Consistent with what we do for indexes, we shouldn't try to record
dependencies on collation OID 0 or the default collation OID (which
is pinned). Also, the fact that indcollation and partcollation can
contain zero OIDs when the data type is not collatable should be
documented.
Amit Langote, per a complaint from me.
Discussion: http://postgr.es/m/CA+Tgmoba5mtPgM3NKfG06vv8na5gGbVOj0h4zvivXQwLw8wXXQ@mail.gmail.com
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and
throws a PANIC if so. At that point, only walsenders are still
active, so one might think this could not happen, but walsenders can
also generate WAL, for instance in BASE_BACKUP and logical decoding
related commands (e.g. via hint bits). So they can trigger this panic
if such a command is run while the shutdown checkpoint is being
written.
To fix this, divide the walsender shutdown into two phases. First,
checkpointer, itself triggered by postmaster, sends a
PROCSIG_WALSND_INIT_STOPPING signal to all walsenders. If the backend
is idle or runs an SQL query this causes the backend to shutdown, if
logical replication is in progress all existing WAL records are
processed followed by a shutdown. Otherwise this causes the walsender
to switch to the "stopping" state. In this state, the walsender will
reject any further replication commands. The checkpointer begins the
shutdown checkpoint once all walsenders are confirmed as
stopping. When the shutdown checkpoint finishes, the postmaster sends
us SIGUSR2. This instructs walsender to send any outstanding WAL,
including the shutdown checkpoint record, wait for it to be replicated
to the standby, and then exit.
Author: Andres Freund, based on an earlier patch by Michael Paquier
Reported-By: Fujii Masao, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
Backpatch: 9.4, where logical decoding was introduced
This reverts commit 086221cf6b, which
was made to master only.
The approach implemented in the above commit has some issues. While
those could easily be fixed incrementally, doing so would make
backpatching considerably harder, so instead first revert this patch.
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
There was a grammar ambiguity between SET PUBLICATION name REFRESH and
SET PUBLICATION SKIP REFRESH, because SKIP is not a reserved word. To
resolve that, fold the refresh choice into the WITH options. Refreshing
is the default now.
Reported-by: tushar <tushar.ahuja@enterprisedb.com>
Previously the changes to the "data" part of the sequence, i.e. the
one containing the current value, were not transactional, whereas the
definition, including minimum and maximum value were. That leads to
odd behaviour if a schema change is rolled back, with the potential
that out-of-bound sequence values can be returned.
To avoid the issue create a new relfilenode fork whenever ALTER
SEQUENCE is executed, similar to how TRUNCATE ... RESTART IDENTITY
already is already handled.
This commit also makes ALTER SEQUENCE RESTART transactional, as it
seems to be too confusing to have some forms of ALTER SEQUENCE behave
transactionally, some forms not. This way setval() and nextval() are
not transactional, but DDL is, which seems to make sense.
This commit also rolls back parts of the changes made in 3d092fe540
and f8dc1985f as they're now not needed anymore.
Author: Andres Freund
Discussion: https://postgr.es/m/20170522154227.nvafbsm62sjpbxvd@alap3.anarazel.de
Backpatch: Bug is in master/v10 only
On some platforms, -fpic fails for sufficiently large shared libraries.
We've mostly not hit that boundary yet, but there are some extensions
such as Citus and pglogical where it's becoming a problem. A bit of
research suggests that the penalty for -fPIC is small, in the
single-digit-percentage range --- and there's none at all on popular
platforms such as x86_64. So let's just default to -fPIC everywhere
and provide one less thing for extension developers to worry about.
Per complaint from Christoph Berg. Back-patch to all supported branches.
(I did not bother to touch the recently-removed Makefiles for sco and
unixware in the back branches, though. We'd have no way to test that
it doesn't break anything on those platforms.)
Discussion: https://postgr.es/m/20170529155850.qojdfrwkkqnjb3ap@msg.df7cb.de
pg_resetwal (formerly pg_resetxlog) doesn't insist on finding a matching
version number in pg_control, and that seems like an important thing to
preserve since recovering from corrupt pg_control is a prime reason to
need to run it. However, that means you can try to run it against a
data directory of a different major version, which is at best useless
and at worst disastrous. So as to provide some protection against that
type of pilot error, inspect PG_VERSION at startup and refuse to do
anything if it doesn't match. PG_VERSION is read-only after initdb,
so it's unlikely to get corrupted, and even if it were corrupted it would
be easy to fix by hand.
This hazard has been there all along, so back-patch to all supported
branches.
Michael Paquier, with some kibitzing by me
Discussion: https://postgr.es/m/f4b8eb91-b934-8a0d-b3cc-68f06e2279d1@enterprisedb.com
Left-justify these comments, remove committer names, remove SGML markup
that was randomly added to some of them. Aside from being more consistent
with previous practice, this keeps the lines shorter than 80 characters,
improving readability in standard terminal windows.
The cash_div_intX functions applied rint() to the result of the division.
That's not merely useless (because the result is already an integer) but
it causes precision loss for values larger than 2^52 or so, because of
the forced conversion to float8.
On the other hand, the cash_mul_fltX functions neglected to apply rint() to
their multiplication results, thus possibly causing off-by-one outputs.
Per C standard, arithmetic between any integral value and a float value is
performed in float format. Thus, cash_mul_flt4 and cash_div_flt4 produced
answers good to only about six digits, even when the float value is exact.
We can improve matters noticeably by widening the float inputs to double.
(It's tempting to consider using "long double" arithmetic if available,
but that's probably too much of a stretch for a back-patched fix.)
Also, document that cash_div_intX operators truncate rather than round.
Per bug #14663 from Richard Pistole. Back-patch to all supported branches.
Discussion: https://postgr.es/m/22403.1495223615@sss.pgh.pa.us
This is more secure, and saves a redirect since we no longer accept
plain HTTP connections on the website.
References in code comments should probably be updated too, but
that doesn't seem to need back-patching, whereas this does.
Also, in the 9.2 branch, remove suggestion that you can get the
source code via FTP, since that service will be shut down soon.
Daniel Gustafsson, with a few additional changes by me
Discussion: https://postgr.es/m/9A2C89A7-0BB8-41A8-B288-8B7BD09D7D44@yesql.se
If one host in a multi-host connection string times out, move on to
the next specified host instead of giving up entirely.
Takayuki Tsunakawa, reviewed by Michael Paquier. I added
a minor adjustment to the documentation.
Discussion: http://postgr.es/m/0A3221C70F24FB45833433255569204D1F6F42F5@G01JPEXMBYT05
This seemed like a good idea originally because there's no way to mark
a range partition as accepting NULL, but that now seems more like a
current limitation than something we want to lock down for all time.
For example, there's a proposal to add the notion of a default
partition which accepts all rows not otherwise routed, which directly
conflicts with the idea that a range-partitioned table should never
allow nulls anywhere. So let's change this while we still can, by
putting the NOT NULL test into the partition constraint instead of
changing the column properties.
Amit Langote and Robert Haas, reviewed by Amit Kapila
Discussion: http://postgr.es/m/8e2dd63d-c6fb-bb74-3c2b-ed6d63629c9d@lab.ntt.co.jp
In 1753b1b027, the pg_sequence system
catalog was introduced. This made sequence metadata changes
transactional, while the actual sequence values are still behaving
nontransactionally. This requires some refinement in how ALTER
SEQUENCE, which operates on both, locks the sequence and the catalog.
The main problems were:
- Concurrent ALTER SEQUENCE causes "tuple concurrently updated" error,
caused by updates to pg_sequence catalog.
- Sequence WAL writes and catalog updates are not protected by same
lock, which could lead to inconsistent recovery order.
- nextval() disregarding uncommitted ALTER SEQUENCE changes.
To fix, nextval() and friends now lock the sequence using
RowExclusiveLock instead of AccessShareLock. ALTER SEQUENCE locks the
sequence using ShareRowExclusiveLock. This means that nextval() and
ALTER SEQUENCE block each other, and ALTER SEQUENCE on the same sequence
blocks itself. (This was already the case previously for the OWNER TO,
RENAME, and SET SCHEMA variants.) Also, rearrange some code so that the
entire AlterSequence is protected by the lock on the sequence.
As an exception, use reduced locking for ALTER SEQUENCE ... RESTART.
Since that is basically a setval(), it does not require the full locking
of other ALTER SEQUENCE actions. So check whether we are only running a
RESTART and run with less locking if so.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reported-by: Jason Petersen <jason@citusdata.com>
Reported-by: Andres Freund <andres@anarazel.de>
Consistently refer to such an entry as a "statistics object", not just
"statistics" or "extended statistics". Previously we had a mismash of
terms, accompanied by utter confusion as to whether the term was
singular or plural. That's not only grating (at least to the ear of
a native English speaker) but could be outright misleading, eg in error
messages that seemed to be referring to multiple objects where only one
could be meant.
This commit fixes the code and a lot of comments (though I may have
missed a few). I also renamed two new SQL functions,
pg_get_statisticsextdef -> pg_get_statisticsobjdef
pg_statistic_ext_is_visible -> pg_statistics_obj_is_visible
to conform better with this terminology.
I have not touched the SGML docs other than fixing those function
names; the docs certainly need work but it seems like a separable task.
Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
Tab-completing DROP STATISTICS would only work if you started writing
the schema name containing the statistics object, because the visibility
clause was missing. To add it, we need to add SQL-callable support for
testing visibility of a statistics object, like all other object types
already have.
Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
This has to be backpatched to all supported releases so release markup
added to HEAD and copied to back branches matches the existing markup.
Reported-by: Peter Eisentraut
Discussion: 2b8a2552-fffa-f7c8-97c5-14db47a87731@2ndquadrant.com
Author: initial patch and sample markup by Peter Eisentraut
Backpatch-through: 9.2
Previously, we had the WITH clause in the middle of the command, where
you'd specify both generic options as well as statistic types. Few
people liked this, so this commit changes it to remove the WITH keyword
from that clause and makes it accept statistic types only. (We
currently don't have any generic options, but if we invent in the
future, we will gain a new WITH clause, probably at the end of the
command).
Also, the column list is now specified without parens, which makes the
whole command look more similar to a SELECT command. This change will
let us expand the command to supporting expressions (not just columns
names) as well as multiple tables and their join conditions.
Tom added lots of code comments and fixed some parts of the CREATE
STATISTICS reference page, too; more changes in this area are
forthcoming. He also fixed a potential problem in the alter_generic
regression test, reducing verbosity on a cascaded drop to avoid
dependency on message ordering, as we do in other tests.
Tom also closed a security bug: we documented that table ownership was
required in order to create a statistics object on it, but didn't
actually implement it.
Implement tab-completion for statistics objects. This can stand some
more improvement.
Authors: Alvaro Herrera, with lots of cleanup by Tom Lane
Discussion: https://postgr.es/m/20170420212426.ltvgyhnefvhixm6i@alvherre.pgsql
For CREATE/ALTER PUBLICATION/SUBSCRIPTION, use similar option style as
other statements that use a WITH clause for options.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Per discussion, "location" is a rather vague term that could refer to
multiple concepts. "LSN" is an unambiguous term for WAL locations and
should be preferred. Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position". Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.
David Rowley, minor additional docs hacking by me
Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
It turned out this approach had problems, because a DROP command should
not have any options other than CASCADE and RESTRICT. Instead, always
attempt to drop the slot if there is one configured, but also add an
ALTER SUBSCRIPTION action to set the slot to NONE.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/29431.1493730652@sss.pgh.pa.us
Robert Haas