Commit Graph

7588 Commits

Author SHA1 Message Date
Heikki Linnakangas 818fd4a67d Support SCRAM-SHA-256 authentication (RFC 5802 and 7677).
This introduces a new generic SASL authentication method, similar to the
GSS and SSPI methods. The server first tells the client which SASL
authentication mechanism to use, and then the mechanism-specific SASL
messages are exchanged in AuthenticationSASLcontinue and PasswordMessage
messages. Only SCRAM-SHA-256 is supported at the moment, but this allows
adding more SASL mechanisms in the future, without changing the overall
protocol.

Support for channel binding, aka SCRAM-SHA-256-PLUS is left for later.

The SASLPrep algorithm, for pre-processing the password, is not yet
implemented. That could cause trouble, if you use a password with
non-ASCII characters, and a client library that does implement SASLprep.
That will hopefully be added later.

Authorization identities, as specified in the SCRAM-SHA-256 specification,
are ignored. SET SESSION AUTHORIZATION provides more or less the same
functionality, anyway.

If a user doesn't exist, perform a "mock" authentication, by constructing
an authentic-looking challenge on the fly. The challenge is derived from
a new system-wide random value, "mock authentication nonce", which is
created at initdb, and stored in the control file. We go through these
motions, in order to not give away the information on whether the user
exists, to unauthenticated users.

Bumps PG_CONTROL_VERSION, because of the new field in control file.

Patch by Michael Paquier and Heikki Linnakangas, reviewed at different
stages by Robert Haas, Stephen Frost, David Steele, Aleksander Alekseev,
and many others.

Discussion: https://www.postgresql.org/message-id/CAB7nPqRbR3GmFYdedCAhzukfKrgBLTLtMvENOmPrVWREsZkF8g%40mail.gmail.com
Discussion: https://www.postgresql.org/message-id/CAB7nPqSMXU35g%3DW9X74HVeQp0uvgJxvYOuA4A-A3M%2B0wfEBv-w%40mail.gmail.com
Discussion: https://www.postgresql.org/message-id/55192AFE.6080106@iki.fi
2017-03-07 14:25:40 +02:00
Heikki Linnakangas 273c458a2b Refactor SHA2 functions and move them to src/common/.
This way both frontend and backends can use them. The functions are taken
from pgcrypto, which now fetches the source files it needs from
src/common/.

A new interface is designed for the SHA2 functions, which allow linking
to either OpenSSL or the in-core stuff taken from KAME as needed.

Michael Paquier, reviewed by Robert Haas.

Discussion: https://www.postgresql.org/message-id/CAB7nPqTGKuTM5jiZriHrNaQeVqp5e_iT3X4BFLWY_HyHxLvySQ%40mail.gmail.com
2017-03-07 14:23:49 +02:00
Andres Freund d4c62a6b62 Make simplehash.h grow hashtable in additional cases.
Increase the size when either the distance between actual and optimal
slot grows too large, or when too many subsequent entries would have
to be moved.

This addresses reports that the simplehash performed, sometimes
considerably, worse than dynahash.

The reason turned out to be that insertions into the hashtable where,
due to the use of parallel query, in effect done from another
hashtable, in hash-value order.  If the target hashtable, due to
mis-estimation, was sized a lot smaller than the source table(s) that
lead to very imbalanced tables; a lot of entries in many close-by
buckets from the source tables were inserted into a single, wider,
bucket on the target table.  As the growth factor was solely computed
based on the fillfactor, the performance of the table decreased
further and further.

b81b5a96f4 was an attempt to address this problem for hash
aggregates (but not for bitmap scans), but it turns out that the
current method of mixing hash values often actually leaves neighboring
hash-values close to each other, just in different value range.  It
might be worth revisiting that independently of the performance issues
addressed in this patch..

To address that problem resize tables in two additional cases: Firstly
when the optimal position for an entry would be far from the actual
position, secondly when many entries would have to be moved to make
space for the new entry (while satisfying the robin hood property).

Due to the additional resizing threshold it seems possible, and
testing confirms that so far, that a higher fillfactor doesn't hurt
performance and saves a bit of memory.  It seems better to increase it
now, before a release containing any of this code, rather than wonder
in some later release.

The various boundaries aren't determined in a particularly scientific
manner, they might need some fine-tuning.

In all my tests the new code now, even with parallelism, performs at
least as good as the old code, in several scenarios significantly
better.

Reported-By: Dilip Kumar, Robert Haas, Kuntal Ghosh
Discussion:
    https://postgr.es/m/CAFiTN-vagvuAydKG9VnWcoK=ADAhxmOa4ZTrmNsViBBooTnriQ@mail.gmail.com
    https://postgr.es/m/CAGz5QC+=fNTYgzMLTBUNeKt6uaWZFXJbkB5+7oWm-n9DwVxcLA@mail.gmail.com
2017-03-06 14:13:06 -08:00
Peter Eisentraut 2ca64c6f71 Replace LookupFuncNameTypeNames() with LookupFuncWithArgs()
The old function took function name and function argument list as
separate arguments.  Now that all function signatures are passed around
as ObjectWithArgs structs, this is no longer necessary and can be
replaced by a function that takes ObjectWithArgs directly.  Similarly
for aggregates and operators.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00
Peter Eisentraut 8b6d6cf853 Remove objname/objargs split for referring to objects
In simpler times, it might have worked to refer to all kinds of objects
by a list of name components and an optional argument list.  But this
doesn't work for all objects, which has resulted in a collection of
hacks to place various other nodes types into these fields, which have
to be unpacked at the other end.  This makes it also weird to represent
lists of such things in the grammar, because they would have to be lists
of singleton lists, to make the unpacking work consistently.  The other
problem is that keeping separate name and args fields makes it awkward
to deal with lists of functions.

Change that by dropping the objargs field and have objname, renamed to
object, be a generic Node, which can then be flexibly assigned and
managed using the normal Node mechanisms.  In many cases it will still
be a List of names, in some cases it will be a string Value, for types
it will be the existing Typename, for functions it will now use the
existing ObjectWithArgs node type.  Some of the more obscure object
types still use somewhat arbitrary nested lists.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00
Peter Eisentraut 550214a4ef Add operator_with_argtypes grammar rule
This makes the handling of operators similar to that of functions and
aggregates.

Rename node FuncWithArgs to ObjectWithArgs, to reflect the expanded use.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00
Peter Eisentraut 63ebd377a6 Use class_args field in opclass_drop
This makes it consistent with the usage in opclass_item.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00
Robert Haas 9fe3c644a7 Mark pg_start_backup and pg_stop_backup as parallel-restricted.
They depend on backend-private state that will not be synchronized by
the parallel machinery, so they should not be marked parallel-safe.
This issue also exists in 9.6, but we obviously can't do anything
about 9.6 clusters that already exist.  Possibly this could be
back-patched so that future 9.6 clusters would come out OK, or
possibly we should back-patch some other fix, but that would need more
discussion.

David Steele, reviewed by Michael Paquier

Discussion: http://postgr.es/m/CA+TgmoYCWfO2UM-t=HUMFJyxJywLDiLL0nAJpx88LKtvBvNECw@mail.gmail.com
2017-03-06 12:41:55 -05:00
Peter Eisentraut 272adf4f9c Disallow CREATE/DROP SUBSCRIPTION in transaction block
Disallow CREATE SUBSCRIPTION and DROP SUBSCRIPTION in a transaction
block when the replication slot is to be created or dropped, since that
cannot be rolled back.

based on patch by Masahiko Sawada <sawada.mshk@gmail.com>
2017-03-03 23:29:13 -05:00
Peter Eisentraut 6f236e1eb8 psql: Add tab completion for logical replication
Add tab completion for publications and subscriptions.  Also, to be able
to get a list of subscriptions, make pg_subscription world-readable but
revoke access to subconninfo using column privileges.

From: Michael Paquier <michael.paquier@gmail.com>
2017-03-03 14:13:48 -05:00
Peter Eisentraut 1e8a850094 Use asynchronous connect API in libpqwalreceiver
This makes the connection attempt from CREATE SUBSCRIPTION and from
WalReceiver interruptable by the user in case the libpq connection is
hanging.  The previous coding required immediate shutdown (SIGQUIT) of
PostgreSQL in that situation.

From: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Tested-by: Thom Brown <thom@linux.com>
2017-03-03 09:13:58 -05:00
Robert Haas 19dc233c32 Add pg_current_logfile() function.
The syslogger will write out the current stderr and csvlog names, if
it's running and there are any, to a new file in the data directory
called "current_logfiles".  We take care to remove this file when it
might no longer be valid (but not at shutdown).  The function
pg_current_logfile() can be used to read the entries in the file.

Gilles Darold, reviewed and modified by Karl O.  Pinc, Michael
Paquier, and me.  Further review by Álvaro Herrera and Christoph Berg.
2017-03-03 11:43:11 +05:30
Robert Haas aea5d29836 Notify bgworker registrant after freeing worker slot.
Tom Lane observed buildfarm failures caused by the select_parallel
regression test trying to launch new parallel queries before the
worker slots used by the previous ones were freed.  Try to fix this by
having the postmaster free the worker slots before it sends the
SIGUSR1 notifications to the registering process.  This doesn't
completely eliminate the possibility that the user backend might
(correctly) observe the worker as dead before the slot is free, but I
believe it should make the window significantly narrower.

Patch by me, per complaint from Tom Lane.  Reviewed by Amit Kapila.

Discussion: http://postgr.es/m/30673.1487310734@sss.pgh.pa.us
2017-03-03 09:25:30 +05:30
Robert Haas 5a73e17317 Improve error reporting for tuple-routing failures.
Currently, the whole row is shown without column names.  Instead,
adopt a style similar to _bt_check_unique() in ExecFindPartition()
and show the failing key: (key1, ...) = (val1, ...).

Amit Langote, per a complaint from Simon Riggs.  Reviewed by me;
I also adjusted the grammar in one of the comments.

Discussion: http://postgr.es/m/9f9dc7ae-14f0-4a25-5485-964d9bfc19bd@lab.ntt.co.jp
2017-03-03 09:09:52 +05:30
Andres Freund 8f7277dfb5 Fix s/ITERTOR/ITERATOR/ typo in simplehash.h.
This could lead to problem when simplehash.h is used to define two
different types of hashtable visible in the same translation unit.

Reported-By: Josh Soref
Discussion: https://postgr.es/m/CACZqfqCC7WdBAY=rQePb9-qW1rjdaTdHsV5KoVejHkDb6qrtOg@mail.gmail.com
2017-03-01 10:17:12 -08:00
Peter Eisentraut 005638e988 Fix naming inconsistency
subobjid -> objsubid

From: Jim Nasby <Jim.Nasby@BlueTreble.com>
2017-03-01 12:22:33 -05:00
Peter Eisentraut 20f6d74242 Collect duplicate copies of oid_cmp() 2017-03-01 11:55:28 -05:00
Peter Eisentraut 788af6f854 Move atooid() definition to a central place 2017-03-01 11:55:28 -05:00
Andres Freund 7e3aa03b41 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
2017-02-28 19:42:44 -08:00
Tom Lane 9b88f27cb4 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.

Discussion: https://postgr.es/m/49527f79-530d-0bfe-3dad-d183596afa92@2ndquadrant.fr
2017-02-27 17:20:34 -05:00
Robert Haas 30df93f698 hash: Refactor overflow page allocation.
As with commit b0f18cb77f, 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.
2017-02-27 22:59:55 +05:30
Robert Haas b0f18cb77f 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.

Amit Kapila, with slight changes by me.
2017-02-27 22:34:21 +05:30
Peter Eisentraut 2ed193c904 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.
2017-02-27 08:54:51 -05:00
Andres Freund 9fab40ad32 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
2017-02-27 03:41:44 -08:00
Andres Freund 58b25e9810 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
2017-02-27 03:41:44 -08:00
Andres Freund bfd12cccbd 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
2017-02-27 03:41:44 -08:00
Robert Haas a315b967cc 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
acf555bc53) 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.

Discussion: http://postgr.es/m/CADyhKSXJK0jUJ8rWv4AmKDhsUh124_rEn39eqgfC5D8fu6xVuw@mail.gmail.com
2017-02-26 13:41:12 +05:30
Tom Lane 2bd7f85796 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.
2017-02-25 18:10:09 -05:00
Tom Lane 9e3755ecb2 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.
2017-02-25 16:12:55 -05:00
Tom Lane 41c16edcf6 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.

Per buildfarm warnings.
2017-02-24 15:21:39 -05:00
Tom Lane c29aff959d 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.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
Discussion: https://postgr.es/m/27694.1487456324@sss.pgh.pa.us
2017-02-23 15:57:08 -05:00
Tom Lane b9d092c962 Remove now-dead code for !HAVE_INT64_TIMESTAMP.
This is a basically mechanical removal of #ifdef HAVE_INT64_TIMESTAMP
tests and the negative-case controlled code.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
2017-02-23 14:04:43 -05:00
Tom Lane d28aafb6dd 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.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
2017-02-23 12:23:12 -05:00
Tom Lane b6aa17e0ae 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.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
2017-02-23 11:40:20 -05:00
Peter Eisentraut e8d016d819 Remove deprecated COMMENT ON RULE syntax
This was only used for allowing upgrades from pre-7.3 instances, which
was a long time ago.
2017-02-23 08:19:52 -05:00
Robert Haas 4c728f3829 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.
2017-02-22 12:18:29 +05:30
Robert Haas 0414b26bac Add optimizer and executor support for parallel index-only scans.
Commit 5262f7a4fc 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

Discussion: http://postgr.es/m/CAOGQiiPEAs4C=TBp0XShxBvnWXuzGL2u++Hm1=qnCpd6_Mf8Fw@mail.gmail.com
2017-02-19 15:57:55 +05:30
Robert Haas 16be2fd100 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 9acb85597f, 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.

Thomas Munro, with some comment changes by me.

Discussion: http://postgr.es/m/CA+Tgmobt7CcF_uQP2UQwWmu4K9qCHehMJP9_9m1urwP8hbOeHQ@mail.gmail.com
2017-02-19 13:59:53 +05:30
Peter Eisentraut e7e4cd1ab5 Fix typo on comment 2017-02-16 23:53:01 -05:00
Robert Haas 9acb85597f Add new function dsa_allocate0.
This does the same thing as dsa_allocate, except that the memory
is guaranteed to be zero-filled on return.

Dilip Kumar, adjusted by me.
2017-02-16 12:57:03 -05:00
Tom Lane 93e6e40574 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).

Back-patch because of the documentation bugs.
2017-02-15 18:15:47 -05:00
Robert Haas 5262f7a4fc Add optimizer and executor support for parallel index scans.
In combination with 569174f1be, 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.
2017-02-15 13:53:24 -05:00
Robert Haas 51ee6f3160 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.

Amit Kapila and Robert Haas

Discussion: http://postgr.es/m/CAA4eK1KowGSYYVpd2qPpaPPA5R90r++QwDFbrRECTE9H_HvpOg@mail.gmail.com
Discussion: http://postgr.es/m/CAA4eK1+TnM4pXQbvn7OXqam+k_HZqb0ROZUMxOiL6DWJYCyYow@mail.gmail.com
2017-02-15 13:37:24 -05:00
Robert Haas 5d40286985 Fix wrong articles in pg_proc descriptions.
This technically should involve a catversion bump, but that seems
pedantic, so I skipped it.

Report and patch by David Christensen.
2017-02-15 12:13:38 -05:00
Peter Eisentraut 6d16ecc646 Add CREATE COLLATION IF NOT EXISTS clause
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.
2017-02-15 10:01:28 -05:00
Robert Haas 569174f1be 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.
2017-02-15 07:41:14 -05:00
Robert Haas 5e6d8d2bbb Allow parallel workers to execute subplans.
This doesn't do anything to make Param nodes anything other than
parallel-restricted, so this only helps with uncorrelated subplans,
and it's not necessarily very cheap because each worker will run the
subplan separately (just as a Hash Join will build a separate copy of
the hash table in each participating process), but it's a first step
toward supporting cases that are more likely to help in practice, and
is occasionally useful on its own.

Amit Kapila, reviewed and tested by Rafia Sabih, Dilip Kumar, and
me.

Discussion: http://postgr.es/m/CAA4eK1+e8Z45D2n+rnDMDYsVEb5iW7jqaCH_tvPMYau=1Rru9w@mail.gmail.com
2017-02-14 18:16:03 -05:00
Robert Haas 8da9a22636 Split index xlog headers from other private index headers.
The xlog-specific headers need to be included in both frontend code -
specifically, pg_waldump - and the backend, but the remainder of the
private headers for each index are only needed by the backend.  By
splitting the xlog stuff out into separate headers, pg_waldump pulls
in fewer backend headers, which is a good thing.

Patch by me, reviewed by Michael Paquier and Andres Freund, per a
complaint from Dilip Kumar.

Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
2017-02-14 15:37:59 -05:00
Robert Haas fb47544d0c Minor fixes for WAL consistency checking.
Michael Paquier, reviewed and slightly revised by me.

Discussion: http://postgr.es/m/CAB7nPqRzCQb=vdfHvMtP0HMLBHU6z1aGdo4GJsUP-HP8jx+Pkw@mail.gmail.com
2017-02-14 12:41:01 -05:00
Peter Eisentraut 2ea5b06c7a Add CREATE SEQUENCE AS <data type> clause
This stores a data type, required to be an integer type, with the
sequence.  The sequences min and max values default to the range
supported by the type, and they cannot be set to values exceeding that
range.  The internal implementation of the sequence is not affected.

Change the serial types to create sequences of the appropriate type.
This makes sure that the min and max values of the sequence for a serial
column match the range of values supported by the table column.  So the
sequence can no longer overflow the table column.

This also makes monitoring for sequence exhaustion/wraparound easier,
which currently requires various contortions to cross-reference the
sequences with the table columns they are used with.

This commit also effectively reverts the pg_sequence column reordering
in f3b421da5f, because the new seqtypid
column allows us to fill the hole in the struct and create a more
natural overall column ordering.

Reviewed-by: Steve Singer <steve@ssinger.info>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-02-10 15:34:35 -05:00