some adjustments by me.
only remnant of this failed experiment is that the server will take
SET AUTOCOMMIT TO ON. Still TODO: provide some client-side autocommit
logic in libpq.
Create objects in public schema.
Make spacing/capitalization consistent.
Remove transaction block use for object creation.
Remove unneeded function GRANTs.
YYERROR_VERBOSE" from contrib/cube and contrib/seg, and adjusts the expected
output accordingly. Hopefully this will consistently pass across multiple
bison versions.
Joe Conway
Noah Misch
Michael Paquier
Andrew Dunstan
Tom Lane
Andrew Gierth
Peter Eisentraut
Alvaro Herrera
Bruce Momjian