Commit Graph

17309 Commits

Author SHA1 Message Date
Andrew Gierth 1add0b15f1 Fix COPY's handling of transition tables with indexes.
Commit c46c0e5202 failed to pass the
TransitionCaptureState object to ExecARInsertTriggers() in the case
where it's using heap_multi_insert and there are indexes.  Repair.

Thomas Munro, from a report by David Fetter
Discussion: https://postgr.es/m/20170708084213.GA14720%40fetter.org
2017-07-10 11:40:08 +01:00
Tom Lane ec4073f641 Avoid unreferenced-function warning on low-functionality platforms.
On platforms lacking both locale_t and ICU, collationcmds.c failed
to make any use of its static function is_all_ascii(), thus probably
drawing a compiler warning.  Oversight in my commit ddb5fdc06.
Per buildfarm member gaur.
2017-07-08 12:42:25 -04:00
Alvaro Herrera 46e9151942 Fix typo
Noticed while reviewing code.
2017-07-07 17:10:36 -04:00
Teodor Sigaev 31b8db8e6c Fix potential data corruption during freeze
Fix oversight in 3b97e6823b bug fix. Bitwise AND is used instead of OR and
it cleans all bits in t_infomask heap tuple field.

Backpatch to 9.3
2017-07-06 17:18:55 +03:00
Dean Rasheed f1dae097f2 Clarify the contract of partition_rbound_cmp().
partition_rbound_cmp() is intended to compare range partition bounds
in a way such that if all the bound values are equal but one is an
upper bound and one is a lower bound, the upper bound is treated as
smaller than the lower bound. This particular ordering is required by
RelationBuildPartitionDesc() when building the PartitionBoundInfoData,
so that it can consistently keep only the upper bounds when upper and
lower bounds coincide.

Update the function comment to make that clearer.

Also, fix a (currently unreachable) corner-case bug -- if the bound
values coincide and they contain unbounded values, fall through to the
lower-vs-upper comparison code, rather than immediately returning
0. Currently it is not possible to define coincident upper and lower
bounds containing unbounded columns, but that may change in the
future, so code defensively.

Discussion: https://postgr.es/m/CAAJ_b947mowpLdxL3jo3YLKngRjrq9+Ej4ymduQTfYR+8=YAYQ@mail.gmail.com
2017-07-06 12:46:08 +01:00
Dean Rasheed c03911d945 Simplify the logic checking new range partition bounds.
The previous logic, whilst not actually wrong, was overly complex and
involved doing two binary searches, where only one was really
necessary. This simplifies that logic and improves the comments.

One visible change is that if the new partition overlaps multiple
existing partitions, the error message now always reports the overlap
with the first existing partition (the one with the lowest
bounds). The old code would sometimes report the clash with the first
partition and sometimes with the last one.

Original patch idea from Amit Langote, substantially rewritten by me.

Discussion: https://postgr.es/m/CAAJ_b947mowpLdxL3jo3YLKngRjrq9+Ej4ymduQTfYR+8=YAYQ@mail.gmail.com
2017-07-06 09:58:06 +01:00
Peter Eisentraut d80e73f229 Fix output of char node fields
WRITE_CHAR_FIELD() didn't do any escaping, so that for example a zero
byte would cause the whole output string to be truncated.  To fix, pass
the char through outToken(), so it is escaped like a string.  Adjust the
reading side to handle this.
2017-07-05 10:51:54 -04:00
Peter Eisentraut cb9079cd51 Improve subscription locking
This avoids "tuple concurrently updated" errors when a ALTER or DROP
SUBSCRIPTION writes to pg_subscription_rel at the same time as a worker.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-07-03 22:47:06 -04:00
Heikki Linnakangas b93827c745 Treat clean shutdown of an SSL connection same as the non-SSL case.
If the client closes an SSL connection, treat it the same as EOF on a
non-SSL connection. In particular, don't write a message in the log about
that.

Michael Paquier.

Discussion: https://www.postgresql.org/message-id/CAB7nPqSfyVV42Q2acFo%3DvrvF2gxoZAMJLAPq3S3KkjhZAYi7aw@mail.gmail.com
2017-07-03 14:51:51 +03:00
Peter Eisentraut d8b3c81335 Refine memory allocation in ICU conversions
The simple calculations done to estimate the size of the output buffers
for ucnv_fromUChars() and ucnv_toUChars() could overflow int32_t for
large strings.  To avoid that, go the long way and run the function
first without an output buffer to get the correct output buffer size
requirement.
2017-07-01 23:08:37 -04:00
Tom Lane f32678c016 Reduce delay for last logicalrep feedback message when master goes idle.
The regression tests contain numerous cases where we do some activity on a
master server and then wait till the slave has ack'd flushing its copy of
that transaction.  Because WAL flush on the slave is asynchronous to the
logicalrep worker process, the worker cannot send such a feedback message
during the LogicalRepApplyLoop iteration where it processes the last data
from the master.  In the previous coding, the feedback message would come
out only when the loop's WaitLatchOrSocket call returned WL_TIMEOUT.  That
requires one full second of delay (NAPTIME_PER_CYCLE); and to add insult
to injury, it could take more than that if the WaitLatchOrSocket was
interrupted a few times by latch-setting events.

In reality we can expect the slave's walwriter process to have flushed the
WAL data after, more or less, WalWriterDelay (typically 200ms).  Hence,
if there are unacked transactions pending, make the wait delay only that
long rather than the full NAPTIME_PER_CYCLE.  Also, move one of the
send_feedback() calls into the loop main line, so that we'll check for the
need to send feedback even if we were woken by a latch event and not either
socket data or timeout.

It's not clear how much this matters for production purposes, but
it's definitely helpful for testing.

Discussion: https://postgr.es/m/30864.1498861103@sss.pgh.pa.us
2017-07-01 12:15:51 -04:00
Tom Lane 799f8bc76a Shorten timeouts while waiting for logicalrep worker slot attach/detach.
When waiting for a logical replication worker process to start or stop,
we have to busy-wait until we see it add or remove itself from the
LogicalRepWorker slot in shared memory.  Those loops were using a
one-second delay between checks, but on any reasonably modern machine, it
doesn't take more than a couple of msec for a worker to spawn or shut down.
Reduce the loop delays to 10ms to avoid wasting quite so much time in the
related regression tests.

In principle, a better solution would be to fix things so that the waiting
process can be awakened via its latch at the right time.  But that seems
considerably more invasive, which is undesirable for a post-beta fix.
Worker start/stop performance likely isn't of huge interest anyway for
production purposes, so we might not ever get around to it.

In passing, rearrange the second wait loop in logicalrep_worker_stop()
so that the lock is held at the top of the loop, thus saving one lock
acquisition/release per call, and making it look more like the other loop.

Discussion: https://postgr.es/m/30864.1498861103@sss.pgh.pa.us
2017-07-01 11:59:44 -04:00
Peter Eisentraut ef74e03ef6 Fix UPDATE of GENERATED ALWAYS identity columns
The bug would previously prevent the update of any column in a table
with identity columns, rather than just the actual identity column.

Reported-by: zam6ak@gmail.com
Bug: #14718
2017-06-30 23:44:17 -04:00
Alvaro Herrera 572d6ee6d4 Fix locking in WAL receiver/sender shmem state structs
In WAL receiver and WAL server, some accesses to their corresponding
shared memory control structs were done without holding any kind of
lock, which could lead to inconsistent and possibly insecure results.

In walsender, fix by clarifying the locking rules and following them
correctly, as documented in the new comment in walsender_private.h;
namely that some members can be read in walsender itself without a lock,
because the only writes occur in the same process.  The rest of the
struct requires spinlock for accesses, as usual.

In walreceiver, fix by always holding spinlock while accessing the
struct.

While there is potentially a problem in all branches, it is minor in
stable ones.  This only became a real problem in pg10 because of quorum
commit in synchronous replication (commit 3901fd70cc), and a potential
security problem in walreceiver because a superuser() check was removed
by default monitoring roles (commit 25fff40798).  Thus, no backpatch.

In passing, clean up some leftover braces which were used to create
unconditional blocks.  Once upon a time these were used for
volatile-izing accesses to those shmem structs, which is no longer
required.  Many other occurrences of this pattern remain.

Author: Michaël Paquier
Reported-by: Michaël Paquier
Reviewed-by: Masahiko Sawada, Kyotaro Horiguchi, Thomas Munro,
	Robert Haas
Discussion: https://postgr.es/m/CAB7nPqTWYqtzD=LN_oDaf9r-hAjUEPAy0B9yRkhcsLdRN8fzrw@mail.gmail.com
2017-06-30 18:06:33 -04:00
Peter Eisentraut b295cc3b9a Fix typo in comment
Author: Masahiko Sawada <sawada.mshk@gmail.com>
2017-06-30 15:54:39 -04:00
Tom Lane 1f201a818a Fix race conditions and missed wakeups in syncrep worker signaling.
When a sync worker is waiting for the associated apply worker to notice
that it's in SYNCWAIT state, wait_for_worker_state_change() would just
patiently wait for that to happen.  This generally required waiting for
the 1-second timeout in LogicalRepApplyLoop to elapse.  Kicking the worker
via its latch makes things significantly snappier.

While at it, fix race conditions that could potentially result in crashes:
we can *not* call logicalrep_worker_wakeup_ptr() once we've released the
LogicalRepWorkerLock, because worker->proc might've been reset to NULL
after we do that (indeed, there's no really solid reason to believe that
the LogicalRepWorker slot even belongs to the same worker anymore).
In logicalrep_worker_wakeup(), we can just move the wakeup inside the
lock scope.  In process_syncing_tables_for_apply(), a bit more code
rearrangement is needed.

Also improve some nearby comments.
2017-06-30 14:57:14 -04:00
Peter Eisentraut da8f26ec4e Fix typo in comment
Author: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
2017-06-30 14:48:43 -04:00
Tom Lane 609fa63db6 Check for error during PQendcopy.
Oversight in commit 78c8c8143; noted while nosing around the
walreceiver startup/shutdown code.
2017-06-30 12:22:33 -04:00
Tom Lane fca85f8ef1 Fix walsender to exit promptly if client requests shutdown.
It's possible for WalSndWaitForWal to be asked to wait for WAL that doesn't
exist yet.  That's fine, in fact it's the normal situation if we're caught
up; but when the client requests shutdown we should not keep waiting.
The previous coding could wait indefinitely if the source server was idle.

In passing, improve the rather weak comments in this area, and slightly
rearrange some related code for better readability.

Back-patch to 9.4 where this code was introduced.

Discussion: https://postgr.es/m/14154.1498781234@sss.pgh.pa.us
2017-06-30 12:00:15 -04:00
Peter Eisentraut 13a57710db Prohibit creating ICU collation with different ctype
ICU does not support "collate" and "ctype" being different, so the
collctype catalog column is ignored.  But for catalog neatness, ensure
that they are the same.
2017-06-30 11:24:00 -04:00
Robert Haas 7d4a1838ef Add missing period to comment.
Masahiko Sawada

Discussion: http://postgr.es/m/CAD21AoA0jjXXhqK6Ym3jZNoUdVhXFyTkWTTTsVSr1vPuKcjsjA@mail.gmail.com
2017-06-30 10:01:45 -04:00
Peter Eisentraut 54baa48139 Copy collencoding in CREATE COLLATION / FROM
This command used to compute the collencoding entry like when a
completely new collation is created.  But for example when copying the
"C" collation, this would then result in a collation that has a
collencoding entry for the current database encoding rather than -1,
thus not making an exact copy.  This has probably no practical impact,
but making this change keeps the catalog contents neat.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
2017-06-30 08:50:39 -04:00
Tom Lane f13ea95f9e Change pg_ctl to detect server-ready by watching status in postmaster.pid.
Traditionally, "pg_ctl start -w" has waited for the server to become
ready to accept connections by attempting a connection once per second.
That has the major problem that connection issues (for instance, a
kernel packet filter blocking traffic) can't be reliably told apart
from server startup issues, and the minor problem that if server startup
isn't quick, we accumulate "the database system is starting up" spam
in the server log.  We've hacked around many of the possible connection
issues, but it resulted in ugly and complicated code in pg_ctl.c.

In commit c61559ec3, I changed the probe rate to every tenth of a second.
That prompted Jeff Janes to complain that the log-spam problem had become
much worse.  In the ensuing discussion, Andres Freund pointed out that
we could dispense with connection attempts altogether if the postmaster
were changed to report its status in postmaster.pid, which "pg_ctl start"
already relies on being able to read.  This patch implements that, teaching
postmaster.c to report a status string into the pidfile at the same
state-change points already identified as being of interest for systemd
status reporting (cf commit 7d17e683f).  pg_ctl no longer needs to link
with libpq at all; all its functions now depend on reading server files.

In support of this, teach AddToDataDirLockFile() to allow addition of
postmaster.pid lines in not-necessarily-sequential order.  This is needed
on Windows where the SHMEM_KEY line will never be written at all.  We still
have the restriction that we don't want to truncate the pidfile; document
the reasons for that a bit better.

Also, fix the pg_ctl TAP tests so they'll notice if "start -w" mode
is broken --- before, they'd just wait out the sixty seconds until
the loop gives up, and then report success anyway.  (Yes, I found that
out the hard way.)

While at it, arrange for pg_ctl to not need to #include miscadmin.h;
as a rather low-level backend header, requiring that to be compilable
client-side is pretty dubious.  This requires moving the #define's
associated with the pidfile into a new header file, and moving
PG_BACKEND_VERSIONSTR someplace else.  For lack of a clearly better
"someplace else", I put it into port.h, beside the declaration of
find_other_exec(), since most users of that macro are passing the value to
find_other_exec().  (initdb still depends on miscadmin.h, but at least
pg_ctl and pg_upgrade no longer do.)

In passing, fix main.c so that PG_BACKEND_VERSIONSTR actually defines the
output of "postgres -V", which remarkably it had never done before.

Discussion: https://postgr.es/m/CAMkU=1xJW8e+CTotojOMBd-yzUvD0e_JZu2xHo=MnuZ4__m7Pg@mail.gmail.com
2017-06-28 17:31:32 -04:00
Andrew Gierth 8c55244ae3 Fix transition tables for ON CONFLICT.
We now disallow having triggers with both transition tables and ON
INSERT OR UPDATE (which was a PG extension to the spec anyway),
because in this case it's not at all clear how the transition tables
should work for an INSERT ... ON CONFLICT query.  Separate ON INSERT
and ON UPDATE triggers with transition tables are allowed, and the
transition tables for these reflect only the inserted and only the
updated tuples respectively.

Patch by Thomas Munro

Discussion: https://postgr.es/m/CAEepm%3D11KHQ0JmETJQihSvhZB5mUZL2xrqHeXbCeLhDiqQ39%3Dw%40mail.gmail.com
2017-06-28 19:00:55 +01:00
Andrew Gierth c46c0e5202 Fix transition tables for wCTEs.
The original coding didn't handle this case properly; each separate
DML substatement needs its own set of transitions.

Patch by Thomas Munro

Discussion: https://postgr.es/m/CAL9smLCDQ%3D2o024rBgtD4WihzX8B3C6u_oSQ2K3%2BR5grJrV0bg%40mail.gmail.com
2017-06-28 18:59:01 +01:00
Andrew Gierth 501ed02cf6 Fix transition tables for partition/inheritance.
We disallow row-level triggers with transition tables on child tables.
Transition tables for triggers on the parent table contain only those
columns present in the parent.  (We can't mix tuple formats in a
single transition table.)

Patch by Thomas Munro

Discussion: https://postgr.es/m/CA%2BTgmoZzTBBAsEUh4MazAN7ga%3D8SsMC-Knp-6cetts9yNZUCcg%40mail.gmail.com
2017-06-28 18:55:03 +01:00
Tom Lane 99255d73c0 Second try at fixing tcp_keepalives_idle option on Solaris.
Buildfarm evidence shows that TCP_KEEPALIVE_THRESHOLD doesn't exist
after all on Solaris < 11.  This means we need to take positive action to
prevent the TCP_KEEPALIVE code path from being taken on that platform.
I've chosen to limit it with "&& defined(__darwin__)", since it's unclear
that anyone else would follow Apple's precedent of spelling the symbol
that way.

Also, follow a suggestion from Michael Paquier of eliminating code
duplication by defining a couple of intermediate symbols for the
socket option.

In passing, make some effort to reduce the number of translatable messages
by replacing "setsockopt(foo) failed" with "setsockopt(%s) failed", etc,
throughout the affected files.  And update relevant documentation so
that it doesn't claim to provide an exhaustive list of the possible
socket option names.

Like the previous commit (f0256c774), back-patch to all supported branches.

Discussion: https://postgr.es/m/20170627163757.25161.528@wrigleys.postgresql.org
2017-06-28 12:30:16 -04:00
Tom Lane f0256c774d Support tcp_keepalives_idle option on Solaris.
Turns out that the socket option for this is named TCP_KEEPALIVE_THRESHOLD,
at least according to the tcp(7P) man page for Solaris 11.  (But since that
text refers to "SunOS", it's likely pretty ancient.)  It appears that the
symbol TCP_KEEPALIVE does get defined on that platform, but it doesn't
seem to represent a valid protocol-level socket option.  This leads to
bleats in the postmaster log, and no tcp_keepalives_idle functionality.

Per bug #14720 from Andrey Lizenko, as well as an earlier report from
Dhiraj Chawla that nobody had followed up on.  The issue's been there
since we added the TCP_KEEPALIVE code path in commit 5acd417c8, so
back-patch to all supported branches.

Discussion: https://postgr.es/m/20170627163757.25161.528@wrigleys.postgresql.org
2017-06-27 18:47:57 -04:00
Tom Lane 9c7dc89282 Re-allow SRFs and window functions within sub-selects within aggregates.
check_agg_arguments_walker threw an error upon seeing a SRF or window
function, but that is too aggressive: if the function is within a
sub-select then it's perfectly fine.  I broke the SRF case in commit
0436f6bde by copying the logic for window functions ... but that was
broken too, and had been since commit eaccfded9.

Repair both cases in HEAD, and the window function case back to 9.3.
9.2 gets this right.
2017-06-27 17:51:11 -04:00
Tom Lane e5d494d78c Don't lose walreceiver start requests due to race condition in postmaster.
When a walreceiver dies, the startup process will notice that and send
a PMSIGNAL_START_WALRECEIVER signal to the postmaster, asking for a new
walreceiver to be launched.  There's a race condition, which at least
in HEAD is very easy to hit, whereby the postmaster might see that
signal before it processes the SIGCHLD from the walreceiver process.
In that situation, sigusr1_handler() just dropped the start request
on the floor, reasoning that it must be redundant.  Eventually, after
10 seconds (WALRCV_STARTUP_TIMEOUT), the startup process would make a
fresh request --- but that's a long time if the connection could have
been re-established almost immediately.

Fix it by setting a state flag inside the postmaster that we won't
clear until we do launch a walreceiver.  In cases where that results
in an extra walreceiver launch, it's up to the walreceiver to realize
it's unwanted and go away --- but we have, and need, that logic anyway
for the opposite race case.

I came across this through investigating unexpected delays in the
src/test/recovery TAP tests: it manifests there in test cases where
a master server is stopped and restarted while leaving streaming
slaves active.

This logic has been broken all along, so back-patch to all supported
branches.

Discussion: https://postgr.es/m/21344.1498494720@sss.pgh.pa.us
2017-06-26 17:31:56 -04:00
Tom Lane ad1b5c842b Ignore old stats file timestamps when starting the stats collector.
The stats collector disregards inquiry messages that bear a cutoff_time
before when it last wrote the relevant stats file.  That's fine, but at
startup when it reads the "permanent" stats files, it absorbed their
timestamps as if they were the times at which the corresponding temporary
stats files had been written.  In reality, of course, there's no data
out there at all.  This led to disregarding inquiry messages soon after
startup if the postmaster had been shut down and restarted within less
than PGSTAT_STAT_INTERVAL; which is a pretty common scenario, both for
testing and in the field.  Requesting backends would hang for 10 seconds
and then report failure to read statistics, unless they got bailed out
by some other backend coming along and making a newer request within
that interval.

I came across this through investigating unexpected delays in the
src/test/recovery TAP tests: it manifests there because the autovacuum
launcher hangs for 10 seconds when it can't get statistics at startup,
thus preventing a second shutdown from occurring promptly.  We might
want to do some things in the autovac code to make it less prone to
getting stuck that way, but this change is a good bug fix regardless.

In passing, also fix pgstat_read_statsfiles() to ensure that it
re-zeroes its global stats variables if they are corrupted by a
short read from the stats file.  (Other reads in that function
go into temp variables, so that the issue doesn't arise.)

This has been broken since we created the separation between permanent
and temporary stats files in 8.4, so back-patch to all supported branches.

Discussion: https://postgr.es/m/16860.1498442626@sss.pgh.pa.us
2017-06-26 16:17:05 -04:00
Tom Lane 5efccc1cb4 Avoid useless "x = ANY(ARRAY[])" test for empty partition list.
This arises in practice if the partition only admits NULL values.

Jeevan Ladhe

Discussion: https://postgr.es/m/CAOgcT0OChrN--uuqH6wG6Z8+nxnCWJ+2Q-uhnK4KOANdRRxuAw@mail.gmail.com
2017-06-26 10:43:20 -04:00
Tom Lane 00c5e511b9 Minor code review for parse_phrase_operator().
Fix its header comment, which described the old behavior of the <N>
phrase distance operator; we missed updating that in commit 028350f61.
Also, reset errno before strtol() call, to defend against the possibility
that it was already ERANGE at entry.  (The lack of complaints says that
it generally isn't, but this is at least a latent bug.)  Very minor
stylistic improvements as well.

Victor Drobny noted the obsolete comment, I noted the errno issue.
Back-patch to 9.6 where this code was added, just in case the errno
issue is a live bug in some cases.

Discussion: https://postgr.es/m/2b5382fdff9b1f79d5eb2c99c4d2cbe2@postgrespro.ru
2017-06-26 10:31:10 -04:00
Tom Lane ddb5fdc068 Further hacking on ICU collation creation and usage.
pg_import_system_collations() refused to create any ICU collations if
the current database's encoding didn't support ICU.  This is wrongheaded:
initdb must initialize pg_collation in an encoding-independent way
since it might be used in other databases with different encodings.
The reason for the restriction seems to be that get_icu_locale_comment()
used icu_from_uchar() to convert the UChar-format display name, and that
unsurprisingly doesn't know what to do in unsupported encodings.
But by the same token that the initial catalog contents must be
encoding-independent, we can't allow non-ASCII characters in the comment
strings.  So we don't really need icu_from_uchar() here: just check for
Unicode codes outside the ASCII range, and if there are none, the format
conversion is trivial.  If there are some, we can simply not install the
comment.  (In my testing, this affects only Norwegian Bokmål, which has
given us trouble before.)

For paranoia's sake, also check for non-ASCII characters in ICU locale
names, and skip such locales, as we do for libc locales.  I don't
currently have a reason to believe that this will ever reject anything,
but then again the libc maintainers should have known better too.

With just the import changes, ICU collations can be found in pg_collation
in databases with unsupported encodings.  This resulted in more or less
clean failures at runtime, but that's not how things act for unsupported
encodings with libc collations.  Make it work the same as our traditional
behavior for libc collations by having collation lookup take into account
whether is_encoding_supported_by_icu().

Adjust documentation to match.  Also, expand Table 23.1 to show which
encodings are supported by ICU.

catversion bump because of likely change in pg_collation/pg_description
initial contents in ICU-enabled builds.

Discussion: https://postgr.es/m/20c74bc3-d6ca-243d-1bbc-12f17fa4fe9a@gmail.com
2017-06-24 13:54:23 -04:00
Simon Riggs a15b47df35 Fix typo in comment in SerializeSnapshot
Author: Masahiko Sawada
2017-06-24 13:51:26 +01:00
Simon Riggs 829f12e269 Revert 1f30295eab
Reported-by: Tom Lane
2017-06-24 13:03:55 +01:00
Tom Lane d1fcc62298 Fix incorrect buffer-length argument to uloc_getDisplayName().
The maxResultSize argument of uloc_getDisplayName is the number of
UChars in the output buffer, not the number of bytes.  In principle
this could result in a stack smash, although at least in my Fedora 25
install there are no ICU locales with display names long enough to
overrun the buffer.  But it's easily proven to be wrong by reducing
the length of displayname to around 20, whereupon a stack smash
does happen.

(This is a rather scary bug, because the same mistake could easily
have been made in other places; but in a quick code search looking
at uses of UChar I could not find any other instances.)
2017-06-23 16:00:55 -04:00
Peter Eisentraut 08859bb5c2 Fix replication with replica identity full
The comparison with the target rows on the subscriber side was done with
datumIsEqual(), which can have false negatives.  For instance, it didn't
work reliably for text columns.  So use the equality operator provided
by the type cache instead.

Also add more user documentation about replica identity requirements.

Reported-by: Tatsuo Ishii <ishii@sraoss.co.jp>
2017-06-23 15:40:17 -04:00
Tom Lane 0b13b2a771 Rethink behavior of pg_import_system_collations().
Marco Atzeri reported that initdb would fail if "locale -a" reported
the same locale name more than once.  All previous versions of Postgres
implicitly de-duplicated the results of "locale -a", but the rewrite
to move the collation import logic into C had lost that property.
It had also lost the property that locale names matching built-in
collation names were silently ignored.

The simplest way to fix this is to make initdb run the function in
if-not-exists mode, which means that there's no real use-case for
non if-not-exists mode; we might as well just drop the boolean argument
and simplify the function's definition to be "add any collations not
already known".  This change also gets rid of some odd corner cases
caused by the fact that aliases were added in if-not-exists mode even
if the function argument said otherwise.

While at it, adjust the behavior so that pg_import_system_collations()
doesn't spew "collation foo already exists, skipping" messages during a
re-run; that's completely unhelpful, especially since there are often
hundreds of them.  And make it return a count of the number of collations
it did add, which seems like it might be helpful.

Also, re-integrate the previous coding's property that it would make a
deterministic selection of which alias to use if there were conflicting
possibilities.  This would only come into play if "locale -a" reports
multiple equivalent locale names, say "de_DE.utf8" and "de_DE.UTF-8",
but that hardly seems out of the question.

In passing, fix incorrect behavior in pg_import_system_collations()'s
ICU code path: it neglected CommandCounterIncrement, which would result
in failures if ICU returns duplicate names, and it would try to create
comments even if a new collation hadn't been created.

Also, reorder operations in initdb so that the 'ucs_basic' collation
is created before calling pg_import_system_collations() not after.
This prevents a failure if "locale -a" were to report a locale named
that.  There's no reason to think that that ever happens in the wild,
but the old coding would have survived it, so let's be equally robust.

Discussion: https://postgr.es/m/20c74bc3-d6ca-243d-1bbc-12f17fa4fe9a@gmail.com
2017-06-23 14:19:58 -04:00
Simon Riggs 9ea3c64124 Improve replication lag interpolation after idle period
After sitting idle and fully replayed for a while and then encountering
a new burst of WAL activity, we interpolate between an ancient sample and the
not-yet-reached one for the new traffic. That produced a corner case report
of lag after receiving first new reply from standby, which might sometimes
be a large spike.

Correct this by resetting last_read time and handle that new case.

Author: Thomas Munro
2017-06-23 18:58:46 +01:00
Tom Lane b6159202c9 Fix memory leakage in ICU encoding conversion, and other code review.
Callers of icu_to_uchar() neglected to pfree the result string when done
with it.  This results in catastrophic memory leaks in varstr_cmp(),
because of our prevailing assumption that btree comparison functions don't
leak memory.  For safety, make all the call sites clean up leaks, though
I suspect that we could get away without it in formatting.c.  I audited
callers of icu_from_uchar() as well, but found no places that seemed to
have a comparable issue.

Add function API specifications for icu_to_uchar() and icu_from_uchar();
the lack of any thought-through specification is perhaps not unrelated
to the existence of this bug in the first place.  Fix icu_to_uchar()
to guarantee a nul-terminated result; although no existing caller appears
to care, the fact that it would have been nul-terminated except in
extreme corner cases seems ideally designed to bite someone on the rear
someday.  Fix ucnv_fromUChars() destCapacity argument --- in the worst
case, that could perhaps have led to a non-nul-terminated result, too.
Fix icu_from_uchar() to have a more reasonable definition of the function
result --- no callers are actually paying attention, so this isn't a live
bug, but it's certainly sloppily designed.  Const-ify icu_from_uchar()'s
input string for consistency.

That is not the end of what needs to be done to these functions, but
it's as much as I have the patience for right now.

Discussion: https://postgr.es/m/1955.1498181798@sss.pgh.pa.us
2017-06-23 12:22:06 -04:00
Alvaro Herrera da2322883b Fix typos in README.dependencies
There was a logic error in a formula, reported by Atsushi Torokoshi.
Ashutosh Bapat furthermore recommended to change notation for a variable
that was re-using a letter from a previous formula, though his proposed
patch contained a small error in attributing what the new letter is for.
Also, instead of his proposed d' I ended up using e, to avoid confusing
the reader with quotes which are used differently in the explaining
prose.

Bugs appeared in commit 2686ee1b7c.

Reported-by: Atsushi Torikoshi, Ashutosh Bapat
Discussion: https://postgr.es/m/CAFjFpRd03YojT4wyuDcjhCfYuygfWfnt68XGn2CKv=rcjRCtTA@mail.gmail.com
2017-06-22 17:12:27 -04:00
Alvaro Herrera 82c1507e30 Fix typo in comment
Once upon a time, WAL pointers could be NULL, but no longer.  We talk about
"valid" now.

Reported-by: Amit Langote
Discussion: https://postgr.es/m/33e9617d-27f1-eee8-3311-e27af98eaf2b@lab.ntt.co.jp
2017-06-22 16:42:38 -04:00
Robert Haas 6af9f1bd4b Document partitioned_rels in create_modifytable_path header comment.
Etsuro Fujita, slightly adjusted by me.

Discussion: http://postgr.es/m/e87c4a6d-23d7-5e7c-e8db-44ed418eb5d1@lab.ntt.co.jp
2017-06-22 13:52:50 -04:00
Alvaro Herrera a4f06606a3 Fix autovacuum launcher attachment to its DSA
The autovacuum launcher doesn't actually do anything with its DSA other
than creating it and attaching to it, but it's been observed that after
longjmp'ing to the standard error handling block (for example after
getting SIGINT) the autovacuum enters an infinite loop reporting that it
cannot attach to its DSA anymore (which is correct, because it's already
attached to it.)  Fix by only attempting to attach if not already
attached.

I introduced this bug together with BRIN autosummarization in
7526e10224.

Reported-by: Yugo Nagata.
Author: Thomas Munro.  I added the comment to go with it.
Discussion: https://postgr.es/m/20170621211538.0c9eae73.nagata@sraoss.co.jp
2017-06-22 13:50:26 -04:00
Robert Haas 2a6db5eba6 Update out-of-date comment in vacuumlazy.c
Commit 15c121b3ed seems to have
overlooked the need to trim this part of the comment.

Pavan Deolasee

Discussion: http://postgr.es/m/CABOikdPq_9+cWRNZ0RLKTwuZyj=uL85X=Usifa-CbPee1ZCM5A@mail.gmail.com
2017-06-22 13:38:53 -04:00
Alvaro Herrera 5dfd564b10 Fix IF NOT EXISTS in CREATE STATISTICS
I misplaced the IF NOT EXISTS clause in commit 7b504eb282, before the
word STATISTICS.  Put it where it belongs.

Patch written independently by Amit Langote and myself.  I adopted his
submitted test case with a slight edit also.

Reported-by: Bruno Wolff III
Discussion: https://postgr.es/m/20170621004237.GB8337@wolff.to
2017-06-22 13:17:08 -04:00
Robert Haas 1300276042 Update comment to account for table partitioning.
Ashutosh Bapat and Amit Langote

Discussion: http://postgr.es/m/CAFjFpRcG_NaAv6cDHD-9VfGdvB8maAtSfB=fTQr5+kxP2_sXzg@mail.gmail.com
2017-06-22 10:53:37 -04:00
Magnus Hagander f0415a30e0 Fix typo in comment
Author: Masahiko Sawada
2017-06-22 15:37:30 +02:00
Andres Freund fb886c153b Fix possibility of creating a "phantom" segment after promotion.
When promoting a standby just after a XLOG_SWITCH record was replayed,
and next segment(s) are already are locally available (via walsender,
restore_command + trigger/recovery target), that segment could
accidentally be recycled onto the past of the new timeline.  Later
checkpointer would create a .ready file for it, assuming there was an
error during creation, and it would get archived.  That causes trouble
if another standby is later brought up from a basebackup from before
the timeline creation, because it would try to read the
segment, because XLogFileReadAnyTLI just tries all possible timelines,
which doesn't have valid contents.  Thus replay would fail.

The problem, if already occurred, can be fixed by removing the segment
and/or having restore_command filter it out.

The reason for the creation of such "phantom" segments was, that after
an XLOG_SWITCH record the EndOfLog variable points to the beginning of
the next segment, and RemoveXlogFile() used XLByteToPrevSeg().
Normally RemoveXlogFile() doing so is harmless, because the last
segment will still exist preventing InstallXLogFileSegment() from
causing harm, but just after promotion there's no previous segment on
the new timeline.

Fix that by using XLByteToSeg() instead of XLByteToPrevSeg().

Author: Andres Freund
Reported-By: Greg Burek
Discussion: https://postgr.es/m/20170619073026.zcwpe6mydsaz5ygd@alap3.anarazel.de
Backpatch: 9.2-, bug older than all supported versions
2017-06-21 14:14:45 -07:00