Previously we were using the SQL:2003 definition, which doesn't allow
this, but that creates a serious dump/restore gotcha: there is no
setting of xmloption that will allow all valid XML data. Hence,
switch to the 2006 definition.
Since libxml doesn't accept <!DOCTYPE> directives in the mode we
use for CONTENT parsing, the implementation is to detect <!DOCTYPE>
in the input and switch to DOCUMENT parsing mode. This should not
cost much, because <!DOCTYPE> should be close to the front of the
input if it's there at all. It's possible that this causes the
error messages for malformed input to be slightly different than
they were before, if said input includes <!DOCTYPE>; but that does
not seem like a big problem.
In passing, buy back a few cycles in parsing of large XML documents
by not doing strlen() of the whole input in parse_xml_decl().
Back-patch because dump/restore failures are not nice. This change
shouldn't break any cases that worked before, so it seems safe to
back-patch.
Chapman Flack (revised a bit by me)
Discussion: https://postgr.es/m/CAN-V+g-6JqUQEQZ55Q3toXEN6d5Ez5uvzL4VR+8KtvJKj31taw@mail.gmail.com
Buildfarm member eelpout sometimes reports the wrong error message for
an SSL connection failure. In HEAD, this problem is believed to be
solved by commit 1f39a1c06, but I'm as yet unwilling to back-patch that.
The problem seems fairly unlikely to be an issue in the field, since (as
far as we can tell) it happens only during a failure of a local-loopback
SSL connection, and it's improbable even then. It seems better to just
live with it for the time being; but let's tweak the regression test to
accept the other error message as a "pass".
Needed in v11 only, since older branches didn't check the message
text anyway.
Discussion: https://postgr.es/m/CAEepm=2n6Nv+5tFfe8YnkUm1fXgvxR0Mm1FoD+QKG-vLNGLyKg@mail.gmail.com
Commit 6f6a6d8b1 introduced a delay of up to 2 seconds if we're trying
to request a checkpoint but the checkpointer hasn't started yet (or,
much less likely, our kill() call fails). However buildfarm experience
shows that that's not quite enough for slow or heavily-loaded machines.
There's no good reason to assume that the checkpointer won't start
eventually, so we may as well make the timeout much longer, say 60 sec.
However, if the caller didn't say CHECKPOINT_WAIT, it seems like a bad
idea to be waiting at all, much less for as long as 60 sec. We can
remove the need for that, and make this whole thing more robust, by
adjusting the code so that the existence of a pending checkpoint
request is clear from the contents of shared memory, and making sure
that the checkpointer process will notice it at startup even if it did
not get a signal. In this way there's no need for a non-CHECKPOINT_WAIT
call to wait at all; if it can't send the signal, it can nonetheless
assume that the checkpointer will eventually service the request.
A potential downside of this change is that "kill -INT" on the checkpointer
process is no longer enough to trigger a checkpoint, should anyone be
relying on something so hacky. But there's no obvious reason to do it
like that rather than issuing a plain old CHECKPOINT command, so we'll
assume that nobody is. There doesn't seem to be a way to preserve this
undocumented quasi-feature without introducing race conditions.
Since a principal reason for messing with this is to prevent intermittent
buildfarm failures, back-patch to all supported branches.
Discussion: https://postgr.es/m/27830.1552752475@sss.pgh.pa.us
Commit f2dec34e1 changed things so that printtup's output stringinfo
buffer was allocated outside the per-row temporary context, not inside
it. This creates a need to free that buffer explicitly when the temp
context is freed, but that was overlooked. In most cases, this is all
happening inside a portal or executor context that will go away shortly
anyhow, but that's not always true. Notably, the stringinfo ends up
getting leaked when JDBC uses row-at-a-time fetches. For a query
that returns wide rows, that adds up after awhile.
Per bug #15700 from Matthias Otterbach. Back-patch to v11 where the
faulty code was added.
Discussion: https://postgr.es/m/15700-8c408321a87d56bb@postgresql.org
We should try to prewarm each database only once. Otherwise, if
prewarming fails for some reason, it will just keep retrying in an
infnite loop. This can happen if, for example, the database has been
dropped. The existing code was intended to implement the try-once
behavior, but failed to do so because it neglected to set
worker.bgw_restart_time to BGW_NEVER_RESTART.
Mithun Cy, per a report from Hans Buschmann
Discussion: http://postgr.es/m/CA+hUKGKpQJCWcgyy3QTC9vdn6uKAR_8r__A-MMm2GYfj45caag@mail.gmail.com
This fixes an issue introduced by 266b6ac, which has added filters to
exclude file patterns on the target and source data directories to
reduce the number of files transferred. Filters get applied to both
the target and source data files, and include pg_internal.init which is
present for each database once relations are created on it. However, if
the target differed from the source with at least one new database with
relations, the rewind would fail due to the exclusion filters applied on
the target files, causing pg_internal.init to still be present on the
target database folder, while its contents should have been completely
removed so as there is nothing remaining inside at the time of the
folder deletion.
Applying exclusion filters on the source files is fine, because this way
the amount of data copied from the source to the target is reduced. And
actually, not applying the filters on the target is what pg_rewind
should do, because this causes such files to be automatically removed
during the rewind on the target. Exclusion filters apply to paths which
are removed or recreated automatically at startup, so removing all those
files on the target during the rewind is a win.
The existing set of TAP tests already stresses the rewind of databases,
but it did not include any tables on those newly-created databases.
Creating extra tables in this case is enough to reproduce the failure,
so the existing tests are extended to close the gap.
Reported-by: Mithun Cy
Author: Michael Paquier
Discussion: https://postgr.es/m/CADq3xVYt6_pO7ZzmjOqPgY9HWsL=kLd-_tNyMtdfjKqEALDyTA@mail.gmail.com
Backpatch-through: 11
pg_verify_checksums is compiled with a given block size and has a hard
dependency to it per the way checksums are calculated via
checksum_impl.h, and trying to use the tool on a data folder which has
not the same block size would result in incorrect checksum calculations
and/or block read errors, meaning that the data folder is corrupted.
This is harmless as checksums are only checked now, but very confusing
for the user so issue an error properly if the block size used at
compilation and the block size used in the data folder do not match.
Reported-by: Sergei Kornilov
Author: Michael Banck, Michael Paquier
Reviewed-by: Fabien Coelho, Magnus Hagander
Discussion: https://postgr.es/m/20190317054657.GA3357@paquier.xyz
ackpatch-through: 11
The assertions added by commits 34ea1ab7f et al found another problem:
set_dummy_rel_pathlist and mark_dummy_rel were failing to label
the dummy paths they create with the correct outer_relids, in case
the relation is necessarily parameterized due to having lateral
references in its tlist. It's likely that this has no user-visible
consequences in production builds, at the moment; but still an assertion
failure is a bad thing, so back-patch the fix.
Per bug #15694 from Roman Zharkov (via Alexander Lakhin)
and an independent report by Tushar Ahuja.
Discussion: https://postgr.es/m/15694-74f2ca97e7044f7f@postgresql.org
Discussion: https://postgr.es/m/7d72ab20-c725-3ce2-f99d-4e64dd8a0de6@enterprisedb.com
This fixes an oversight from 5c99513. This has no actual consequence as
PG_TEMP_FILE_PREFIX and PG_TEMP_FILES_DIR have the same value so when
bumping on a temporary path the directory scan was still moving on to
the next entry instead of skipping the rest of the scan, but let's keep
the logic correct.
Author: Michael Banck
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20190314.115417.58230569.horiguchi.kyotaro@lab.ntt.co.jp
Backpatch-through: 11
pg_verify_checksums performs a read of the control file, and the data it
fetches should be from a data folder compatible with the major version
of Postgres the binary has been compiled with, but we never actually
checked that compatibility.
Reported-by: Sergei Kornilov
Author: Michael Paquier
Reviewed-by: Sergei Kornilov
Discussion: https://postgr.es/m/155231347133.16480.11453587097036807558.pgcf@coridan.postgresql.org
Backpatch-through: 11
In commit 960df2a971 ("Correctly assess parallel-safety of tlists when
SRFs are used."), the testing of scan/join target was done incorrectly,
which caused a plan-quality problem. Backpatch through to v11 where
the aforementioned commit went in, since this is a regression from v10.
Author: Etsuro Fujita
Reviewed-by: Robert Haas and Tom Lane
Discussion: https://postgr.es/m/5C75303E.8020303@lab.ntt.co.jp
1. The PARTITION OF clause of CREATE FOREIGN TABLE was not explained in
the CREATE FOREIGN TABLE reference page. Add it.
(Postgres 10 onwards)
2. The limitation that tuple routing cannot target partitions that are
foreign tables was not documented clearly enough. Improve wording.
(Postgres 10 onwards)
3. The UPDATE tuple re-routing concurrency behavior was explained in
the DDL chapter, which doesn't seem the right place. Move it to the
UPDATE reference page instead. (Postgres 11 onwards).
Authors: Amit Langote, David Rowley.
Reviewed-by: Etsuro Fujita.
Reported-by: Derek Hans
Discussion: https://postgr.es/m/CAGrP7a3Xc1Qy_B2WJcgAD8uQTS_NDcJn06O5mtS_Ne1nYhBsyw@mail.gmail.com
None of the code that uses GUC values is really prepared for them to
hold NaN, but parse_real() didn't have any defense against accepting
such a value. Treat it the same as a syntax error.
I haven't attempted to analyze the exact consequences of setting any
of the float GUCs to NaN, but since they're quite unlikely to be good,
this seems like a back-patchable bug fix.
Note: we don't need an explicit test for +-Infinity because those will
be rejected by existing range checks. I added a regression test for
that in HEAD, but not older branches because the spelling of the value
in the error message will be platform-dependent in branches where we
don't always use port/snprintf.c.
Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us
When we introduced separate ProjectSetPath nodes for application of
set-returning functions in v10, we inadvertently broke some cases where
we're supposed to recognize that the result of a subquery is known to be
empty (contain zero rows). That's because IS_DUMMY_REL was just looking
for a childless AppendPath without allowing for a ProjectSetPath being
possibly stuck on top. In itself, this didn't do anything much worse
than produce slightly worse plans for some corner cases.
Then in v11, commit 11cf92f6e rearranged things to allow the scan/join
targetlist to be applied directly to partial paths before they get
gathered. But it inserted a short-circuit path for dummy relations
that was a little too short: it failed to insert a ProjectSetPath node
at all for a targetlist containing set-returning functions, resulting in
bogus "set-valued function called in context that cannot accept a set"
errors, as reported in bug #15669 from Madelaine Thibaut.
The best way to fix this mess seems to be to reimplement IS_DUMMY_REL
so that it drills down through any ProjectSetPath nodes that might be
there (and it seems like we'd better allow for ProjectionPath as well).
While we're at it, make it look at rel->pathlist not cheapest_total_path,
so that it gives the right answer independently of whether set_cheapest
has been done lately. That dependency looks pretty shaky in the context
of code like apply_scanjoin_target_to_paths, and even if it's not broken
today it'd certainly bite us at some point. (Nastily, unsafe use of the
old coding would almost always work; the hazard comes down to possibly
looking through a dangling pointer, and only once in a blue moon would
you find something there that resulted in the wrong answer.)
It now looks like it was a mistake for IS_DUMMY_REL to be a macro: if
there are any extensions using it, they'll continue to use the old
inadequate logic until they're recompiled, after which they'll fail
to load into server versions predating this fix. Hopefully there are
few such extensions.
Having fixed IS_DUMMY_REL, the special path for dummy rels in
apply_scanjoin_target_to_paths is unnecessary as well as being wrong,
so we can just drop it.
Also change a few places that were testing for partitioned-ness of a
planner relation but not using IS_PARTITIONED_REL for the purpose; that
seems unsafe as well as inconsistent, plus it required an ugly hack in
apply_scanjoin_target_to_paths.
In passing, save a few cycles in apply_scanjoin_target_to_paths by
skipping processing of pre-existing paths for partitioned rels,
and do some cosmetic cleanup and comment adjustment in that function.
I renamed IS_DUMMY_PATH to IS_DUMMY_APPEND with the intention of breaking
any code that might be using it, since in almost every case that would
be wrong; IS_DUMMY_REL is what to be using instead.
In HEAD, also make set_dummy_rel_pathlist static (since it's no longer
used from outside allpaths.c), and delete is_dummy_plan, since it's no
longer used anywhere.
Back-patch as appropriate into v11 and v10.
Tom Lane and Julien Rouhaud
Discussion: https://postgr.es/m/15669-02fb3296cca26203@postgresql.org
For some reason the dump test with names with high bits set fails on
Msys2 (although not Msys1). Disable the tests for now, so that other
tests can run.
This test fails if the containing directory contains a funny character
such as a space or some perl metacharacter. To avoid that, we check for
files names using readdir and a regex, rather than using a glob pattern.
Discussion: https://postgr.es/m/CAM6_UM6dGdU39PKAC24T+HD9ouy0jLN9vH6163K8QEEzr__iZw@mail.gmail.com
Author: Fabien COELHO
Reviewed-by: Raúl Marín Rodríguez
The implementation of readdir() in src/port/ which gets used by MSVC has
been added in 399a36a, and since the beginning it considers all errors
on the first file lookup as ENOENT, setting errno accordingly and
letting the routine caller think that the directory is empty. While
this is normally enough for the case of the backend, this can confuse
callers of this routine on Windows as all errors would map to the same
behavior. So, for example, even permission errors would be thought as
having an empty directory, while there could be contents in it.
This commit changes the error handling so as readdir() gets a behavior
similar to native implementations: force errno=0 when seeing
ERROR_FILE_NOT_FOUND as error and consider other errors as plain
failures.
While looking at the patch, I noticed that MinGW does not enforce
errno=0 when looking at the first file, but it gets enforced on the next
file lookups. A comment related to that was incorrect in the code.
Reported-by: Yuri Kurenkov
Diagnosed-by: Yuri Kurenkov, Grigory Smolkin
Author: Konstantin Knizhnik
Reviewed-by: Andrew Dunstan, Michael Paquier
Discussion: https://postgr.es/m/2cad7829-8d66-e39c-b937-ac825db5203d@postgrespro.ru
Backpatch-through: 9.4
Previously, rewriteTargetListIU() generated a list of attribute
numbers from the targetlist, which were passed to rewriteValuesRTE(),
which expected them to contain the same number of entries as there are
columns in the VALUES RTE, and to be in the same order. That was fine
when the target relation was a table, but for an updatable view it
could be broken in at least three different ways ---
rewriteTargetListIU() could insert additional targetlist entries for
view columns with defaults, the view columns could be in a different
order from the columns of the underlying base relation, and targetlist
entries could be merged together when assigning to elements of an
array or composite type. As a result, when recursing to the base
relation, the list of attribute numbers generated from the rewritten
targetlist could no longer be relied upon to match the columns of the
VALUES RTE. We got away with that prior to 41531e42d3 because it used
to always be the case that rewriteValuesRTE() did nothing for the
underlying base relation, since all DEFAULTS had already been replaced
when it was initially invoked for the view, but that was incorrect
because it failed to apply defaults from the base relation.
Fix this by examining the targetlist entries more carefully and
picking out just those that are simple Vars referencing the VALUES
RTE. That's sufficient for the purposes of rewriteValuesRTE(), which
is only responsible for dealing with DEFAULT items in the VALUES
RTE. Any DEFAULT item in the VALUES RTE that doesn't have a matching
simple-Var-assignment in the targetlist is an error which we complain
about, but in theory that ought to be impossible.
Additionally, move this code into rewriteValuesRTE() to give a clearer
separation of concerns between the 2 functions. There is no need for
rewriteTargetListIU() to know about the details of the VALUES RTE.
While at it, fix the comment for rewriteValuesRTE() which claimed that
it doesn't support array element and field assignments --- that hasn't
been true since a3c7a993d5 (9.6 and later).
Back-patch to all supported versions, with minor differences for the
pre-9.6 branches, which don't support array element and field
assignments to the same column in multi-row VALUES lists.
Reviewed by Amit Langote.
Discussion: https://postgr.es/m/15623-5d67a46788ec8b7f@postgresql.org
Reflecting an updated parameter value requires a server restart, which
was not mentioned in the documentation and in postgresql.conf.sample.
Reported-by: Thomas Poty
Discussion: https://postgr.es/m/15659-0cd812f13027a2d8@postgresql.org
When using a libpq client linked with OpenSSL 1.0.1 or older to connect
to a backend linked with OpenSSL 1.0.2 or newer, the server would send
SCRAM-SHA-256-PLUS and SCRAM-SHA-256 as valid mechanisms for the SASL
exchange, and the client would choose SCRAM-SHA-256-PLUS even if it does
not support channel binding, leading to a confusing error. In this
case, what the client ought to do is switch to SCRAM-SHA-256 so as the
authentication can move on and succeed.
So for a SCRAM authentication over SSL, here are all the cases present
and how we deal with them using libpq:
1) Server supports channel binding, it sends SCRAM-SHA-256-PLUS and
SCRAM-SHA-256 as allowed mechanisms.
1-1) Client supports channel binding, chooses SCRAM-SHA-256-PLUS.
1-2) Client does not support channel binding, chooses SCRAM-SHA-256.
2) Server does not support channel binding, sends SCRAM-SHA-256 as
allowed mechanism.
2-1) Client supports channel binding, still it has no choice but to
choose SCRAM-SHA-256.
2-2) Client does not support channel binding, it chooses SCRAM-SHA-256.
In all these scenarios the connection should succeed, and the one which
was handled incorrectly prior this commit is 1-2), causing the
connection attempt to fail because client chose SCRAM-SHA-256-PLUS over
SCRAM-SHA-256.
Reported-by: Hugh Ranalli
Diagnosed-by: Peter Eisentraut
Author: Michael Paquier
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/CAAhbUMO89SqUk-5mMY+OapgWf-twF2NA5sCucbHEzMfGbvcepA@mail.gmail.com
Backpatch-through: 11
Commit 16be2fd1 introduced the flag DSA_ALLOC_NO_OOM to control whether
the DSA allocator would raise an error or return InvalidDsaPointer on
failure to allocate. One edge case was not handled correctly: if we
fail to allocate an internal "span" object for a large allocation, we
would always return InvalidDsaPointer regardless of the flag; a caller
not expecting that could then dereference a null pointer.
This is a plausible explanation for a one-off report of a segfault.
Remove a redundant pair of braces so that all three stanzas that handle
DSA_ALLOC_NO_OOM match in style, for visual consistency.
While fixing inconsistencies, if FreePageManagerGet() can't supply the
pages that our book-keeping says it should be able to supply, then we
should always report a FATAL error. Previously we treated that as a
regular allocation failure in one code path, but as a FATAL condition
in another.
Back-patch to 10, where dsa.c landed.
Author: Thomas Munro
Reported-by: Jakub Glapa
Discussion: https://postgr.es/m/CAEepm=2oPqXxyWQ-1o60tpOLrwkw=VpgNXqqF1VN2EyO9zKGQw@mail.gmail.com
The Bison documentation clearly states that a semicolon is required
after every grammar rule, and our scripts that generate ecpg's
grammar from the backend's implicitly assumed this is true. But it
turns out that only ancient versions of Bison actually enforce that.
There have been a couple of rules without trailing semicolons in
gram.y for some time, and as a consequence, ecpg's grammar was faulty
and produced wrong output for the affected statements.
To fix, add the missing semis, and add some cross-checks to ecpg's
scripts so that they'll bleat if we mess this up again.
The cases that were broken were:
* "SET variable = DEFAULT" (but not "SET variable TO DEFAULT"),
as well as allied syntaxes such as ALTER SYSTEM SET ... DEFAULT.
These produced syntactically invalid output that the server
would reject.
* Multiple type names in DROP TYPE/DOMAIN commands. Only the
first type name would be listed in the emitted command.
Per report from Daisuke Higuchi. Back-patch to all supported versions.
Discussion: https://postgr.es/m/1803D792815FC24D871C00D17AE95905DB51CE@g01jpexmbkw24
Previously, we tolerated EBADF as a way for the operating system to
indicate that it doesn't support fsync() on a directory. Tolerate
EINVAL too, for older versions of Linux CIFS.
Bug #15636. Back-patch all the way.
Reported-by: John Klann
Discussion: https://postgr.es/m/15636-d380890dafd78fc6@postgresql.org
One unintended consequence of commit 9ccdd7f6 was that Windows WSL
users started getting a panic whenever we tried to initiate data
flushing with sync_file_range(), because WSL does not implement that
system call. Previously, they got a stream of periodic warnings,
which was also undesirable but at least ignorable.
Prevent the panic by handling ENOSYS specially and skipping the panic
promotion with data_sync_elevel(). Also suppress future attempts
after the first such failure so that the pre-existing problem of
noisy warnings is improved.
Back-patch to 9.6 (older branches were not affected in this way by
9ccdd7f6).
Author: Thomas Munro and James Sewell
Tested-by: James Sewell
Reported-by: Bruce Klein
Discussion: https://postgr.es/m/CA+mCpegfOUph2U4ZADtQT16dfbkjjYNJL1bSTWErsazaFjQW9A@mail.gmail.com
In the case where inheritance_planner() finds that every table has
been excluded by constraints, it thought it could get away with
making a plan consisting of just a dummy Result node. While certainly
there's no updating or deleting to be done, this had two user-visible
problems: the plan did not report the correct set of output columns
when a RETURNING clause was present, and if there were any
statement-level triggers that should be fired, it didn't fire them.
Hence, rather than only generating the dummy Result, we need to
stick a valid ModifyTable node on top, which requires a tad more
effort here.
It's been broken this way for as long as inheritance_planner() has
known about deleting excluded subplans at all (cf commit 635d42e9c),
so back-patch to all supported branches.
Amit Langote and Tom Lane, per a report from Petr Fedorov.
Discussion: https://postgr.es/m/5da6f0f0-1364-1876-6978-907678f89a3e@phystech.edu
In previous releases, the input file of dbtoepub was postgres.xml, and
dbtoepub knows to derive the output file name postgres.epub from that
automatically. But now the intput file is postgres.sgml (since
postgres.sgml is itself an XML file and we no longer need the
intermediate postgres.xml file), but dbtoepub doesn't know how to deal
with the .sgml suffix, so the automatically derived output file name
becomes postgres.sgml.epub. Fix by adding an explicit -o option.
Check ec_relids before bothering to iterate through the EC members.
On a perhaps extreme, but still real-world, query in which
match_eclasses_to_foreign_key_col() accounts for the bulk of the
planner's runtime, this saves nearly 40% of the runtime. It's a bit
of a stopgap fix, but it's simple enough to be back-patched to 9.6
where this code came in; so let's do that.
David Rowley
Discussion: https://postgr.es/m/6970.1545327857@sss.pgh.pa.us
The recursion in contain_nonstrict_functions_walker() was done wrong,
causing the strictness check to be bypassed for a parse node that
is the immediate input of an ArrayCoerceExpr node. This could allow,
for example, incorrect decisions about whether a strict SQL function
can be inlined.
I didn't add a regression test, because (a) the bug is so narrow
and (b) I couldn't think of a test case that wasn't dependent on a
large number of other behaviors, to the point where it would likely
soon rot to the point of not testing what it was intended to.
I broke this in commit c12d570fa, so back-patch to v11.
Discussion: https://postgr.es/m/27571.1550617881@sss.pgh.pa.us
pg_identify_object_as_address crashes when passed certain tuples from
inconsistent system catalogs. Make it more defensive.
Author: Álvaro Herrera
Reviewed-by: Michaël Paquier
Discussion: https://postgr.es/m/20190218202743.GA12392@alvherre.pgsql
INSERT ... VALUES for a single VALUES row is implemented differently
from a multi-row VALUES list, which causes inconsistent behaviour in
the way that DEFAULT items are handled. In particular, when inserting
into an auto-updatable view on top of a table with a column default, a
DEFAULT item in a single VALUES row gets correctly replaced with the
table column's default, but for a multi-row VALUES list it is replaced
with NULL.
Fix this by allowing rewriteValuesRTE() to leave DEFAULT items in the
VALUES list untouched if the target relation is an auto-updatable view
and has no column default, deferring DEFAULT-expansion until the query
against the base relation is rewritten. For all other types of target
relation, including tables and trigger- and rule-updatable views, we
must continue to replace DEFAULT items with NULL in the absence of a
column default.
This is somewhat complicated by the fact that if an auto-updatable
view has DO ALSO rules attached, the VALUES lists for the product
queries need to be handled differently from the original query, since
the product queries need to act like rule-updatable views whereas the
original query has auto-updatable view semantics.
Back-patch to all supported versions.
Reported by Roger Curley (bug #15623). Patch by Amit Langote and me.
Discussion: https://postgr.es/m/15623-5d67a46788ec8b7f@postgresql.org
When building an initial slot snapshot, snapshots are marked with
historic MVCC snapshots as type with the marker field being set in
SnapBuildBuildSnapshot() but not overriden in SnapBuildInitialSnapshot().
Existing callers of SnapBuildBuildSnapshot() do not care about the type
of snapshot used, but extensions calling it actually may, as reported.
Author: Antonin Houska
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/23215.1527665193@localhost
Backpatch-through: 9.4
ee9e145 has fixed the tests of pg_basebackup for checksums a first time,
still one seek() call missed the shot. Also, the data written in files
to emulate corruptions was not actually writing zeros as the quoting
style was incorrect.
Author: Michael Banck
Discussion: https://postgr.es/m/1550153276.796.35.camel@credativ.de
Backpatch-through: 11
Teach dsm_unpin_segment() to skip segments that are in the process
of being destroyed by another backend, when searching for a handle.
Such a segment cannot possibly be the one we are looking for, even
if its handle matches. Another slot might hold a recently created
segment that has the same handle value by coincidence, and we need
to keep searching for that one.
The bug caused rare "cannot unpin a segment that is not pinned"
errors on 10 and 11. Similar to commit 6c0fb941 for dsm_attach().
Back-patch to 10, where dsm_unpin_segment() landed.
Author: Thomas Munro
Reported-by: Justin Pryzby
Tested-by: Justin Pryzby (along with other recent DSA/DSM fixes)
Discussion: https://postgr.es/m/20190216023854.GF30291@telsasoft.com
The dblink documentation claims that an empty string is returned if there
has been no error, however OK is actually returned in that case. Also,
clarify that an async error may not be seen unless dblink_is_busy() or
dblink_get_result() have been called first.
Backpatch to all supported branches.
Reported-by: realyota
Backpatch-through: 9.4
Discussion: https://postgr.es/m/153371978486.1298.2091761143788088262@wrigleys.postgresql.org
We should logically have allowed this case when we allowed zero-column
tables, but it was overlooked.
Although this might be thought a feature addition, it's really a bug
fix, because it was possible to create a zero-column view via
the convert-table-to-view code path, and then you'd have a situation
where dump/reload would fail. Hence, back-patch to all supported
branches.
Arrange the added test cases to provide coverage of the related
pg_dump code paths (since these views will be dumped and reloaded
during the pg_upgrade regression test). I also made them test
the case where pg_dump has to postpone the view rule into post-data,
which disturbingly had no regression coverage before.
Report and patch by Ashutosh Sharma (test case by me)
Discussion: https://postgr.es/m/CAE9k0PkmHdeSaeZt2ujnb_cKucmK3sDDceDzw7+d5UZoNJPYOg@mail.gmail.com
The grammar IF NOT EXISTS for CTAS is supported since 9.5 and documented
as such, however the case of using EXECUTE as query has never been
covered as EXECUTE CTAS statements and normal CTAS statements are parsed
separately.
Author: Andreas Karlsson
Discussion: https://postgr.es/m/2ddcc188-e37c-a0be-32bf-a56b07c3559e@proxel.se
Backpatch-through: 9.5
DSM handle values can be reused as soon as the underlying shared memory
object has been destroyed. That means that for a brief moment we
might have two DSM slots with the same handle. While trying to attach,
if we encounter a slot with refcnt == 1, meaning that it is currently
being destroyed, we should continue our search in case the same handle
exists in another slot.
The race manifested as a rare "dsa_area could not attach to segment"
error, and was more likely in 10 and 11 due to the lack of distinct
seed for random() in parallel workers. It was made very unlikely in
in master by commit 197e4af9, and older releases don't usually create
new DSM segments in background workers so it was also unlikely there.
This fixes the root cause of bug report #15585, in which the error
could also sometimes result in a self-deadlock in the error path.
It's not yet clear if further changes are needed to avoid that failure
mode.
Back-patch to 9.4, where dsm.c arrived.
Author: Thomas Munro
Reported-by: Justin Pryzby, Sergei Kornilov
Discussion: https://postgr.es/m/20190207014719.GJ29720@telsasoft.com
Discussion: https://postgr.es/m/15585-324ff6a93a18da46@postgresql.org
In a corner case, a btree page was allocated during a clean-up operation
that could cause the tracking of the largest contiguous span of free
space to get out of whack. That was supposed to be prevented by the use
of the "soft" flag to avoid allocating internal pages during incidental
clean-up work, but the flag was ignored in the case where the FPM was
promoted from singleton format to btree format. Repair.
Remove an obsolete comment in passing.
Back-patch to 10, where freepage.c arrived (as support for dsa.c).
Author: Robert Haas
Diagnosed-by: Thomas Munro and Robert Haas
Reported-by: Justin Pryzby, Rick Otten, Sand Stone, Arne Roland and others
Discussion: https://postgr.es/m/CAMAYy4%2Bw3NTBM5JLWFi8twhWK4%3Dk_5L4nV5%2BbYDSPu8r4b97Zg%40mail.gmail.com
