Previously the duplicated paragraphs were used next to each other
in the document to demonstrate that the changes in the stream
were not consumed by pg_logical_slot_peek_changes function.
But some users misunderstood that the duplication of the same
paragraph was just typo. So this commit rewords the sentence in
the latter paragraph for less confusing.
Christoph Moench-Tegeder
The documentation of ALTER TABLESPACE ... MOVE was added without any
markup, not even paragraph breaks. Fix that, and clarify the text in a
few places.
findDependencyLoops() was not bright about cases where there are multiple
dependency paths between the same two dumpable objects. In most scenarios
this did not hurt us too badly; but since the introduction of section
boundary pseudo-objects in commit a1ef01fe16,
it was possible for this code to take unreasonable amounts of time (tens
of seconds on a database with a couple thousand objects), as reported in
bug #11033 from Joe Van Dyk. Joe's particular problem scenario involved
"pg_dump -a" mode with long chains of foreign key constraints, but I think
that similar problems could arise with other situations as long as there
were enough objects. To fix, add a flag array that lets us notice when we
arrive at the same object again while searching from a given start object.
This simple change seems to be enough to eliminate the performance problem.
Back-patch to 9.1, like the patch that introduced section boundary objects.
This return code is possible wherever we pass bAlertable = TRUE; it
arises when Windows caused the current thread to run an "I/O completion
routine" or an "asynchronous procedure call". PostgreSQL does not
provoke either of those Windows facilities, hence this bug remaining
largely unnoticed, but other local code might do so. Due to a shortage
of complaints, no back-patch for now.
Per report from Shiv Shivaraju Gowda, this bug can cause
PGSemaphoreLock() to PANIC. The bug can also cause select() to report
timeout expiration too early, which might confuse pgstat_init() and
CheckRADIUSAuth().
shm_mq_send_bytes didn't invariably initialize *bytes_written before
returning, which would cause shm_mq_send to read from uninitialized
memory and add the value it found there to mqh->mqh_partial_bytes.
This could cause the next attempt to send a message via the queue to
fail an assertion (if the queue was detached) or copy data from a
garbage pointer value into the queue (if non-blocking mode was in use).
Nothing in the checkpointer calls InitXLOGAccess(), so WALInsertLocks
never got initialized there. Without EXEC_BACKEND, it works anyway
because the correct value is inherited from the postmaster, but
with EXEC_BACKEND we've got a problem. The problem appears to have
been introduced by commit 68a2e52bba.
To fix, move the relevant initialization steps from InitXLOGAccess()
to XLOGShmemInit(), making this more parallel to what we do
elsewhere.
Amit Kapila
Ephemeral slots - slots that shouldn't survive database restarts -
weren't properly cleaned up after a immediate/crash restart. They were
ignored in the sense that they weren't restored into memory and thus
didn't cause unwanted resource retention; but they prevented a new
slot with the same name from being created.
Now ephemeral slots are fully removed during startup.
Backpatch to 9.4 where replication slots where added.
The syntax summary previously failed to clarify that the first
argument is also optional. The textual description did mention it,
but all the way at the bottom. It fits better with the command
overview, so move it there, and fix the summary also.
Dilip Kumar, reviewed by Fabien Coelho
The problem is that pg_receivexlog calls select(2) with timeout=0 and
goes into busy loop when --status-interval option is set to 0. This bug
was introduced by the commit,
74cbe966fe.
Per report from Sawada Masahiko
Break the list of available options into an <itemizedlist> instead of
inline sentences. This is mostly motivated by wanting to ensure that the
cross-references to the FSM and VM docs don't cross page boundaries in PDF
format; but it seems to me to read more easily this way anyway. I took the
liberty of editorializing a bit further while at it.
Per complaint from Magnus about 9.0.18 docs not building in A4 format.
Patch all active branches so we don't get blind-sided by this particular
issue again in future.
This is consistent with the POSIX verdict that kill() shall not report
ESRCH for a zombie process. Back-patch to 9.0 (all supported versions).
Test code from commit d7cdf6ee36 depends
on it, and log messages about kill() reporting "Invalid argument" will
cease to appear for this not-unexpected condition.
The executor has thrown errors for negative OFFSET values since 8.4 (see
commit bfce56eea4), but in a moment of brain
fade I taught the planner that OFFSET with a constant negative value was a
no-op (commit 1a1832eb08). Reinstate the
former behavior by only discarding OFFSET with a value of exactly 0. In
passing, adjust a planner comment that referenced the ancient behavior.
Back-patch to 9.3 where the mistake was introduced.
get_raw_page tried to validate the supplied block number against
RelationGetNumberOfBlocks(), which of course is only right when
accessing the main fork. In most cases, the main fork is longer
than the others, so that the check was too weak (allowing a
lower-level error to be reported, but no real harm to be done).
However, very small tables could have an FSM larger than their heap,
in which case the mistake prevented access to some FSM pages.
Per report from Torsten Foertsch.
In passing, make the bad-block-number error into an ereport not elog
(since it's certainly not an internal error); and fix sloppily
maintained comment for RelationGetNumberOfBlocksInFork.
This has been wrong since we invented relation forks, so back-patch
to all supported branches.
With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, PostgreSQL
backends can crash at exit. Raise a warning during "configure" based on
the compile-time OpenLDAP version number, and test the crash scenario in
the dblink test suite. Back-patch to 9.0 (all supported versions).
Unset environment variables that control message language, so that we
can compare some program output with expected strings. This is very
similar to what pg_regress does.
In commit 631dc390f4, we started to handle
simple numeric timezone offsets via the zic library instead of the old
CTimeZone/HasCTZSet kluge. However, we overlooked the fact that the zic
code will reject UTC offsets exceeding a week (which seems a bit arbitrary,
but not because it's too tight ...). This led to possibly setting
session_timezone to NULL, which results in crashes in most timezone-related
operations as of 9.4, and crashes in a small number of places even before
that. So check for NULL return from pg_tzset_offset() and report an
appropriate error message. Per bug #11014 from Duncan Gillis.
Back-patch to all supported branches, like the previous patch.
(Unfortunately, as of today that no longer includes 8.4.)
In commit a61daa14d5, we fixed pg_upgrade so
that it would install sane relminmxid and datminmxid values, but that does
not cure the problem for installations that were already pg_upgraded to
9.3; they'll initially have "1" in those fields. This is not a big problem
so long as 1 is "in the past" compared to the current nextMultiXact
counter. But if an installation were more than halfway to the MXID wrap
point at the time of upgrade, 1 would appear to be "in the future" and
that would effectively disable tracking of oldest MXIDs in those
tables/databases, until such time as the counter wrapped around.
While in itself this isn't worse than the situation pre-9.3, where we did
not manage MXID wraparound risk at all, the consequences of premature
truncation of pg_multixact are worse now; so we ought to make some effort
to cope with this. We discussed advising users to fix the tracking values
manually, but that seems both very tedious and very error-prone.
Instead, this patch adopts two amelioration rules. First, a relminmxid
value that is "in the future" is allowed to be overwritten with a
full-table VACUUM's actual freeze cutoff, ignoring the normal rule that
relminmxid should never go backwards. (This essentially assumes that we
have enough defenses in place that wraparound can never occur anymore,
and thus that a value "in the future" must be corrupt.) Second, if we see
any "in the future" values then we refrain from truncating pg_clog and
pg_multixact. This prevents loss of clog data until we have cleaned up
all the broken tracking data. In the worst case that could result in
considerable clog bloat, but in practice we expect that relfrozenxid-driven
freezing will happen soon enough to fix the problem before clog bloat
becomes intolerable. (Users could do manual VACUUM FREEZEs if not.)
Note that this mechanism cannot save us if there are already-wrapped or
already-truncated-away MXIDs in the table; it's only capable of dealing
with corrupt tracking values. But that's the situation we have with the
pg_upgrade bug.
For consistency, apply the same rules to relfrozenxid/datfrozenxid. There
are not known mechanisms for these to get messed up, but if they were, the
same tactics seem appropriate for fixing them.
As usual, the release notes for older branches will be made by cutting
these down, but put them up for community review first.
Note: a few of these items actually don't apply to 9.3, but only to older
branches. I'll sort that out when copying the text into the older
release-X.Y.sgml files.
When a view has a function-returning-composite in FROM, and there are
some dropped columns in the underlying composite type, ruleutils.c
printed junk in the column alias list for the reconstructed FROM entry.
Before 9.3, this was prevented by doing get_rte_attribute_is_dropped
tests while printing the column alias list; but that solution is not
currently available to us for reasons I'll explain below. Instead,
check for empty-string entries in the alias list, which can only exist
if that column position had been dropped at the time the view was made.
(The parser fills in empty strings to preserve the invariant that the
aliases correspond to physical column positions.)
While this is sufficient to handle the case of columns dropped before
the view was made, we have still got issues with columns dropped after
the view was made. In particular, the view could contain Vars that
explicitly reference such columns! The dependency machinery really
ought to refuse the column drop attempt in such cases, as it would do
when trying to drop a table column that's explicitly referenced in
views. However, we currently neglect to store dependencies on columns
of composite types, and fixing that is likely to be too big to be
back-patchable (not to mention that existing views in existing databases
would not have the needed pg_depend entries anyway). So I'll leave that
for a separate patch.
Pre-9.3, ruleutils would print such Vars normally (with their original
column names) even though it suppressed their entries in the RTE's
column alias list. This is certainly bogus, since the printed view
definition would fail to reload, but at least it didn't crash. However,
as of 9.3 the printed column alias list is tightly tied to the names
printed for Vars; so we can't treat columns as dropped for one purpose
and not dropped for the other. This is why we can't just put back the
get_rte_attribute_is_dropped test: it results in an assertion failure
if the view in fact contains any Vars referencing the dropped column.
Once we've got dependencies preventing such cases, we'll probably want
to do it that way instead of relying on the empty-string test used here.
This fix turned up a very ancient bug in outfuncs/readfuncs, namely
that T_String nodes containing empty strings were not dumped/reloaded
correctly: the node was printed as "<>" which is read as a string
value of <>. Since (per SQL) we disallow empty-string identifiers,
such nodes don't occur normally, which is why we'd not noticed.
(Such nodes aren't used for literal constants, just identifiers.)
Per report from Marc Schablewski. Back-patch to 9.3 which is where
the rule printing behavior changed. The dangling-variable case is
broken all the way back, but that's not what his complaint is about.
~/.pgpass is a sound choice everywhere, and "peer" authentication is
safe on every platform it supports. Cease to recommend "trust"
authentication, the safety of which is deeply configuration-specific.
Back-patch to 9.0, where pg_upgrade was introduced.
If pg_regcomp failed after having invoked markst/cleanst, it would leak any
"struct subre" nodes it had created. (We've already detected all regex
syntax errors at that point, so the only likely causes of later failure
would be query cancel or out-of-memory.) To fix, make sure freesrnode
knows the difference between the pre-cleanst and post-cleanst cleanup
procedures. Add some documentation of this less-than-obvious point.
Also, newlacon did the wrong thing with an out-of-memory failure from
realloc(), so that the previously allocated array would be leaked.
Both of these are pretty low-probability scenarios, but a bug is a bug,
so patch all the way back.
Per bug #10976 from Arthur O'Dwyer.
pg_ctl will log to the Windows event log when it is running as a service,
which is the primary way of running PostgreSQL on Windows. This option
makes it possible to specify which event source to use for this, in order
to separate different instances. The server logging itself is still controlled
by the regular logging parameters, including a separate setting for the event
source. The parameter to pg_ctl only controlls the logging from pg_ctl itself.
MauMau, review in many iterations by Amit Kapila and me.
The consistent function contained several bugs:
* The "if (which2) { ... }" block was broken. It compared the argument's
lower bound against centroid's upper bound, while it was supposed to compare
the argument's upper bound against the centroid's lower bound (the comment
was correct, code was wrong). Also, it cleared bits in the "which1"
variable, while it was supposed to clear bits in "which2".
* If the argument's upper bound was equal to the centroid's lower bound, we
descended to both halves (= all quadrants). That's unnecessary, searching
the right quadrants is sufficient. This didn't lead to incorrect query
results, but was clearly wrong, and slowed down queries unnecessarily.
* In the case that argument's lower bound is adjacent to the centroid's
upper bound, we also don't need to visit all quadrants. Per similar
reasoning as previous point.
* The code where we compare the previous centroid with the current centroid
should match the code where we compare the current centroid with the
argument. The point of that code is to redo the calculation done in the
previous level, to see if we were supposed to traverse left or right (or up
or down), and if we actually did. If we moved in the different direction,
then we know there are no matches for bound.
Refactor the code and adds comments to make it more readable and easier to
reason about.
Backpatch to 9.3 where SP-GiST support for range types was introduced.
We can remove a left join to a relation if the relation's output is
provably distinct for the columns involved in the join clause (considering
only equijoin clauses) and the relation supplies no variables needed above
the join. Previously, the join removal logic could only prove distinctness
by reference to unique indexes of a table. This patch extends the logic
to consider subquery relations, wherein distinctness might be proven by
reference to GROUP BY, DISTINCT, etc.
We actually already had some code to check that a subquery's output was
provably distinct, but it was hidden inside pathnode.c; which was a pretty
bad place for it really, since that file is mostly boilerplate Path
construction and comparison. Move that code to analyzejoins.c, which is
arguably a more appropriate location, and is certainly the site of the
new usage for it.
David Rowley, reviewed by Simon Riggs
Trying to reassign objects owned by a user that had text search
dictionaries or configurations used to fail with:
ERROR: unexpected classid 3600
or
ERROR: unexpected classid 3602
Fix by adding cases for those object types in a switch in pg_shdepend.c.
Both REASSIGN OWNED and text search objects go back all the way to 8.1,
so backpatch to all supported branches. In 9.3 the alter-owner code was
made generic, so the required change in recent branches is pretty
simple; however, for 9.2 and older ones we need some additional
reshuffling to enable specifying objects by OID rather than name.
Text search templates and parsers are not owned objects, so there's no
change required for them.
Per bug #9749 reported by Michal Novotný
Apparently we still build against OpenSSL so old that it doesn't
have this function, so add an autoconf check for it to make the
buildfarm happy. If the function doesn't exist, always return
that compression is disabled, since presumably the actual
compression functionality is always missing.
For now, hardcode the function as present on MSVC, since we should
hopefully be well beyond those old versions on that platform.
Fujii Masao
Tom Lane
Peter Eisentraut
Noah Misch
Robert Haas
Andres Freund
Andrew Dunstan
Magnus Hagander
Heikki Linnakangas
Alvaro Herrera