Table partitioning is like table inheritance and reuses much of the
existing infrastructure, but there are some important differences.
The parent is called a partitioned table and is always empty; it may
not have indexes or non-inherited constraints, since those make no
sense for a relation with no data of its own. The children are called
partitions and contain all of the actual data. Each partition has an
implicit partitioning constraint. Multiple inheritance is not
allowed, and partitioning and inheritance can't be mixed. Partitions
can't have extra columns and may not allow nulls unless the parent
does. Tuples inserted into the parent are automatically routed to the
correct partition, so tuple-routing ON INSERT triggers are not needed.
Tuple routing isn't yet supported for partitions which are foreign
tables, and it doesn't handle updates that cross partition boundaries.
Currently, tables can be range-partitioned or list-partitioned. List
partitioning is limited to a single column, but range partitioning can
involve multiple columns. A partitioning "column" can be an
expression.
Because table partitioning is less general than table inheritance, it
is hoped that it will be easier to reason about properties of
partitions, and therefore that this will serve as a better foundation
for a variety of possible optimizations, including query planner
optimizations. The tuple routing based which this patch does based on
the implicit partitioning constraints is an example of this, but it
seems likely that many other useful optimizations are also possible.
Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat,
Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova,
Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
If the PAGER environment variable is set but contains an empty string,
psql would pass it to "sh" which would silently exit, causing whatever
query output we were printing to vanish entirely. This is quite
mystifying; it took a long time for us to figure out that this was the
cause of Joseph Brenner's trouble report. Rather than allowing that
to happen, we should treat this as another way to specify "no pager".
(We could alternatively treat it as selecting the default pager, but
it seems more likely that the former is what the user meant to achieve
by setting PAGER this way.)
Nonempty, but all-white-space, PAGER values have the same behavior, and
it's pretty easy to test for that, so let's handle that case the same way.
Most other cases of faulty PAGER values will result in the shell printing
some kind of complaint to stderr, which should be enough to diagnose the
problem, so we don't need to work harder than this. (Note that there's
been an intentional decision not to be very chatty about apparent failure
returns from the pager process, since that may happen if, eg, the user
quits the pager with control-C or some such. I'd just as soon not start
splitting hairs about which exit codes might merit making our own report.)
libpq's old PQprint() function was already on board with ignoring empty
PAGER values, but for consistency, make it ignore all-white-space values
as well.
It's been like this a long time, so back-patch to all supported branches.
Discussion: https://postgr.es/m/CAFfgvXWLOE2novHzYjmQK8-J6TmHz42G8f3X0SORM44+stUGmw@mail.gmail.com
Previously, a prepared statement created via a Parse message could get
a parallel plan, but one created with a PREPARE statement could not.
This state of affairs was due to confusion on my (rhaas) part: I
erroneously believed that a CREATE TABLE .. AS EXECUTE statement could
only be performed with a prepared statement by PREPARE, but in fact
one created by a Prepare message works just as well. Therefore, it
makes no sense to allow parallel query in one case but not the other.
To fix, allow parallel query with all prepared statements, but run
the parallel plan serially (i.e. without workers) in the case of
CREATE TABLE .. AS EXECUTE. Also, document this.
Amit Kapila and Tobias Bussman, plus an extra sentence of
documentation by me.
Add the descriptions of possible values in "state" and "sync_state" columns
of pg_stat_replication view.
Author: Michael Paquier, slightly modified by me
Discussion: <CAB7nPqT7APWrvPFZrcjKEHoq4=g3z2ErxtTdojSf+sDALzuemA@mail.gmail.com>
We have had support for restrictive RLS policies since 9.5, but they
were only available through extensions which use the appropriate hooks.
This adds support into the grammer, catalog, psql and pg_dump for
restrictive RLS policies, thus reducing the cases where an extension is
necessary.
In passing, also move away from using "AND"d and "OR"d in comments.
As pointed out by Alvaro, it's not really appropriate to attempt
to make verbs out of "AND" and "OR", so reword those comments which
attempted to.
Reviewed By: Jeevan Chalke, Dean Rasheed
Discussion: https://postgr.es/m/20160901063404.GY4028@tamriel.snowman.net
Commit b460f5d669 -- at my suggestion --
increased the default value of max_worker_processes from 8 to 16, on
the theory that this would be harmless and convenient for users.
Unfortunately, this caused some buildfarm machines with low connection
limits to start failing, so apparently it's not harmless after all.
This adds a new routine, pg_strong_random() for generating random bytes,
for use in both frontend and backend. At the moment, it's only used in
the backend, but the upcoming SCRAM authentication patches need strong
random numbers in libpq as well.
pg_strong_random() is based on, and replaces, the existing implementation
in pgcrypto. It can acquire strong random numbers from a number of sources,
depending on what's available:
- OpenSSL RAND_bytes(), if built with OpenSSL
- On Windows, the native cryptographic functions are used
- /dev/urandom
Unlike the current pgcrypto function, the source is chosen by configure.
That makes it easier to test different implementations, and ensures that
we don't accidentally fall back to a less secure implementation, if the
primary source fails. All of those methods are quite reliable, it would be
pretty surprising for them to fail, so we'd rather find out by failing
hard.
If no strong random source is available, we fall back to using erand48(),
seeded from current timestamp, like PostmasterRandom() was. That isn't
cryptographically secure, but allows us to still work on platforms that
don't have any of the above stronger sources. Because it's not very secure,
the built-in implementation is only used if explicitly requested with
--disable-strong-random.
This replaces the more complicated Fortuna algorithm we used to have in
pgcrypto, which is unfortunate, but all modern platforms have /dev/urandom,
so it doesn't seem worth the maintenance effort to keep that. pgcrypto
functions that require strong random numbers will be disabled with
--disable-strong-random.
Original patch by Magnus Hagander, tons of further work by Michael Paquier
and me.
Discussion: https://www.postgresql.org/message-id/CAB7nPqRy3krN8quR9XujMVVHYtXJ0_60nqgVc6oUk8ygyVkZsA@mail.gmail.com
Discussion: https://www.postgresql.org/message-id/CAB7nPqRWkNYRRPJA7-cF+LfroYV10pvjdz6GNvxk-Eee9FypKA@mail.gmail.com
deleteWhatDependsOn() had grown an uncomfortably large number of
assumptions about what it's used for. There are actually only two minor
differences between what it does and what a regular performDeletion() call
can do, so let's invent additional bits in performDeletion's existing flags
argument that specify those behaviors, and get rid of deleteWhatDependsOn()
as such. (We'd probably have done it this way from the start, except that
performDeletion didn't originally have a flags argument, IIRC.)
Also, add a SKIP_EXTENSIONS flag bit that prevents ever recursing to an
extension, and use that when dropping temporary objects at session end.
This provides a more general solution to the problem addressed in a hacky
way in commit 08dd23cec: if an extension script creates temp objects and
forgets to remove them again, the whole extension went away when its
contained temp objects were deleted. The previous solution only covered
temp relations, but this solves it for all object types.
These changes require minor additions in dependency.c to pass the flags
to subroutines that previously didn't get them, but it's still a net
savings of code, and it seems cleaner than before.
Having done this, revert the special-case code added in 08dd23cec that
prevented addition of pg_depend records for temp table extension
membership, because that caused its own oddities: dropping an extension
that had created such a table didn't automatically remove the table,
leading to a failure if the table had another dependency on the extension
(such as use of an extension data type), or to a duplicate-name failure if
you then tried to recreate the extension. But we keep the part that
prevents the pg_temp_nnn schema from becoming an extension member; we never
want that to happen. Add a regression test case covering these behaviors.
Although this fixes some arguable bugs, we've heard few field complaints,
and any such problems are easily worked around by explicitly dropping temp
objects at the end of extension scripts (which seems like good practice
anyway). So I won't risk a back-patch.
Discussion: https://postgr.es/m/e51f4311-f483-4dd0-1ccc-abec3c405110@BlueTreble.com
There was always documentation of the GUC that controlled what the
limit actually was, but previously the documentation of the field
itself made no mention of that limit.
Ian Barwick
Increase the default value of the existing max_worker_processes GUC
from 8 to 16, and add a new max_parallel_workers GUC with a maximum
of 8. This way, even if the maximum amount of parallel query is
happening, there is still room for background workers that do other
things, as originally envisioned when max_worker_processes was added.
Julien Rouhaud, reviewed by Amit Kapila and by revised by me.
Per bug #14441 from Mark Pether, the documentation could be misread,
mainly because some of the examples failed to show what happens with
a multicharacter "characters to trim" string. Also, while the text
description in most of these entries was fairly clear that the
"characters" argument is a set of characters not a substring to match,
some of them used variant wording that was a bit less clear.
trim() itself suffered from both deficiencies and was thus pretty
misinterpretable.
Also fix failure to explain which of LEADING/TRAILING/BOTH is the
default.
Discussion: https://postgr.es/m/20161130011710.6539.53657@wrigleys.postgresql.org
Commit 274bb2b385 made it possible to
specify multiple IPs in a connection string, but that's not good
enough for the case where you have a read-write master and a bunch of
read-only standbys and want to connect to whichever server is the
master at the current time. This commit allows that, by making it
possible to specify target_session_attrs=read-write as a connection
parameter.
There was extensive discussion of the best name for the connection
parameter and its values as well as the best way to distinguish master
and standbys. For now, adopt the same solution as JDBC: if the user
wants a read-write connection, issue 'show transaction_read_only' and
rejection the connection if the result is 'on'. In the future, we
could add additional values of this new target_session_attrs parameter
that issue different queries; or we might have some way of
distinguishing the server type without resorting to an SQL query; but
right now, we have this, and that's (hopefully) a good start.
Victor Wagner and Mithun Cy. Design review by Álvaro Herrera, Catalin
Iacob, Takayuki Tsunakawa, and Craig Ringer; code review by me. I
changed Mithun's patch to skip all remaining IPs for a host if we
reject a connection based on this new parameter, rewrote the
documentation, and did some other cosmetic cleanup.
Discussion: http://postgr.es/m/CAD__OuhqPRGpcsfwPHz_PDqAGkoqS1UvnUnOnAB-LBWBW=wu4A@mail.gmail.com
Add an option to exclude blobs when running pg_dump. By default, blobs
are included but this option can be used to exclude them while keeping
the rest of the dump.
Commment updates and regression tests from me.
Author: Guillaume Lelarge
Reviewed-by: Amul Sul
Discussion: https://postgr.es/m/VisenaEmail.48.49926ea6f91dceb6.15355a48249@tc7-visena
The documentation around the -b/--blobs option to pg_dump seemed to
imply that it might be possible to add blobs to a "schema-only" dump or
similar. Clarify that blobs are data and therefore will only be
included in dumps where data is being included, even when -b is used to
request blobs be included.
The -b option has been around since before 9.2, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/20161119173316.GA13284@tamriel.snowman.net
An example in the psql documentation had an incorrect field name from
what the command actually produced.
Pointed out by Fabien COELHO
Back-patch to 9.6 where the example was added.
Discussion: https://postgr.es/m/alpine.DEB.2.20.1611291349400.19314@lancre
Instead of confusingly stating platform-dependent defaults for these
parameters in the comments in postgresql.conf.sample (with the main
entry being a lie on Linux), teach initdb to install the correct
platform-dependent value in postgresql.conf, similarly to the way
we handle other platform-dependent defaults. This won't do anything
for existing 9.6 installations, but since it's effectively only a
documentation improvement, that seems OK.
Since this requires initdb to have access to the default values,
move the #define's for those to pg_config_manual.h; the original
placement in bufmgr.h is unworkable because that file can't be
included by frontend programs.
Adjust the default value for wal_writer_flush_after so that it is 1MB
regardless of XLOG_BLCKSZ, conforming to what is stated in both the
SGML docs and postgresql.conf. (We could alternatively make it scale
with XLOG_BLCKSZ, but I'm not sure I see the point.)
Copy-edit related SGML documentation.
Fabien Coelho and Tom Lane, per a gripe from Tomas Vondra.
Discussion: <30ebc6e3-8358-09cf-44a8-578252938424@2ndquadrant.com>
Create a section specifically for the syntactic rules around whole-row
variable usage, such as expansion of "foo.*". This was previously
documented only haphazardly, with some critical info buried in
unexpected places like xfunc-sql-composite-functions. Per repeated
questions in different mailing lists.
Discussion: <16288.1479610770@sss.pgh.pa.us>
Avoid memory leak in conninfo_uri_parse_options. Use the current host
rather than the comma-separated list of host names when the host name
is needed for GSS, SSPI, or SSL authentication. Document the way
connect_timeout interacts with multiple host specifications.
Takayuki Tsunakawa
Previously, the right-hand side of a multiple-column assignment, if it
wasn't a sub-SELECT, had to be a simple parenthesized expression list,
because gram.y was responsible for "bursting" the construct into
independent column assignments. This had the minor defect that you
couldn't write ROW (though you should be able to, since the standard says
this is a row constructor), and the rather larger defect that unlike other
uses of row constructors, we would not expand a "foo.*" item into multiple
columns.
Fix that by changing the RHS to be just "a_expr" in the grammar, leaving
it to transformMultiAssignRef to separate the elements of a RowExpr;
which it will do only after performing standard transformation of the
RowExpr, so that "foo.*" behaves as expected.
The key reason we didn't do that before was the hard-wired handling of
DEFAULT tokens (SetToDefault nodes). This patch deals with that issue by
allowing DEFAULT in any a_expr and having parse analysis throw an error
if SetToDefault is found in an unexpected place. That's an improvement
anyway since the error can be more specific than just "syntax error".
The SQL standard suggests that the RHS could be any a_expr yielding a
suitable row value. This patch doesn't really move the goal posts in that
respect --- you're still limited to RowExpr or a sub-SELECT --- but it does
fix the grammar restriction, so it provides some tangible progress towards
a full implementation. And the limitation is now documented by an explicit
error message rather than an unhelpful "syntax error".
Discussion: <8542.1479742008@sss.pgh.pa.us>
There are assorted references to RETURNING in Part II, but nothing
that would qualify as an explanation of the feature, which seems
like an oversight considering how useful it is. Add something.
Noted while looking for a place to point a cross-reference to ...
Like pg_tables, pg_views, and others, this view contains information
about sequences in a way that is independent of the system catalog
layout but more comprehensive than the information schema.
To help implement the view, add a new internal function
pg_sequence_last_value() to return the last value of a sequence. This
is kept separate from pg_sequence_parameters() to separate querying
run-time state from catalog-like information.
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Cut out some expensive stuff from the HTML head element that we don't
really need.
This was previously discussed as part of
e8306745e3, but ended up separate because
it changes the output contents slightly.
This allows us to avoid running the regression tests in contrib modules
like pg_stat_statement in a less ugly manner.
Discussion: <22432.1478968242@sss.pgh.pa.us>
Commit 3c4cf08087 should have removed SET TABLESPACE from the synopsis
of ALTER MATERIALIZE VIEW as a possible "action" when it added a
separate line for it in the main command listing, but failed to.
Repair.
Backpatch to 9.4, like the aforementioned commit.
The documentation for ts_headline() recommends using a sub-select to
avoid extra evaluations of ts_headline() in a query with ORDER BY+LIMIT.
Since commit 9118d03a8 this contortionism is unnecessary, so remove the
recommendation. Noted by Oleg Bartunov.
Discussion: <CAF4Au4w6rrH_j1bvVhzpOsRiHCog7sGJ3LSX0tY8ZdwhHT88LQ@mail.gmail.com>
Commit 23a27b039 widened these from uint32 to uint64, but I overlooked
that the documentation explicitly showed them as uint32. Per report
from Vicky Vergara.
Report: <20161111135422.8761.36733@wrigleys.postgresql.org>
We just pass the data to the INSTEAD trigger.
Haribabu Kommi, reviewed by Dilip Kumar
Patch: <CAJrrPGcSQkrNkO+4PhLm4B8UQQQmU9YVUuqmtgM=pmzMfxWaWQ@mail.gmail.com>
The idea behind SPI_push was to allow transitioning back into an
"unconnected" state when a SPI-using procedure calls unrelated code that
might or might not invoke SPI. That sounds good, but in practice the only
thing it does for us is to catch cases where a called SPI-using function
forgets to call SPI_connect --- which is a highly improbable failure mode,
since it would be exposed immediately by direct testing of said function.
As against that, we've had multiple bugs induced by forgetting to call
SPI_push/SPI_pop around code that might invoke SPI-using functions; these
are much harder to catch and indeed have gone undetected for years in some
cases. And we've had to band-aid around some problems of this ilk by
introducing conditional push/pop pairs in some places, which really kind
of defeats the purpose altogether; if we can't draw bright lines between
connected and unconnected code, what's the point?
Hence, get rid of SPI_push[_conditional], SPI_pop[_conditional], and the
underlying state variable _SPI_curid. It turns out SPI_restore_connection
can go away too, which is a nice side benefit since it was never more than
a kluge. Provide no-op macros for the deleted functions so as to avoid an
API break for external modules.
A side effect of this removal is that SPI_palloc and allied functions no
longer permit being called when unconnected; they'll throw an error
instead. The apparent usefulness of the previous behavior was a mirage
as well, because it was depended on by only a few places (which I fixed in
preceding commits), and it posed a risk of allocations being unexpectedly
long-lived if someone forgot a SPI_push call.
Discussion: <20808.1478481403@sss.pgh.pa.us>
Invent a new function heap_modify_tuple_by_cols() that is functionally
equivalent to SPI_modifytuple except that it always allocates its result
by simple palloc. I chose however to make the API details a bit more
like heap_modify_tuple: pass a tupdesc rather than a Relation, and use
bool convention for the isnull array.
Use this function in place of SPI_modifytuple at all call sites where the
intended behavior is to allocate in current context. (There actually are
only two call sites left that depend on the old behavior, which makes me
wonder if we should just drop this function rather than keep it.)
This new function is easier to use than heap_modify_tuple() for purposes
of replacing a single column (or, really, any fixed number of columns).
There are a number of places where it would simplify the code to change
over, but I resisted that temptation for the moment ... everywhere except
in plpgsql's exec_assign_value(); changing that might offer some small
performance benefit, so I did it.
This is on the way to removing SPI_push/SPI_pop, but it seems like
good code cleanup in its own right.
Discussion: <9633.1478552022@sss.pgh.pa.us>
There's basically no scenario where it's sensible for this to match
dropped columns, so put a test for dropped-ness into SPI_fnumber()
itself, and excise the test from the small number of callers that
were paying attention to the case. (Most weren't :-(.)
In passing, normalize tests at call sites: always reject attnum <= 0
if we're disallowing system columns. Previously there was a mixture
of "< 0" and "<= 0" tests. This makes no practical difference since
SPI_fnumber() never returns 0, but I'm feeling pedantic today.
Also, in the places that are actually live user-facing code and not
legacy cruft, distinguish "column not found" from "can't handle
system column".
Per discussion with Jim Nasby; thi supersedes his original patch
that just changed the behavior at one call site.
Discussion: <b2de8258-c4c0-1cb8-7b97-e8538e5c975c@BlueTreble.com>
This reverts commit c8ead2a397.
Seems there is no way to do this that doesn't cause MSVC to give
warnings, so let's just go back to the way we've been doing it.
Discussion: <11843.1478358206@sss.pgh.pa.us>
For a very long time, pltcl's spi_exec and spi_execp commands have had
a behavior of storing the current row number as an element of output
arrays, but this was never documented. Fix that.
For an equally long time, pltcl_trigger_handler had a behavior of silently
ignoring ".tupno" as an output column name, evidently so that the result
of spi_exec could be used directly as a trigger result tuple. Not sure
how useful that really is, but in any case it's bad that it would break
attempts to use ".tupno" as an actual column name. We can fix it by not
checking for ".tupno" until after we check for a column name match. This
comports with the effective behavior of spi_exec[p] that ".tupno" is only
magic when you don't have an actual column named that.
In passing, wordsmith the description of returning modified tuples from
a pltcl trigger.
Noted while working on Jim Nasby's patch to support composite results
from pltcl. The inability to return trigger tuples using ".tupno" as
a column name is a bug, so back-patch to all supported branches.
Second try at the change originally made in commit 8518583cd;
this time with contrib updates so that manual extern declarations
are also marked with PGDLLEXPORT. The release notes should point
this out as a significant source-code change for extension authors,
since they'll have to make similar additions to avoid trouble on Windows.
Laurenz Albe, doc change by me
Patch: <A737B7A37273E048B164557ADEF4A58B53962ED8@ntex2010a.host.magwien.gv.at>
This function is unreferenced in modern usage; it was superseded in 9.1
by a core function of the same name. It has been left in place in the C
code only so that pre-9.1 SQL definitions of the contrib/xml2 functions
would continue to work. Six years seems like enough time for people to
have updated to the extension-style version of the xml2 module, so let's
drop this.
The key reason for not keeping it any longer is that we want to stick
an explicit PGDLLEXPORT into PG_FUNCTION_INFO_V1(), and the similarity
of name to the core function creates a conflict that compilers will
complain about.
Extracted from a larger patch for that purpose. I'm committing this
change separately to give it more visibility in the commit logs.
While at it, remove the documentation entry that claimed that
xml_is_well_formed() is a function provided by contrib/xml2, and
instead mention the even more ancient alias xml_valid().
Laurenz Albe, doc change by me
Patch: <A737B7A37273E048B164557ADEF4A58B53962ED8@ntex2010a.host.magwien.gv.at>
Robert Haas