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
Extend the PG_TEST_EXTRA documentation to mention resource intensive
tests as well. The previous wording only mentioned special software
and security in the main paragraph, with resource usage listed on one
of the tests in the list.
Backpatch to v15 where f47ed79cc8 added wal_consistenct_checking as
a PG_TEST_EXTRA target.
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/CAN55FZ0OthTuBdiNkaX2BvxuHdK4Y1MVEb8_uEuD1yHMPmT9Og@mail.gmail.com
Backpatch-through: 15
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
By default, triggers and rules do not fire on a logical replication
subscriber based on the "session_replication_role" GUC being set to
"replica". However, the docs in the logical replication section assumed
that the reader understood how this GUC worked. This modifies the docs to
be more explicit and links back to the GUC itself.
Author: Jonathan Katz, Peter Smith
Reviewed-by: Vignesh C, Euler Taveira
Backpatch-through: 11
Discussion: https://postgr.es/m/5bb2c9a2-499f-e1a2-6e33-5ce96b35cc4a@postgresql.org
Statistics defined by the CREATE STATISTICS command are only used to
assist with the selectivity estimations of base relations, never for
joins. Here we mention this fact in the notes section of the CREATE
STATISTICS command.
Discussion: https://postgr.es/m/CAApHDvrMuVgDOrmg_EtFDZ=AOovq6EsJNnHH1ddyZ8EqL4yzMw@mail.gmail.com
Backpatch-through: 11
The existing errhint message and docs were missing the fact that we can't
disassociate from the slot unless the subscription is disabled.
Author: Robert Sjöblom, Peter Smith
Reviewed-by: Peter Eisentraut, Amit Kapila
Backpatch-through: 11
Discussion: https://postgr.es/m/807bdf85-61ea-88e2-5712-6d9fcd4eabff@fortnox.se
In the documentation, previously the example command for
ALTER FOREIGN TABLE ... OPTIONS incorrectly included both
the option name and value with the DROP operation.
The correct syntax for the DROP operation requires only
the name of the option to be specified. This commit fixes
the example by removing the option value from the DROP operation.
Back-patch to all supported versions.
Author: Mehmet Emin KARAKAS <emin100@gmail.com>
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CANQrdXAHzbcEYhjGoe5A42OmfvdQhHFJzyKj9gJvHuDKyOF5Ng@mail.gmail.com
Non-leaf pages of GiST indexes contain key attributes, leaf pages
contain both key and non-key attributes, and gist_page_items() ignored
the handling of non-key attributes. This caused a few problems when
using gist_page_items() on a GiST index with INCLUDE:
- On a non-leaf page, the function would crash.
- On a leaf page, the function would work, but miss to display all the
values for included attributes.
This commit fixes gist_page_items() to handle such cases in a more
appropriate way, and now displays the values of key and non-key
attributes for each item separately in a style consistent with what
ruleutils.c would generate for the attribute list, depending on the page
type dealt with. In a way similar to how a record is displayed, values
would be double-quoted for key or non-key attributes if required.
ruleutils.c did not provide a routine able to control if non-key
attributes should be displayed, so an extended() routine for index
definitions is added to work around the leaf and non-leaf page
differences.
While on it, this commit fixes a third problem related to the amount of
data reported for key attributes. The code originally relied on
BuildIndexValueDescription() (used for error reports on constraints)
that would not print all the data stored in the index but the index
opclass's input type, so this limited the amount of information
available. This switch makes gist_page_items() much cheaper as there is
no need to run ACL checks for each item printed, which is not an issue
anyway as superuser rights are required to execute the functions of
pageinspect. Opclasses whose data cannot be displayed can rely on
gist_page_items_bytea().
The documentation of this function was slightly incorrect for the
output results generated on HEAD and v15, so adjust it on these
branches.
Author: Alexander Lakhin, Michael Paquier
Discussion: https://postgr.es/m/17884-cb8c326522977acb@postgresql.org
Backpatch-through: 14
Don't use PSQL_WATCH_PAGER when stdin/stdout are not a terminal.
This corresponds to the restrictions on when other commands will
use [PSQL_]PAGER. There isn't a lot of sense in trying to use a
pager in non-interactive cases, and doing so allows an environment
setting to break our tests.
Also, ignore PSQL_WATCH_PAGER if it is set but empty or all-blank,
for the same reasons we ignore such settings of [PSQL_]PAGER (see
commit 18f8f784c).
No documentation change is really needed, since there is nothing
suggesting that these constraints on [PSQL_]PAGER didn't already
apply to PSQL_WATCH_PAGER too. But I rearranged the text
a little to make it read more naturally (IMHO anyway).
Per report from Pavel Stehule. Back-patch to v15 where
PSQL_WATCH_PAGER was introduced.
Discussion: https://postgr.es/m/CAFj8pRDTwFzmEWdA-gdAcUh0ZnxUioSfTMre71WyB_wNJy-8gw@mail.gmail.com
Fix a link from the "Heap-Only Tuples" documentation section.
Previously, its "fillfactor" link pointed to the "CREATE TABLE"
command's documentation. Now the link directly points to the fillfactor
storage parameter documentation (which is about half way into the
"CREATE TABLE" sect1).
Oversight in commit 115464bb.
Backpatch: 12-, the first version with a usable reloption link.
An update of the GUC stats_fetch_consistency in a transaction would be
able to trigger an assertion when doing cache->snapshot. In this case,
when retrieving a pgstat entry after the switch, a new snapshot would be
rebuilt, confusing pgstat_build_snapshot() because a snapshot is already
cached with an unexpected mode ("cache").
In order to fix this problem, this commit adds a flag to force a
snapshot clear each time this GUC is changed. Some tests are added to
check, while on it.
Some optimizations in avoiding the snapshot clear should be possible
depending on what is cached and the current GUC value, I guess, but this
solution is simple, and ensures that the state of the cache is updated
each time a new pgstat entry is fetched, hence being consistent with the
level wanted by the client that has set the GUC.
Note that cache->none and snapshot->none would not cause issues, as
fetching a pgstat entry would be retrieved from shared memory on the
second attempt, however a snapshot would still be cached. Similarly,
none->snapshot and none->cache would build a new snapshot on the second
fetch attempt. Finally, snapshot->cache would cache a new snapshot on
the second attempt.
Reported-by: Alexander Lakhin
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/17804-2a118cd046f2d0e5@postgresql.org
backpatch-through: 15
Tom Lane
Michael Paquier
Peter Geoghegan
Robert Haas
David Rowley
Bruce Momjian
Daniel Gustafsson
Etsuro Fujita
Andres Freund
Amit Kapila
Fujii Masao