Once upon a time we did not have a separate CREATEROLE privilege, and
CREATEUSER effectively meant SUPERUSER. When we invented CREATEROLE
(in 8.1) we also added SUPERUSER so as to have a less confusing keyword
for this role property. However, we left CREATEUSER in place as a
deprecated synonym for SUPERUSER, because of backwards-compatibility
concerns. It's still there and is still confusing people, as for example
in bug #13694 from Justin Catterson. 9.6 will be ten years or so later,
which surely ought to be long enough to end the deprecation and just
remove these old keywords. Hence, do so.
This fixes a long-standing bug which was discovered while investigating
the interaction between the new join pushdown code and the EvalPlanQual
machinery: if a ForeignScan appears on the inner side of a paramaterized
nestloop, an EPQ recheck would re-return the original tuple even if
it no longer satisfied the pushed-down quals due to changed parameter
values.
This fix adds a new member to ForeignScan and ForeignScanState and a
new argument to make_foreignscan, and requires changes to FDWs which
push down quals to populate that new argument with a list of quals they
have chosen to push down. Therefore, I'm only back-patching to 9.5,
even though the bug is not new in 9.5.
Etsuro Fujita, reviewed by me and by Kyotaro Horiguchi.
We hyphenate "fixed-length" earlier in the same sentence, and overall we
more often use "variable-length" rather than "variable length".
Nikolay Shaplov
In general one may have to run both REASSIGN OWNED and DROP OWNED to get
rid of all the dependencies of a role to be dropped. This was alluded to
in the REASSIGN OWNED man page, but not really spelled out in full; and in
any case the procedure ought to be documented in a more prominent place
than that. Add a section to the "Database Roles" chapter explaining this,
and do a bit of wordsmithing in the relevant commands' man pages.
Failure to perform garbage collection now has a user-visible effect, so
explain that and explain that reducing pgss_max is the way to prevent it.
Per gripe from Andrew Dunstan.
The documentation for the autovacuum_multixact_freeze_max_age and
autovacuum_freeze_max_age relation level parameters contained:
"Note that while you can set autovacuum_multixact_freeze_max_age very
small, or even zero, this is usually unwise since it will force frequent
vacuuming."
which hasn't been true since these options were made relation options,
instead of residing in the pg_autovacuum table (834a6da4f7).
Remove the outdated sentence. Even the lowered limits from 2596d70 are
high enough that this doesn't warrant calling out the risk in the CREATE
TABLE docs.
Per discussion with Tom Lane and Alvaro Herrera
Discussion: 26377.1443105453@sss.pgh.pa.us
Backpatch: 9.0- (in parts)
To allow users to force RLS to always be applied, even for table owners,
add ALTER TABLE .. FORCE ROW LEVEL SECURITY.
row_security=off overrides FORCE ROW LEVEL SECURITY, to ensure pg_dump
output is complete (by default).
Also add SECURITY_NOFORCE_RLS context to avoid data corruption when
ALTER TABLE .. FORCE ROW SECURITY is being used. The
SECURITY_NOFORCE_RLS security context is used only during referential
integrity checks and is only considered in check_enable_rls() after we
have already checked that the current user is the owner of the relation
(which should always be the case during referential integrity checks).
Back-patch to 9.5 where RLS was added.
Specifically, make its effect independent from the row_security GUC, and
make it affect permission checks pertinent to views the BYPASSRLS role
owns. The row_security GUC thereby ceases to change successful-query
behavior; it can only make a query fail with an error. Back-patch to
9.5, where BYPASSRLS was introduced.
Without CASCADE, if an extension has an unfullfilled dependency on
another extension, CREATE EXTENSION ERRORs out with "required extension
... is not installed". That is annoying, especially when that dependency
is an implementation detail of the extension, rather than something the
extension's user can make sense of.
In addition to CASCADE this also includes a small set of regression
tests around CREATE EXTENSION.
Author: Petr Jelinek, editorialized by Michael Paquier, Andres Freund
Reviewed-By: Michael Paquier, Andres Freund, Jeff Janes
Discussion: 557E0520.3040800@2ndquadrant.com
It's not terribly hard to devise regular expressions that take large
amounts of time and/or memory to process. Recent testing by Greg Stark has
also shown that machines with small stack limits can be driven to stack
overflow by suitably crafted regexps. While we intend to fix these things
as much as possible, it's probably impossible to eliminate slow-execution
cases altogether. In any case we don't want to treat such things as
security issues. The history of that code should already discourage
prudent DBAs from allowing execution of regexp patterns coming from
possibly-hostile sources, but it seems like a good idea to warn about the
hazard explicitly.
Currently, similar_escape() allows access to enough of the underlying
regexp behavior that the warning has to apply to SIMILAR TO as well.
We might be able to make it safer if we tightened things up to allow only
SQL-mandated capabilities in SIMILAR TO; but that would be a subtly
non-backwards-compatible change, so it requires discussion and probably
could not be back-patched.
Per discussion among pgsql-security list.
The "floatrange" example is a bit too simple because float8mi can be
used without any additional type conversion. Add an example that does
have to account for that, and do some minor other wordsmithing.
Previously it was documented that the details on HeapTupleHeaderData
struct could be found in htup.h. This is not correct because it's now
defined in htup_details.h.
Back-patch to 9.3 where the definition of HeapTupleHeaderData struct
was moved from htup.h to htup_details.h.
Michael Paquier
A Gather executor node runs any number of copies of a plan in an equal
number of workers and merges all of the results into a single tuple
stream. It can also run the plan itself, if the workers are
unavailable or haven't started up yet. It is intended to work with
the Partial Seq Scan node which will be added in future commits.
It could also be used to implement parallel query of a different sort
by itself, without help from Partial Seq Scan, if the single_copy mode
is used. In that mode, a worker executes the plan, and the parallel
leader does not, merely collecting the worker's results. So, a Gather
node could be inserted into a plan to split the execution of that plan
across two processes. Nested Gather nodes aren't currently supported,
but we might want to add support for that in the future.
There's nothing in the planner to actually generate Gather nodes yet,
so it's not quite time to break out the champagne. But we're getting
close.
Amit Kapila. Some designs suggestions were provided by me, and I also
reviewed the patch. Single-copy mode, documentation, and other minor
changes also by me.
With the arrival of the CUBE key word/feature, the index entries for the
cube extension and the CUBE feature were collapsed into one. Tweak the
entry for the cube extension so they are separate entries.
Every query of a single ENABLE ROW SECURITY table has two meanings, with
the row_security GUC selecting between them. With row_security=force
available, every function author would have been advised to either set
the GUC locally or test both meanings. Non-compliance would have
threatened reliability and, for SECURITY DEFINER functions, security.
Authors already face an obligation to account for search_path, and we
should not mimic that example. With this change, only BYPASSRLS roles
need exercise the aforementioned care. Back-patch to 9.5, where the
row_security GUC was introduced.
Since this narrows the domain of pg_db_role_setting.setconfig and
pg_proc.proconfig, one might bump catversion. A row_security=force
setting in one of those columns will elicit a clear message, so don't.
Commit 924bcf4f16 introduced a framework
for parallel computation in PostgreSQL that makes most but not all
built-in functions safe to execute in parallel mode. In order to have
parallel query, we'll need to be able to determine whether that query
contains functions (either built-in or user-defined) that cannot be
safely executed in parallel mode. This requires those functions to be
labeled, so this patch introduces an infrastructure for that. Some
functions currently labeled as safe may need to be revised depending on
how pending issues related to heavyweight locking under paralllelism
are resolved.
Parallel plans can't be used except for the case where the query will
run to completion. If portal execution were suspended, the parallel
mode restrictions would need to remain in effect during that time, but
that might make other queries fail. Therefore, this patch introduces
a framework that enables consideration of parallel plans only when it
is known that the plan will be run to completion. This probably needs
some refinement; for example, at bind time, we do not know whether a
query run via the extended protocol will be execution to completion or
run with a limited fetch count. Having the client indicate its
intentions at bind time would constitute a wire protocol break. Some
contexts in which parallel mode would be safe are not adjusted by this
patch; the default is not to try parallel plans except from call sites
that have been updated to say that such plans are OK.
This commit doesn't introduce any parallel paths or plans; it just
provides a way to determine whether they could potentially be used.
I'm committing it on the theory that the remaining parallel sequential
scan patches will also get committed to this release, hopefully in the
not-too-distant future.
Robert Haas and Amit Kapila. Reviewed (in earlier versions) by Noah
Misch.
The docs claimed that \uhhhh would be interpreted as a Unicode value
regardless of the database encoding, but it's never been implemented
that way: \uhhhh and \xhhhh actually mean exactly the same thing, namely
the character that pg_mb2wchar translates to 0xhhhh. Moreover we were
falsely dismissive of the usefulness of Unicode code points above FFFF.
Fix that.
It's been like this for ages, so back-patch to all supported branches.
This patch adds an option to replace the "time since pgbench run
started" with a Unix epoch timestamp in the progress report so that,
for instance, it is easier to compare timelines with pgsql log
Fabien COELHO <coelho@cri.ensmp.fr>
COMMENT supports POLICY but the documentation hadn't caught up with
that fact.
Patch by Charles Clavadetscher
Back-patch to 9.5 where POLICY was added.
Patch provides command line option --strict-names which requires that at
least one table/schema should present for each -t/-n option.
Pavel Stehule <pavel.stehule@gmail.com>
Per discussion, nowadays it is possible to have tablespaces that have
wildly different I/O characteristics from others. Setting different
effective_io_concurrency parameters for those has been measured to
improve performance.
Author: Julien Rouhaud
Reviewed by: Andres Freund
This new function provides information about SSL extensions present in
the X509 certificate used for the current connection.
Extension version updated to version 1.1.
Author: Дмитрий Воронин (Dmitry Voronin)
Reviewed by: Michael Paquier, Heikki Linnakangas, Álvaro Herrera
Since 6fcd885 it is possible to immediately reserve WAL when creating a
slot via pg_create_physical_replication_slot(). Extend the replication
protocol to allow that as well.
Although, in contrast to the SQL interface, it is possible to update the
reserved location via the replication interface, it is still useful
being able to reserve upon creation there. Otherwise the logic in
ReplicationSlotReserveWal() has to be repeated in slot employing
clients.
Author: Michael Paquier
Discussion: CAB7nPqT0Wc1W5mdYGeJ_wbutbwNN+3qgrFR64avXaQCiJMGaYA@mail.gmail.com
Remove the code in plpgsql that suppressed the innermost line of CONTEXT
for messages emitted by RAISE commands. That was never more than a quick
backwards-compatibility hack, and it's pretty silly in cases where the
RAISE is nested in several levels of function. What's more, it violated
our design theory that verbosity of error reports should be controlled
on the client side not the server side.
To alleviate the resulting noise increase, introduce a feature in libpq
and psql whereby the CONTEXT field of messages can be suppressed, either
always or only for non-error messages. Printing CONTEXT for errors only
is now their default behavior.
The actual code changes here are pretty small, but the effects on the
regression test outputs are widespread. I had to edit some of the
alternative expected outputs by hand; hopefully the buildfarm will soon
find anything I fat-fingered.
In passing, fix up (again) the output line counts in psql's various
help displays. Add some commentary about how to verify them.
Pavel Stehule, reviewed by Petr Jelínek, Jeevan Chalke, and others
The setting values of some parameters including max_worker_processes
must be equal to or higher than the values on the master. However,
previously max_worker_processes was not listed as such parameter
in the document. So this commit adds it to that list.
Back-patch to 9.4 where max_worker_processes was added.
The default argument, if given, has to be of exactly the same datatype
as the first argument; but this was not stated in so many words, and
the error message you get about it might not lead your thought in the
right direction. Per bug #13587 from Robert McGehee.
A quick scan says that these are the only two built-in functions with two
anyelement arguments and no other polymorphic arguments. There are plenty
of cases of, eg, anyarray and anyelement, but those seem less likely to
confuse. For instance this doesn't seem terribly hard to figure out:
"function array_remove(integer[], numeric) does not exist". So I've
contented myself with fixing these two cases.
Although commit 79af9a1d2 was initially applied to HEAD only, we later
back-patched the change into all branches (commits 6bbf75192 et al).
So it's not a new behavior in 9.5 and should not be release-noted here.
This behavior wasn't documented, but it should be because it's user-visible
in triggers and other functions executed on the remote server.
Per question from Adam Fuchs.
Back-patch to 9.3 where postgres_fdw was added.
The table-rewriting forms of ALTER TABLE are MVCC-unsafe, in much the same
way as TRUNCATE, because they replace all rows of the table with newly-made
rows with a new xmin. (Ideally, concurrent transactions with old snapshots
would continue to see the old table contents, but the data is not there
anymore --- and if it were there, it would be inconsistent with the table's
updated rowtype, so there would be serious implementation problems to fix.)
This was nowhere documented though, and the problem was only documented for
TRUNCATE in a note in the TRUNCATE reference page. Create a new "Caveats"
section in the MVCC chapter that can be home to this and other limitations
on serializable consistency.
In passing, fix a mistaken statement that VACUUM and CLUSTER would reclaim
space occupied by a dropped column. They don't reconstruct existing tuples
so they couldn't do that.
Back-patch to all supported branches.
Reduce lock levels down to ShareUpdateExclusiveLock for all autovacuum-related
relation options when setting them using ALTER TABLE.
Add infrastructure to allow varying lock levels for relation options in later
patches. Setting multiple options together uses the highest lock level required
for any option. Works for both main and toast tables.
Fabrízio Mello, reviewed by Michael Paquier, mild edit and additional regression
tests from myself
Fix docs build failure introduced by commit 6fcd88511f.
I failed to resist the temptation to rearrange the description of
pg_create_physical_replication_slot(), too.
When creating a physical slot it's often useful to immediately reserve
the current WAL position instead of only doing after the first feedback
message arrives. That e.g. allows slots to guarantee that all the WAL
for a base backup will be available afterwards.
Logical slots already have to reserve WAL during creation, so generalize
that logic into being usable for both physical and logical slots.
Catversion bump because of the new parameter.
Author: Gurjeet Singh
Reviewed-By: Andres Freund
Discussion: CABwTF4Wh_dBCzTU=49pFXR6coR4NW1ynb+vBqT+Po=7fuq5iCw@mail.gmail.com
There's no reason not to expose both restart_lsn and confirmed_flush
since they have rather distinct meanings. The former is the oldest WAL
still required and valid for both physical and logical slots, whereas
the latter is the location up to which a logical slot's consumer has
confirmed receiving data. Most of the time a slot will require older
WAL (i.e. restart_lsn) than the confirmed
position (i.e. confirmed_flush_lsn).
Author: Marko Tiikkaja, editorialized by me
Discussion: 559D110B.1020109@joh.to
Immediately starting to stream after --create-slot is inconvenient in a
number of situations (e.g. when configuring a slot for use in
recovery.conf) and it's easy to just call pg_receivexlog twice in the
rest of the cases.
Author: Michael Paquier
Discussion: CAB7nPqQ9qEtuDiKY3OpNzHcz5iUA+DUX9FcN9K8GUkCZvG7+Ew@mail.gmail.com
Backpatch: 9.5, where the option was introduced
The allowed syntax for OVERLAPS, viz "row OVERLAPS row", is sufficiently
constrained that we don't actually need a precedence declaration for
OVERLAPS; indeed removing this declaration does not change the generated
gram.c file at all. Let's remove it to avoid confusion about whether
OVERLAPS has precedence or not. If we ever generalize what we allow for
OVERLAPS, we might need to put back a precedence declaration for it,
but we might want some other level than what it has today --- and leaving
the declaration there would just risk confusion about whether that would
be an incompatible change.
Likewise, remove OVERLAPS from the documentation's precedence table.
Per discussion with Noah Misch. Back-patch to 9.5 where we hacked up some
nearby precedence decisions.
Amit reviewed the replication origins patch and made some good
points. Address them. This fixes typos in error messages, docs and
comments and adds a missing error check (although in a
should-never-happen scenario).
Discussion: CAA4eK1JqUBVeWWKwUmBPryFaje4190ug0y-OAUHWQ6tD83V4xg@mail.gmail.com
Backpatch: 9.5, where replication origins were introduced.
Make it more clear that bgw_main is usually not what you want. Put the
background worker flags in a variablelist rather than having them as
part of a paragraph. Explain important limits on how bgw_main_arg can
be used.
Craig Ringer, substantially revised by me.
On Windows, use listen_address=127.0.0.1 to allow TCP connections. We were
already using "pg_regress --config-auth" to set up HBA appropriately. The
standard_initdb helper function now sets up the server's
unix_socket_directories or listen_addresses in the config file, so that
they don't need to be specified in the pg_ctl command line anymore. That
way, the pg_ctl invocations in test programs don't need to differ between
Windows and Unix.
Add another helper function to configure the server's pg_hba.conf to allow
replication connections. The configuration is done similarly to "pg_regress
--config-auth": trust on domain sockets on Unix, and SSPI authentication on
Windows.
Replace calls to "cat" and "touch" programs with built-in perl code, as
those programs don't normally exist on Windows.
Add instructions in the docs on how to install IPC::Run on Windows. Adjust
vcregress.pl to not replace PERL5LIB completely in vcregress.pl, because
otherwise cannot install IPC::Run in a non-standard location easily.
Michael Paquier, reviewed by Noah Misch, some additional tweaking by me.
This option specifies a replication slot for WAL streaming (-X stream),
so that there can be continuous replication slot use between WAL
streaming during the base backup and the start of regular streaming
replication.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
CreatePolicy() and AlterPolicy() omit to create a pg_shdepend entry for
each role in the TO clause. Fix this by creating a new shared dependency
type called SHARED_DEPENDENCY_POLICY and assigning it to each role.
Reported by Noah Misch. Patch by me, reviewed by Alvaro Herrera.
Back-patch to 9.5 where RLS was introduced.
Although initdb has long discouraged use of a filesystem mount-point
directory as a PG data directory, this point was covered nowhere in the
user-facing documentation. Also, with the popularity of pg_upgrade,
we really need to recommend that the PG user own not only the data
directory but its parent directory too. (Without a writable parent
directory, operations such as "mv data data.old" fail immediately.
pg_upgrade itself doesn't do that, but wrapper scripts for it often do.)
Hence, adjust the "Creating a Database Cluster" section to address
these points. I also took the liberty of wordsmithing the discussion
of NFS a bit.
These considerations aren't by any means new, so back-patch to all
supported branches.
The pg_stats view is supposed to be restricted to only show rows
about tables the user can read. However, it sometimes can leak
information which could not otherwise be seen when row level security
is enabled. Fix that by not showing pg_stats rows to users that would
be subject to RLS on the table the row is related to. This is done
by creating/using the newly introduced SQL visible function,
row_security_active().
Along the way, clean up three call sites of check_enable_rls(). The second
argument of that function should only be specified as other than
InvalidOid when we are checking as a different user than the current one,
as in when querying through a view. These sites were passing GetUserId()
instead of InvalidOid, which can cause the function to return incorrect
results if the current user has the BYPASSRLS privilege and row_security
has been set to OFF.
Additionally fix a bug causing RI Trigger error messages to unintentionally
leak information when RLS is enabled, and other minor cleanup and
improvements. Also add WITH (security_barrier) to the definition of pg_stats.
Bumped CATVERSION due to new SQL functions and pg_stats view definition.
Back-patch to 9.5 where RLS was introduced. Reported by Yaroslav.
Patch by Joe Conway and Dean Rasheed with review and input by
Michael Paquier and Stephen Frost.
While postgres' use of SSL renegotiation is a good idea in theory, it
turned out to not work well in practice. The specification and openssl's
implementation of it have lead to several security issues. Postgres' use
of renegotiation also had its share of bugs.
Additionally OpenSSL has a bunch of bugs around renegotiation, reported
and open for years, that regularly lead to connections breaking with
obscure error messages. We tried increasingly complex workarounds to get
around these bugs, but we didn't find anything complete.
Since these connection breakages often lead to hard to debug problems,
e.g. spuriously failing base backups and significant latency spikes when
synchronous replication is used, we have decided to change the default
setting for ssl renegotiation to 0 (disabled) in the released
backbranches and remove it entirely in 9.5 and master.
Author: Andres Freund
Discussion: 20150624144148.GQ4797@alap3.anarazel.de
Backpatch: 9.5 and master, 9.0-9.4 get a different patch
