Robert Haas [Thu, 2 Mar 2017 11:48:19 +0000 (17:18 +0530)]
Don't uselessly rewrite, truncate, VACUUM, or ANALYZE partitioned tables.
Also, recursively perform VACUUM and ANALYZE on partitions when the
command is applied to a partitioned table. In passing, some related
documentation updates.
Amit Langote, reviewed by Michael Paquier, Ashutosh Bapat, and by me.
Noah Misch [Thu, 2 Mar 2017 05:03:27 +0000 (00:03 -0500)]
Handle unaligned SerializeSnapshot() buffer.
Likewise in RestoreSnapshot(). Do so by copying between the user buffer
and a stack buffer of known alignment. Back-patch to 9.6, where this
last applies cleanly. In master, the select_parallel test dies with
SIGBUS on "Oracle Solaris 10 1/13 s10s_u11wos_24a SPARC", building
32-bit with gcc 4.9.2. In 9.6 and 9.5, the buffers in question happen
to be sufficiently-aligned, and this change is mere insurance against
future 9.6 changes or extension code compromising that.
Amit Kapila, with slight changes by me. The larger patch series of
which this is a part has been reviewed and tested by Álvaro Herrera,
Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper Pedersen.
Andres Freund [Wed, 1 Mar 2017 04:41:44 +0000 (20:41 -0800)]
Fix assertion failure due to over-eager code deduplication.
In the previous commit I'd made MemoryContextContains() use
GetMemoryChunkContext(), but that causes trouble when the passed
pointer isn't allocated in any memory context - that's probably
something we shouldn't do, but the previous commit isn't a place for a
"policy" change.
Andres Freund [Tue, 28 Feb 2017 18:36:29 +0000 (10:36 -0800)]
Overhaul memory management README.
The README was written as a "historical account", and that style
hasn't aged particularly well. Rephrase it to describe the current
situation, instead of having various version specific comments.
This also updates the description of how allocated chunks are
associated with their corresponding context, the method of which has
changed in the preceding commit.
Author: Andres Freund
Discussion: https://postgr.es/m/20170228074420.aazv4iw6k562mnxg@alap3.anarazel.de
Andres Freund [Tue, 28 Feb 2017 07:32:22 +0000 (23:32 -0800)]
Reduce size of common allocation header.
The new slab allocator needs different per-allocation information than
the classical aset.c. The definition in 58b25e981 wasn't sufficiently
careful on 32 platforms with 8 byte alignment, leading to buildfarm
failures. That's not entirely easy to fix by just adjusting the
definition.
As slab.c doesn't actually need the size part(s) of the common header,
all chunks are equally sized after all, it seems better to instead
reduce the header to the part needed by all allocators, namely which
context an allocation belongs to. That has the advantage of reducing
the overhead of slab allocations, and also allows for more flexibility
in future allocators.
To avoid spreading the logic about accessing a chunk's context around,
centralize it in GetMemoryChunkContext(), which allows to delete a
good number of lines.
A followup commit will revise the mmgr/README portion about
StandardChunkHeader, and more.
Author: Andres Freund
Discussion: https://postgr.es/m/20170228074420.aazv4iw6k562mnxg@alap3.anarazel.de
Tom Lane [Mon, 27 Feb 2017 22:20:34 +0000 (17:20 -0500)]
Allow index AMs to return either HeapTuple or IndexTuple format during IOS.
Previously, only IndexTuple format was supported for the output data of
an index-only scan. This is fine for btree, which is just returning a
verbatim index tuple anyway. It's not so fine for SP-GiST, which can
return reconstructed data that's much larger than a page.
To fix, extend the index AM API so that index-only scan data can be
returned in either HeapTuple or IndexTuple format. There's other ways
we could have done it, but this way avoids an API break for index AMs
that aren't concerned with the issue, and it costs little except a couple
more fields in IndexScanDescs.
I changed both GiST and SP-GiST to use the HeapTuple method. I'm not
very clear on whether GiST can reconstruct data that's too large for an
IndexTuple, but that seems possible, and it's not much of a code change to
fix.
Per a complaint from Vik Fearing. Reviewed by Jason Li.
Robert Haas [Mon, 27 Feb 2017 17:26:34 +0000 (22:56 +0530)]
hash: Refactor overflow page allocation.
As with commit b0f18cb77f50a54e997d857d592f6a511617f52c, the goal
here is to move all of the related page modifications to a single
section of code, in preparation for adding write-ahead logging.
Amit Kapila, with slight changes by me. The larger patch series
of which this is a part has been reviewed and tested by Álvaro
Herrera, Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper
Pedersen, all of whom should also have been credited in the
previous commit message.
Robert Haas [Mon, 27 Feb 2017 17:04:21 +0000 (22:34 +0530)]
hash: Refactor bucket squeeze code.
In preparation for adding write-ahead logging to hash indexes,
refactor _hash_freeovflpage and _hash_squeezebucket so that all
related page modifications happen in a single section of code. The
previous coding assumed that it would be fine to move tuples one at a
time, and also that the various operations involved in freeing an
overflow page didn't necessarily all need to be done together, all
of which is true if you don't care about write-ahead logging.
Tom Lane [Mon, 27 Feb 2017 16:20:22 +0000 (11:20 -0500)]
Remove PL/Tcl's "module" facility.
PL/Tcl has long had a facility whereby Tcl code could be autoloaded from
a database table named "pltcl_modules". However, nobody is using it, as
evidenced by the recent discovery that it's never been fixed to work with
standard_conforming_strings turned on. Moreover, it's rather shaky from
a security standpoint, and the table design is very old and crufty (partly
because it dates from before we had TOAST). A final problem is that
because the table-population scripts depend on the Tcl client library
Pgtcl, which we removed from the core distribution in 2004, it's
impossible to create a self-contained regression test for the feature.
Rather than try to surmount these problems, let's just remove it.
A follow-on patch will provide a way to execute user-defined
initialization code, similar to features that exist in plperl and plv8.
With that, it will be possible to implement this feature or similar ones
entirely in userspace, which is where it belongs.
Peter Eisentraut [Mon, 27 Feb 2017 13:30:06 +0000 (08:30 -0500)]
chomp PQerrorMessage() in backend uses
PQerrorMessage() returns an error message with a trailing newline, but
in backend use (dblink, postgres_fdw, libpqwalreceiver), we want to have
the error message without that for emitting via ereport(). To simplify
that, add a function pchomp() that returns a pstrdup'ed string with the
trailing newline characters removed.
Andres Freund [Mon, 27 Feb 2017 11:41:44 +0000 (03:41 -0800)]
Use the new "Slab" context for some allocations in reorderbuffer.h.
Note that this change alone does not yet fully address the performance
problems triggering this work, a large portion of the slowdown is
triggered by the tuple allocator, which isn't converted to the new
allocator. It would be possible to do so, but using evenly sized
objects, like both the current implementation in reorderbuffer.c and
slab.c, wastes a fair amount of memory. A later patch by Tomas will
introduce a better approach.
Author: Tomas Vondra Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/d15dff83-0b37-28ed-0809-95a5cc7292ad@2ndquadrant.com
Andres Freund [Mon, 27 Feb 2017 11:41:44 +0000 (03:41 -0800)]
Add "Slab" MemoryContext implementation for efficient equal-sized allocations.
The default general purpose aset.c style memory context is not a great
choice for allocations that are all going to be evenly sized,
especially when those objects aren't small, and have varying
lifetimes. There tends to be a lot of fragmentation, larger
allocations always directly go to libc rather than have their cost
amortized over several pallocs.
These problems lead to the introduction of ad-hoc slab allocators in
reorderbuffer.c. But it turns out that the simplistic implementation
leads to problems when a lot of objects are allocated and freed, as
aset.c is still the underlying implementation. Especially freeing can
easily run into O(n^2) behavior in aset.c.
While the O(n^2) behavior in aset.c can, and probably will, be
addressed, custom allocators for this behavior are more efficient
both in space and time.
This allocator is for evenly sized allocations, and supports both
cheap allocations and freeing, without fragmenting significantly. It
does so by allocating evenly sized blocks via malloc(), and carves
them into chunks that can be used for allocations. In order to
release blocks to the OS as early as possible, chunks are allocated
from the fullest block that still has free objects, increasing the
likelihood of a block being entirely unused.
A subsequent commit uses this in reorderbuffer.c, but a further
allocator is needed to resolve the performance problems triggering
this work.
There likely are further potentialy uses of this allocator besides
reorderbuffer.c.
There's potential further optimizations of the new slab.c, in
particular the array of freelists could be replaced by a more
intelligent structure - but for now this looks more than good enough.
Author: Tomas Vondra, editorialized by Andres Freund Reviewed-By: Andres Freund, Petr Jelinek, Robert Haas, Jim Nasby
Discussion: https://postgr.es/m/d15dff83-0b37-28ed-0809-95a5cc7292ad@2ndquadrant.com
Andres Freund [Mon, 27 Feb 2017 11:41:44 +0000 (03:41 -0800)]
Make useful infrastructure from aset.c generally available.
An upcoming patch introduces a new type of memory context. To avoid
duplicating debugging infrastructure within aset.c, move useful pieces
to memdebug.[ch].
While touching aset.c, fix printf format code in AllocFree* debug
macros.
Author: Tomas Vondra Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/b3b2245c-b37a-e1e5-ebc4-857c914bc747@2ndquadrant.com
Robert Haas [Sun, 26 Feb 2017 08:06:49 +0000 (13:36 +0530)]
Allow custom and foreign scans to have shutdown callbacks.
This is expected to be useful mostly when performing such scans in
parallel, because in that case it allows (in combination with commit acf555bc53acb589b5a2827e65d655fa8c9adee0) nodes below a Gather to get
control just before the DSM segment goes away.
KaiGai Kohei, except that I rewrote the documentation. Reviewed by
Claudio Freire.
Tom Lane [Sat, 25 Feb 2017 23:34:09 +0000 (18:34 -0500)]
Put back #include <windows.h> in dirmod.c.
I removed this in commit 9e3755ecb, reasoning that the win32.h
port-specific header file included by c.h would have provided it.
However, that's only true on native win32 builds, not Cygwin builds.
It may be that some of the other <windows.h> inclusions also need
to be put back on the same grounds; but this is the only one that
is clearly meant to be included #ifdef __CYGWIN__, so maybe this is
the extent of the problem. Awaiting further buildfarm results.
Tom Lane [Sat, 25 Feb 2017 23:10:09 +0000 (18:10 -0500)]
Remove some configure header-file checks that we weren't really using.
We had some AC_CHECK_HEADER tests that were really wastes of cycles,
because the code proceeded to #include those headers unconditionally
anyway, in all or a large majority of cases. The lack of complaints
shows that those headers are available on every platform of interest,
so we might as well let configure run a bit faster by not probing
those headers at all.
I suspect that some of the tests I left alone are equally useless, but
since all the existing #includes of the remaining headers are properly
guarded, I didn't touch them.
Tom Lane [Sat, 25 Feb 2017 21:12:24 +0000 (16:12 -0500)]
Remove useless duplicate inclusions of system header files.
c.h #includes a number of core libc header files, such as <stdio.h>.
There's no point in re-including these after having read postgres.h,
postgres_fe.h, or c.h; so remove code that did so.
While at it, also fix some places that were ignoring our standard pattern
of "include postgres[_fe].h, then system header files, then other Postgres
header files". While there's not any great magic in doing it that way
rather than system headers last, it's silly to have just a few files
deviating from the general pattern. (But I didn't attempt to enforce this
globally, only in files I was touching anyway.)
I'd be the first to say that this is mostly compulsive neatnik-ism,
but over time it might save enough compile cycles to be useful.
Bruce Momjian [Sat, 25 Feb 2017 17:59:23 +0000 (12:59 -0500)]
pg_upgrade docs: clarify instructions on standby extensions
Previously the pg_upgrade standby upgrade instructions said not to
execute pgcrypto.sql, but it should have referenced the extension
command "CREATE EXTENSION pgcrypto". This patch makes that doc change.
Reported-by: a private bug report
Backpatch-through: 9.4, where standby instructions were added
Tom Lane [Fri, 24 Feb 2017 21:45:32 +0000 (16:45 -0500)]
Suppress compiler warnings in ecpg test on newer Windows toolchains.
nan_test.pgc supposed that it could unconditionally #define isnan()
and isinf() on WIN32. This was evidently copied at some point from
src/include/port/win32.h, but nowadays there's a test on _MSC_VER
there. Make nan_test.pgc look the same.
Per buildfarm warnings. There's no evidence this produces anything
worse than a warning, and besides it's only a test case, so I don't
feel a need to back-patch.
Tom Lane [Fri, 24 Feb 2017 20:21:39 +0000 (15:21 -0500)]
Fix unportable definition of BSWAP64() macro.
We have a portable way of writing uint64 constants, but whoever wrote
this macro didn't know about it.
While at it, fix unsafe under-parenthesization of arguments. That might
be moot, because there are already good reasons not to use the macro on
anything more complicated than a simple variable, but it's still poor
practice.
Tom Lane [Fri, 24 Feb 2017 03:08:10 +0000 (22:08 -0500)]
Add an Assert that enum_cmp_internal() gets passed an FmgrInfo pointer.
If someone were to try to call one of the enum comparison functions
using DirectFunctionCallN, it would very likely seem to work, because
only in unusual cases does enum_cmp_internal() need to access the
typcache. But once such a case occurred, code like that would crash
with a null pointer dereference. To make an oversight of that sort
less likely to escape detection, add a non-bypassable Assert that
fcinfo->flinfo isn't NULL.
Tom Lane [Thu, 23 Feb 2017 20:57:08 +0000 (15:57 -0500)]
Consistently declare timestamp variables as TimestampTz.
Twiddle the replication-related code so that its timestamp variables
are declared TimestampTz, rather than the uninformative "int64" that
was previously used for meant-to-be-always-integer timestamps.
This resolves the int64-vs-TimestampTz declaration inconsistencies
introduced by commit 7c030783a, though in the opposite direction to
what was originally suggested.
This required including datatype/timestamp.h in a couple more places
than before. I decided it would be a good idea to slim down that
header by not having it pull in <float.h> etc, as those headers are
no longer at all relevant to its purpose. Unsurprisingly, a small number
of .c files turn out to have been depending on those inclusions, so add
them back in the .c files as needed.
Tom Lane [Thu, 23 Feb 2017 17:23:12 +0000 (12:23 -0500)]
Remove pg_control's enableIntTimes field.
We don't need it any more.
pg_controldata continues to report that date/time type storage is
"64-bit integers", but that's now a hard-wired behavior not something
it sees in the data. This avoids breaking pg_upgrade, and perhaps other
utilities that inspect pg_control this way. Ditto for pg_resetwal.
I chose to remove the "bigint_timestamps" output column of
pg_control_init(), though, as that function hasn't been around long
and probably doesn't have ossified users.
Tom Lane [Thu, 23 Feb 2017 16:40:12 +0000 (11:40 -0500)]
De-support floating-point timestamps.
Per discussion, the time has come to do this. The handwriting has been
on the wall at least since 9.0 that this would happen someday, whenever
it got to be too much of a burden to support the float-timestamp option.
The triggering factor now is the discovery that there are multiple bugs
in the code that attempts to implement use of integer timestamps in the
replication protocol even when the server is built for float timestamps.
The internal float timestamps leak into the protocol fields in places.
While we could fix the identified bugs, there's a very high risk of
introducing more. Trying to build a wall that would positively prevent
mixing integer and float timestamps is more complexity than we want to
undertake to maintain a long-deprecated option. The fact that these
bugs weren't found through testing also indicates a lack of interest
in float timestamps.
This commit disables configure's --disable-integer-datetimes switch
(it'll still accept --enable-integer-datetimes, though), removes direct
references to USE_INTEGER_DATETIMES, and removes discussion of float
timestamps from the user documentation. A considerable amount of code is
rendered dead by this, but removing that will occur as separate mop-up.
Tom Lane [Wed, 22 Feb 2017 20:04:07 +0000 (15:04 -0500)]
Fix contrib/pg_trgm's extraction of trigrams from regular expressions.
The logic for removing excess trigrams from the result was faulty.
It intends to avoid merging the initial and final states of the NFA,
which is necessary, but in testing whether removal of a specific trigram
would cause that, it failed to consider the combined effects of all the
state merges that that trigram's removal would cause. This could result
in a broken final graph that would never match anything, leading to GIN
or GiST indexscans not finding anything.
To fix, add a "tentParent" field that is used only within this loop,
and set it to show state merges that we are tentatively going to do.
While examining a particular arc, we must chase up through tentParent
links as well as regular parent links (the former can only appear atop
the latter), and we must account for state init/fin flag merges that
haven't actually been done yet.
To simplify the latter, combine the separate init and fin bool fields
into a bitmap flags field. I also chose to get rid of the "children"
state list, which seems entirely inessential.
Per bug #14563 from Alexey Isayko, which the added test cases are based on.
Back-patch to 9.3 where this code was added.
Andrew Dunstan [Wed, 22 Feb 2017 16:10:49 +0000 (11:10 -0500)]
Correctly handle array pseudotypes in to_json and to_jsonb
Columns with array pseudotypes have not been identified as arrays, so
they have been rendered as strings in the json and jsonb conversion
routines. This change allows them to be rendered as json arrays, making
it possible to deal correctly with the anyarray columns in pg_stats.
Robert Haas [Wed, 22 Feb 2017 06:45:17 +0000 (12:15 +0530)]
Pass the source text for a parallel query to the workers.
With this change, you can see the query that a parallel worker is
executing in pg_stat_activity, and if the worker crashes you can
see what query it was executing when it crashed.
Rafia Sabih, reviewed by Kuntal Ghosh and Amit Kapila and slightly
revised by me.
Robert Haas [Wed, 22 Feb 2017 02:29:27 +0000 (07:59 +0530)]
Shut down Gather's children before shutting down Gather itself.
It turns out that the original shutdown order here does not work well.
Multiple people attempting to develop further parallel query patches
have discovered that they need to do cleanup before the DSM goes away,
and you can't do that if the parent node gets cleaned up first.
Patch by me, reviewed by KaiGai Kohei and Dilip Kumar.
Tom Lane [Tue, 21 Feb 2017 22:51:27 +0000 (17:51 -0500)]
Fix sloppy handling of corner-case errors in fd.c.
Several places in fd.c had badly-thought-through handling of error returns
from lseek() and close(). The fact that those would seldom fail on valid
FDs is probably the reason we've not noticed this up to now; but if they
did fail, we'd get quite confused.
LruDelete and LruInsert actually just Assert'd that lseek never fails,
which is pretty awful on its face.
In LruDelete, we indeed can't throw an error, because that's likely to get
called during error abort and so throwing an error would probably just lead
to an infinite loop. But by the same token, throwing an error from the
close() right after that was ill-advised, not to mention that it would've
left the LRU state corrupted since we'd already unlinked the VFD from the
list. I also noticed that really, most of the time, we should know the
current seek position and it shouldn't be necessary to do an lseek here at
all. As patched, if we don't have a seek position and an lseek attempt
doesn't give us one, we'll close the file but then subsequent re-open
attempts will fail (except in the somewhat-unlikely case that a
FileSeek(SEEK_SET) call comes between and allows us to re-establish a known
target seek position). This isn't great but it won't result in any state
corruption.
Meanwhile, having an Assert instead of an honest test in LruInsert is
really dangerous: if that lseek failed, a subsequent read or write would
read or write from the start of the file, not where the caller expected,
leading to data corruption.
In both LruDelete and FileClose, if close() fails, just LOG that and mark
the VFD closed anyway. Possibly leaking an FD is preferable to getting
into an infinite loop or corrupting the VFD list. Besides, as far as I can
tell from the POSIX spec, it's unspecified whether or not the file has been
closed, so treating it as still open could be the wrong thing anyhow.
I also fixed a number of other places that were being sloppy about
behaving correctly when the seekPos is unknown.
Also, I changed FileSeek to return -1 with EINVAL for the cases where it
detects a bad offset, rather than throwing a hard elog(ERROR). It seemed
pretty inconsistent that some bad-offset cases would get a failure return
while others got elog(ERROR). It was missing an offset validity check for
the SEEK_CUR case on a closed file, too.
Back-patch to all supported branches, since all this code is fundamentally
identical in all of them.
Fujii Masao [Tue, 21 Feb 2017 18:11:58 +0000 (03:11 +0900)]
Make walsender always initialize the buffers.
Walsender uses the local buffers for each outgoing and incoming message.
Previously when creating replication slot, walsender forgot to initialize
one of them and which can cause the segmentation fault error. To fix this
issue, this commit changes walsender so that it always initialize them
before it executes the requested replication command.
Back-patch to 9.4 where replication slot was introduced.
Problem report and initial patch by Stas Kelvich, modified by me.
Report: https://www.postgresql.org/message-id/A1E9CB90-1FAC-4CAD-8DBA-9AA62A6E97C5@postgrespro.ru
Tom Lane [Tue, 21 Feb 2017 17:18:22 +0000 (12:18 -0500)]
Use less-generic table name in new regression test case.
Creating global objects named "foo" isn't an especially wise thing,
but especially not in a test script that has already used that name
for something else, and most especially not in a script that runs
in parallel with other scripts that use that name :-(
Tom Lane [Tue, 21 Feb 2017 16:28:23 +0000 (11:28 -0500)]
Reject too-old Python versions a bit sooner.
Commit 04aad4018 added this check after the search for a Python shared
library, which seems to me to be a pretty unfriendly ordering. The
search might fail for what are basically version-related reasons, and
in such a case it'd be better to say "your Python is too old" than
"could not find shared library for Python".
Peter Eisentraut [Tue, 21 Feb 2017 14:27:02 +0000 (09:27 -0500)]
Drop support for Python 2.3
There is no specific reason for this right now, but keeping support for
old Python versions around indefinitely increases the maintenance
burden. The oldest supported Python version is now Python 2.4, which is
still shipped in RHEL/CentOS 5 by default.
In configure, add a check for the required Python version and give a
friendly error message for an old version, instead of relying on an
obscure build error later on.
Tom Lane [Mon, 20 Feb 2017 15:27:48 +0000 (10:27 -0500)]
Improve error message for misuse of TZ, tz, OF formatting patterns.
Be specific about which pattern is being complained of, and avoid saying
"it's not supported in to_date", which is just confusing if the error is
actually coming out of to_timestamp. We can phrase it as "is only
supported in to_char", instead. Also, use the term "formatting field" not
"format pattern", because other error messages in the same file prefer that
terminology. (This isn't terribly consistent with the documentation, so
maybe we should change all these error messages?)
Tom Lane [Mon, 20 Feb 2017 15:05:00 +0000 (10:05 -0500)]
Fix documentation of to_char/to_timestamp TZ, tz, OF formatting patterns.
These are only supported in to_char, not in the other direction, but the
documentation failed to mention that. Also, describe TZ/tz as printing the
time zone "abbreviation", not "name", because what they print is elsewhere
referred to that way. Per bug #14558.
Tom Lane [Sun, 19 Feb 2017 21:41:51 +0000 (16:41 -0500)]
Dept of second thoughts: rename new perl script.
It didn't take long at all for me to become irritated that the original
choice of name for this script resulted in "warning" showing up in several
places in build logs, because I tend to grep for that. Change the script
name to avoid that.
Tom Lane [Sun, 19 Feb 2017 21:14:52 +0000 (16:14 -0500)]
Adjust PL/Tcl regression test to dodge a possible bug or zone dependency.
One case in the PL/Tcl tests is observed to fail on RHEL5 with a Turkish
time zone setting. It's not clear if this is an old Tcl bug or something
odd about the zone data, but in any case that test is meant to see if the
Tcl [clock] command works at all, not what its corner-case behaviors are.
Therefore we have no need to test exactly which week a Sunday midnight is
considered to fall into. Probe the following Tuesday instead.
Tom Lane [Sun, 19 Feb 2017 18:04:30 +0000 (13:04 -0500)]
Suppress "unused variable" warnings with older versions of flex.
Versions of flex before 2.5.36 might generate code that results in an
"unused variable" warning, when using %option reentrant. Historically
we've worked around that by specifying -Wno-error, but that's an
unsatisfying solution. The official "fix" for this was just to insert a
dummy reference to the variable, so write a small perl script that edits
the generated C code similarly.
The MSVC side of this is untested, but the buildfarm should soon reveal
if I broke that.
Robert Haas [Sun, 19 Feb 2017 10:23:59 +0000 (15:53 +0530)]
Add optimizer and executor support for parallel index-only scans.
Commit 5262f7a4fc44f651241d2ff1fa688dd664a34874 added similar support
for parallel index scans; this extends that work to index-only scans.
As with parallel index scans, this requires support from the index AM,
so currently parallel index-only scans will only be possible for btree
indexes.
Rafia Sabih, reviewed and tested by Rahila Syed, Tushar Ahuja,
and Amit Kapila
Robert Haas [Sun, 19 Feb 2017 08:29:53 +0000 (13:59 +0530)]
Make dsa_allocate interface more like MemoryContextAlloc.
A new function dsa_allocate_extended now takes flags which indicate
that huge allocations should be permitted, that out-of-memory
conditions should not throw an error, and/or that the returned memory
should be zero-filled, just like MemoryContextAllocateExtended.
Commit 9acb85597f1223ac26a5b19a9345849c43d0ff54, which added
dsa_allocate0, was broken because it failed to account for the
possibility that dsa_allocate() might return InvalidDsaPointer.
This fixes that problem along the way.
Magnus Hagander [Sat, 18 Feb 2017 12:45:14 +0000 (13:45 +0100)]
Fix help message for pg_basebackup -R
The recovery.conf file that's generated is specifically for replication,
and not needed (or wanted) for regular backup restore, so indicate that
in the message.
Peter Eisentraut [Sat, 18 Feb 2017 00:32:15 +0000 (19:32 -0500)]
Optimize query for information_schema.constraint_column_usage
The way the old query was written prevented some join optimizations
because the join conditions were hidden inside a CASE expression. With
a large number of constraints, the query became unreasonably slow. The
new query performs much better.
Tom Lane [Thu, 16 Feb 2017 16:30:07 +0000 (11:30 -0500)]
Doc: remove duplicate index entry.
This causes a warning with the old html-docs toolchain, though not with the
new. I had originally supposed that we needed both <indexterm> entries to
get both a primary index entry and a see-also link; but evidently not,
as pointed out by Fabien Coelho.
Tom Lane [Wed, 15 Feb 2017 23:15:47 +0000 (18:15 -0500)]
Formatting and docs corrections for logical decoding output plugins.
Make the typedefs for output plugins consistent with project style;
they were previously not even consistent with each other as to layout
or inclusion of parameter names. Make the documentation look the same,
and fix errors therein (missing and misdescribed parameters).
Tom Lane [Wed, 15 Feb 2017 21:40:05 +0000 (16:40 -0500)]
Make sure that hash join's bulk-tuple-transfer loops are interruptible.
The loops in ExecHashJoinNewBatch(), ExecHashIncreaseNumBatches(), and
ExecHashRemoveNextSkewBucket() are all capable of iterating over many
tuples without ever doing a CHECK_FOR_INTERRUPTS, so that the backend
might fail to respond to SIGINT or SIGTERM for an unreasonably long time.
Fix that. In the case of ExecHashJoinNewBatch(), it seems useful to put
the added CHECK_FOR_INTERRUPTS into ExecHashJoinGetSavedTuple() rather
than directly in the loop, because that will also ensure that both
principal code paths through ExecHashJoinOuterGetTuple() will do a
CHECK_FOR_INTERRUPTS, which seems like a good idea to avoid surprises.
Tom Lane [Wed, 15 Feb 2017 20:23:19 +0000 (15:23 -0500)]
Fix tab completion for "ALTER SYSTEM SET variable ...".
It wouldn't complete "TO" after the variable name, which is certainly
minor enough. But since we do complete "TO" after "SET variable ...",
and since this case used to work pre-9.6, I think this is a bug.
Also, fix the query used to collect the variable names; whoever last
touched it evidently didn't understand how the pieces are supposed
to fit together. It accidentally worked anyway, because readline
ignores irrelevant completions, but it was randomly unlike the ones
around it, and could be a source of actual bugs if someone copied
it as a prototype for another query.
Tom Lane [Wed, 15 Feb 2017 19:43:59 +0000 (14:43 -0500)]
Fix YA unwanted behavioral difference with operator_precedence_warning.
Jeff Janes noted that the error cursor position shown for some errors
would vary when operator_precedence_warning is turned on. We'd prefer
that option to have no undocumented effects, so this isn't desirable.
To fix, make sure that an AEXPR_PAREN node has the same exprLocation
as its child node.
(Note: it would be a little cheaper to use @2 here instead of an
exprLocation call, but there are cases where that wouldn't produce
the identical answer, so don't do it like that.)
Back-patch to 9.5 where this feature was introduced.
Robert Haas [Wed, 15 Feb 2017 18:53:24 +0000 (13:53 -0500)]
Add optimizer and executor support for parallel index scans.
In combination with 569174f1be92be93f5366212cc46960d28a5c5cd, which
taught the btree AM how to perform parallel index scans, this allows
parallel index scan plans on btree indexes. This infrastructure
should be general enough to support parallel index scans for other
index AMs as well, if someone updates them to support parallel
scans.
Amit Kapila, reviewed and tested by Anastasia Lubennikova, Tushar
Ahuja, and Haribabu Kommi, and me.
Robert Haas [Wed, 15 Feb 2017 18:37:24 +0000 (13:37 -0500)]
Replace min_parallel_relation_size with two new GUCs.
When min_parallel_relation_size was added, the only supported type
of parallel scan was a parallel sequential scan, but there are
pending patches for parallel index scan, parallel index-only scan,
and parallel bitmap heap scan. Those patches introduce two new
types of complications: first, what's relevant is not really the
total size of the relation but the portion of it that we will scan;
and second, index pages and heap pages shouldn't necessarily be
treated in exactly the same way. Typically, the number of index
pages will be quite small, but that doesn't necessarily mean that
a parallel index scan can't pay off.
Therefore, we introduce min_parallel_table_scan_size, which works
out a degree of parallelism for scans based on the number of table
pages that will be scanned (and which is therefore equivalent to
min_parallel_relation_size for parallel sequential scans) and also
min_parallel_index_scan_size which can be used to work out a degree
of parallelism based on the number of index pages that will be
scanned.
Robert Haas [Wed, 15 Feb 2017 16:03:41 +0000 (11:03 -0500)]
Document new libpq connection statuses for target_session_attrs.
I didn't realize these would ever be visible to clients, but Michael
figured out that it can happen when using asynchronous interfaces
such as PQconnectPoll.
The core of the functionality was already implemented when
pg_import_system_collations was added. This just exposes it as an
option in the SQL command.
Robert Haas [Wed, 15 Feb 2017 12:41:14 +0000 (07:41 -0500)]
btree: Support parallel index scans.
This isn't exposed to the optimizer or the executor yet; we'll add
support for those things in a separate patch. But this puts the
basic mechanism in place: several processes can attach to a parallel
btree index scan, and each one will get a subset of the tuples that
would have been produced by a non-parallel scan. Each index page
becomes the responsibility of a single worker, which then returns
all of the TIDs on that page.
Rahila Syed, Amit Kapila, Robert Haas, reviewed and tested by
Anastasia Lubennikova, Tushar Ahuja, and Haribabu Kommi.
projects / postgresql / log