Commit Graph

7798 Commits

Author SHA1 Message Date
6e1dd2773e Unify SIGHUP handling between normal and walsender backends.
Because walsender and normal backends share the same main loop it's
problematic to have two different flag variables, set in signal
handlers, indicating a pending configuration reload.  Only certain
walsender commands reach code paths checking for the
variable (START_[LOGICAL_]REPLICATION, CREATE_REPLICATION_SLOT
... LOGICAL, notably not base backups).

This is a bug present since the introduction of walsender, but has
gotten worse in releases since then which allow walsender to do more.

A later patch, not slated for v10, will similarly unify SIGHUP
handling in other types of processes as well.

Author: Petr Jelinek, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170423235941.qosiuoyqprq4nu7v@alap3.anarazel.de
Backpatch: 9.2-, bug is present since 9.0
2017-06-05 19:18:16 -07:00
c6c3334364 Prevent possibility of panics during shutdown checkpoint.
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and
throws a PANIC if so.  At that point, only walsenders are still
active, so one might think this could not happen, but walsenders can
also generate WAL, for instance in BASE_BACKUP and logical decoding
related commands (e.g. via hint bits).  So they can trigger this panic
if such a command is run while the shutdown checkpoint is being
written.

To fix this, divide the walsender shutdown into two phases.  First,
checkpointer, itself triggered by postmaster, sends a
PROCSIG_WALSND_INIT_STOPPING signal to all walsenders.  If the backend
is idle or runs an SQL query this causes the backend to shutdown, if
logical replication is in progress all existing WAL records are
processed followed by a shutdown.  Otherwise this causes the walsender
to switch to the "stopping" state. In this state, the walsender will
reject any further replication commands. The checkpointer begins the
shutdown checkpoint once all walsenders are confirmed as
stopping. When the shutdown checkpoint finishes, the postmaster sends
us SIGUSR2. This instructs walsender to send any outstanding WAL,
including the shutdown checkpoint record, wait for it to be replicated
to the standby, and then exit.

Author: Andres Freund, based on an earlier patch by Michael Paquier
Reported-By: Fujii Masao, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
Backpatch: 9.4, where logical decoding was introduced
2017-06-05 19:18:15 -07:00
703f148e98 Revert "Prevent panic during shutdown checkpoint"
This reverts commit 086221cf6b1727c2baed4703c582f657b7c5350e, which
was made to master only.

The approach implemented in the above commit has some issues.  While
those could easily be fixed incrementally, doing so would make
backpatching considerably harder, so instead first revert this patch.

Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
2017-06-05 19:18:15 -07:00
9907b55ceb Fix ALTER SUBSCRIPTION grammar ambiguity
There was a grammar ambiguity between SET PUBLICATION name REFRESH and
SET PUBLICATION SKIP REFRESH, because SKIP is not a reserved word.  To
resolve that, fold the refresh choice into the WITH options.  Refreshing
is the default now.

Reported-by: tushar <tushar.ahuja@enterprisedb.com>
2017-06-05 21:43:25 -04:00
3e60c6f723 Code review for shm_toc.h/.c.
Declare the toc_nentry field as uint32 not Size.  Since shm_toc_lookup()
reads the field without any lock, it has to be atomically readable, and
we do not assume that for fields wider than 32 bits.  Performance would
be impossibly bad for entry counts approaching 2^32 anyway, so there is
no need to try to preserve maximum width here.

This is probably an academic issue, because even if reading int64 isn't
atomic, the high order half would never change in practice.  Still, it's
a coding rule violation, so let's fix it.

Adjust some other not-terribly-well-chosen data types too, and copy-edit
some comments.  Make shm_toc_attach's Asserts consistent with
shm_toc_create's.

None of this looks to be a live bug, so no need for back-patch.

Discussion: https://postgr.es/m/16984.1496679541@sss.pgh.pa.us
2017-06-05 14:50:59 -04:00
d466335064 Don't be so trusting that shm_toc_lookup() will always succeed.
Given the possibility of race conditions and so on, it seems entirely
unsafe to just assume that shm_toc_lookup() always finds the key it's
looking for --- but that was exactly what all but one call site were
doing.  To fix, add a "bool noError" argument, similarly to what we
have in many other functions, and throw an error on an unexpected
lookup failure.  Remove now-redundant Asserts that a rather random
subset of call sites had.

I doubt this will throw any light on buildfarm member lorikeet's
recent failures, because if an unnoticed lookup failure were involved,
you'd kind of expect a null-pointer-dereference crash rather than the
observed symptom.  But you never know ... and this is better coding
practice even if it never catches anything.

Discussion: https://postgr.es/m/9697.1496675981@sss.pgh.pa.us
2017-06-05 12:05:42 -04:00
553e16951c Fix comments in simplehash.h.
Jeff Janes and me.

Discussion: https://www.postgresql.org/message-id/CAMkU=1zYnniLYg+W9itL93DXebCjx6Uk6m_=Xa8p_zM65X3S0Q@mail.gmail.com
2017-06-05 11:07:42 +03:00
9db7d47f90 #ifdef out assorted unused GEQO code.
I'd always assumed that backend/optimizer/geqo/'s remarkably poor
showing on code coverage metrics was because we weren't exercising
it much in the regression tests.  But it turns out that a good chunk
of the problem is that there's a bunch of code that is physically
unreachable (because the calls to it are #ifdef'd out in geqo_main.c)
but is being built anyway.  Making the called code have #if guards
similar to the calling code saves a couple of kilobytes of executable
size and should make the coverage numbers more reflective of reality.

It's arguable that we should just delete all the unused recombination
mechanisms altogether, but I didn't feel a need to go that far today.
2017-06-04 13:34:05 -04:00
0d18852666 Disallow CREATE INDEX if table is already in use in current session.
If we allow this, whatever outer command has the table open will not know
about the new index and may fail to update it as needed, as shown in a
report from Laurenz Albe.  We already had such a prohibition in place for
ALTER TABLE, but the CREATE INDEX syntax missed the check.

Fixing it requires an API change for DefineIndex(), which conceivably
would break third-party extensions if we were to back-patch it.  Given
how long this problem has existed without being noticed, fixing it in
the back branches doesn't seem worth that risk.

Discussion: https://postgr.es/m/A737B7A37273E048B164557ADEF4A58B53A4DC9A@ntex2010i.host.magwien.gv.at
2017-06-04 12:02:41 -04:00
9fcf670c2e Fix signal handling in logical replication workers
The logical replication worker processes now use the normal die()
handler for SIGTERM and CHECK_FOR_INTERRUPTS() instead of custom code.
One problem before was that the apply worker would not exit promptly
when a subscription was dropped, which could lead to deadlocks.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Masahiko Sawada <sawada.mshk@gmail.com>
2017-06-02 14:49:23 -04:00
b5b3229141 Avoid -Wconversion warnings from direct use of GET_n_BYTES macros.
The GET/SET_n_BYTES macros are meant to be infrastructure for the
DatumGetFoo/FooGetDatum macros, which include a cast to the intended
target type.  Using them directly without a cast, as DatumGetFloat4
and friends previously did, can yield warnings when -Wconversion is on.
This is of little significance when building Postgres proper, because
there are such a huge number of such warnings in the server that nobody
would think -Wconversion is of any use.  But some extensions build with
-Wconversion due to outside constraints.  Commit 14cca1bf8 did a disservice
to those extensions by moving DatumGetFloat4 et al into postgres.h,
where they can now cause warnings in extension builds.

To fix, use DatumGetInt32 and friends in place of the low-level macros.
This is arguably a bit cleaner anyway.

Chapman Flack

Discussion: https://postgr.es/m/592E4D04.1070609@anastigmatix.net
2017-05-31 11:27:21 -04:00
54e839fe29 Sort syscache identifiers into alphabetical order.
Not much point in having a convention about this if we don't enforce it.

Mark Dilger

Discussion: https://postgr.es/m/7F67FBEF-C3B3-404E-8EC6-E02ACB15D894@gmail.com
2017-05-30 18:47:13 -04:00
80f583ffe9 Fix omission of locations in outfuncs/readfuncs partitioning node support.
We could have limped along without this for v10, which was my intention
when I annotated the bug in commit 76a3df6e5.  But consensus is that it's
better to fix it now and take the cost of a post-beta1 initdb (which is
needed because these node types are stored in pg_class.relpartbound).

Since we're forcing initdb anyway, take the opportunity to make the node
type identification strings match the node struct names, instead of being
randomly different from them.

Discussion: https://postgr.es/m/E1dFBEX-0004wt-8t@gemulon.postgresql.org
2017-05-30 11:32:41 -04:00
76a3df6e5e Code review focused on new node types added by partitioning support.
Fix failure to check that we got a plain Const from const-simplification of
a coercion request.  This is the cause of bug #14666 from Tian Bing: there
is an int4 to money cast, but it's only stable not immutable (because of
dependence on lc_monetary), resulting in a FuncExpr that the code was
miserably unequipped to deal with, or indeed even to notice that it was
failing to deal with.  Add test cases around this coercion behavior.

In view of the above, sprinkle the code liberally with castNode() macros,
in hope of catching the next such bug a bit sooner.  Also, change some
functions that were randomly declared to take Node* to take more specific
pointer types.  And change some struct fields that were declared Node*
but could be given more specific types, allowing removal of assorted
explicit casts.

Place PARTITION_MAX_KEYS check a bit closer to the code it's protecting.
Likewise check only-one-key-for-list-partitioning restriction in a less
random place.

Avoid not-per-project-style usages like !strcmp(...).

Fix assorted failures to avoid scribbling on the input of parse
transformation.  I'm not sure how necessary this is, but it's entirely
silly for these functions to be expending cycles to avoid that and not
getting it right.

Add guards against partitioning on system columns.

Put backend/nodes/ support code into an order that matches handling
of these node types elsewhere.

Annotate the fact that somebody added location fields to PartitionBoundSpec
and PartitionRangeDatum but forgot to handle them in
outfuncs.c/readfuncs.c.  This is fairly harmless for production purposes
(since readfuncs.c would just substitute -1 anyway) but it's still bogus.
It's not worth forcing a post-beta1 initdb just to fix this, but if we
have another reason to force initdb before 10.0, we should go back and
clean this up.

Contrariwise, somebody added location fields to PartitionElem and
PartitionSpec but forgot to teach exprLocation() about them.

Consolidate duplicative code in transformPartitionBound().

Improve a couple of error messages.

Improve assorted commentary.

Re-pgindent the files touched by this patch; this affects a few comment
blocks that must have been added quite recently.

Report: https://postgr.es/m/20170524024550.29935.14396@wrigleys.postgresql.org
2017-05-28 23:20:28 -04:00
a6fd7b7a5f Post-PG 10 beta1 pgindent run
perltidy run not included.
2017-05-17 16:31:56 -04:00
944dc0f9ce Check relkind of tables in CREATE/ALTER SUBSCRIPTION
We used to only check for a supported relkind on the subscriber during
replication, which is needed to ensure that the setup is valid and we
don't crash.  But it's also useful to tell the user immediately when
CREATE or ALTER SUBSCRIPTION is executed that the relation being added
to the subscription is not of a supported relkind.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: tushar <tushar.ahuja@enterprisedb.com>
2017-05-16 22:57:16 -04:00
c079673dcb Preventive maintenance in advance of pgindent run.
Reformat various places in which pgindent will make a mess, and
fix a few small violations of coding style that I happened to notice
while perusing the diffs from a pgindent dry run.

There is one actual bug fix here: the need-to-enlarge-the-buffer code
path in icu_convert_case was obviously broken.  Perhaps it's unreachable
in our usage?  Or maybe this is just sadly undertested.
2017-05-16 20:36:35 -04:00
59f40566ca Fix relcache leak when row triggers on partitions are fired by COPY.
Thomas Munro, reviewed by Amit Langote

Discussion: http://postgr.es/m/CAEepm=15Jss-yhFApuKzxcoCuFnb8TR8iQiWMjG=CLYPx48QLw@mail.gmail.com
2017-05-16 12:46:32 -04:00
5ad367a35b Stamp 10beta1. 2017-05-15 17:20:59 -04:00
b5b0db19b8 Fix handling of extended statistics during ALTER COLUMN TYPE.
ALTER COLUMN TYPE on a column used by a statistics object fails since
commit 928c4de30, because the relevant switch in ATExecAlterColumnType
is unprepared for columns to have dependencies from OCLASS_STATISTIC_EXT
objects.

Although the existing types of extended statistics don't actually need us
to do any work for a column type change, it seems completely indefensible
that that assumption is hidden behind the failure of an unrelated module
to contain any code for the case.  Hence, create and call an API function
in statscmds.c where the assumption can be explained, and where we could
add code to deal with the problem when it inevitably becomes real.

Also, the reason this wasn't handled before, neither for extended stats
nor for the last half-dozen new OCLASS kinds :-(, is that the default:
in that switch suppresses compiler warnings, allowing people to miss the
need to consider it when adding an OCLASS.  We don't really need a default
because surely getObjectClass should only return valid values of the enum;
so remove it, and add the missed OCLASS entries where they should be.

Discussion: https://postgr.es/m/20170512221010.nglatgt5azzdxjlj@alvherre.pgsql
2017-05-14 12:22:25 -04:00
f674743487 Remove no-longer-needed fields of Hash plan nodes.
skewColType/skewColTypmod are no longer used in the wake of commit
9aab83fc5, and seem unlikely to be wanted in future, so let's drop 'em.

Discussion: https://postgr.es/m/16364.1494520862@sss.pgh.pa.us
2017-05-14 11:07:40 -04:00
f04c9a6146 Standardize terminology for pg_statistic_ext entries.
Consistently refer to such an entry as a "statistics object", not just
"statistics" or "extended statistics".  Previously we had a mismash of
terms, accompanied by utter confusion as to whether the term was
singular or plural.  That's not only grating (at least to the ear of
a native English speaker) but could be outright misleading, eg in error
messages that seemed to be referring to multiple objects where only one
could be meant.

This commit fixes the code and a lot of comments (though I may have
missed a few).  I also renamed two new SQL functions,
pg_get_statisticsextdef -> pg_get_statisticsobjdef
pg_statistic_ext_is_visible -> pg_statistics_obj_is_visible
to conform better with this terminology.

I have not touched the SGML docs other than fixing those function
names; the docs certainly need work but it seems like a separable task.

Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
2017-05-14 10:55:01 -04:00
955a684e04 Fix race condition leading to hanging logical slot creation.
The snapshot assembly during the creation of logical slots relied
waiting for transactions in xl_running_xacts to end, by checking for
their commit/abort records.  Unfortunately, despite locking, it is
possible to see an xl_running_xact record listing transactions as
ready, that have already WAL-logged an commit/abort record, as the
locking just prevents the ProcArray to be adjusted, and the commit
record has to be logged first.

That lead to either delayed or hanging snapshot creation, because
snapbuild.c would wait "forever" to see commit/abort records for some
transactions.  That hang resolved only if a xl_running_xacts record
without any running transactions happened to be logged, far from
certain on a busy server.

It's impractical to prevent that via more heavyweight locking, the
likelihood of deadlocks and significantly increased contention would
be too big.

Instead change the initial snapshot creation to be solely based on
tracking the oldest running transaction via
xl_running_xacts->oldestRunningXid - that actually ends up
significantly simplifying the code.  That has two disadvantages:
1) Because we cannot fully "trust" the contents of xl_running_xacts,
   we cannot use it to build the initial snapshot.  Instead we have to
   wait twice for all running transactions to finish.
2) Previously a slot, unless the race occurred, could be created when
   the all transaction perceived as running based on commit/abort
   records, now we have to wait for the next xl_running_xacts record.
To address that, trigger logging new xl_running_xacts record from
within snapbuild.c exactly when necessary.

Unfortunately snabuild.c's SnapBuild is stored on disk, one of the
stupider ideas of a certain Mr Freund, so we can't change it in a
minor release.  As this is going to be backpatched, we have to hack
around a bit to keep on-disk compatibility.  A later commit will
rejigger that on master.

Author: Andres Freund, based on a quite different patch from Petr Jelinek
Analyzed-By: Petr Jelinek
Reviewed-By: Petr Jelinek
Discussion: https://postgr.es/m/f37e975c-908f-858e-707f-058d3b1eb214@2ndquadrant.com
Backpatch: 9.4-, where logical decoding has been introduced
2017-05-13 14:21:00 -07:00
9aab83fc50 Redesign get_attstatsslot()/free_attstatsslot() for more safety and speed.
The mess cleaned up in commit da0759600 is clear evidence that it's a
bug hazard to expect the caller of get_attstatsslot()/free_attstatsslot()
to provide the correct type OID for the array elements in the slot.
Moreover, we weren't even getting any performance benefit from that,
since get_attstatsslot() was extracting the real type OID from the array
anyway.  So we ought to get rid of that requirement; indeed, it would
make more sense for get_attstatsslot() to pass back the type OID it found,
in case the caller isn't sure what to expect, which is likely in binary-
compatible-operator cases.

Another problem with the current implementation is that if the stats array
element type is pass-by-reference, we incur a palloc/memcpy/pfree cycle
for each element.  That seemed acceptable when the code was written because
we were targeting O(10) array sizes --- but these days, stats arrays are
almost always bigger than that, sometimes much bigger.  We can save a
significant number of cycles by doing one palloc/memcpy/pfree of the whole
array.  Indeed, in the now-probably-common case where the array is toasted,
that happens anyway so this method is basically free.  (Note: although the
catcache code will inline any out-of-line toasted values, it doesn't
decompress them.  At the other end of the size range, it doesn't expand
short-header datums either.  In either case, DatumGetArrayTypeP would have
to make a copy.  We do end up using an extra array copy step if the element
type is pass-by-value and the array length is neither small enough for a
short header nor large enough to have suffered compression.  But that
seems like a very acceptable price for winning in pass-by-ref cases.)

Hence, redesign to take these insights into account.  While at it,
convert to an API in which we fill a struct rather than passing a bunch
of pointers to individual output arguments.  That will make it less
painful if we ever want further expansion of what get_attstatsslot can
pass back.

It's certainly arguable that this is new development and not something to
push post-feature-freeze.  However, I view it as primarily bug-proofing
and therefore something that's better to have sooner not later.  Since
we aren't quite at beta phase yet, let's put it in.

Discussion: https://postgr.es/m/16364.1494520862@sss.pgh.pa.us
2017-05-13 15:14:39 -04:00
1848b73d45 Teach \d+ to show partitioning constraints.
The fact that we didn't have this in the first place is likely why
the problem fixed by f8bffe9e6d700fd34759a92e47930ce9ba7dcbd5
escaped detection.

Patch by Amit Langote, reviewed and slightly adjusted by me.

Discussion: http://postgr.es/m/CA+TgmoYWnV2GMnYLG-Czsix-E1WGAbo4D+0tx7t9NdfYBDMFsA@mail.gmail.com
2017-05-13 12:04:53 -04:00
f8bffe9e6d Fix multi-column range partitioning constraints.
The old logic was just plain wrong.

Report by Olaf Gawenda.  Patch by Amit Langote, reviewed by
Beena Emerson and by me.  Minor adjustments by me also.
2017-05-13 11:36:41 -04:00
d99d58cdc8 Complete tab completion for DROP STATISTICS
Tab-completing DROP STATISTICS would only work if you started writing
the schema name containing the statistics object, because the visibility
clause was missing.  To add it, we need to add SQL-callable support for
testing visibility of a statistics object, like all other object types
already have.

Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
2017-05-13 01:05:48 -03:00
2df5d46555 Avoid searching for callback functions in CallSyscacheCallbacks().
We have now grown enough registerable syscache-invalidation callback
functions that the original assumption that there would be few of them
is causing performance problems.  In particular, let's fix things so that
CallSyscacheCallbacks doesn't have to search the whole array to find
which callback(s) to invoke for a given cache ID.  Preserve the original
behavior that callbacks are called in order of registration, just in
case there's someplace that depends on that (which I doubt).

In support of this, export the number of syscaches from syscache.h.
People could have found that out anyway from the enum, but adding a
#define makes that much safer.

This provides a useful additional speedup in Mathieu Fenniak's
logical-decoding test case, although we're reaching the point of
diminishing returns there.  I think any further improvement will have
to come from reducing the number of cache invalidations that are
triggered in the first place.  Still, we can hope that this change
gives some incremental benefit for all invalidation scenarios.

Back-patch to 9.4 where logical decoding was introduced.

Discussion: https://postgr.es/m/CAHoiPjzea6N0zuCi=+f9v_j94nfsy6y8SU7-=bp4=7qw6_i=Rg@mail.gmail.com
2017-05-12 19:05:27 -04:00
50ee1c7462 Avoid searching for the target catcache in CatalogCacheIdInvalidate.
A test case provided by Mathieu Fenniak shows that the initial search for
the target catcache in CatalogCacheIdInvalidate consumes a very significant
amount of overhead in cases where cache invalidation is triggered but has
little useful work to do.  There is no good reason for that search to exist
at all, as the index array maintained by syscache.c allows direct lookup of
the catcache from its ID.  We just need a frontend function in syscache.c,
matching the division of labor for most other cache-accessing operations.

While there's more that can be done in this area, this patch alone reduces
the runtime of Mathieu's example by 2X.  We can hope that it offers some
useful benefit in other cases too, although usually cache invalidation
overhead is not such a striking fraction of the total runtime.

Back-patch to 9.4 where logical decoding was introduced.  It might be
worth going further back, but presently the only case we know of where
cache invalidation is really a significant burden is in logical decoding.
Also, older branches have fewer catcaches, reducing the possible benefit.

(Note: although this nominally changes catcache's API, we have always
documented CatalogCacheIdInvalidate as a private function, so I would
have little sympathy for an external module calling it directly.  So
backpatching should be fine.)

Discussion: https://postgr.es/m/CAHoiPjzea6N0zuCi=+f9v_j94nfsy6y8SU7-=bp4=7qw6_i=Rg@mail.gmail.com
2017-05-12 18:17:29 -04:00
928c4de309 Fix dependencies for extended statistics objects.
A stats object ought to have a dependency on each individual column
it reads, not the entire table.  Doing this honestly lets us get rid
of the hard-wired logic in RemoveStatisticsExt, which seems to have
been misguidedly modeled on RemoveStatistics; and it will be far easier
to extend to multiple tables later.

Also, add overlooked dependency on owner, and make the dependency on
schema be NORMAL like every other such dependency.

There remains some unfinished work here, which is to allow statistics
objects to be extension members.  That takes more effort than just
adding the dependency call, though, so I left it out for now.

initdb forced because this changes the set of pg_depend records that
should exist for a statistics object.

Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
2017-05-12 16:26:31 -04:00
bc085205c8 Change CREATE STATISTICS syntax
Previously, we had the WITH clause in the middle of the command, where
you'd specify both generic options as well as statistic types.  Few
people liked this, so this commit changes it to remove the WITH keyword
from that clause and makes it accept statistic types only.  (We
currently don't have any generic options, but if we invent in the
future, we will gain a new WITH clause, probably at the end of the
command).

Also, the column list is now specified without parens, which makes the
whole command look more similar to a SELECT command.  This change will
let us expand the command to supporting expressions (not just columns
names) as well as multiple tables and their join conditions.

Tom added lots of code comments and fixed some parts of the CREATE
STATISTICS reference page, too; more changes in this area are
forthcoming.  He also fixed a potential problem in the alter_generic
regression test, reducing verbosity on a cascaded drop to avoid
dependency on message ordering, as we do in other tests.

Tom also closed a security bug: we documented that table ownership was
required in order to create a statistics object on it, but didn't
actually implement it.

Implement tab-completion for statistics objects.  This can stand some
more improvement.

Authors: Alvaro Herrera, with lots of cleanup by Tom Lane
Discussion: https://postgr.es/m/20170420212426.ltvgyhnefvhixm6i@alvherre.pgsql
2017-05-12 14:59:35 -03:00
d496a65790 Standardize "WAL location" terminology
Other previously used terms were "WAL position" or "log position".
2017-05-12 13:51:27 -04:00
c1a7f64b4a Replace "transaction log" with "write-ahead log"
This makes documentation and error messages match the renaming of "xlog"
to "wal" in APIs and file naming.
2017-05-12 11:52:43 -04:00
b807f59828 Rework the options syntax for logical replication commands
For CREATE/ALTER PUBLICATION/SUBSCRIPTION, use similar option style as
other statements that use a WITH clause for options.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-05-12 08:57:49 -04:00
024711bb54 Lag tracking for logical replication
Lag tracking is called for each commit, but we introduce
a pacing delay to ensure we don't swamp the lag tracker.

Author: Petr Jelinek, with minor pacing delay code from me
2017-05-12 10:50:56 +01:00
d10c626de4 Rename WAL-related functions and views to use "lsn" not "location".
Per discussion, "location" is a rather vague term that could refer to
multiple concepts.  "LSN" is an unambiguous term for WAL locations and
should be preferred.  Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position".  Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.

David Rowley, minor additional docs hacking by me

Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
2017-05-11 11:49:59 -04:00
b66adb7b0c Revert "Permit dump/reload of not-too-large >1GB tuples"
This reverts commits fa2fa9955280 and 42f50cb8fa98.

While the functionality that was intended to be provided by these
commits is desired, the patch didn't actually solve as many of the
problematic situations as we hoped, and it created a bunch of its own
problems.  Since we're going to require more extensive changes soon for
other reasons and users have been working around these problems for a
long time already, there is no point in spending effort in fixing this
halfway measure.

Per complaint from Tom Lane.
Discussion: https://postgr.es/m/21407.1484606922@sss.pgh.pa.us

(Commit fa2fa9955280 had already been reverted in branches 9.5 as
f858524ee4f and 9.6 as e9e44a0953, so this touches master only.
Commit 42f50cb8fa98 was not present in the older branches.)
2017-05-10 18:41:27 -03:00
489b96e80b Improve memory use in logical replication apply
Previously, the memory used by the logical replication apply worker for
processing messages would never be freed, so that could end up using a
lot of memory.  To improve that, change the existing ApplyContext memory
context to ApplyMessageContext and reset that after every
message (similar to MessageContext used elsewhere).  For consistency of
naming, rename the ApplyCacheContext to ApplyContext.

Author: Stas Kelvich <s.kelvich@postgrespro.ru>
2017-05-09 14:51:49 -04:00
013c1178fd Remove the NODROP SLOT option from DROP SUBSCRIPTION
It turned out this approach had problems, because a DROP command should
not have any options other than CASCADE and RESTRICT.  Instead, always
attempt to drop the slot if there is one configured, but also add an
ALTER SUBSCRIPTION action to set the slot to NONE.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/29431.1493730652@sss.pgh.pa.us
2017-05-09 10:20:42 -04:00
da07596006 Further patch rangetypes_selfuncs.c's statistics slot management.
Values in a STATISTIC_KIND_RANGE_LENGTH_HISTOGRAM slot are float8,
not of the type of the column the statistics are for.

This bug is at least partly the fault of sloppy specification comments
for get_attstatsslot()/free_attstatsslot(): the type OID they want is that
of the stavalues entries, not of the underlying column.  (I double-checked
other callers and they seem to get this right.)  Adjust the comments to be
more correct.

Per buildfarm.

Security: CVE-2017-7484
2017-05-08 15:03:14 -04:00
e2d4ef8de8 Add security checks to selectivity estimation functions
Some selectivity estimation functions run user-supplied operators over
data obtained from pg_statistic without security checks, which allows
those operators to leak pg_statistic data without having privileges on
the underlying tables.  Fix by checking that one of the following is
satisfied: (1) the user has table or column privileges on the table
underlying the pg_statistic data, or (2) the function implementing the
user-supplied operator is leak-proof.  If neither is satisfied, planning
will proceed as if there are no statistics available.

At least one of these is satisfied in most cases in practice.  The only
situations that are negatively impacted are user-defined or
not-leak-proof operators on a security-barrier view.

Reported-by: Robert Haas <robertmhaas@gmail.com>
Author: Peter Eisentraut <peter_e@gmx.net>
Author: Tom Lane <tgl@sss.pgh.pa.us>

Security: CVE-2017-7484
2017-05-08 09:26:32 -04:00
eb61136dc7 Remove support for password_encryption='off' / 'plain'.
Storing passwords in plaintext hasn't been a good idea for a very long
time, if ever. Now seems like a good time to finally forbid it, since we're
messing with this in PostgreSQL 10 anyway.

Remove the CREATE/ALTER USER UNENCRYPTED PASSSWORD 'foo' syntax, since
storing passwords unencrypted is no longer supported. ENCRYPTED PASSWORD
'foo' is still accepted, but ENCRYPTED is now just a noise-word, it does
the same as just PASSWORD 'foo'.

Likewise, remove the --unencrypted option from createuser, but accept
--encrypted as a no-op for backward compatibility. AFAICS, --encrypted was
a no-op even before this patch, because createuser encrypted the password
before sending it to the server even if --encrypted was not specified. It
added the ENCRYPTED keyword to the SQL command, but since the password was
already in encrypted form, it didn't make any difference. The documentation
was not clear on whether that was intended or not, but it's moot now.

Also, while password_encryption='on' is still accepted as an alias for
'md5', it is now marked as hidden, so that it is not listed as an accepted
value in error hints, for example. That's not directly related to removing
'plain', but it seems better this way.

Reviewed by Michael Paquier

Discussion: https://www.postgresql.org/message-id/16e9b768-fd78-0b12-cfc1-7b6b7f238fde@iki.fi
2017-05-08 11:26:07 +03:00
086221cf6b Prevent panic during shutdown checkpoint
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and throws
a PANIC if so.  At that point, only walsenders are still active, so one
might think this could not happen, but walsenders can also generate WAL,
for instance in BASE_BACKUP and certain variants of
CREATE_REPLICATION_SLOT.  So they can trigger this panic if such a
command is run while the shutdown checkpoint is being written.

To fix this, divide the walsender shutdown into two phases.  First, the
postmaster sends a SIGUSR2 signal to all walsenders.  The walsenders
then put themselves into the "stopping" state.  In this state, they
reject any new commands.  (For simplicity, we reject all new commands,
so that in the future we do not have to track meticulously which
commands might generate WAL.)  The checkpointer waits for all walsenders
to reach this state before proceeding with the shutdown checkpoint.
After the shutdown checkpoint is done, the postmaster sends
SIGINT (previously unused) to the walsenders.  This triggers the
existing shutdown behavior of sending out the shutdown checkpoint record
and then terminating.

Author: Michael Paquier <michael.paquier@gmail.com>
Reported-by: Fujii Masao <masao.fujii@gmail.com>
2017-05-05 10:31:42 -04:00
0557a5dc2c Make SCRAM salts and nonces longer.
The salt is stored base64-encoded. With the old 10 bytes raw length, it was
always padded to 16 bytes after encoding. We might as well use 12 raw bytes
for the salt, and it's still encoded into 16 bytes.

Similarly for the random nonces, use a raw length that's divisible by 3, so
that there's no padding after base64 encoding. Make the nonces longer while
we're at it. 10 bytes was probably enough to prevent replay attacks, but
there's no reason to be skimpy here.

Per suggestion from Álvaro Hernández Tortosa.

Discussion: https://www.postgresql.org/message-id/df8c6e27-4d8e-5281-96e5-131a4e638fc8@8kdata.com
2017-05-05 10:02:13 +03:00
e6e9c4da3a Misc cleanup of SCRAM code.
* Remove is_scram_verifier() function. It was unused.
* Fix sanitize_char() function, used in error messages on protocol
  violations, to print bytes >= 0x7F correctly.
* Change spelling of scram_MockSalt() function to be more consistent with
  the surroundings.
* Change a few more references to "server proof" to "server signature" that
  I missed in commit d981074c24.
2017-05-05 10:01:44 +03:00
8f8b9be51f Add PQencryptPasswordConn function to libpq, use it in psql and createuser.
The new function supports creating SCRAM verifiers, in addition to md5
hashes. The algorithm is chosen based on password_encryption, by default.

This fixes the issue reported by Jeff Janes, that there was previously
no way to create a SCRAM verifier with "\password".

Michael Paquier and me

Discussion: https://www.postgresql.org/message-id/CAMkU%3D1wfBgFPbfAMYZQE78p%3DVhZX7nN86aWkp0QcCp%3D%2BKxZ%3Dbg%40mail.gmail.com
2017-05-03 11:19:07 +03:00
23c6eb0336 Remove create_singleton_array(), hard-coding the case in its sole caller.
create_singleton_array() was not really as useful as we perhaps thought
when we added it.  It had never accreted more than one call site, and is
only saving a dozen lines of code at that one, which is considerably less
bulk than the function itself.  Moreover, because of its insistence on
using the caller's fn_extra cache space, it's arguably a coding hazard.
text_to_array_internal() does not currently use fn_extra in any other way,
but if it did it would be subtly broken, since the conflicting fn_extra
uses could be needed within a single query, in the seldom-tested case that
the field separator varies during the query.  The same objection seems
likely to apply to any other potential caller.

The replacement code is a bit uglier, because it hardwires knowledge of
the storage parameters of type TEXT, but it's not like we haven't got
dozens or hundreds of other places that do the same.  Uglier seems like
a good tradeoff for smaller, faster, and safer.

Per discussion with Neha Khatri.

Discussion: https://postgr.es/m/CAFO0U+_fS5SRhzq6uPG+4fbERhoA9N2+nPrtvaC9mmeWivxbsA@mail.gmail.com
2017-05-02 20:41:37 -04:00
92a43e4857 Reduce semijoins with unique inner relations to plain inner joins.
If the inner relation can be proven unique, that is it can have no more
than one matching row for any row of the outer query, then we might as
well implement the semijoin as a plain inner join, allowing substantially
more freedom to the planner.  This is a form of outer join strength
reduction, but it can't be implemented in reduce_outer_joins() because
we don't have enough info about the individual relations at that stage.
Instead do it much like remove_useless_joins(): once we've built base
relations, we can make another pass over the SpecialJoinInfo list and
get rid of any entries representing reducible semijoins.

This is essentially a followon to the inner-unique patch (commit 9c7f5229a)
and makes use of the proof machinery that that patch created.  We need only
minor refactoring of innerrel_is_unique's API to support this usage.

Per performance complaint from Teodor Sigaev.

Discussion: https://postgr.es/m/f994fc98-389f-4a46-d1bc-c42e05cb43ed@sigaev.ru
2017-05-01 14:53:42 -04:00
9414e41ea7 Fix logical replication launcher wake up and reset
After the logical replication launcher was told to wake up at
commit (for example, by a CREATE SUBSCRIPTION command), the flag to wake
up was not reset, so it would be woken up at every following commit as
well.  So fix that by resetting the flag.

Also, we don't need to wake up anything if the transaction was rolled
back.  Just reset the flag in that case.

Author: Masahiko Sawada <sawada.mshk@gmail.com>
Reported-by: Fujii Masao <masao.fujii@gmail.com>
2017-05-01 10:18:09 -04:00
e180c8aa8c Fire per-statement triggers on partitioned tables.
Even though no actual tuples are ever inserted into a partitioned
table (the actual tuples are in the partitions, not the partitioned
table itself), we still need to have a ResultRelInfo for the
partitioned table, or per-statement triggers won't get fired.

Amit Langote, per a report from Rajkumar Raghuwanshi.  Reviewed by me.

Discussion: http://postgr.es/m/CAKcux6%3DwYospCRY2J4XEFuVy0L41S%3Dfic7rmkbsU-GXhhSbmBg%40mail.gmail.com
2017-05-01 08:23:01 -04:00