The wording changed here comes from 991bfe11d2, when the only way to
trigger a promotion was with a trigger file. There are more options to
achieve this operation these days, like the SQL function pg_promote() or
the command `pg_ctl promote`, so it is confusing to assume that only a
trigger file is able to do the work.
Note also that promote_trigger_file has been removed as of cd4329d939
in 16~.
Author: Shinya Kato
Discussion: https://postgr.es/m/201b08ea29aa61f96162080e75be503c@oss.nttdata.com
Backpatch-through: 12
One of the examples on the SELECT page was missing a semicolon from
a listing which has the look and feel of being a psql session. This
adds the missing semicolon and also removes the newline between the
query and results to match the other examples nearby.
Backpatch to all supported branches to avoid backpatching issues on
this page.
Reported-by: tim.needham2@gmail.com
Discussion: https://postgr.es/m/169965004097.225187.12941375915673151540@wrigleys.postgresql.org
Backpatch-through: v12
This text left one with the impression that an ON SELECT rule could
be attached to a plain table, which has not been true since commit
264c06820 (meaning the text was already misleading when written,
evidently by me in 96bd67f61). However, it didn't get really bad
until b23cd185f removed the convert-a-table-to-a-view logic, which
had made it possible for scripts that thought they were attaching
ON SELECTs to tables to still work.
Rewrite into a form that makes it clear that an ON SELECT rule
is better regarded as an implementation detail of a view.
Pre-v16, point out that adding ON SELECT to a table actually
converts it to a view.
Per bug #18178 from Joshua Uyehara. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/18178-05534d7064044d2d@postgresql.org
This part of the documentation refers to exceptions as handled by
PL/pgSQL, and using the internal error code is confusing.
Per thinko in 66bde49d96.
Reported-by: Euler Taveira, Bruce Momjian
Discussion: https://postgr.es/m/ZUEUnLevXyW7DlCs@momjian.us
Backpatch-through: 11
As far as I can see, ecpg has no notion of a "default" open
connection. You can do "CONNECT TO DEFAULT" but that just specifies
letting libpq use all its default connection parameters --- the
resulting connection is not special subsequently. In particular,
SET CONNECTION = DEFAULT and DISCONNECT DEFAULT simply act on a
connection named DEFAULT, if you've made one; they do not have
special lookup rules. But the documentation of these commands
makes it look like they do.
Simplest fix, I think, is just to remove the paras suggesting that
DEFAULT is special here.
Also, SET CONNECTION *does* have one special lookup rule, which
is that it recognizes CURRENT as an alias for the currently selected
connection. SET CONNECTION = CURRENT is a no-op, so it's pretty
useless, but nonetheless it does something different from selecting
a connection by name; so we'd better document it.
Per report from Sylvain Frandaz. Back-patch to all supported
versions.
Discussion: https://postgr.es/m/169824721149.1769274.1553568436817652238@wrigleys.postgresql.org
Clearly spell out the limitations of aminsert()'s indexUnchanged hinting
mechanism in the index AM documentation.
Oversight in commit 9dc718bd, which added the "logically unchanged
index" hint (which is used to trigger bottom-up index deletion).
Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-By: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAH2-WzmU_BQ=-H9L+bxTSMQBqHMjp1DSwGypvL0gKs+dTOfkKg@mail.gmail.com
Backpatch: 14-, where indexUnchanged hinting was introduced.
This doco said that use of => as an operator "is deprecated".
It's been fully disallowed since 865f14a2d back in 9.5, but
evidently that commit missed updating this statement.
Do so now.
The old documentation encourages entering single-user mode for no
reason, which is a bad plan in most cases. Instead, discourage users
from doing that, and explain the limited cases in which it may be
desirable.
The old documentation claims that running VACUUM as anyone but the
superuser can't possibly work, which is not really true, because it
might be that some other user has enough permissions to VACUUM all
the tables that matter. Weaken the language just a bit.
The old documentation claims that you can't run any commands
when near XID exhaustion, which is false because you can still
run commands that don't require an XID, like a SELECT without a
locking clause.
The old documentation doesn't clearly explain that it's a good idea
to get rid of prepared transactons, long-running transactions, and
replication slots that are preventing (M)XID horizon advancement.
Spell out the steps to do that.
Also, discourage the use of VACUUM FULL and VACUUM FREEZE in
this type of scenario.
Back-patch to v14. Much of this is good advice on all supported
versions, but before 60f1f09ff4
the chances of VACUUM failing in multi-user mode were much higher.
Alexander Alekseev, John Naylor, Robert Haas, reviewed at various
times by Peter Geoghegan, Hannu Krosing, and Andres Freund.
Discussion: http://postgr.es/m/CA+TgmoYtsUDrzaHcmjFhLzTk1VEv29mO_u-MT+XWHrBJ_4nD8A@mail.gmail.com
While these two built-in functions do exactly the same thing,
CURRENT_USER seems preferable to use in documentation examples.
It's easier to look up if the reader is unsure what it is.
Also, this puts these examples in sync with an adjacent example
that already used CURRENT_USER.
Per question from Kirk Parker.
Discussion: https://postgr.es/m/CANwZ8rmN_Eb0h0hoMRS8Feftaik0z89PxVsKg+cP+PctuOq=Qg@mail.gmail.com
Commit 7d3b7011b added a link to the statistics functions, which at the
time were anchored under the section for statistics views. aebe989477
added a separate section for statistics functions, but the link was not
updated to point to the new anchor. Fix by changing the xref.
Backpatch to all supported branches.
Author: Peter Smith <peter.b.smith@fujitsu.com>
Discussion: https://postgr.es/m/CAHut+Ptr0jKzNNtWnssLq+3jNhbyaBseqf6NPrWHk08mQFRoTg@mail.gmail.com
Backpatch-through: 11
The previous wording had a faint archaic whiff to it, and more
importantly used "catalogs" as a verb, which while cutely
self-referential seems likely to provoke confusion in this
particular context. Also consistently use "kind" not "type" to
refer to the different kinds of relations distinguished by relkind.
Per gripe from Martin Nash. Back-patch to supported versions.
Discussion: https://postgr.es/m/169518739902.3727338.4793815593763320945@wrigleys.postgresql.org
cursor_to_xmlschema() assumed that any Portal must have a tupDesc,
which is not so. Add a defensive check.
It's plausible that this mistake occurred because of the rather
poorly chosen name of the lookup function SPI_cursor_find(),
which in such cases is returning something that isn't very much
like a cursor. Add some documentation to try to forestall future
errors of the same ilk.
Report and patch by Boyu Yang (docs changes by me). Back-patch
to all supported branches.
Discussion: https://postgr.es/m/dd343010-c637-434c-a8cb-418f53bda3b8.yangboyu.yby@alibaba-inc.com
The list of external language drivers and procedural languages was
never complete or exhaustive, and rather than attempting to manage
it the content has migrated to the wiki. This replaces the tables
altogether with links to the wiki as we regularly get requests for
adding various projects, which we reject without any clear policy
for why or how the content should be managed.
The threads linked to below are the most recent discussions about
this, the archives contain many more.
Backpatch to all supported branches since the list on the wiki
applies to all branches.
Author: Jonathan Katz <jkatz@postgresql.org>
Discussion: https://postgr.es/m/169165415312.635.10247434927885764880@wrigleys.postgresql.org
Discussion: https://postgr.es/m/169177958824.635.11087800083040275266@wrigleys.postgresql.org
Backpatch-through: v11
IN and NOT IN work fine on records and arrays, so just say that
they accept "expressions" not "scalar expressions". I think that
that phrasing was meant to say that they don't work on set-returning
expressions, but that's not the common meaning of "scalar".
Revise the description of row-constructor comparisons to make it
perhaps a bit less confusing. (This partially reverts some
dubious wording changes made by commit f56651519.)
Per gripe from Ilya Nenashev. Back-patch to supported branches.
In HEAD and v16, also drop a NOTE about pre-8.2 behavior, which
is hopefully no longer of interest to anybody.
Discussion: https://postgr.es/m/168968062460.632.14303906825812821399@wrigleys.postgresql.org
The "count" argument of SPI_exec() only limits execution when
the query is actually returning rows. This was not the case
before PG 9.0, so this example was correct when written; but
we missed updating it in commit 2ddc600f8. Extend the example
to show the behavior both with and without RETURNING.
While here, improve the commentary and markup for the rest
of the example.
David G. Johnston and Tom Lane, per report from Curt Kolovson.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/CANhYJV6HWtgz_qjx_APfK0PAgLUzY-2vjLuj7i_o=TZF1LAQew@mail.gmail.com
Until now, when DROP DATABASE got interrupted in the wrong moment, the removal
of the pg_database row would also roll back, even though some irreversible
steps have already been taken. E.g. DropDatabaseBuffers() might have thrown
out dirty buffers, or files could have been unlinked. But we continued to
allow connections to such a corrupted database.
To fix this, mark databases invalid with an in-place update, just before
starting to perform irreversible steps. As we can't add a new column in the
back branches, we use pg_database.datconnlimit = -2 for this purpose.
An invalid database cannot be connected to anymore, but can still be
dropped.
Unfortunately we can't easily add output to psql's \l to indicate that some
database is invalid, it doesn't fit in any of the existing columns.
Add tests verifying that a interrupted DROP DATABASE is handled correctly in
the backend and in various tools.
Reported-by: Evgeny Morozov <postgresql3@realityexists.net>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20230509004637.cgvmfwrbht7xm7p6@awork3.anarazel.de
Discussion: https://postgr.es/m/20230314174521.74jl6ffqsee5mtug@awork3.anarazel.de
Backpatch: 11-, bug present in all supported versions
