| Age | Commit message (Collapse) | Author |
|---|
|
We put it aside as invalidated_at, which let us show "lost" in
pg_replication slot. Prior to this change, the state value was reported
as NULL.
Backpatch to 13.
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20200617.101707.1735599255100002667.horikyota.ntt@gmail.com
Discussion: https://postgr.es/m/20200407.120905.1507671100168805403.horikyota.ntt@gmail.com
|
|
The current definition is dangerous. No bugs exist in our code at
present, but backpatch to 11 nonetheless where it was introduced.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
|
|
explain_get_index_name() applied quote_identifier() to the index name.
This is fine for text output, but the non-text output formats all have
their own quoting conventions and would much rather start from the
actual index name. For example in JSON you'd get something like
"Index Name": "\"My Index\"",
which is surely not desirable, especially when the same does not
happen for table names. Hence, move the responsibility for applying
quoting out to the callers, where it can go into already-existing
special code paths for text format.
This changes the API spec for users of explain_get_index_name_hook:
before, they were supposed to apply quote_identifier() if necessary,
now they should not. Research suggests that the only publicly
available user of the hook is hypopg, and it actually forgot to
apply quoting anyway, so it's fine. (In any case, there's no
behavioral change for the output of a hook as seen in non-text
EXPLAIN formats, so this won't break any case that programs should
be relying on.)
Digging in the commit logs, it appears that quoting was included in
explain_get_index_name's duties when commit 604ffd280 invented it;
and that was fine at the time because we only had text output format.
This should have been rethought when non-text formats were invented,
but it wasn't.
This is a fairly clear bug for users of non-text EXPLAIN formats,
so back-patch to all supported branches.
Per bug #16502 from Maciek Sakrejda. Patch by me (based on
investigation by Euler Taveira); thanks to Julien Rouhaud for review.
Discussion: https://postgr.es/m/16502-57bd1c9f913ed1d1@postgresql.org
|
|
Source-Git-URL: https://git.postgresql.org/git/pgtranslation/messages.git
Source-Git-Hash: 434134899af310153f7511ccaa3f376e4c817e66
|
|
spg_mask() didn't take into account that pd_lower equal to SizeOfPageHeaderData
is still valid value. This commit fixes that. Backpatch to 11, where
spg_mask() pg_lower check was introduced.
Reported-by: Michael Paquier
Discussion: https://postgr.es/m/20200615131405.GM52676%40paquier.xyz
Backpatch-through: 11
|
|
A few places calling fwrite and gzwrite were not setting errno to ENOSPC
when reporting errors, as is customary; this led to some failures being
reported as
"could not write file: Success"
which makes us look silly. Make a few of these places in pg_dump and
pg_basebackup use our customary pattern.
Backpatch-to: 9.5
Author: Justin Pryzby <pryzby@telsasoft.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20200611153753.GU14879@telsasoft.com
|
|
The IANA time zone folk have deprecated use of a "posixrules" file in
the tz database. While for now it's our choice whether to keep
supplying one in our own builds, installations built with
--with-system-tzdata will soon be needing to cope with that file not
being present, at least on some platforms.
This causes a problem for the horology test, which expected the
nonstandard POSIX zone spec "CST7CDT" to apply pre-2007 US daylight
savings rules. That does happen if the posixrules file supplies such
information, but otherwise the test produces undesired results.
To fix, add an explicit transition date rule that matches 2005 practice.
(We could alternatively have switched the test to use some real time
zone, but it seems useful to have coverage of this type of zone spec.)
While at it, update a documentation example that also relied on
"CST7CDT"; use a real-world zone name instead. Also, document why
the zone names EST5EDT, CST6CDT, MST7MDT, PST8PDT aren't subject to
similar failures when "posixrules" is missing.
Back-patch to all supported branches, since the hazard is the same
for all.
Discussion: https://postgr.es/m/1665379.1592581287@sss.pgh.pa.us
|
|
It was possible for deduplication's single value strategy to mistakenly
believe that a very small duplicate tuple counts as one of the six large
tuples that it aims to leave behind after the page finally splits. This
could cause slightly suboptimal space utilization with very low
cardinality indexes, though only under fairly narrow conditions.
To fix, be particular about what kind of tuple counts as a
maxpostingsize-capped tuple. This avoids confusion in the event of a
small tuple that gets "wedged" between two large tuples, where all
tuples on the page are duplicates of the same value.
Discussion: https://postgr.es/m/CAH2-Wz=Y+sgSFc-O3LpiZX-POx2bC+okec2KafERHuzdVa7-rQ@mail.gmail.com
Backpatch: 13-, where deduplication was introduced (by commit 0d861bbb)
|
|
This commit fixes the following issues.
1. There is the case where the slot is dropped while trying to invalidate it.
InvalidateObsoleteReplicationSlots() did not handle this case, and
which could cause checkpoint to fail.
2. InvalidateObsoleteReplicationSlots() could emit the same log message
multiple times unnecessary. It should be logged only once.
3. When marking the slot as used, we always searched the target slot from
all the replication slots even if we already found it. This could cause
useless waste of cycles.
Back-patch to v13 where these issues were added as a part of
max_slot_wal_keep_size code.
Author: Fujii Masao
Reviewed-by: Kyotaro Horiguchi, Alvaro Herrera
Discussion: https://postgr.es/m/66c05b67-3396-042c-1b41-bfa6c3ddcf82@oss.nttdata.com
|
|
Since 1f39bce02, HashAgg nodes have had the ability to spill to disk when
memory consumption exceeds work_mem. That commit added new properties to
EXPLAIN ANALYZE to show the maximum memory usage and disk usage, however,
it didn't quite go as far as showing that information for parallel
workers. Since workers may have experienced something very different from
the main process, we should show this information per worker, as is done
in Sort.
Reviewed-by: Justin Pryzby
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/CAApHDvpEKbfZa18mM1TD7qV6PG+w97pwCWq5tVD0dX7e11gRJw@mail.gmail.com
Backpatch-through: 13, where the hashagg spilling code was added.
|
|
This was a danger only for --disable-spinlocks in combination with
atomic operations unsupported by the current platform.
While atomics.c was careful to signal that a separate semaphore ought
to be used when spinlock emulation is active, spin.c didn't actually
implement that mechanism. That's my (Andres') fault, it seems to have
gotten lost during the development of the atomic operations support.
Fix that issue and add test for nesting atomic operations inside a
spinlock.
Author: Andres Freund
Discussion: https://postgr.es/m/20200605023302.g6v3ydozy5txifji@alap3.anarazel.de
Backpatch: 9.5-
|
|
As s_lock_test, the already existing test for spinlocks, isn't run in
an automated fashion (and doesn't test a normal backend environment),
adding tests that are run as part of a normal regression run is a good
idea. Particularly in light of several recent and upcoming spinlock
related fixes.
Currently the new tests are run as part of the pre-existing
test_atomic_ops() test. That perhaps can be quibbled about, but for
now seems ok.
The only operations that s_lock_test tests but the new tests don't are
the detection of a stuck spinlock and S_LOCK_FREE (which is otherwise
unused, not implemented on all platforms, and will be removed).
This currently contains a test for more than INT_MAX spinlocks (only
run with --disable-spinlocks), to ensure the recent commit fixing a
bug with more than INT_MAX spinlock initializations is correct. That
test is somewhat slow, so we might want to disable it after a few
days.
It might be worth retiring s_lock_test after this. The added coverage
of a stuck spinlock probably isn't worth the added complexity?
Author: Andres Freund
Discussion: https://postgr.es/m/20200606023103.avzrctgv7476xj7i@alap3.anarazel.de
|
|
Advancing a replication slot did not recompute the oldest xmin and LSN
values across replication slots, preventing resource removal like
segments not recycled at checkpoint time. The original commit that
introduced the slot advancing in 9c7d06d never did the update of those
oldest values, and b0afdca removed this code.
This commit adds a TAP test to check segment recycling with advancing
for physical slots, enforcing an extra segment switch before advancing
to check if the segment gets correctly recycled after a checkpoint.
Reported-by: Andres Freund
Reviewed-by: Alexey Kondratov, Kyptaro Horiguchi
Discussion: https://postgr.es/m/20200609171904.kpltxxvjzislidks@alap3.anarazel.de
Backpatch-through: 11
|
|
This absorbs a leap-second-related bug fix in localtime.c, and
teaches zic to handle an expiration marker in the leapseconds file.
Neither are of any interest to us (for the foreseeable future
anyway), but we need to stay more or less in sync with upstream.
Also adjust some over-eager changes in the README from commit 957338418.
I have no intention of making changes that require C99 in this code,
until such time as all the live back branches require C99. Otherwise
back-patching will get too exciting.
For the same reason, absorb assorted whitespace and other cosmetic
changes from HEAD into the back branches; mostly this reflects use of
improved versions of pgindent.
All in all then, quite a boring update. But I figured I'd get it
done while I was looking at this code.
|
|
Oversight in commit 0d861bbb.
|
|
Once the counter goes negative we ended up with spinlocks that errored
out on first use (due to check in tas_sema).
Author: Andres Freund
Reviewed-By: Robert Haas
Discussion: https://postgr.es/m/20200606023103.avzrctgv7476xj7i@alap3.anarazel.de
Backpatch: 9.5-
|
|
On platforms without support for 64bit atomic operations where we also
cannot rely on 64bit reads to have single copy atomicity, such atomics
are implemented using a spinlock based fallback. That means it's not
safe to even read such atomics from within a signal handler (since the
signal handler might run when the spinlock already is held).
To avoid this issue defer global barrier processing out of the signal
handler. Instead of checking local / shared barrier generation to
determine whether to set ProcSignalBarrierPending, introduce
PROCSIGNAL_BARRIER and always set ProcSignalBarrierPending when
receiving such a signal. Additionally avoid redundant work in
ProcessProcSignalBarrier if ProcSignalBarrierPending is unnecessarily.
Also do a small amount of other polishing.
Author: Andres Freund
Reviewed-By: Robert Haas
Discussion: https://postgr.es/m/20200609193723.eu5ilsjxwdpyxhgz@alap3.anarazel.de
Backpatch: 13-, where the code was introduced.
|
|
Broken by move of fe_archive.c to fe_utils.
|
|
Convert buffile.c error handling to use ereport. This fixes cases where
I/O errors were indistinguishable from EOF or not reported. Also remove
"%m" from error messages where errno would be bogus. While we're
modifying those strings, add block numbers and short read byte counts
where appropriate.
Back-patch to all supported releases.
Reported-by: Amit Khandekar <amitdkhan.pg@gmail.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Ibrar Ahmed <ibrar.ahmad@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA%2BhUKGJE04G%3D8TLK0DLypT_27D9dR8F1RQgNp0jK6qR0tZGWOw%40mail.gmail.com
|
|
Non-zero vacuum_defer_cleanup_age values cause pg_upgrade freezing of
the system catalogs to be incomplete, or do nothing. This will cause
the upgrade to fail in confusing ways.
Reported-by: Laurenz Albe
Discussion: https://postgr.es/m/7d6f6c22ba05ce0c526e9e8b7bfa8105e7da45e6.camel@cybertec.at
Backpatch-through: 9.5
|
|
When there is just one non-null input value, and it is infinity or NaN,
aggregates such as stddev_pop and covar_pop should produce a NaN
result, because the calculation is not well-defined. They used to do
so, but since we adopted Youngs-Cramer aggregation in commit e954a727f,
they produced zero instead. That's an oversight, so fix it. Add tests
exercising these edge cases.
Affected aggregates are
var_pop(double precision)
stddev_pop(double precision)
var_pop(real)
stddev_pop(real)
regr_sxx(double precision,double precision)
regr_syy(double precision,double precision)
regr_sxy(double precision,double precision)
regr_r2(double precision,double precision)
regr_slope(double precision,double precision)
regr_intercept(double precision,double precision)
covar_pop(double precision,double precision)
corr(double precision,double precision)
Back-patch to v12 where the behavior change was accidentally introduced.
Report and patch by me; thanks to Dean Rasheed for review.
Discussion: https://postgr.es/m/353062.1591898766@sss.pgh.pa.us
|
|
Reported-By: Tom Lane
Discussion: https://postgr.es/m/841649.1592065060@sss.pgh.pa.us
|
|
In passing, also remove a few surplus empty lines from pg_ltoa and
pg_ulltoa_n in numutils.c
Reported-by: Andrew Gierth
Discussion: https://postgr.es/m/87y2ou3xuh.fsf@news-spur.riddles.org.uk
Backpatch-through: 13, where these changes were introduced
|
|
Rewrite the documentation of these functions, in light of recent bug fix
commit 5940ffb2.
Back-patch to 13 where the check-for-conflict-out code was split up into
AM-specific and generic parts, and new documentation was added that now
looked wrong.
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/db7b729d-0226-d162-a126-8a8ab2dc4443%40jepsen.io
|
|
When merging two NumericAggStates, the code missed adding the new
state's NaNcount unless its N was also nonzero; since those counts
are independent, this is wrong.
This would only have visible effect if some partial aggregate scans
found only NaNs while earlier ones found only non-NaNs; then we could
end up falsely deciding that there were no NaNs and fail to return a
NaN final result as expected. That's pretty improbable, so it's no
surprise this hasn't been reported from the field. Still, it's a bug.
I didn't try to produce a regression test that would show the bug,
but I did notice that these functions weren't being reached at all
in our regression tests, so I improved the tests to at least
exercise them. With these additions, I see pretty complete code
coverage on the aggregation-related functions in numeric.c.
Back-patch to 9.6 where this code was introduced. (I only added
the improved test case as far back as v10, though, since the
relevant part of aggregates.sql isn't there at all in 9.6.)
|
|
Eliminate enable_groupingsets_hash_disk, which was primarily useful
for testing grouping sets that use HashAgg and spill. Instead, hack
the table stats to convince the planner to choose hashed aggregation
for grouping sets that will spill to disk. Suggested by Melanie
Plageman.
Rename enable_hashagg_disk to hashagg_avoid_disk_plan, and invert the
meaning of on/off. The new name indicates more strongly that it only
affects the planner. Also, the word "avoid" is less definite, which
should avoid surprises when HashAgg still needs to use the
disk. Change suggested by Justin Pryzby, though I chose a different
GUC name.
Discussion: https://postgr.es/m/CAAKRu_aisiENMsPM2gC4oUY1hHG3yrCwY-fXUg22C6_MJUwQdA%40mail.gmail.com
Discussion: https://postgr.es/m/20200610021544.GA14879@telsasoft.com
Backpatch-through: 13
|
|
SSI's HeapCheckForSerializableConflictOut() test failed to correctly
handle conditions involving a concurrently inserted tuple which is later
concurrently updated by a separate transaction . A SELECT statement
that called HeapCheckForSerializableConflictOut() could end up using the
same XID (updater's XID) for both the original tuple, and the successor
tuple, missing the XID of the xact that created the original tuple
entirely. This only happened when neither tuple from the chain was
visible to the transaction's MVCC snapshot.
The observable symptoms of this bug were subtle. A pair of transactions
could commit, with the later transaction failing to observe the effects
of the earlier transaction (because of the confusion created by the
update to the non-visible row). This bug dates all the way back to
commit dafaa3ef, which added SSI.
To fix, make sure that we check the xmin of concurrently inserted tuples
that happen to also have been updated concurrently.
Author: Peter Geoghegan
Reported-By: Kyle Kingsbury
Reviewed-By: Thomas Munro
Discussion: https://postgr.es/m/db7b729d-0226-d162-a126-8a8ab2dc4443@jepsen.io
Backpatch: All supported versions
|
|
Reported-by: John Naylor
Author: John Naylor
Backpatch-through: 9.5
Discussion: https://postgr.es/m/CACPNZCtRuvs6G+EYqejhVJgBq2AKeZdXRVJsbX4syhO9gn5SNQ@mail.gmail.com
|
|
fe_archive.c was compiled only for the frontend in src/common/, but as
it will never share anything with the backend, it makes most sense to
move this file to src/fe_utils/.
Reported-by: Peter Eisentraut
Discussion: https://postgr.es/m/e9766d71-8655-ac86-bdf6-77e0e7169977@2ndquadrant.com
Backpatch-through: 13
|
|
The previous description string still described the pre-PostgreSQL
10 (pre eb61136dc75a76caef8460fa939244d8593100f2) behavior of
selecting between encrypted and unencrypted, but it is now choosing
between encryption algorithms.
|
|
Commit cec2edfa78 introduced logical_decoding_work_mem to limit
ReorderBuffer memory usage. We spill the changes once the memory occupied
by changes exceeds logical_decoding_work_mem. There was an assumption
in the code that by evicting the largest (sub)transaction we will come
under the memory limit as the selected transaction will be at least as
large as the most recent change (which caused us to go over the memory
limit). However, that is not true because a user can reduce the
logical_decoding_work_mem to a smaller value before the most recent
change.
We fix it by allowing to evict the transactions until we reach under the
memory limit.
Reported-by: Fujii Masao
Author: Amit Kapila
Reviewed-by: Fujii Masao
Backpatch-through: 13, where it was introduced
Discussion: https://postgr.es/m/2b7ba291-22e0-a187-d167-9e5309a3458d@oss.nttdata.com
|
|
similar to 0fd2a79a637f9f96b9830524823df0454e962f96
|
|
These appear to have been forgotten when the functions were renamed in
1fd687a03.
Backpatch-through: 13, where the functions were renamed
|
|
Commit 0c882e52a tried to force table atest12 to have more-accurate-
than-default statistics; but transiently setting default_statistics_target
isn't enough for that, because autovacuum could come along and overwrite
the stats later. This evidently explains some intermittent buildfarm
failures we've seen since then. Repair by disabling autovac on this table.
Thanks to David Rowley for correctly diagnosing the cause.
Discussion: https://postgr.es/m/CA+hUKG+OUkQSOUTg=qo=S=fWa_tbm99i7rB7mfbHz1SYm4v-jQ@mail.gmail.com
|
|
Diagnosis by Andres.
Reported-by: Pavel Stehule
Discussion: https://postgr.es/m/CAFj8pRDLVakD5Aagt3yZeEQeTeEWaS3YE5h8XC3Q3qJ6TYkc2Q%40mail.gmail.com
Backpatch-through: 13
|
|
Previously we used pg_atomic_write_64_impl inside
pg_atomic_init_u64. That works correctly, but on platforms without
64bit single copy atomicity it could trigger spurious valgrind errors
about uninitialized memory, because we use compare_and_swap for atomic
writes on such platforms.
I previously suppressed one instance of this problem (6c878edc1df),
but as Tom reports that wasn't enough. As the atomic variable cannot
yet be concurrently accessible during initialization, it seems better
to have pg_atomic_init_64_impl set the value directly.
Change pg_atomic_init_u32_impl for symmetry.
Reported-By: Tom Lane
Author: Andres Freund
Discussion: https://postgr.es/m/1714601.1591503815@sss.pgh.pa.us
Backpatch: 9.5-
|
|
The redo routines for XLOG_CHECKPOINT_{ONLINE,SHUTDOWN} must acquire
ControlFileLock before modifying ControlFile->checkPointCopy, or the
checkpointer could write out a control file with a bad checksum.
Likewise, XLogReportParameters() must acquire ControlFileLock before
modifying ControlFile and calling UpdateControlFile().
Back-patch to all supported releases.
Author: Nathan Bossart <bossartn@amazon.com>
Author: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/70BF24D6-DC51-443F-B55A-95735803842A%40amazon.com
|
|
Since database connections can be used with WAL senders in 9.4, it is
possible to use physical replication. This commit fixes a crash when
starting physical replication with a WAL sender using a database
connection, caused by the refactoring done in 850196b.
There have been discussions about forbidding the use of physical
replication in a database connection, but this is left for later,
taking care only of the crash new to 13.
While on it, add a test to check for a failure when attempting logical
replication if the WAL sender does not have a database connection. This
part is extracted from a larger patch by Kyotaro Horiguchi.
Reported-by: Vladimir Sitnikov
Author: Michael Paquier, Kyotaro Horiguchi
Reviewed-by: Kyotaro Horiguchi, Álvaro Herrera
Discussion: https://postgr.es/m/CAB=Je-GOWMj1PTPkeUhjqQp-4W3=nW-pXe2Hjax6rJFffB5_Aw@mail.gmail.com
Backpatch-through: 13
|
|
Commit 7be5d8df1f74b78620167d3abf32ee607e728919 surfaced the logic
error, which had no functional implications, by adding "use warnings".
The buildfarm always customizes PROVE_FLAGS, so the warning did not
appear there. Back-patch to 9.5 (all supported versions).
|
|
pgperltidy and reformat-dat-files too, though those didn't
find anything to change.
|
|
Even when we've concluded that we have a hard write failure on the
socket, we should continue to try to read data. This gives us an
opportunity to collect any final error message that the backend might
have sent before closing the connection; moreover it is the job of
pqReadData not pqSendSome to close the socket once EOF is detected.
Due to an oversight in 1f39a1c06, pqSendSome failed to try to collect
data in the case where we'd already set write_failed. The problem was
masked for ordinary query operations (which really only make one write
attempt anyway), but COPY to the server would continue to send data
indefinitely after a mid-COPY connection loss.
Hence, add pqReadData calls into the paths where pqSendSome drops data
because of write_failed. If we've lost the connection, this will
eventually result in closing the socket and setting CONNECTION_BAD,
which will cause PQputline and siblings to report failure, allowing
the application to terminate the COPY sooner. (Basically this restores
what happened before 1f39a1c06.)
There are related issues that this does not solve; for example, if the
backend sends an error but doesn't drop the connection, we did and
still will keep pumping COPY data as long as the application sends it.
Fixing that will require application-visible behavior changes though,
and anyway it's an ancient behavior that we've had few complaints about.
For now I'm just trying to fix the regression from 1f39a1c06.
Per a complaint from Andres Freund. Back-patch into v12 where
1f39a1c06 came in.
Discussion: https://postgr.es/m/20200603201242.ofvm4jztpqytwfye@alap3.anarazel.de
|
|
As it stands, this flag is only set when we've successfully sent a
cancel request, not if we get SIGINT and then fail to send a cancel.
However, for almost all callers, that's the Wrong Thing: we'd prefer
to abort processing after control-C even if no cancel could be sent.
As an example, since commit 1d468b9ad "pgbench -i" fails to give up
sending COPY data even after control-C, if the postmaster has been
stopped, which is clearly not what the code intends and not what anyone
would want. (The fact that it keeps going at all is the fault of a
separate bug in libpq, but not letting CancelRequested become set is
clearly not what we want here.)
The sole exception, as far as I can find, is that scripts_parallel.c's
ParallelSlotsGetIdle tries to consume a query result after issuing a
cancel, which of course might not terminate quickly if no cancel
happened. But that behavior was poorly thought out too. No user of
ParallelSlotsGetIdle tries to continue processing after a cancel,
so there is really no point in trying to clear the connection's state.
Moreover this has the same defect as for other users of cancel.c,
that if the cancel request fails for some reason then we end up with
control-C being completely ignored. (On top of that, select_loop failed
to distinguish clearly between SIGINT and other reasons for select(2)
failing, which means that it's possible that the existing code would
think that a cancel has been sent when it hasn't.)
Hence, redefine CancelRequested as simply meaning that SIGINT was
received. We could add a second flag with the other meaning, but
in the absence of any compelling argument why such a flag is needed,
I think it would just offer an opportunity for future callers to
get it wrong. Also remove the consumeQueryResult call in
ParallelSlotsGetIdle's failure exit. In passing, simplify the
API of select_loop.
It would now be possible to re-unify psql's cancel_pressed with
CancelRequested, partly undoing 5d43c3c54. But I'm not really
convinced that that's worth the trouble, so I left psql alone,
other than fixing a misleading comment.
This code is new in v13 (cf a4fd3aa71), so no need for back-patch.
Per investigation of a complaint from Andres Freund.
Discussion: https://postgr.es/m/20200603201242.ofvm4jztpqytwfye@alap3.anarazel.de
|
|
Commit 24d85952 made a change that indirectly caused a performance
regression by triggering a change in the way GCC optimizes memcpy() on
some platforms.
The behavior seemed to contradict a GCC document, so I filed a report:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95556
This patch implements a narrow workaround which eliminates the
regression I observed. The workaround is benign enough that it seems
unlikely to cause a different regression on another platform.
Discussion: https://postgr.es/m/99b2eab335c1592c925d8143979c8e9e81e1575f.camel@j-davis.com
|
|
|
|
Two parts of the same message shouldn't be split across two function
calls.
|
|
|
|
|
|
|
|
Back-patch to 9.5, where commit 4f700bcd20c087f60346cb8aefd0e269be8e2157
first appeared.
Reviewed by Tom Lane. Reported by Andrew Dunstan.
Discussion: https://postgr.es/m/4dfabec2-a3ad-0546-2d62-f816c97edd0c@2ndQuadrant.com
|
|
ineq_histogram_selectivity() can be invoked in situations where the
ordering we care about is not that of the column's histogram. We could
be considering some other collation, or even more drastically, the
query operator might not agree at all with what was used to construct
the histogram. (We'll get here for anything using scalarineqsel-based
estimators, so that's quite likely to happen for extension operators.)
Up to now we just ignored this issue and assumed we were dealing with
an operator/collation whose sort order exactly matches the histogram,
possibly resulting in junk estimates if the binary search gets confused.
It's past time to improve that, since the use of nondefault collations
is increasing. What we can do is verify that the given operator and
collation match what's recorded in pg_statistic, and use the existing
code only if so. When they don't match, instead execute the operator
against each histogram entry, and take the fraction of successes as our
selectivity estimate. This gives an estimate that is probably good to
about 1/histogram_size, with no assumptions about ordering. (The quality
of the estimate is likely to degrade near the ends of the value range,
since the two orderings probably don't agree on what is an extremal value;
but this is surely going to be more reliable than what we did before.)
At some point we might further improve matters by storing more than one
histogram calculated according to different orderings. But this code
would still be good fallback logic when no matches exist, so that is
not an argument for not doing this.
While here, also improve get_variable_range() to deal more honestly
with non-default collations.
This isn't back-patchable, because it requires adding another argument
to ineq_histogram_selectivity, and because it might have significant
impact on the estimation results for extension operators relying on
scalarineqsel --- mostly for the better, one hopes, but in any case
destabilizing plan choices in back branches is best avoided.
Per investigation of a report from James Lucas.
Discussion: https://postgr.es/m/CAAFmbbOvfi=wMM=3qRsPunBSLb8BFREno2oOzSBS=mzfLPKABw@mail.gmail.com
|
