On a primary, sets of XLOG_RUNNING_XACTS records are generated on a
periodic basis to allow recovery to build the initial state of
transactions for a hot standby. The set of transaction IDs is created
by scanning all the entries in ProcArray. However it happens that its
logic never counted on the fact that two-phase transactions finishing to
prepare can put ProcArray in a state where there are two entries with
the same transaction ID, one for the initial transaction which gets
cleared when prepare finishes, and a second, dummy, entry to track that
the transaction is still running after prepare finishes. This way
ensures a continuous presence of the transaction so as callers of for
example TransactionIdIsInProgress() are always able to see it as alive.
So, if a XLOG_RUNNING_XACTS takes a standby snapshot while a two-phase
transaction finishes to prepare, the record can finish with duplicated
XIDs, which is a state expected by design. If this record gets applied
on a standby to initial its recovery state, then it would simply fail,
so the odds of facing this failure are very low in practice. It would
be tempting to change the generation of XLOG_RUNNING_XACTS so as
duplicates are removed on the source, but this requires to hold on
ProcArrayLock for longer and this would impact all workloads,
particularly those using heavily two-phase transactions.
XLOG_RUNNING_XACTS is also actually used only to initialize the standby
state at recovery, so instead the solution is taken to discard
duplicates when applying the initial snapshot.
Diagnosed-by: Konstantin Knizhnik
Author: Michael Paquier
Discussion: https://postgr.es/m/0c96b653-4696-d4b4-6b5d-78143175d113@postgrespro.ru
Backpatch-through: 9.3
Set the release date. Do a bunch of copy-editing and markup improvement,
rearrange some stuff into what seemed a more sensible order, move some
things that did not seem to be in the right section.
In the back branches, drop these tables after the regression tests are
done with them. This fixes failures of cross-branch pg_upgrade testing
caused by these types having been removed in v12. We do lose the ability
to test dump/restore behavior with these types in the back branches, but
the actual loss of code coverage seems to be nil given that there's nothing
very special about these types.
Discussion: https://postgr.es/m/20181009192237.34wjp3nmw7oynmmr@alap3.anarazel.de
We can allow this macro to accept either abbreviated or non-abbreviated
allocation parameters by making use of __VA_ARGS__. As noted by Andres
Freund, it's unlikely that any compiler would have __builtin_constant_p
but not __VA_ARGS__, so this gives up little or no error checking, and
it avoids a minor but annoying API break for extensions.
With this change, there is no reason for anybody to call
AllocSetContextCreateExtended directly, so in HEAD I renamed it to
AllocSetContextCreateInternal. It's probably too late for an ABI
break like that in 11, though.
Discussion: https://postgr.es/m/20181012170355.bhxi273skjt6sag4@alap3.anarazel.de
There was no code to handle foreign key constraints on partitioned
tables in the case of ALTER TABLE DETACH; and if you happened to ATTACH
a partition that already had an equivalent constraint, that one was
ignored and a new constraint was created. Adding this to the fact that
foreign key cloning reuses the constraint name on the partition instead
of generating a new name (as it probably should, to cater to SQL
standard rules about constraint naming within schemas), the result was a
pretty poor user experience -- the most visible failure was that just
detaching a partition and re-attaching it failed with an error such as
ERROR: duplicate key value violates unique constraint "pg_constraint_conrelid_contypid_conname_index"
DETAIL: Key (conrelid, contypid, conname)=(26702, 0, test_result_asset_id_fkey) already exists.
because it would try to create an identically-named constraint in the
partition. To make matters worse, if you tried to drop the constraint
in the now-independent partition, that would fail because the constraint
was still seen as dependent on the constraint in its former parent
partitioned table:
ERROR: cannot drop inherited constraint "test_result_asset_id_fkey" of relation "test_result_cbsystem_0001_0050_monthly_2018_09"
This fix attacks the problem from two angles: first, when the partition
is detached, the constraint is also marked as independent, so the drop
now works. Second, when the partition is re-attached, we scan existing
constraints searching for one matching the FK in the parent, and if one
exists, we link that one to the parent constraint. So we don't end up
with a duplicate -- and better yet, we don't need to scan the referenced
table to verify that the constraint holds.
To implement this I made a small change to previously planner-only
struct ForeignKeyCacheInfo to contain the constraint OID; also relcache
now maintains the list of FKs for partitioned tables too.
Backpatch to 11.
Reported-by: Michael Vitale (bug #15425)
Discussion: https://postgr.es/m/15425-2dbc9d2aa999f816@postgresql.org
Repeatedly rewriting a mapped catalog table with VACUUM FULL or
CLUSTER could cause logical decoding to fail with:
ERROR, "could not map filenode \"%s\" to relation OID"
To trigger the problem the rewritten catalog had to have live tuples
with toasted columns.
The problem was triggered as during catalog table rewrites the
heap_insert() check that prevents logical decoding information to be
emitted for system catalogs, failed to treat the new heap's toast table
as a system catalog (because the new heap is not recognized as a
catalog table via RelationIsLogicallyLogged()). The relmapper, in
contrast to the normal catalog contents, does not contain historical
information. After a single rewrite of a mapped table the new relation
is known to the relmapper, but if the table is rewritten twice before
logical decoding occurs, the relfilenode cannot be mapped to a
relation anymore. Which then leads us to error out. This only
happens for toast tables, because the main table contents aren't
re-inserted with heap_insert().
The fix is simple, add a new heap_insert() flag that prevents logical
decoding information from being emitted, and accept during decoding
that there might not be tuple data for toast tables.
Unfortunately that does not fix pre-existing logical decoding
errors. Doing so would require not throwing an error when a filenode
cannot be mapped to a relation during decoding, and that seems too
likely to hide bugs. If it's crucial to fix decoding for an existing
slot, temporarily changing the ERROR in ReorderBufferCommit() to a
WARNING appears to be the best fix.
Author: Andres Freund
Discussion: https://postgr.es/m/20180914021046.oi7dm4ra3ot2g2kt@alap3.anarazel.de
Backpatch: 9.4-, where logical decoding was introduced
gcc 6.3 does not whine about this mistake I made in 39808e8868 but
evidently lots of other compilers do, according to Michael Paquier,
Peter Eisentraut, Arthur Zakirov, Tomas Vondra.
Discussion: too many to list
Error messages for creating a foreign key on a partitioned table using
ONLY or NOT VALID were wrong in mentioning the objects they worked on.
This commit adds on the way some regression tests missing for those
cases.
Author: Laurenz Albe
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/c11c05810a9ed65e9b2c817a9ef442275a32fe80.camel@cybertec.at
Commit 2fbdf1b38b changed the order in which we inserted catalog rows
when creating partitions, so that we could remove an unsightly hack
required for untimely relcache invalidations. However, that commit only
changed the ordering for CREATE TABLE PARTITION OF, and left ALTER TABLE
ATTACH PARTITION unchanged, so the latter can be affected when catalog
invalidations occur, for instance when the partition key involves an SQL
function.
Reported-by: Rajkumar Raghuwanshi
Author: Amit Langote
Reviewed-by: Michaël Paquier
Discussion: https://postgr.es/m/CAKcux6=nTz9KSfTr_6Z2mpzLJ_09JN-rK6=dWic6gGyTSWueyQ@mail.gmail.com
Index DDL cascading on partitioned tables introduced a way for ALTER
TABLE to be called reentrantly. This caused an an important deficiency
in event trigger support to be exposed: on exiting the reentrant call,
the alter table state object was clobbered, causing a crash when the
outer alter table tries to finalize its processing. Fix the crash by
creating a stack of event trigger state objects. There are still ways
to cause things to misbehave (and probably other crashers) with more
elaborate tricks, but at least it now doesn't crash in the obvious
scenario.
Backpatch to 9.5, where DDL deparsing of event triggers was introduced.
Reported-by: Marco Slot
Authors: Michaël Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/CANNhMLCpi+HQ7M36uPfGbJZEQLyTy7XvX=5EFkpR-b1bo0uJew@mail.gmail.com
Previously, a worker process would establish values for these based on
its own start time. In v10 and up, this can trivially be shown to cause
misbehavior of transaction_timestamp(), timestamp_in(), and related
functions which are (perhaps unwisely?) marked parallel-safe. It seems
likely that other behaviors might diverge from what happens in the parent
as well.
It's not as trivial to demonstrate problems in 9.6 or 9.5, but I'm sure
it's still possible, so back-patch to all branches containing parallel
worker infrastructure.
In HEAD only, mark now() and statement_timestamp() as parallel-safe
(other affected functions already were). While in theory we could
still squeeze that change into v11, it doesn't seem important enough
to force a last-minute catversion bump.
Konstantin Knizhnik, whacked around a bit by me
Discussion: https://postgr.es/m/6406dbd2-5d37-4cb6-6eb2-9c44172c7e7c@postgrespro.ru
This is for example used when attaching a partition to a partitioned
table which includes foreign keys, and in this case the constraint name
has been missing in the data cloned. This could lead to hard crashes,
as when validating the foreign key constraint, the constraint name is
always expected. Particularly, when using log_min_messages >= DEBUG1, a
log message would be generated with this unassigned constraint name,
leading to an assertion failure on HEAD.
While on it, rename a variable in ATExecAttachPartition which was
declared twice with the same name.
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20181005042236.GG1629@paquier.xyz
Backpatch-through: 11
Historically we forbade datatype-specific comparison functions from
returning INT_MIN, so that it would be safe to invert the sort order
just by negating the comparison result. However, this was never
really safe for comparison functions that directly return the result
of memcmp(), strcmp(), etc, as POSIX doesn't place any such restriction
on those library functions. Buildfarm results show that at least on
recent Linux on s390x, memcmp() actually does return INT_MIN sometimes,
causing sort failures.
The agreed-on answer is to remove this restriction and fix relevant
call sites to not make such an assumption; code such as "res = -res"
should be replaced by "INVERT_COMPARE_RESULT(res)". The same is needed
in a few places that just directly negated the result of memcmp or
strcmp.
To help find places having this problem, I've also added a compile option
to nbtcompare.c that causes some of the commonly used comparators to
return INT_MIN/INT_MAX instead of their usual -1/+1. It'd likely be
a good idea to have at least one buildfarm member running with
"-DSTRESS_SORT_INT_MIN". That's far from a complete test of course,
but it should help to prevent fresh introductions of such bugs.
This is a longstanding portability hazard, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/20180928185215.ffoq2xrq5d3pafna@alap3.anarazel.de
I (Andres) was more than a bit hasty in committing 33001fd7a7
after last minute changes, leading to a number of problems (jit output
was only shown for JIT in parallel workers, and just EXPLAIN without
ANALYZE didn't work). Lukas luckily found these issues quickly.
Instead of combining instrumentation in in standard_ExecutorEnd(), do
so on demand in the new ExplainPrintJITSummary().
Also update a documentation example of the JIT output, changed in
52050ad8eb.
Author: Lukas Fittl, with minor changes by me
Discussion: https://postgr.es/m/CAP53PkxmgJht69pabxBXJBM+0oc6kf3KHMborLP7H2ouJ0CCtQ@mail.gmail.com
Backpatch: 11, where JIT compilation was introduced
The API (EOH_flatten_into) that flattens the expanded value representation
expects the target address to be maxaligned. All it's usage adhere to that
principle except when serializing datums for parallel query. Fix that
usage.
Diagnosed-by: Tom Lane
Author: Tom Lane and Amit Kapila
Backpatch-through: 9.6
Discussion: https://postgr.es/m/11629.1536550032@sss.pgh.pa.us
Previously, we used the platform's NL_ARGMAX if any, otherwise 16.
The trouble with this is that the platform value is hugely variable,
ranging from the POSIX-minimum 9 to as much as 64K on recent FreeBSD.
Values of more than a dozen or two have no practical use and slow down
the initialization of the argtypes array. Worse, they cause snprintf.c
to consume far more stack space than was the design intention, possibly
resulting in stack-overflow crashes.
Standardize on 31, which is comfortably more than we need (it looks like
no existing translatable message has more than about 10 parameters).
I chose that, not 32, to make the array sizes powers of 2, for some
possible small gain in speed of the memset.
The lack of reported crashes suggests that the set of platforms we
use snprintf.c on (in released branches) may have no overlap with
the set where NL_ARGMAX has unreasonably large values. But that's
not entirely clear, so back-patch to all supported branches.
Per report from Mateusz Guzik (via Thomas Munro).
Discussion: https://postgr.es/m/CAEepm=3VF=PUp2f8gU8fgZB22yPE_KBS0+e1AHAtQ=09schTHg@mail.gmail.com
The variants of these functions that take numeric inputs (OIDs or
column numbers) are supposed to return NULL rather than failing
on bad input; this rule reduces problems with snapshot skew when
queries apply the functions to all rows of a catalog.
has_column_privilege() had careless handling of the case where the
table OID didn't exist. You might get something like this:
select has_column_privilege(9999,'nosuchcol','select');
ERROR: column "nosuchcol" of relation "(null)" does not exist
or you might get a crash, depending on the platform's printf's response
to a null string pointer.
In addition, while applying the column-number variant to a dropped
column returned NULL as desired, applying the column-name variant
did not:
select has_column_privilege('mytable','........pg.dropped.2........','select');
ERROR: column "........pg.dropped.2........" of relation "mytable" does not exist
It seems better to make this case return NULL as well.
Also, the OID-accepting variants of has_foreign_data_wrapper_privilege,
has_server_privilege, and has_tablespace_privilege didn't follow the
principle of returning NULL for nonexistent OIDs. Superusers got TRUE,
everybody else got an error.
Per investigation of Jaime Casanova's report of a new crash in HEAD.
These behaviors have been like this for a long time, so back-patch to
all supported branches.
Patch by me; thanks to Stephen Frost for discussion and review
Discussion: https://postgr.es/m/CAJGNTeP=-6Gyqq5TN9OvYEydi7Fv1oGyYj650LGTnW44oAzYCg@mail.gmail.com
This was claimed to have been done in
0a63f996e0, but that actually only
changed the documentation and not the grammar. (That commit did fully
change it for CREATE TRIGGER.)
contrib/pageinspect's tuple_data_split() function thought it could get
away with opening the referenced relation with NoLock. In practice
there's no guarantee that the current session holds any lock on that
rel (even if we just read a page from it), so that this is unsafe.
Switch to using AccessShareLock. Also, postpone closing the relation,
so that we needn't copy its tupdesc. Also, fix unsafe use of
att_isnull() for attributes past the end of the tuple.
Per testing with a patch that complains if we open a relation without
holding any lock on it. I don't plan to back-patch that patch, but we
should close the holes it identifies in all supported branches.
Discussion: https://postgr.es/m/2038.1538335244@sss.pgh.pa.us
If the column being modified is referenced by a foreign key constraint
of another table, ALTER TABLE would open the other table (to re-parse
the constraint's definition) without having first obtained a lock on it.
This was evidently intentional, but that doesn't mean it's really safe.
It's especially not safe in 9.3, which pre-dates use of MVCC scans for
catalog reads, but even in current releases it doesn't seem like a good
idea.
We know we'll need AccessExclusiveLock shortly to drop the obsoleted
constraint, so just get that a little sooner to close the hole.
Per testing with a patch that complains if we open a relation without
holding any lock on it. I don't plan to back-patch that patch, but we
should close the holes it identifies in all supported branches.
Discussion: https://postgr.es/m/2038.1538335244@sss.pgh.pa.us
The method we've traditionally used, of redeclaring strerror_r() to
see if the compiler complains of inconsistent declarations, turns out
not to work reliably because some compilers only report a warning,
not an error. Amazingly, this has gone undetected for years, even
though it certainly breaks our detection of whether strerror_r
succeeded.
Let's instead test whether the compiler will take the result of
strerror_r() as a switch() argument. It's possible this won't
work universally either, but it's the best idea I could come up with
on the spur of the moment.
Back-patch of commit 751f532b9. Buildfarm results indicate that only
icc-on-Linux actually has an issue here; perhaps the lack of field
reports indicates that people don't build PG for production that way.
Discussion: https://postgr.es/m/10877.1537993279@sss.pgh.pa.us
When the checkpointer receives a SIGHUP signal to update its configuration,
it may need to update the shared memory for full_page_writes and need to
write a WAL record for it. Now, it is quite possible that the XLOG
machinery has not been initialized by that time and it will lead to
assertion failure while doing that. Fix is to allow the initialization of
the XLOG machinery outside critical section.
This bug has been introduced by the commit 2c03216d83 which added the XLOG
machinery initialization in RecoveryInProgress code path.
Reported-by: Dilip Kumar
Author: Dilip Kumar
Reviewed-by: Michael Paquier and Amit Kapila
Backpatch-through: 9.5
Discussion: https://postgr.es/m/CAFiTN-u4BA8KXcQUWDPNgaKAjDXC=C2whnzBM8TAcv=stckYUw@mail.gmail.com
A restart point or a checkpoint recycling WAL segments treats segments
marked with neither ".done" (archiving is done) or ".ready" (segment is
ready to be archived) in archive_status the same way for archive_mode
being "on" or "always". While for a primary this is fine, a standby
running a restart point with archive_mode = on would try to mark such a
segment as ready for archiving, which is something that will never
happen except after the standby is promoted.
Note that this problem applies only to WAL segments coming from the
local pg_wal the first time archive recovery is run. Segments part of a
self-contained base backup are the most common case where this could
happen, however even in this case normally the .done markers would be
most likely part of the backup. Segments recovered from an archive are
marked as .ready or .done by the startup process, and segments finished
streaming are marked as such by the WAL receiver, so they are handled
already.
Reported-by: Haruka Takatsuka
Author: Michael Paquier
Discussion: https://postgr.es/m/15402-a453c90ed4cf88b2@postgresql.org
Backpatch-through: 9.5, where archive_mode = always has been added.
It failed if passed a nonexistent relation OID, or one that was a non-heap
relation, because of blindly applying heap_open to a user-supplied OID.
This is not OK behavior for a SQL-exposed function; we have a project
policy that we should return NULL in such cases. Moreover, since
pg_get_partition_constraintdef ought now to work on indexes, restricting
it to heaps is flat wrong anyway.
The underlying function generate_partition_qual() wasn't on board with
indexes having partition quals either, nor for that matter with rels
having relispartition set but yet null relpartbound. (One wonders
whether the person who wrote the function comment blocks claiming that
these functions allow a missing relpartbound had ever tested it.)
Fix by testing relispartition before opening the rel, and by using
relation_open not heap_open. (If any other relkinds ever grow the
ability to have relispartition set, the code will work with them
automatically.) Also, don't reject null relpartbound in
generate_partition_qual.
Back-patch to v11, and all but the null-relpartbound change to v10.
(It's not really necessary to change generate_partition_qual at all
in v10, but I thought s/heap_open/relation_open/ would be a good
idea anyway just to keep the code in sync with later branches.)
Per report from Justin Pryzby.
Discussion: https://postgr.es/m/20180927200020.GJ776@telsasoft.com
When a table ownership is changed, we must apply that also to any owned
sequences. (Otherwise, it would result in a situation that cannot be
restored, because linked sequences must have the same owner as the
table.) But this was previously only applied to regular tables and
materialized views. But it should also apply to at least foreign
tables. This patch removes the relkind check altogether, because it
doesn't save very much and just introduces the possibility of similar
omissions.
Bug: #15238
Reported-by: Christoph Berg <christoph.berg@credativ.de>
The activation and deactivation of commit timestamp tracking has not
been handled consistently for a primary or standbys at recovery. The
facility can be activated at three different moments of recovery:
- The beginning, where a primary would use the GUC value for the
decision-making, and where a standby relies on the contents of the
control file.
- When replaying a XLOG_PARAMETER_CHANGE record at redo.
- The end, where both primary and standby rely on the GUC value.
Using the GUC value for a primary at the beginning of recovery causes
problems with commit timestamp access when doing crash recovery.
Particularly, when replaying transaction commits, it could be possible
that an attempt to read commit timestamps is done for a transaction
which committed at a moment when track_commit_timestamp was disabled.
A test case is added to reproduce the failure. The test works down to
v11 as it takes advantage of transaction commits within procedures.
Reported-by: Hailong Li
Author: Masahiko Sawasa, Michael Paquier
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/11224478-a782-203b-1f17-e4797b39bdf0@qunar.com
Backpatch-through: 9.5, where commit timestamps have been introduced.
Previously, when using parallel query, EXPLAIN (ANALYZE)'s JIT
compilation timings did not include the overhead from doing so on the
workers. Fix that.
We do so by simply aggregating the cost of doing JIT compilation on
workers and the leader together. Arguably that's not quite accurate,
because the total time spend doing so is spent in parallel - but it's
hard to do much better. For additional detail, when VERBOSE is
specified, the stats for workers are displayed separately.
Author: Amit Khandekar and Andres Freund
Discussion: https://postgr.es/m/CAJ3gD9eLrz51RK_gTkod+71iDcjpB_N8eC6vU2AW-VicsAERpQ@mail.gmail.com
Backpatch: 11-
Apple's latest rearrangements of the system-supplied headers have broken
building of PL/Perl and PL/Tcl. The only practical way to fix PL/Tcl is to
start using the "-isysroot" compiler flag to point to SDK-supplied headers,
as Apple expects. We must also start distinguishing where to find Perl's
headers from where to find its shared library; but that seems like good
cleanup anyway.
Extensions that formerly did something like -I$(perl_archlibexp)/CORE
should now do -I$(perl_includedir)/CORE instead. perl_archlibexp
is still the place to look for libperl.so, though.
If for some reason you don't like the default -isysroot setting, you can
override that by setting PG_SYSROOT in configure's arguments. I don't
currently think people would need to do so, unless maybe for cross-version
build purposes.
In addition, teach configure where to find tclConfig.sh. Our traditional
method of searching $auto_path hasn't worked for the last couple of macOS
releases, and it now seems clear that Apple's not going to change that.
The workaround of manually specifying --with-tclconfig was annoying
already, but Mojave's made it a lot more so because the sysroot path now
has to be included as well. Let's just wire the knowledge into configure
instead. To avoid breaking builds against non-default Tcl installations
(e.g. MacPorts) wherein the $auto_path method probably still works,
arrange to try the additional case only after all else has failed.
Back-patch to all supported versions, since at least the buildfarm
cares about that. The changes are set up to not do anything on macOS
releases that are old enough to not have functional sysroot trees.
96e1cb4 has added support for --no-publications in pg_dump, pg_dumpall
and pg_restore, but forgot the fact that publication tables also need to
be ignored when this option is used.
Author: Gilles Darold
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/3f48e812-b0fa-388e-2043-9a176bdee27e@dalibo.com
Backpatch-through: 10, where publications have been added.
Commit 25fff40 has granted execute permission of the function
pg_stat_statements_reset() to default role "pg_read_all_stats", but this
role is meant to read statistics, and not to reset them. The
permissions on this function are revoked from "pg_read_all_stats". The
version of pg_stat_statements is bumped up in consequence.
Author: Haribabu Kommi
Reviewed-by: Michael Paquier, Amit Kapila
Discussion: https://postgr.es/m/CAJrrPGf5fCnKqXObpwGN9nMyD--tzOf-7LFCJiz59Z1wJ5qj9A@mail.gmail.com
A discussion about also reporting JIT compilation overhead on workers
brought unhappiness with the verbosity of the current explain format
to light. Make the text format more dense, and restructure the
structured output to mirror that more closely.
As we're re-jiggering the output format anyway: The denser format
allows us to report all flags for JIT compilation (now also reporting
PGJIT_EXPR and PGJIT_DEFORM), and report the total time in addition to
the individual times.
Per complaint from Tom Lane.
Author: Andres Freund
Discussion: https://postgr.es/m/27812.1537221015@sss.pgh.pa.us
Backpatch: 11-, where JIT compilation was introduced
Ensure that triggers get properly filled in tuples for the OLD value.
Also fix the logic of detecting missing null values. The previous logic
failed to detect a missing null column before the first missing column
with a default. Fixing this has simplified the logic a bit.
Regression tests are added to test changes. This should ensure better
coverage of expand_tuple().
Original bug reports, and some code and test scripts from Tomas Vondra
Backpatch to release 11.
Alexander Korotkov
Michael Paquier
Tom Lane
Greg Stark
Alvaro Herrera
Andres Freund
Peter Eisentraut
Magnus Hagander
Bruce Momjian
Amit Kapila
Andrew Dunstan