INSERT .. ON CONFLICT runs a pre-check of the possible conflicting
constraints before performing the actual speculative insertion. In case
the inserted tuple included TOASTed columns the ON CONFLICT condition
would be handled correctly in case the conflict was caught by the
pre-check, but if two transactions entered the speculative insertion
phase at the same time, one would have to re-try, and the code for
aborting a speculative insertion did not handle deleting the
speculatively inserted TOAST datums correctly.
TOAST deletion would fail with "ERROR: attempted to delete invisible
tuple" as we attempted to remove the TOAST tuples using
simple_heap_delete which reasoned that the given tuples should not be
visible to the command that wrote them.
This commit updates the heap_abort_speculative() function which aborts
the conflicting tuple to use itself, via toast_delete, for deleting
associated TOAST datums. Like before, the inserted toast rows are not
marked as being speculative.
This commit also adds a isolationtester spec test, exercising the
relevant code path. Unfortunately 9.5 cannot handle two waiting
sessions, and thus cannot execute this test.
Reported-By: Viren Negi, Oskari Saarenmaa
Author: Oskari Saarenmaa, edited a bit by me
Bug: #14150
Discussion: <20160519123338.12513.20271@wrigleys.postgresql.org>
Backpatch: 9.5, where ON CONFLICT was introduced
regexp_match() is like regexp_matches(), but it disallows the 'g' flag
and in consequence does not need to return a set. Instead, it returns
a simple text array value, or NULL if there's no match. Previously people
usually got that behavior with a sub-select, but this way is considerably
more efficient.
Documentation adjusted so that regexp_match() is presented first and then
regexp_matches() is introduced as a more complicated version. This is
a bit historically revisionist but seems pedagogically better.
Still TODO: extend contrib/citext to support this function.
Emre Hasegeli, reviewed by David Johnston
Discussion: <CAE2gYzy42sna2ME_e3y1KLQ-4UBrB-eVF0SWn8QG39sQSeVhEw@mail.gmail.com>
Slot creation did not clear all fields upon creation. After start the
memory is zeroed, but when a physical replication slot was created in
the shared memory of a previously existing logical slot, catalog_xmin
would not be cleared. That in turn would prevent vacuum from doing its
duties.
To fix initialize all the fields. To make similar future bugs less
likely, zero all of ReplicationSlotPersistentData, and re-order the
rest of the initialization to be in struct member order.
Analysis: Andrew Gierth
Reported-By: md@chewy.com
Author: Michael Paquier
Discussion: <20160705173502.1398.70934@wrigleys.postgresql.org>
Backpatch: 9.4, where replication slots were introduced
As implemented, -e ran an EXPLAIN but then discarded the output, which
certainly seems pointless. Make it print to stdout instead. It's been
like that forever, so back-patch to all supported branches.
Daniel Gustafsson, reviewed by Andreas Scherbaum
Patch: <B97BDCB7-A3B3-4734-90B5-EDD586941629@yesql.se>
In some cases, exiting out of a plpgsql statement due to an error, then
catching the error in a surrounding exception block, led to leakage of
temporary data the statement was working with, because we kept all such
data in the function-lifespan SPI Proc context. Iterating such behavior
many times within one function call thus led to noticeable memory bloat.
To fix, create an additional memory context meant to have statement
lifespan. Since many plpgsql statements, particularly the simpler/more
common ones, don't need this, create it only on demand. Reset this context
at the end of any statement that uses it, and arrange for exception cleanup
to reset it too, thereby fixing the memory-leak issue. Allow a stack of
such contexts to exist to handle cases where a compound statement needs
statement-lifespan data that persists across calls of inner statements.
While at it, clean up code and improve comments referring to the existing
short-term memory context, which by plpgsql convention is the per-tuple
context of the eval_econtext ExprContext. We now uniformly refer to that
as the eval_mcontext, whereas the new statement-lifespan memory contexts
are called stmt_mcontext.
This change adds some context-creation overhead, but on the other hand
it allows removal of some retail pfree's in favor of context resets.
On balance it seems to be about a wash performance-wise.
In principle this is a bug fix, but it seems too invasive for a back-patch,
and the infrequency of complaints weighs against taking the risk in the
back branches. So we'll fix it only in HEAD, at least for now.
Tom Lane, reviewed by Pavel Stehule
Discussion: <17863.1469142152@sss.pgh.pa.us>
The performance overhead of this can be significant on Windows, and most
people don't have the tools to view it anyway as Windows does not have
native support for process titles.
Discussion: <0A3221C70F24FB45833433255569204D1F5BE3E8@G01JPEXMBYT05>
Takayuki Tsunakawa
We implement a dozen or so parameterless functions that the SQL standard
defines special syntax for. Up to now, that was done by converting them
into more or less ad-hoc constructs such as "'now'::text::date". That's
messy for multiple reasons: it exposes what should be implementation
details to users, and performance is worse than it needs to be in several
cases. To improve matters, invent a new expression node type
SQLValueFunction that can represent any of these parameterless functions.
Bump catversion because this changes stored parsetrees for rules.
Discussion: <30058.1463091294@sss.pgh.pa.us>
I'm not sure which bozo thought it's a problem to use strtol() only
for its endptr result, but silence the warning using same method
used elsewhere.
Report: <f845d3a6-5328-3e2a-924f-f8e91aa2b6d2@2ndquadrant.com>
This is somewhat cosmetic, since as long as you know what you are looking
at, "10.0" is a serviceable substitute for "10". But there is a potential
for confusion between version numbers with minor numbers and those without
--- we don't want people asking "why is psql saying 10.0 when my server is
10.2". Therefore, back-patch as far as practical, which turns out to be
9.3. I could have redone the patch to use fprintf(stderr) in place of
psql_error(), but it seems more work than is warranted for branches that
will be EOL or nearly so by the time v10 comes out.
Although only psql seems to contain any code that needs this, I chose
to put the support function into fe_utils, since it seems likely we'll
need it in other client programs in future. (In 9.3-9.5, use dumputils.c,
the predecessor of fe_utils/string_utils.c.)
In HEAD, also fix the backend code that whines about loadable-library
version mismatch. I don't see much need to back-patch that.
Up to now we've manually adjusted these numbers in several different
Makefiles at the start of each development cycle. While that's not
much work, it's easily forgotten, so let's get rid of it by setting
the SO_MINOR_VERSION values directly from $(MAJORVERSION).
In the case of libpq, this dev cycle's value of SO_MINOR_VERSION happens
to be "10" anyway, so this switch is transparent. For ecpg's shared
libraries, this will result in skipping one or two minor version numbers
between v9.6 and v10, which seems like no big problem; and it was a bit
inconsistent that they didn't have equal minor version numbers anyway.
Discussion: <21969.1471287988@sss.pgh.pa.us>
Commit af33039317 aimed to reduce
leakage from tqueue.c, which is good. Unfortunately, by changing the
memory context in which all of gather_readnext() executes, it also
changed the context in which ExecShutdownGatherWorkers executes, which
is not good, because that function eventually causes a call to
ExecParallelRetrieveInstrumentation, which proceeds to allocate
planstate->worker_instrument in a short-lived context, causing a
crash.
Rushabh Lathia, reviewed by Amit Kapila and by me.
Once upon a time, it made sense for the ecpg preprocessor to have its
own version number, because it used a manually-maintained grammar that
wasn't always in sync with the core grammar. But those days are
thankfully long gone, leaving only a maintenance nuisance behind.
Let's use the PG v10 version numbering changeover as an excuse to get
rid of the ecpg version number and just have ecpg identify itself by
PG_VERSION. From the user's standpoint, ecpg will go from "4.12" in
the 9.6 branch to "10" in the 10 branch, so there's no failure of
monotonicity.
Discussion: <1471332659.4410.67.camel@postgresql.org>
Prior to commit 7882c3b0b9, it was
possible to use LWLocks within DSM segments, but that commit broke
this use case by switching from a doubly linked list to a circular
linked list. Switch back, using a new bit of general infrastructure
for maintaining lists of PGPROCs.
Thomas Munro, reviewed by me.
This is a good bit more complicated than the average new-version stamping
commit, because it includes various adjustments in pursuit of changing
from three-part to two-part version numbers. It's likely some further
work will be needed around that change; but this is enough to get through
the regression tests, at least in Unix builds.
Peter Eisentraut and Tom Lane
Wrap the perltidy invocation into a shell script to reduce the risk of
copy-and-paste errors. Include removal of *.bak files in the script,
so they don't accidentally get committed. Improve the directions in
the README file.
NUMERIC_MAX_PRECISION is a purely arbitrary constraint on the precision
and scale you can write in a numeric typmod. It might once have had
something to do with the allowed range of a typmod-less numeric value,
but at least since 9.1 we've allowed, and documented that we allowed,
any value that would physically fit in the numeric storage format;
which is something over 100000 decimal digits, not 1000.
Hence, get rid of numeric_in()'s use of NUMERIC_MAX_PRECISION as a limit
on the allowed range of the exponent in scientific-format input. That was
especially silly in view of the fact that you can enter larger numbers as
long as you don't use 'e' to do it. Just constrain the value enough to
avoid localized overflow, and let make_result be the final arbiter of what
is too large. Likewise adjust ecpg's equivalent of this code.
Also get rid of numeric_recv()'s use of NUMERIC_MAX_PRECISION to limit the
number of base-NBASE digits it would accept. That created a dump/restore
hazard for binary COPY without doing anything useful; the wire-format
limit on number of digits (65535) is about as tight as we would want.
In HEAD, also get rid of pg_size_bytes()'s unnecessary intimacy with what
the numeric range limit is. That code doesn't exist in the back branches.
Per gripe from Aravind Kumar. Back-patch to all supported branches,
since they all contain the documentation claim about allowed range of
NUMERIC (cf commit cabf5d84b).
Discussion: <2895.1471195721@sss.pgh.pa.us>
In blinsert(), cope with the possibility that a page we pull from the
notFullPage list is marked BLOOM_DELETED. This could happen if VACUUM
recently marked it deleted but hasn't (yet) updated the metapage.
We can re-use such a page safely, but we *must* reinitialize it so that
it's no longer marked deleted.
Fix blvacuum() so that it updates the notFullPage list even if it's
going to update it to empty. The previous "optimization" of skipping
the update seems pretty dubious, since it means that the next blinsert()
will uselessly visit whatever pages we left in the list.
Uniformly treat PageIsNew pages the same as deleted pages. This should
allow proper recovery if a crash occurs just after relation extension.
Properly use vacuum_delay_point, not assorted ad-hoc CHECK_FOR_INTERRUPTS
calls, in the blvacuum() main loop.
Fix broken tuple-counting logic: blvacuum.c counted the number of live
index tuples over again in each scan, leading to VACUUM VERBOSE reporting
some multiple of the actual number of surviving index tuples after any
vacuum that removed any tuples (since they'd be counted in blvacuum, maybe
more than once, and then again in blvacuumcleanup, without ever zeroing the
counter). It's sufficient to count them in blvacuumcleanup.
stats->estimated_count is a boolean, not a counter, and we don't want
to set it true, so don't add tuple counts to it.
Add a couple of Asserts that we don't overrun available space on a bloom
page. I don't think there's any bug there today, but the way the
FreeBlockNumberArray size calculation is set up is scarily fragile, and
BloomPageGetFreeSpace isn't much better. The Asserts should help catch
any future mistakes.
Per investigation of a report from Jeff Janes. I think the first item
above may explain his report; the other changes were things I noticed
while casting about for an explanation.
Report: <CAMkU=1xEUuBphDwDmB1WjN4+td4kpnEniFaTBxnk1xzHCw8_OQ@mail.gmail.com>
Per discussion, we should provide such functions to replace the lost
ability to discover AM properties by inspecting pg_am (cf commit
65c5fcd35). The added functionality is also meant to displace any code
that was looking directly at pg_index.indoption, since we'd rather not
believe that the bit meanings in that field are part of any client API
contract.
As future-proofing, define the SQL API to not assume that properties that
are currently AM-wide or index-wide will remain so unless they logically
must be; instead, expose them only when inquiring about a specific index
or even specific index column. Also provide the ability for an index
AM to override the behavior.
In passing, document pg_am.amtype, overlooked in commit 473b93287.
Andrew Gierth, with kibitzing by me and others
Discussion: <87mvl5on7n.fsf@news-spur.riddles.org.uk>
Apparently that's not obvious to everybody, so let's belabor the point.
In passing, document that DROP POLICY has CASCADE/RESTRICT options (which
it does, per gram.y) but they do nothing (I assume, anyway). Also update
some long-obsolete commentary in gram.y.
Discussion: <20160805104837.1412.84915@wrigleys.postgresql.org>
EXPLAIN (ANALYZE, TIMING OFF) would print an elapsed time of zero for
a trigger function, because no measurement has been taken but it printed
the field anyway. This isn't what EXPLAIN does elsewhere, so suppress it.
In the same vein, EXPLAIN (ANALYZE, BUFFERS) with non-text output format
would print buffer I/O timing numbers even when no measurement has been
taken because track_io_timing is off. That seems not per policy, either,
so change it.
Back-patch to 9.2 where these features were introduced.
Maksim Milyutin
Discussion: <081c0540-ecaa-bd29-3fd2-6358f3b359a9@postgrespro.ru>
Commit 14e8803f1 removed LWLocks when accessing MyProc->syncRepState
but didn't clean up the surrounding code and comments.
Cleanup and backpatch to 9.5, to keep code similar.
Julien Rouhaud, improved by suggestion from Michael Paquier,
implemented trivially by myself.
Commit 874fe3aea changed the command tag returned for CREATE MATVIEW/CREATE
TABLE AS ... WITH NO DATA, but missed that there was code in spi.c that
expected the command tag to always be "SELECT". Fortunately, the
consequence was only an Assert failure, so this oversight should have no
impact in production builds.
Since this code path was evidently un-exercised, add a regression test.
Per report from Shivam Saxena. Back-patch to 9.3, like the previous commit.
Michael Paquier
Report: <97218716-480B-4527-B5CD-D08D798A0C7B@dresources.com>
Several places in NUM_numpart_from_char(), which is called from the SQL
function to_number(text, text), could accidentally read one byte past
the end of the input buffer (which comes from the input text datum and
is not null-terminated).
1. One leading space character would be skipped, but there was no check
that the input was at least one byte long. This does not happen in
practice, but for defensiveness, add a check anyway.
2. Commit 4a3a1e2cf apparently accidentally doubled that code that skips
one space character (so that two spaces might be skipped), but there
was no overflow check before skipping the second byte. Fix by
removing that duplicate code.
3. A logic error would allow a one-byte over-read when looking for a
trailing sign (S) placeholder.
In each case, the extra byte cannot be read out directly, but looking at
it might cause a crash.
The third item was discovered by Piotr Stefaniak, the first two were
found and analyzed by Tom Lane and Peter Eisentraut.
ExecEvalCase() tried to save a cycle or two by passing
&econtext->caseValue_isNull as the isNull argument to its sub-evaluation of
the CASE value expression. If that subexpression itself contained a CASE,
then *isNull was an alias for econtext->caseValue_isNull within the
recursive call of ExecEvalCase(), leading to confusion about whether the
inner call's caseValue was null or not. In the worst case this could lead
to a core dump due to dereferencing a null pointer. Fix by not assigning
to the global variable until control comes back from the subexpression.
Also, avoid using the passed-in isNull pointer transiently for evaluation
of WHEN expressions. (Either one of these changes would have been
sufficient to fix the known misbehavior, but it's clear now that each of
these choices was in itself dangerous coding practice and best avoided.
There do not seem to be any similar hazards elsewhere in execQual.c.)
Also, it was possible for inlining of a SQL function that implements the
equality operator used for a CASE comparison to result in one CASE
expression's CaseTestExpr node being inserted inside another CASE
expression. This would certainly result in wrong answers since the
improperly nested CaseTestExpr would be caused to return the inner CASE's
comparison value not the outer's. If the CASE values were of different
data types, a crash might result; moreover such situations could be abused
to allow disclosure of portions of server memory. To fix, teach
inline_function to check for "bare" CaseTestExpr nodes in the arguments of
a function to be inlined, and avoid inlining if there are any.
Heikki Linnakangas, Michael Paquier, Tom Lane
Report: https://github.com/greenplum-db/gpdb/pull/327
Report: <4DDCEEB8.50602@enterprisedb.com>
Security: CVE-2016-5423
Due to simplistic quoting and confusion of database names with conninfo
strings, roles with the CREATEDB or CREATEROLE option could escalate to
superuser privileges when a superuser next ran certain maintenance
commands. The new coding rule for PQconnectdbParams() calls, documented
at conninfo_array_parse(), is to pass expand_dbname=true and wrap
literal database names in a trivial connection string. Escape
zero-length values in appendConnStrVal(). Back-patch to 9.1 (all
supported versions).
Nathan Bossart, Michael Paquier, and Noah Misch. Reviewed by Peter
Eisentraut. Reported by Nathan Bossart.
Security: CVE-2016-5424
Rename these newly-extern functions with terms more typical of their new
neighbors. No functional changes; a subsequent commit will use them in
more places. Back-patch to 9.1 (all supported versions). Back branches
lack src/fe_utils, so instead rename the functions in place; the
subsequent commit will copy them into the other programs using them.
Security: CVE-2016-5424
The incorrect quoting may have permitted arbitrary command execution.
At a minimum, it gave broader control over the command line to actors
supposed to have control over a single argument. Back-patch to 9.1 (all
supported versions).
Security: CVE-2016-5424
These characters prematurely terminate Windows shell command processing,
causing the shell to execute a prefix of the intended command. The
chief alternative to rejecting these characters was to bypass the
Windows shell with CreateProcess(), but the ability to use such names
has little value. Back-patch to 9.1 (all supported versions).
This change formally revokes support for these characters in database
names and roles names. Don't document this; the error message is
self-explanatory, and too few users would benefit. A future major
release may forbid creation of databases and roles so named. For now,
check only at known weak points in pg_dumpall. Future commits will,
without notice, reject affected names from other frontend programs.
Also extend the restriction to pg_dumpall --dbname=CONNSTR arguments and
--file arguments. Unlike the effects on role name arguments and
database names, this does not reflect a broad policy change. A
migration to CreateProcess() could lift these two restrictions.
Reviewed by Peter Eisentraut.
Security: CVE-2016-5424
Andres Freund