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
plperl, plpython, and pltcl all provide query-execution functions
that are thin wrappers around SPI_execute() or its variants.
The SPI functions document their row-count limit arguments clearly,
as "maximum number of rows to return, or 0 for no limit". However
the PLs' documentation failed to explain this special behavior of
zero, so that a reader might well assume it means "fetch zero
rows". Improve that.
Daniel Gustafsson and Tom Lane, per report from Kieran McCusker
Discussion: https://postgr.es/m/CAGgUQ6H6qYScctOhktQ9HLFDDoafBKHyUgJbZ6q_dOApnzNTXg@mail.gmail.com
Unaligned siglen could lead to an unaligned access to subsequent key fields.
Backpatch to 13, where opclass options were introduced.
Reported-by: Alexander Lakhin
Bug: 17847
Discussion: https://postgr.es/m/17847-171232970bea406b%40postgresql.org
Reviewed-by: Tom Lane, Pavel Borisov, Alexander Lakhin
Backpatch-through: 13
indexes-unique.html mentioned nothing about the availability of NULLS NOT
DISTINCT to modify the NULLs-are-not-equal behavior of unique indexes.
Add this to the synopsis and clarify what it does regarding NULLs.
Author: David Gilman, David Rowley
Reviewed-by: Corey Huinker
Discussion: https://postgr.es/m/CALBH9DDr3NLqzWop1z5uZE-M5G_GYUuAeHFHQeyzFbNd8W0d=Q@mail.gmail.com
Backpatch-through: 15, where NULLS NOT DISTINCT was added
Starting with OpenSSL 1.1.0 there is no need to call PQinitOpenSSL
or PQinitSSL to avoid duplicate initialization of OpenSSL. Add a
note to the documentation to explain this.
Backpatch to all supported versions as older OpenSSL versions are
equally likely to be used for all branches.
Reported-by: Sebastien Flaesch <sebastien.flaesch@4js.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/DBAP191MB12895BFFEC4B5FE0460D0F2FB0459@DBAP191MB1289.EURP191.PROD.OUTLOOK.COM
Backpatch-through: 11, all supported versions
The tables in "71.3. Extensibility" listing the support functions
for bloom and minmax-multi opclasses should include the associated
options function. While this isn't quite as required as the rest,
you need it for full functionality of the opclass.
Back-patch to v14 where these functions were added.
EXTRACT(EPOCH), EXTRACT(SECOND), and some related cases print more
trailing zeroes than they used to. This behavior change happened
with commit a2da77cdb (Change return type of EXTRACT to numeric),
and it was intentional according to the commit log:
- Return values when extracting fields with possibly fractional
values, such as second and epoch, now have the full scale that the
value has internally (so, for example, '1.000000' instead of just
'1').
It's been like that for two releases now, so while I suggested
changing this back, it's probably better to adjust the documentation
examples.
Per bug #17866 from Евгений Жужнев. Back-patch to v14 where the
change came in.
Discussion: https://postgr.es/m/17866-18eb70095b1594e2@postgresql.org
Since 8b9e9644d, the messages for failed permissions checks report
"table" where appropriate, rather than "relation".
Backpatch to all supported branches
The explanation describing the dependency to system read() calls for
these two functions has been removed in ddfc2d9. And after more
discussion about d69c404, we have concluded that adding more details
makes them easier to understand.
While on it, use the term "block read requests" (maybe found in cache)
rather than "buffers fetched" and "buffer hits".
Per discussion with Melanie Plageman, Kyotaro Horiguchi, Bertrand
Drouvot and myself.
Discussion: https://postgr.es/m/CAAKRu_ZmdiScT4q83OAbfmR5AH-L5zWya3SXjaxiJvhCob-e2A@mail.gmail.com
Backpatch-through: 11
This commit adds some documentation about two monitoring functions:
- pg_stat_get_xact_blocks_fetched()
- pg_stat_get_xact_blocks_hit()
The description of these functions has been removed in ddfc2d9, later
simplified by 5f2b089, assuming that all the functions whose
descriptions were removed are used in system views. Unfortunately, some
of them were are not used in any system views, so they lacked
documentation.
This gap exists in the docs for a long time, so backpatch all the way
down.
Reported-by: Michael Paquier
Author: Bertrand Drouvot
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/ZBeeH5UoNkTPrwHO@paquier.xyz
Backpatch-through: 11
Hash partitioning on an enum is problematic because the hash codes are
derived from the OIDs assigned to the enum values, which will almost
certainly be different after a dump-and-reload than they were before.
This means that some rows probably end up in different partitions than
before, causing restore to fail because of partition constraint
violations. (pg_upgrade dodges this problem by using hacks to force
the enum values to keep the same OIDs, but that's not possible nor
desirable for pg_dump.)
Users can work around that by specifying --load-via-partition-root,
but since that's a dump-time not restore-time decision, one might
find out the need for it far too late. Instead, teach pg_dump to
apply that option automatically when dealing with a partitioned
table that has hash-on-enum partitioning.
Also deal with a pre-existing issue for --load-via-partition-root
mode: in a parallel restore, we try to TRUNCATE target tables just
before loading them, in order to enable some backend optimizations.
This is bad when using --load-via-partition-root because (a) we're
likely to suffer deadlocks from restore jobs trying to restore rows
into other partitions than they came from, and (b) if we miss getting
a deadlock we might still lose data due to a TRUNCATE removing rows
from some already-completed restore job.
The fix for this is conceptually simple: just don't TRUNCATE if we're
dealing with a --load-via-partition-root case. The tricky bit is for
pg_restore to identify those cases. In dumps using COPY commands we
can inspect each COPY command to see if it targets the nominal target
table or some ancestor. However, in dumps using INSERT commands it's
pretty impractical to examine the INSERTs in advance. To provide a
solution for that going forward, modify pg_dump to mark TABLE DATA
items that are using --load-via-partition-root with a comment.
(This change also responds to a complaint from Robert Haas that
the dump output for --load-via-partition-root is pretty confusing.)
pg_restore checks for the special comment as well as checking the
COPY command if present. This will fail to identify the combination
of --load-via-partition-root and --inserts in pre-existing dump files,
but that should be a pretty rare case in the field. If it does
happen you will probably get a deadlock failure that you can work
around by not using parallel restore, which is the same as before
this bug fix.
Having done this, there seems no remaining reason for the alarmism
in the pg_dump man page about combining --load-via-partition-root
with parallel restore, so remove that warning.
Patch by me; thanks to Julien Rouhaud for review. Back-patch to
v11 where hash partitioning was introduced.
Discussion: https://postgr.es/m/1376149.1675268279@sss.pgh.pa.us
Clarify that ATTACH/DETACH PARTITION can be used to perform partition
maintenance with less locking than straight CREATE TABLE/DROP TABLE.
This was already stated in some places, but not emphasized.
Back-patch to v14 where DETACH PARTITION CONCURRENTLY was added.
(We had lower lock levels for ATTACH PARTITION before that, but
this wording wouldn't apply.)
Justin Pryzby, reviewed by Robert Treat and Jakub Wartak;
a little further wordsmithing by me
Discussion: https://postgr.es/m/20220718143304.GC18011@telsasoft.com
Beginning in v15, if you apply ALTER TABLE ENABLE/DISABLE TRIGGER to
a partitioned table, it also affects the partitions' cloned versions
of the affected trigger(s). The initial implementation of this
located the clones by name, but that fails on foreign-key triggers
which have names incorporating their own OIDs. We can fix that, and
also make the behavior more bulletproof in the face of user-initiated
trigger renames, by identifying the cloned triggers by tgparentid.
Following the lead of earlier commits in this area, I took care not
to break ABI in the v15 branch, even though I rather doubt there
are any external callers of EnableDisableTrigger.
While here, update the documentation, which was not touched when
the semantics were changed.
Per bug #17817 from Alan Hodgson. Back-patch to v15; older versions
do not have this behavior.
Discussion: https://postgr.es/m/17817-31dfb7c2100d9f3d@postgresql.org
It appears no longer possible to build the SGML docs without a local
installation of the DocBook DTD, because sourceforge.net now only
permits HTTPS access, and no common version of xsltproc supports that.
Hence, remove the bits of our documentation suggesting that that's
possible or useful.
In fact, we might as well add the --nonet option to the build recipes
automatically, for a bit of extra security.
Also fix our documentation-tool-installation recipes for macOS to
ensure that xmllint and xsltproc are pulled in from MacPorts or
Homebrew. The previous recipes assumed you could use the
Apple-supplied versions of these tools; which still works, except that
you'd need to set an environment variable to ensure that they would
find DTD files provided by those package managers. Simpler and easier
to just recommend pulling in the additional packages.
In HEAD, also document how to build docs using Meson, and adjust
"ninja docs" to just build the HTML docs, for consistency with the
default behavior of doc/src/sgml/Makefile.
In a fit of neatnik-ism, I also made the ordering of the package
lists match the order in which the tools are described at the head
of the appendix.
Aleksander Alekseev, Peter Eisentraut, Tom Lane
Discussion: https://postgr.es/m/CAJ7c6TO8Aro2nxg=EQsVGiSDe-TstP4EsSvDHd7DSRsP40PgGA@mail.gmail.com
Breaking <phrase> over two lines is not handled by psql's
create_help.pl. (It creates faulty \help output.)
Undo the formatting change introduced by
9bdad1b515 to fix this for now.
Tom Lane
Etsuro Fujita
Andres Freund
David Rowley
Bruce Momjian
Amit Kapila
Fujii Masao
Daniel Gustafsson
Michael Paquier
Peter Geoghegan
Alexander Korotkov
Robert Haas
John Naylor
Peter Eisentraut
Dean Rasheed