Commit Graph

9004 Commits

Author SHA1 Message Date
Tom Lane d5b90cd648 Fix bogus handling of XQuery regex option flags.
The SQL spec defers to XQuery to define what the option flags are
for LIKE_REGEX patterns.  XQuery says that:
* 's' allows the dot character to match newlines, which by
  default it will not;
* 'm' allows ^ and $ to match at newlines, not only at the
  start/end of the whole string.
Thus, these are *not* inverses as they are for the similarly-named
POSIX options, and neither one corresponds to the POSIX 'n' option.
Fortunately, Spencer's library does expose these two behaviors as
separately twiddlable flags, so we just have to fix the mapping from
JSP flag bits to REG flag bits.  I also chose to rename the symbol
for 's' to DOTALL, to make it clearer that it's not the inverse
of MLINE.

Also, XQuery says that if the 'q' flag "is used together with the m, s,
or x flag, that flag has no effect".  I read this as saying that 'q'
overrides the other flags; whoever wrote our code seems to have read
it backwards.

Lastly, while XQuery's 'x' flag is related to what Spencer's code
does for REG_EXPANDED, it's not the same or a subset.  It seems best
to treat XQuery's 'x' as unimplemented for now.  Maybe later we can
expand our regex code to offer 'x'-style parsing as a separate option.

While at it, refactor the jsonpath code so that (a) there's only
one copy of the flag transformation logic not two, and (b) the
processing of flags is independent of the order in which the flags
are written.

We need some documentation updates to go with this, but I'll
tackle that separately.

Back-patch to v12 where this code originated.

Discussion: https://postgr.es/m/CAPpHfdvDci4iqNF9fhRkTqhe-5_8HmzeLt56drH%2B_Rv2rNRqfg@mail.gmail.com
Reference: https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/#flags
2019-09-17 15:39:51 -04:00
Alexander Korotkov d589f94460 Support for FF1-FF6 datetime format patterns
SQL Standard 2016 defines FF1-FF9 format patters for fractions of seconds in
jsonpath .datetime() method and CAST (... FORMAT ...) SQL clause.  Parsing
engine of upcoming .datetime() method will be shared with to_date()/
to_timestamp().

This patch implements FF1-FF6 format patterns for upcoming jsonpath .datetime()
method.  to_date()/to_timestamp() functions will also get support of this
format patterns as positive side effect.  FF7-FF9 are not supported due to
lack of precision in our internal timestamp representation.

Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Heavily revised by me.

Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Alexander Korotkov
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
2019-09-16 21:14:32 +03:00
Noah Misch 87e9fae069 Revert "For all ppc compilers, implement pg_atomic_fetch_add_ with inline asm."
This reverts commit e7ff59686e.  It
defined pg_atomic_fetch_add_u32_impl() without defining
pg_atomic_compare_exchange_u32_impl(), which is incompatible with
src/include/port/atomics/fallback.h.  Per buildfarm member prairiedog.

Discussion: https://postgr.es/m/7517.1568470247@sss.pgh.pa.us
2019-09-14 19:38:41 -07:00
Noah Misch e7ff59686e For all ppc compilers, implement pg_atomic_fetch_add_ with inline asm.
This is more like how we handle s_lock.h and arch-x86.h.  This does not
materially affect code generation for gcc 7.2.0 or xlc 13.1.3.

Reviewed by Tom Lane.

Discussion: https://postgr.es/m/20190831071157.GA3251746@rfd.leadboat.com
2019-09-13 19:34:30 -07:00
Noah Misch dd50f1a432 Replace xlc __fetch_and_add() with inline asm.
PostgreSQL has been unusable when built with xlc 13 and newer, which are
incompatible with our use of __fetch_and_add().  Back-patch to 9.5,
which introduced pg_atomic_fetch_add_u32().

Reviewed by Tom Lane.

Discussion: https://postgr.es/m/20190831071157.GA3251746@rfd.leadboat.com
2019-09-13 19:34:06 -07:00
Alvaro Herrera ce5d04b646 Fix under-parenthesized macro definitions
Lack of parens in the definitions could cause a statement using these
macros to have unexpected semantics.  In current code no bug is
apparent, but best to fix the definitions to avoid problems down the
line.

Reported-by: Tom Lane
Discussion: https://postgr.es/m/19795.1568400476@sss.pgh.pa.us
2019-09-13 16:26:55 -03:00
Alvaro Herrera 6212276e43 Fix progress reporting of CLUSTER / VACUUM FULL
The progress state was being clobbered once the first index completed
being rebuilt, causing the final phases of the operation not show
anything in the progress view.  This was inadvertently broken in
03f9e5cba0, which added progress tracking for REINDEX.

(The reason this bugfix is this small is that I had already noticed this
problem when writing monitoring for CREATE INDEX, and had already worked
around it, as can be seen in discussion starting at
https://postgr.es/m/20190329150218.GA25010@alvherre.pgsql Fixing the
problem is just a matter of fixing one place touched by the REINDEX
monitoring.)

Reported by: Álvaro Herrera
Author: Álvaro Herrera
Discussion: https://postgr.es/m/20190801184333.GA21369@alvherre.pgsql
2019-09-13 14:54:26 -03:00
Peter Geoghegan 3b6b54f178 Fix nbtree page split rmgr desc routine.
Include newitemoff in rmgr desc output for nbtree page split records.
In passing, correct an obsolete comment that claimed that newitemoff is
only logged for _L variant nbtree page split WAL records.

Both issues were oversights in commit 2c03216d83, which revamped the
WAL format.

Author: Peter Geoghegan
Backpatch: 9.5-, where the WAL format was revamped.
2019-09-12 15:45:08 -07:00
Peter Geoghegan 614cdeaa89 Reorder two nbtree.h function prototypes.
Make the function prototype order consistent with the definition order
in nbtinsert.c.
2019-09-12 09:59:16 -07:00
Tom Lane 9a86f03b4e Rearrange postmaster's startup sequence for better syslogger results.
This is a second try at what commit 57431a911 tried to do, namely,
launch the syslogger before we open postmaster sockets so that our
messages about the sockets end up in the syslogger files.  That
commit fell foul of a bunch of subtle issues caused by trying to
launch a postmaster child process before creating shared memory.
Rather than messing with that interaction, let's postpone opening
the sockets till after we launch the syslogger.

This would not have been terribly safe before commit 7de19fbc0,
because we relied on socket opening to detect whether any competing
postmasters were using the same port number.  But now that we choose
IPC keys without regard to the port number, there's no interaction
to worry about.

Also delay creation of the external PID file (if requested) till after
the sockets are open, since external code could plausibly be relying
on that ordering of events.  And postpone most of the work of
RemovePgTempFiles() so that that potentially-slow processing still
happens after we make the external PID file.  We have to be a bit
careful about that last though: as noted in the discussion subsequent to
bug #15804, EXEC_BACKEND builds still have to clear the parameter-file
temp dir before launching the syslogger.

Patch by me; thanks to Michael Paquier for review/testing.

Discussion: https://postgr.es/m/15804-3721117bf40fb654@postgresql.org
2019-09-11 11:43:01 -04:00
Tomas Vondra d06215d03b Allow setting statistics target for extended statistics
When building statistics, we need to decide how many rows to sample and
how accurate the resulting statistics should be. Until now, it was not
possible to explicitly define statistics target for extended statistics
objects, the value was always computed from the per-attribute targets
with a fallback to the system-wide default statistics target.

That's a bit inconvenient, as it ties together the statistics target set
for per-column and extended statistics. In some cases it may be useful
to require larger sample / higher accuracy for extended statics (or the
other way around), but with this approach that's not possible.

So this commit introduces a new command, allowing to specify statistics
target for individual extended statistics objects, overriding the value
derived from per-attribute targets (and the system default).

  ALTER STATISTICS stat_name SET STATISTICS target_value;

When determining statistics target for an extended statistics object we
first look at this explicitly set value. When this value is -1, we fall
back to the old formula, looking at the per-attribute targets first and
then the system default. This means the behavior is backwards compatible
with older PostgreSQL releases.

Author: Tomas Vondra
Discussion: https://postgr.es/m/20190618213357.vli3i23vpkset2xd@development
Reviewed-by: Kirk Jamison, Dean Rasheed
2019-09-11 00:25:51 +02:00
Andres Freund 27cc7cd2bc Reorder EPQ work, to fix rowmark related bugs and improve efficiency.
In ad0bda5d24 I changed the EvalPlanQual machinery to store
substitution tuples in slot, instead of using plain HeapTuples. The
main motivation for that was that using HeapTuples will be inefficient
for future tableams.  But it turns out that that conversion was buggy
for non-locking rowmarks - the wrong tuple descriptor was used to
create the slot.

As a secondary issue 5db6df0c0 changed ExecLockRows() to begin EPQ
earlier, to allow to fetch the locked rows directly into the EPQ
slots, instead of having to copy tuples around. Unfortunately, as Tom
complained, that forces some expensive initialization to happen
earlier.

As a third issue, the test coverage for EPQ was clearly insufficient.

Fixing the first issue is unfortunately not trivial: Non-locked row
marks were fetched at the start of EPQ, and we don't have the type
information for the rowmarks available at that point. While we could
change that, it's not easy. It might be worthwhile to change that at
some point, but to fix this bug, it seems better to delay fetching
non-locking rowmarks when they're actually needed, rather than
eagerly. They're referenced at most once, and in cases where EPQ
fails, might never be referenced. Fetching them when needed also
increases locality a bit.

To be able to fetch rowmarks during execution, rather than
initialization, we need to be able to access the active EPQState, as
that contains necessary data. To do so move EPQ related data from
EState to EPQState, and, only for EStates creates as part of EPQ,
reference the associated EPQState from EState.

To fix the second issue, change EPQ initialization to allow use of
EvalPlanQualSlot() to be used before EvalPlanQualBegin() (but
obviously still requiring EvalPlanQualInit() to have been done).

As these changes made struct EState harder to understand, e.g. by
adding multiple EStates, significantly reorder the members, and add a
lot more comments.

Also add a few more EPQ tests, including one that fails for the first
issue above. More is needed.

Reported-By: yi huang
Author: Andres Freund
Reviewed-By: Tom Lane
Discussion:
    https://postgr.es/m/CAHU7rYZo_C4ULsAx_LAj8az9zqgrD8WDd4hTegDTMM1LMqrBsg@mail.gmail.com
    https://postgr.es/m/24530.1562686693@sss.pgh.pa.us
Backpatch: 12-, where the EPQ changes were introduced
2019-09-09 05:14:11 -07:00
Alexander Korotkov 02f90879e7 Fix handling of NULL distances in KNN-GiST
In order to implement NULL LAST semantic GiST previously assumed distance to
the NULL value to be Inf.  However, our distance functions can return Inf and
NaN for non-null values.  In such cases, NULL LAST semantic appears to be
broken.  This commit fixes that by introducing separate array of null flags for
distances.

Backpatch to all supported versions.

Discussion: https://postgr.es/m/CAPpHfdsNvNdA0DBS%2BwMpFrgwT6C3-q50sFVGLSiuWnV3FqOJuQ%40mail.gmail.com
Author: Alexander Korotkov
Backpatch-through: 9.4
2019-09-08 22:08:12 +03:00
Tom Lane ca70bdaefe Fix issues around strictness of SIMILAR TO.
As a result of some long-ago quick hacks, the SIMILAR TO operator
and the corresponding flavor of substring() interpreted "ESCAPE NULL"
as selecting the default escape character '\'.  This is both
surprising and not per spec: the standard is clear that these
functions should return NULL for NULL input.

Additionally, because of inconsistency of the strictness markings
of 3-argument substring() and similar_escape(), the planner could not
inline the SQL definition of substring(), resulting in a substantial
performance penalty compared to the underlying POSIX substring()
function.

The simplest fix for this would be to change the strictness marking
of similar_escape(), but if we do that we risk breaking existing views
that depend on that function.  Hence, leave similar_escape() as-is
as a compatibility function, and instead invent a new function
similar_to_escape() that comes in two strict variants.

There are a couple of other behaviors in this area that are also
not per spec, but they are documented and seem generally at least
as sane as the spec's definition, so leave them alone.  But improve
the documentation to describe them fully.

Patch by me; thanks to Álvaro Herrera and Andrew Gierth for review
and discussion.

Discussion: https://postgr.es/m/14047.1557708214@sss.pgh.pa.us
2019-09-07 14:21:59 -04:00
Robert Haas bd124996ef Create an API for inserting and deleting rows in TOAST tables.
This moves much of the non-heap-specific logic from toast_delete and
toast_insert_or_update into a helper functions accessible via a new
header, toast_helper.h.  Using the functions in this module, a table
AM can implement creation and deletion of TOAST table rows with
much less code duplication than was possible heretofore.  Some
table AMs won't want to use the TOAST logic at all, but for those
that do this will make that easier.

Patch by me, reviewed and tested by Prabhat Sabu, Thomas Munro,
Andres Freund, and Álvaro Herrera.

Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com
2019-09-06 10:38:51 -04:00
Tom Lane 7de19fbc0b Use data directory inode number, not port, to select SysV resource keys.
This approach provides a much tighter binding between a data directory
and the associated SysV shared memory block (and SysV or named-POSIX
semaphores, if we're using those).  Key collisions are still possible,
but only between data directories stored on different filesystems,
so the situation should be negligible in practice.  More importantly,
restarting the postmaster with a different port number no longer
risks failing to identify a relevant shared memory block, even when
postmaster.pid has been removed.  A standalone backend is likewise
much more certain to detect conflicting leftover backends.

(In the longer term, we might now think about deprecating the port as
a cluster-wide value, so that one postmaster could support sockets
with varying port numbers.  But that's for another day.)

The hazards fixed here apply only on Unix systems; our Windows code
paths already use identifiers derived from the data directory path
name rather than the port.

src/test/recovery/t/017_shm.pl, which intends to test key-collision
cases, has been substantially rewritten since it can no longer use
two postmasters with identical port numbers to trigger the case.
Instead, use Perl's IPC::SharedMem module to create a conflicting
shmem segment directly.  The test script will be skipped if that
module is not available.  (This means that some older buildfarm
members won't run it, but I don't think that that results in any
meaningful coverage loss.)

Patch by me; thanks to Noah Misch and Peter Eisentraut for discussion
and review.

Discussion: https://postgr.es/m/16908.1557521200@sss.pgh.pa.us
2019-09-05 13:31:46 -04:00
Robert Haas 8b94dab066 Split tuptoaster.c into three separate files.
detoast.c/h contain functions required to detoast a datum, partially
or completely, plus a few other utility functions for examining the
size of toasted datums.

toast_internals.c/h contain functions that are used internally to the
TOAST subsystem but which (mostly) do not need to be accessed from
outside.

heaptoast.c/h contains code that is intrinsically specific to the
heap AM, either because it operates on HeapTuples or is based on the
layout of a heap page.

detoast.c and toast_internals.c are placed in
src/backend/access/common rather than src/backend/access/heap.  At
present, both files still have dependencies on the heap, but that will
be improved in a future commit.

Patch by me, reviewed and tested by Prabhat Sabu, Thomas Munro,
Andres Freund, and Álvaro Herrera.

Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com
2019-09-05 13:15:10 -04:00
Peter Eisentraut 74a308cf52 Use explicit_bzero
Use the explicit_bzero() function in places where it is important that
security information such as passwords is cleared from memory.  There
might be other places where it could be useful; this is just an
initial collection.

For platforms that don't have explicit_bzero(), provide various
fallback implementations.  (explicit_bzero() itself isn't standard,
but as Linux/glibc, FreeBSD, and OpenBSD have it, it's the most common
spelling, so it makes sense to make that the invocation point.)

Discussion: https://www.postgresql.org/message-id/flat/42d26bde-5d5b-c90d-87ae-6cab875f73be%402ndquadrant.com
2019-09-05 08:30:42 +02:00
Alvaro Herrera 25dcc9d35d Make XLogReaderInvalReadState static
This function is only used by xlogreader.c itself, so there's no need to
export it.  It was introduced by commit 3b02ea4f07 with the apparent
intention that it could be used externally, but I couldn't find any
external code calling it.

I (Álvaro) couldn't resist the urge to sort nearby function prototypes
properly while at it.

Author: Antonin Houska
Discussion: https://postgr.es/m/14984.1554998742@spoje.net
2019-09-03 17:41:43 -04:00
Alvaro Herrera fe66125974 Remove 'msg' parameter from convert_tuples_by_name
The message was included as a parameter when this function was added in
dcb2bda9b7, but I don't think it has ever served any useful purpose.
Let's stop spreading it pointlessly.

Reviewed by Amit Langote and Peter Eisentraut.

Discussion: https://postgr.es/m/20190806224728.GA17233@alvherre.pgsql
2019-09-03 14:47:29 -04:00
Michael Paquier 7dedfd22b7 Add overflow-safe math inline functions for unsigned integers
Similarly to the signed versions added in 4d6ad31, this adds a set of
inline functions for overflow checks with unsigned integers, including
uint16, uint32 and uint64.  This relies on compiler built-in overflow
checks by default if available.  The behavior of unsigned integers is
well-defined so the fallback implementations checks are simple for
additions and subtractions.  Multiplications avoid division-based checks
which are expensive if possible, still this can happen for uint64 if
128-bit integers are not available.

While on it, the code in common/int.h is reorganized to avoid too many
duplicated comments.  The new macros will be used in a follow-up patch.

All thanks to Andres Freund for the input provided.

Author: Fabien Coelho, Michael Paquier
Discussion: https://postgr.es/m/20190830073423.GB2354@paquier.xyz
2019-09-02 09:38:23 +09:00
Thomas Munro 720b59b55b Avoid catalog lookups in RelationAllowsEarlyPruning().
RelationAllowsEarlyPruning() performed a catalog scan, but is used
in two contexts where that was a bad idea:

1.  In heap_page_prune_opt(), which runs very frequently in some large
    scans.  This caused major performance problems in a field report
    that was easy to reproduce.

2.  In TestForOldSnapshot(), which runs while we hold a buffer content
    lock.  It's not clear if this was guaranteed to be free of buffer
    deadlock risk.

The check was introduced in commit 2cc41acd8 and defended against a
real problem: 9.6's hash indexes have no page LSN and so we can't
allow early pruning (ie the snapshot-too-old feature).  We can remove
the check from all later releases though: hash indexes are now logged,
and there is no way to create UNLOGGED indexes on regular logged
tables.

If a future release allows such a combination, it might need to put
a similar check in place, but it'll need some more thought.

Back-patch to 10.

Author: Thomas Munro
Reviewed-by: Tom Lane, who spotted the second problem
Discussion: https://postgr.es/m/CA%2BhUKGKT8oTkp5jw_U4p0S-7UG9zsvtw_M47Y285bER6a2gD%2Bg%40mail.gmail.com
Discussion: https://postgr.es/m/CAA4eK1%2BWy%2BN4eE5zPm765h68LrkWc3Biu_8rzzi%2BOYX4j%2BiHRw%40mail.gmail.com
2019-08-28 16:18:29 +12:00
Tom Lane 348778ddbc Make comment in fmgr.h match the one in fmgr.c.
Incompletely quoting an API spec does nobody any good.  Noted by
Paul Jungwirth.  Looks like the discrepancy was my fault originally :-(

Discussion: https://postgr.es/m/CA+renyU_J8TU_d3Kr0PkuOgFbpypextendu7a+_d5NOfVdvDeA@mail.gmail.com
2019-08-26 14:32:48 -04:00
Peter Geoghegan 091bd6befc Update comments on nbtree stack struct.
Adjust the struct comment that describes how page splits use their
descent stack to cascade up the tree from the leaf level.

In passing, fix up some unrelated nbtree comments that had typos or were
obsolete.
2019-08-21 13:50:27 -07:00
Peter Eisentraut c45643d618 Remove configure detection of crypt()
crypt() hasn't been needed since crypt detection was removed from
PostgreSQL, so these configure checks are not necessary.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/21f88934-f00c-27f6-a9d8-7ea06d317781%402ndquadrant.com
2019-08-21 21:36:54 +02:00
Alvaro Herrera 8f75e8e446 Fix typo
In early development patches, "replication origins" were called "identifiers";
almost everything was renamed, but these references to the old terminology
went unnoticed.

Reported-by: Craig Ringer
2019-08-21 11:12:44 -04:00
Andres Freund 4c01a11103 Add fmgr.h include to selfuncs.h.
Necessary after fb3b098f. That previously escaped notice, because all
including sites already include fmgr.h some other way.

Reported-By: Tom Lane
Author: Andres Freund
Discussion: https://postgr.es/m/17463.1566153454@sss.pgh.pa.us
2019-08-19 12:51:38 -07:00
Michael Paquier c96581abe4 Fix inconsistencies and typos in the tree, take 11
This fixes various typos in docs and comments, and removes some orphaned
definitions.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/5da8e325-c665-da95-21e0-c8a99ea61fbf@gmail.com
2019-08-19 16:21:39 +09:00
Tom Lane 927f34ce8a Avoid conflicts with library versions of inet_net_ntop() and friends.
Prefix inet_net_ntop and sibling routines with "pg_" to ensure that
they aren't mistaken for C-library functions.  This fixes warnings
from cpluspluscheck on some platforms, and should help reduce reader
confusion everywhere, since our functions aren't exactly interchangeable
with the library versions (they may have different ideas about address
family codes).

This shouldn't be fixing any actual bugs, unless somebody's linker
is misbehaving, so no need to back-patch.

Discussion: https://postgr.es/m/20518.1559494394@sss.pgh.pa.us
2019-08-18 19:27:23 -04:00
Tom Lane 232720be9b Fix incidental warnings from cpluspluscheck.
Remove use of "register" keyword in hashfn.c.  It's obsolescent
according to recent C++ compilers, and no modern C compiler pays
much attention to it either.

Also fix one cosmetic warning about signed vs unsigned comparison.

Discussion: https://postgr.es/m/20518.1559494394@sss.pgh.pa.us
2019-08-18 19:01:40 -04:00
Peter Eisentraut d78d452bc5 Improve Assert output
If an assertion expression contained a macro, the failed assertion
message would print the expanded macro, which is usually unhelpful and
confusing.  Restructure the Assert macros to not expand any macros
when constructing the failure message.

This also fixes that the existing output for Assert et al. shows
the *inverted* condition, which is also confusing and not how
assertions usually work.

Discussion: https://www.postgresql.org/message-id/flat/6c68efe3-117a-dcc1-73d4-18ba1ec532e2%402ndquadrant.com
2019-08-17 12:50:50 +02:00
Andres Freund fb3b098fe8 Remove fmgr.h includes from headers that don't really need it.
Most of the fmgr.h includes were obsoleted by 352a24a1f9. A
few others can be obsoleted using the underlying struct type in an
implementation detail.

Author: Andres Freund
Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de
2019-08-16 10:35:31 -07:00
Andres Freund 6a04d345fd Don't include utils/array.h from acl.h.
For most uses of acl.h the details of how "Acl" internally looks like
are irrelevant. It might make sense to move a lot of the
implementation details into a separate header at a later point.

The main motivation of this change is to avoid including fmgr.h (via
array.h, which needs it for exposed structs) in a lot of files that
otherwise don't need it. A subsequent commit will remove the fmgr.h
include from a lot of files.

Directly include utils/array.h and utils/expandeddatum.h from the
files that need them, but previously included them indirectly, via
acl.h.

Author: Andres Freund
Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de
2019-08-16 10:33:30 -07:00
Andres Freund 0ae2dc4db2 Remove redundant prototypes for SQL callable functions.
These aren't needed after 352a24a1f9. The remaining prototypes are
not defined on the SQL level.

Author: Andres Freund
Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de
2019-08-16 10:17:32 -07:00
Peter Geoghegan 9c02cf5661 Remove block number field from nbtree stack.
The initial value of the nbtree stack downlink block number field
recorded during an initial descent of the tree wasn't actually used.
Both _bt_getstackbuf() callers overwrote the value with their own value.

Remove the block number field from the stack struct, and add a child
block number argument to _bt_getstackbuf() in its place.  This makes the
overall design of _bt_getstackbuf() clearer.

Author: Peter Geoghegan
Reviewed-By: Anastasia Lubennikova
Discussion: https://postgr.es/m/CAH2-Wzmx+UbXt2YNOUCZ-a04VdXU=S=OHuAuD7Z8uQq-PXTYUg@mail.gmail.com
2019-08-14 11:32:35 -07:00
Michael Paquier 66bde49d96 Fix inconsistencies and typos in the tree, take 10
This addresses some issues with unnecessary code comments, fixes various
typos in docs and comments, and removes some orphaned structures and
definitions.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/9aabc775-5494-b372-8bcb-4dfc0bd37c68@gmail.com
2019-08-13 13:53:41 +09:00
Tom Lane 3c926587b5 Remove EState.es_range_table_array.
Now that list_nth is O(1), there's no good reason to maintain a
separate array of RTE pointers rather than indexing into
estate->es_range_table.  Deleting the array doesn't save all that
much either; but just on cleanliness grounds, it's better not to
have duplicate representations of the identical information.

Discussion: https://postgr.es/m/14960.1565384592@sss.pgh.pa.us
2019-08-12 11:58:35 -04:00
Tom Lane 5ee190f8ec Rationalize use of list_concat + list_copy combinations.
In the wake of commit 1cff1b95a, the result of list_concat no longer
shares the ListCells of the second input.  Therefore, we can replace
"list_concat(x, list_copy(y))" with just "list_concat(x, y)".

To improve call sites that were list_copy'ing the first argument,
or both arguments, invent "list_concat_copy()" which produces a new
list sharing no ListCells with either input.  (This is a bit faster
than "list_concat(list_copy(x), y)" because it makes the result list
the right size to start with.)

In call sites that were not list_copy'ing the second argument, the new
semantics mean that we are usually leaking the second List's storage,
since typically there is no remaining pointer to it.  We considered
inventing another list_copy variant that would list_free the second
input, but concluded that for most call sites it isn't worth worrying
about, given the relative compactness of the new List representation.
(Note that in cases where such leakage would happen, the old code
already leaked the second List's header; so we're only discussing
the size of the leak not whether there is one.  I did adjust two or
three places that had been troubling to free that header so that
they manually free the whole second List.)

Patch by me; thanks to David Rowley for review.

Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
2019-08-12 11:20:18 -04:00
Tom Lane 1661a40505 Cosmetic improvements in setup of planner's per-RTE arrays.
Merge setup_append_rel_array into setup_simple_rel_arrays.  There's no
particularly good reason to keep them separate, and it's inconsistent
with the lack of separation in expand_planner_arrays.  The only apparent
benefit was that the fast path for trivial queries in query_planner()
doesn't need to set up the append_rel_array; but all we're saving there
is an if-test and NULL assignment, which surely ought to be negligible.

Also improve some obsolete comments.

Discussion: https://postgr.es/m/17220.1565301350@sss.pgh.pa.us
2019-08-09 12:33:43 -04:00
Michael Paquier b8f2da0ac5 Refactor logic to remove trailing CR/LF characters from strings
b654714 has reworked the way trailing CR/LF characters are removed from
strings.  This commit introduces a new routine in common/string.c and
refactors the code so as the logic is in a single place, mostly.

Author: Michael Paquier
Reviewed-by: Bruce Momjian
Discussion: https://postgr.es/m/20190801031820.GF29334@paquier.xyz
2019-08-09 11:05:14 +09:00
Peter Geoghegan 98eab30b93 Show specific OID suggestion in unused_oids output.
Commit a6417078 established a new project policy around OID assignment:
new patches are encouraged to choose a random OID in the 8000..9999
range when a manually-assigned OID is required (if multiple OIDs are
required, a consecutive block of OIDs starting from the random point
should be used).  Catalog entries added by committed patches that use
OIDs from this "unstable" range are renumbered after feature freeze.
This practice minimizes OID collisions among concurrently-developed
patches.

Show a specific random OID suggestion when the unused_oids script is
run.  This makes it easy for patch authors to use a random OID from the
unstable range, per the new policy.

Author: Julien Rouhaud, Peter Geoghegan
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/CAH2-WzkkRs2ScmuBQ7xWi7xzp7fC1B3w0Nt8X+n4rBw5k+Z=zA@mail.gmail.com
2019-08-05 11:47:34 -07:00
Noah Misch ffa2d37e5f Require the schema qualification in pg_temp.type_name(arg).
Commit aa27977fe2 introduced this
restriction for pg_temp.function_name(arg); do likewise for types
created in temporary schemas.  Programs that this breaks should add
"pg_temp." schema qualification or switch to arg::type_name syntax.
Back-patch to 9.4 (all supported versions).

Reviewed by Tom Lane.  Reported by Tom Lane.

Security: CVE-2019-10208
2019-08-05 07:48:41 -07:00
Michael Paquier 8548ddc61b Fix inconsistencies and typos in the tree, take 9
This addresses more issues with code comments, variable names and
unreferenced variables.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/7ab243e0-116d-3e44-d120-76b3df7abefd@gmail.com
2019-08-05 12:14:58 +09:00
Tomas Vondra 75506195da Revert "Add log_statement_sample_rate parameter"
This reverts commit 88bdbd3f74.

As committed, statement sampling used the existing duration threshold
(log_min_duration_statement) when decide which statements to sample.
The issue is that even the longest statements are subject to sampling,
and so may not end up logged. An improvement was proposed, introducing
a second duration threshold, but it would not be backwards compatible.
So we've decided to revert this feature - the separate threshold should
be part of the feature itself.

Discussion: https://postgr.es/m/CAFj8pRDS8tQ3Wviw9%3DAvODyUciPSrGeMhJi_WPE%2BEB8%2B4gLL-Q%40mail.gmail.com
2019-08-04 23:38:27 +02:00
Alvaro Herrera 489247b0e6 Improve pruning of a default partition
When querying a partitioned table containing a default partition, we
were wrongly deciding to include it in the scan too early in the
process, failing to exclude it in some cases.  If we reinterpret the
PruneStepResult.scan_default flag slightly, we can do a better job at
detecting that it can be excluded.  The change is that we avoid setting
the flag for that pruning step unless the step absolutely requires the
default partition to be scanned (in contrast with the previous
arrangement, which was to set it unless the step was able to prune it).
So get_matching_partitions() must explicitly check the partition that
each returned bound value corresponds to in order to determine whether
the default one needs to be included, rather than relying on the flag
from the final step result.

Author: Yuzuko Hosoya <hosoya.yuzuko@lab.ntt.co.jp>
Reviewed-by: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Discussion: https://postgr.es/m/00e601d4ca86$932b8bc0$b982a340$@lab.ntt.co.jp
2019-08-04 11:18:45 -04:00
Andres Freund 2abd7ae9b2 Fix representation of hash keys in Hash/HashJoin nodes.
In 5f32b29c18 I changed the creation of HashState.hashkeys to
actually use HashState as the parent (instead of HashJoinState, which
was incorrect, as they were executed below HashState), to fix the
problem of hashkeys expressions otherwise relying on slot types
appropriate for HashJoinState, rather than HashState as would be
correct. That reliance was only introduced in 12, which is why it
previously worked to use HashJoinState as the parent (although I'd be
unsurprised if there were problematic cases).

Unfortunately that's not a sufficient solution, because before this
commit, the to-be-hashed expressions referenced inner/outer as
appropriate for the HashJoin, not Hash. That didn't have obvious bad
consequences, because the slots containing the tuples were put into
ecxt_innertuple when hashing a tuple for HashState (even though Hash
doesn't have an inner plan).

There are less common cases where this can cause visible problems
however (rather than just confusion when inspecting such executor
trees). E.g. "ERROR: bogus varno: 65000", when explaining queries
containing a HashJoin where the subsidiary Hash node's hash keys
reference a subplan. While normally hashkeys aren't displayed by
EXPLAIN, if one of those expressions references a subplan, that
subplan may be printed as part of the Hash node - which then failed
because an inner plan was referenced, and Hash doesn't have that.

It seems quite possible that there's other broken cases, too.

Fix the problem by properly splitting the expression for the HashJoin
and Hash nodes at plan time, and have them reference the proper
subsidiary node. While other workarounds are possible, fixing this
correctly seems easy enough. It was a pretty ugly hack to have
ExecInitHashJoin put the expression into the already initialized
HashState, in the first place.

I decided to not just split inner/outer hashkeys inside
make_hashjoin(), but also to separate out hashoperators and
hashcollations at plan time. Otherwise we would have ended up having
two very similar loops, one at plan time and the other during executor
startup. The work seems to more appropriately belong to plan time,
anyway.

Reported-By: Nikita Glukhov, Alexander Korotkov
Author: Andres Freund
Reviewed-By: Tom Lane, in an earlier version
Discussion: https://postgr.es/m/CAPpHfdvGVegF_TKKRiBrSmatJL2dR9uwFCuR+teQ_8tEXU8mxg@mail.gmail.com
Backpatch: 12-
2019-08-02 00:02:46 -07:00
Jeff Davis 6ae4e8eae7 Allow simplehash to use already-calculated hash values.
Add _lookup_hash and _insert_hash functions for callers that have
already calculated the hash value of the key.

The immediate use case is for hash algorithms that write to disk in
partitions. The hash value can be calculated once, used to perform a
lookup, used to select the partition, then written to the partition
along with the tuple. When the tuple is read back, the hash value does
not need to be recalculated.

Author: Jeff Davis
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/48abe675e1330f0c264ab2fe0d4ff23eb244f9ef.camel%40j-davis.com
2019-08-01 16:05:49 -07:00
Tom Lane 7266d0997d Allow functions-in-FROM to be pulled up if they reduce to constants.
This allows simplification of the plan tree in some common usage
patterns: we can get rid of a join to the function RTE.

In principle we could pull up any immutable expression, but restricting
it to Consts avoids the risk that multiple evaluations of the expression
might cost more than we can save.  (Possibly this could be improved in
future --- but we've more or less promised people that putting a function
in FROM guarantees single evaluation, so we'd have to tread carefully.)

To do this, we need to rearrange when eval_const_expressions()
happens for expressions in function RTEs.  I moved it to
inline_set_returning_functions(), which already has to iterate over
every function RTE, and in consequence renamed that function to
preprocess_function_rtes().  A useful consequence is that
inline_set_returning_function() no longer has to do this for itself,
simplifying that code.

In passing, break out pull_up_simple_subquery's code that knows where
everything that needs pullup_replace_vars() processing is, so that
the new pull_up_constant_function() routine can share it.  We'd
gotten away with one-and-a-half copies of that code so far, since
pull_up_simple_values() could assume that a lot of cases didn't apply
to it --- but I don't think pull_up_constant_function() can make any
simplifying assumptions.  Might as well make pull_up_simple_values()
use it too.

(Possibly this refactoring should go further: maybe we could share
some of the code to fill in the pullup_replace_vars_context struct?
For now, I left it that the callers fill that completely.)

Note: the one existing test case that this patch changes has to be
changed because inlining its function RTEs would destroy the point
of the test, namely to check join order.

Alexander Kuzmenkov and Aleksandr Parfenov, reviewed by
Antonin Houska and Anastasia Lubennikova, and whacked around
some more by me

Discussion: https://postgr.es/m/402356c32eeb93d4fed01f66d6c7fe2d@postgrespro.ru
2019-08-01 18:50:22 -04:00
Peter Geoghegan a8d6a95eb9 Bump catversion.
Oversight in commit 71dcd743.
2019-08-01 12:29:19 -07:00
Peter Geoghegan 71dcd74386 Add sort support routine for the inet data type.
Add sort support for inet, including support for abbreviated keys.
Testing has shown that this reduces the time taken to sort medium to
large inet/cidr inputs by ~50-60% in realistic cases.

Author: Brandur Leach
Reviewed-By: Peter Geoghegan, Edmund Horner
Discussion: https://postgr.es/m/CABR_9B-PQ8o2MZNJ88wo6r-NxW2EFG70M96Wmcgf99G6HUQ3sw@mail.gmail.com
2019-08-01 09:34:14 -07:00
Tom Lane 4886da8327 Mark advisory-lock functions as parallel restricted, not parallel unsafe.
There seems no good reason not to allow a parallel leader to execute
these functions.  (The workers still can't, though.  Although the code
would work, any such lock would go away at worker exit, which is not
the documented behavior of advisory locks.)

Discussion: https://postgr.es/m/11847.1564496844@sss.pgh.pa.us
2019-08-01 11:36:21 -04:00
Andres Freund 870b1d6800 Remove superfluous newlines in function prototypes.
These were introduced by pgindent due to fixe to broken
indentation (c.f. 8255c7a5ee). Previously the mis-indentation of
function prototypes was creatively used to reduce indentation in a few
places.

As that formatting only exists in master and REL_12_STABLE, it seems
better to fix it in both, rather than having some odd indentation in
v12 that somebody might copy for future patches or such.

Author: Andres Freund
Discussion: https://postgr.es/m/20190728013754.jwcbe5nfyt3533vx@alap3.anarazel.de
Backpatch: 12-
2019-07-31 00:05:21 -07:00
Heikki Linnakangas a29834beb1 Allow table AM's to use rd_amcache, too.
The rd_amcache allows an index AM to cache arbitrary information in a
relcache entry. This commit moves the cleanup of rd_amcache so that it
can also be used by table AMs. Nothing takes advantage of that yet, but
I'm sure it'll come handy for anyone writing new table AMs.

Backpatch to v12, where table AM interface was introduced.

Reviewed-by: Julien Rouhaud
2019-07-30 21:43:27 +03:00
Michael Paquier 04cf0bfc90 Fix memory leak coming from simple lists built in reindexdb
When building a list of relations for a parallel processing of a schema
or a database (or just a single-entry list for the non-parallel case
with the database name), the list is allocated and built on-the-fly for
each database processed, leaking after one database-level reindex is
done.  This accumulates leaks when processing all databases, and could
become a visible issue with thousands of relations.

This is fixed by introducing a new routine in simple_list.c to free all
the elements in a simple list made of strings or OIDs.  The header of
the list may be using a variable declaration or an allocated pointer,
so we don't have a routine to free this part to keep the interface
simple.

Per report from coverity for an issue introduced by 5ab892c, and
valgrind complains about the leak as well.  The idea to introduce a new
routine in simple_list.c is from Tom Lane.

Author: Michael Paquier
Reviewed-by: Tom Lane
2019-07-30 10:54:48 +09:00
Michael Paquier eb43f3d193 Fix inconsistencies and typos in the tree
This is numbered take 8, and addresses again a set of issues with code
comments, variable names and unreferenced variables.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/b137b5eb-9c95-9c2f-586e-38aba7d59788@gmail.com
2019-07-29 12:28:30 +09:00
Michael Paquier 7cce159349 Fix handling of expressions and predicates in REINDEX CONCURRENTLY
When copying the definition of an index rebuilt concurrently for the new
entry, the index information was taken directly from the old index using
the relation cache.  In this case, predicates and expressions have
some post-processing to prepare things for the planner, which loses some
information including the collations added in any of them.

This inconsistency can cause issues when attempting for example a table
rewrite, and makes the new indexes rebuilt concurrently inconsistent
with the old entries.

In order to fix the problem, fetch expressions and predicates directly
from the catalog of the old entry, and fill in IndexInfo for the new
index with that.  This makes the process more consistent with
DefineIndex(), and the code is refactored with the addition of a routine
to create an IndexInfo node.

Reported-by: Manuel Rigger
Author: Michael Paquier
Discussion: https://postgr.es/m/CA+u7OA5Hp0ra235F3czPom_FyAd-3+XwSJmX95r1+sRPOJc9VQ@mail.gmail.com
Backpatch-through: 12
2019-07-29 09:58:49 +09:00
Heikki Linnakangas 6655a7299d Use full 64-bit XID for checking if a deleted GiST page is old enough.
Otherwise, after a deleted page gets even older, it becomes unrecyclable
again. B-tree has the same problem, and has had since time immemorial,
but let's at least fix this in GiST, where this is new.

Backpatch to v12, where GiST page deletion was introduced.

Reviewed-by: Andrey Borodin
Discussion: https://www.postgresql.org/message-id/835A15A5-F1B4-4446-A711-BF48357EB602%40yandex-team.ru
2019-07-24 20:24:07 +03:00
Tom Lane a0555ddab9 Install dependencies to prevent dropping partition key columns.
The logic in ATExecDropColumn that rejects dropping partition key
columns is quite an inadequate defense, because it doesn't execute
in cases where a column needs to be dropped due to cascade from
something that only the column, not the whole partitioned table,
depends on.  That leaves us with a badly broken partitioned table;
even an attempt to load its relcache entry will fail.

We really need to have explicit pg_depend entries that show that the
column can't be dropped without dropping the whole table.  Hence,
add those entries.  In v12 and HEAD, bump catversion to ensure that
partitioned tables will have such entries.  We can't do that in
released branches of course, so in v10 and v11 this patch affords
protection only to partitioned tables created after the patch is
installed.  Given the lack of field complaints (this bug was found
by fuzz-testing not by end users), that's probably good enough.

In passing, fix ATExecDropColumn and ATPrepAlterColumnType
messages to be more specific about which partition key column
they're complaining about.

Per report from Manuel Rigger.  Back-patch to v10 where partitioned
tables were added.

Discussion: https://postgr.es/m/CA+u7OA4JKCPFrdrAbOs7XBiCyD61XJxeNav4LefkSmBLQ-Vobg@mail.gmail.com
Discussion: https://postgr.es/m/31920.1562526703@sss.pgh.pa.us
2019-07-22 14:55:40 -04:00
Peter Eisentraut 7961886580 Revert "initdb: Change authentication defaults"
This reverts commit 09f08930f0.

The buildfarm client needs some adjustments first.
2019-07-22 19:28:25 +02:00
Peter Eisentraut 09f08930f0 initdb: Change authentication defaults
Change the defaults for the pg_hba.conf generated by initdb to "peer"
for local (if supported, else "md5") and "md5" for host.

(Changing from "md5" to SCRAM is left as a separate exercise.)

"peer" is currently not supported on AIX, HP-UX, and Windows.  Users
on those operating systems will now either have to provide a password
to initdb or choose a different authentication method when running
initdb.

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/bec17f0a-ddb1-8b95-5e69-368d9d0a3390%40postgresql.org
2019-07-22 15:14:27 +02:00
Peter Eisentraut 19781729f7 Make identity sequence management more robust
Some code could get confused when certain catalog state involving both
identity and serial sequences was present, perhaps during an attempt
to upgrade the latter to the former.  Specifically, dropping the
default of a serial column maintains the ownership of the sequence by
the column, and so it would then be possible to afterwards make the
column an identity column that would now own two sequences.  This
causes the code that looks up the identity sequence to error out,
making the new identity column inoperable until the ownership of the
previous sequence is released.

To fix this, make the identity sequence lookup only consider sequences
with the appropriate dependency type for an identity sequence, so it
only ever finds one (unless something else is broken).  In the above
example, the old serial sequence would then be ignored.  Reorganize
the various owned-sequence-lookup functions a bit to make this
clearer.

Reported-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://www.postgresql.org/message-id/flat/470c54fc8590be4de0f41b0d295fd6390d5e8a6c.camel@cybertec.at
2019-07-22 12:07:10 +02:00
Michael Paquier 23bccc823d Fix inconsistencies and typos in the tree
This is numbered take 7, and addresses a set of issues with code
comments, variable names and unreferenced variables.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/dff75442-2468-f74f-568c-6006e141062f@gmail.com
2019-07-22 10:01:50 +09:00
David Rowley 3373c71553 Speed up finding EquivalenceClasses for a given set of rels
Previously in order to determine which ECs a relation had members in, we
had to loop over all ECs stored in PlannerInfo's eq_classes and check if
ec_relids mentioned the relation.  For the most part, this was fine, as
generally, unless queries were fairly complex, the overhead of performing
the lookup would have not been that significant.  However, when queries
contained large numbers of joins and ECs, the overhead to find the set of
classes matching a given set of relations could become a significant
portion of the overall planning effort.

Here we allow a much more efficient method to access the ECs which match a
given relation or set of relations.  A new Bitmapset field in RelOptInfo
now exists to store the indexes into PlannerInfo's eq_classes list which
each relation is mentioned in.  This allows very fast lookups to find all
ECs belonging to a single relation.  When we need to lookup ECs belonging
to a given pair of relations, we can simply bitwise-AND the Bitmapsets from
each relation and use the result to perform the lookup.

We also take the opportunity to write a new implementation of
generate_join_implied_equalities which makes use of the new indexes.
generate_join_implied_equalities_for_ecs must remain as is as it can be
given a custom list of ECs, which we can't easily determine the indexes of.

This was originally intended to fix the performance penalty of looking up
foreign keys matching a join condition which was introduced by 100340e2d.
However, we're speeding up much more than just that here.

Author: David Rowley, Tom Lane
Reviewed-by: Tom Lane, Tomas Vondra
Discussion: https://postgr.es/m/6970.1545327857@sss.pgh.pa.us
2019-07-21 17:30:58 +12:00
Tomas Vondra e38a55ba46 Rework examine_opclause_expression to use varonleft
The examine_opclause_expression function needs to return information on
which side of the operator we found the Var, but the variable was called
"isgt" which is rather misleading (it assumes the operator is either
less-than or greater-than, but it may be equality or something else).
Other places in the planner use a variable called "varonleft" for this
purpose, so just adopt the same convention here.

The code also assumed we don't care about this flag for equality, as
(Var = Const) and (Const = Var) should be the same thing. But that does
not work for cross-type operators, in which case we need to pass the
parameters to the procedure in the right order. So just use the same
code for all types of expressions.

This means we don't need to care about the selectivity estimation
function anymore, at least not in this code. We should only get the
supported cases here (thanks to statext_is_compatible_clause).

Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
2019-07-20 16:37:30 +02:00
Peter Geoghegan d004147eb3 Fix nbtree metapage cache upgrade bug.
Commit 857f9c36cd, which taught nbtree VACUUM to avoid unnecessary
index scans, bumped the nbtree version number from 2 to 3, while adding
the ability for nbtree indexes to be upgraded on-the-fly.  Various
assertions that assumed that an nbtree index was always on version 2 had
to be changed to accept any supported version (version 2 or 3 on
Postgres 11).

However, a few assertions were missed in the initial commit, all of
which were in code paths that cache a local copy of the metapage
metadata, where the index had been expected to be on the current version
(no longer version 2) as a generic sanity check.  Rather than simply
update the assertions, follow-up commit 0a64b45152 intentionally made
the metapage caching code update the per-backend cached metadata version
without changing the on-disk version at the same time.  This could even
happen when the planner needed to determine the height of a B-Tree for
costing purposes.  The assertions only fail on Postgres v12 when
upgrading from v10, because they were adjusted to use the authoritative
shared memory metapage by v12's commit dd299df8.

To fix, remove the cache-only upgrade mechanism entirely, and update the
assertions themselves to accept any supported version (go back to using
the cached version in v12).  The fix is almost a full revert of commit
0a64b45152 on the v11 branch.

VACUUM only considers the authoritative metapage, and never bothers with
a locally cached version, whereas everywhere else isn't interested in
the metapage fields that were added by commit 857f9c36cd.  It seems
unlikely that this bug has affected any user on v11.

Reported-By: Christoph Berg
Bug: #15896
Discussion: https://postgr.es/m/15896-5b25e260fdb0b081%40postgresql.org
Backpatch: 11-, where VACUUM was taught to avoid unnecessary index scans.
2019-07-18 13:22:56 -07:00
Tom Lane bc8393cf27 Further adjust SPITupleTable to provide a public row-count field.
Now that commit fec0778c8 drew a clear line between public and private
fields in SPITupleTable, it seems pretty silly that the count of valid
tuples isn't on the public side of that line.  The reason why not was
that there wasn't such a count.  For reasons lost in the mists of time,
spi.c preferred to keep a count of remaining free entries in the array.
But that seems pretty pointless: it's unlike the way we handle similar
code everywhere else, and it involves extra subtractions that surely
outweigh having to do a comparison rather than test-for-zero to check
for array-full.

Hence, rearrange so that this code does the expansible array logic
the same as everywhere else, with a count of valid entries alongside
the allocated array length.  And document the count as public.

I looked for core-code callers where it would make sense to start
relying on tuptable->numvals rather than the separate SPI_processed
variable.  Right now there don't seem to be places where it'd be
a win to do so without more code restructuring than I care to
undertake today.  In principle, though, having SPITupleTables be
fully self-contained should be helpful down the line.

Discussion: https://postgr.es/m/16852.1563395722@sss.pgh.pa.us
2019-07-18 10:37:13 -04:00
Tomas Vondra e8b6ae2130 Fix handling of opclauses in extended statistics
We expect opclauses to have exactly one Var and one Const, but the code
was checking the Const by calling is_pseudo_constant_clause() which is
incorrect - we need a proper constant.

Fixed by using plain IsA(x,Const) to check type of the node. We need to
do these checks in two places, so move it into a separate function that
can be called in both places.

Reported by Andreas Seltenreich, based on crash reported by sqlsmith.

Backpatch to v12, where this code was introduced.

Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
2019-07-18 11:29:38 +02:00
Andres Freund 21039555cd tableam: comment improvements.
Author: Brad DeJong
Discussion: https://postgr.es/m/CAJnrtnxDYOQFsDfWz2iri0T_fFL2ZbbzgCOE=4yaMcszgcsf4A@mail.gmail.com
Backpatch: 12-
2019-07-17 19:48:47 -07:00
Tom Lane fec0778c80 Clarify the distinction between public and private SPITupleTable fields.
The fields that we consider public are "tupdesc" and "vals", which
historically are in the middle of the struct.  Move them to the front
(this should be perfectly safe to do in HEAD) and add comments to make
it quite clear which fields are public or not.

Also adjust spi.sgml's documentation of the struct to match.
That doc had bit-rotted somewhat, as it was missing some fields.
(Arguably we should just remove all the private fields from the docs,
but for now I refrained.)

Daniel Gustafsson, reviewed by Fabien Coelho

Discussion: https://postgr.es/m/0D19F836-B743-4340-B6A2-F148CA3DD1F0@yesql.se
2019-07-17 14:55:13 -04:00
Tom Lane d97b714a21 Avoid using lcons and list_delete_first where it's easy to do so.
Formerly, lcons was about the same speed as lappend, but with the new
List implementation, that's not so; with a long List, data movement
imposes an O(N) cost on lcons and list_delete_first, but not lappend.

Hence, invent list_delete_last with semantics parallel to
list_delete_first (but O(1) cost), and change various places to use
lappend and list_delete_last where this can be done without much
violence to the code logic.

There are quite a few places that construct result lists using lcons not
lappend.  Some have semantic rationales for that; I added comments about
it to a couple that didn't have them already.  In many such places though,
I think the coding is that way only because back in the dark ages lcons
was faster than lappend.  Hence, switch to lappend where this can be done
without causing semantic changes.

In ExecInitExprRec(), this results in aggregates and window functions that
are in the same plan node being executed in a different order than before.
Generally, the executions of such functions ought to be independent of
each other, so this shouldn't result in visibly different query results.
But if you push it, as one regression test case does, you can show that
the order is different.  The new order seems saner; it's closer to
the order of the functions in the query text.  And we never documented
or promised anything about this, anyway.

Also, in gistfinishsplit(), don't bother building a reverse-order list;
it's easy now to iterate backwards through the original list.

It'd be possible to go further towards removing uses of lcons and
list_delete_first, but it'd require more extensive logic changes,
and I'm not convinced it's worth it.  Most of the remaining uses
deal with queues that probably never get long enough to be worth
sweating over.  (Actually, I doubt that any of the changes in this
patch will have measurable performance effects either.  But better
to have good examples than bad ones in the code base.)

Patch by me, thanks to David Rowley and Daniel Gustafsson for review.

Discussion: https://postgr.es/m/21272.1563318411@sss.pgh.pa.us
2019-07-17 11:15:34 -04:00
Thomas Munro dfd0121dc7 Move some md.c-specific logic from smgr.c to md.c.
Potential future SMGR implementations may not want to create
tablespace directories when creating an SMGR relation.  Move that
logic to mdcreate().  Move the initialization of md-specific
data structures from smgropen() to a new callback mdopen().

Author: Thomas Munro
Reviewed-by: Shawn Debnath (as part of an earlier patch set)
Discussion: https://postgr.es/m/CA%2BhUKG%2BOZqOiOuDm5tC5DyQZtJ3FH4%2BFSVMqtdC4P1atpJ%2Bqhg%40mail.gmail.com
2019-07-17 15:00:22 +12:00
Tom Lane c245776906 Remove lappend_cell...() family of List functions.
It seems worth getting rid of these functions because they require the
caller to retain a ListCell pointer into a List that it's modifying,
which is a dangerous practice with the new List implementation.
(The only other List-modifying function that takes a ListCell pointer
as input is list_delete_cell, which nowadays is preferentially used
via the constrained API foreach_delete_current.)

There was only one remaining caller of these functions after commit
2f5b8eb5a, and that was some fairly ugly GEQO code that can be much
more clearly expressed using a list-index variable and list_insert_nth.
Hence, rewrite that code, and remove the functions.

Discussion: https://postgr.es/m/26193.1563228600@sss.pgh.pa.us
2019-07-16 13:12:24 -04:00
Tom Lane 2f5b8eb5a2 Clean up some ad-hoc code for sorting and de-duplicating Lists.
heap.c and relcache.c contained nearly identical copies of logic
to insert OIDs into an OID list while preserving the list's OID
ordering (and rejecting duplicates, in one case but not the other).

The comments argue that this is faster than qsort for small numbers
of OIDs, which is at best unproven, and seems even less likely to be
true now that lappend_cell_oid has to move data around.  In any case
it's ugly and hard-to-follow code, and if we do have a lot of OIDs
to consider, it's O(N^2).

Hence, replace with simply lappend'ing OIDs to a List, then list_sort
the completed List, then remove adjacent duplicates if necessary.
This is demonstrably O(N log N) and it's much simpler for the
callers.  It's possible that this would be somewhat inefficient
if there were a very large number of duplicates, but that seems
unlikely in the existing usage.

This adds list_deduplicate_oid and list_oid_cmp infrastructure
to list.c.  I didn't bother with equivalent functionality for
integer or pointer Lists, but such could always be added later
if we find a use for it.

Discussion: https://postgr.es/m/26193.1563228600@sss.pgh.pa.us
2019-07-16 12:04:06 -04:00
Tom Lane 569ed7f483 Redesign the API for list sorting (list_qsort becomes list_sort).
In the wake of commit 1cff1b95a, the obvious way to sort a List
is to apply qsort() directly to the array of ListCells.  list_qsort
was building an intermediate array of pointers-to-ListCells, which
we no longer need, but getting rid of it forces an API change:
the comparator functions need to do one less level of indirection.

Since we're having to touch the callers anyway, let's do two additional
changes: sort the given list in-place rather than making a copy (as
none of the existing callers have any use for the copying behavior),
and rename list_qsort to list_sort.  It was argued that the old name
exposes more about the implementation than it should, which I find
pretty questionable, but a better reason to rename it is to be sure
we get the attention of any external callers about the need to fix
their comparator functions.

While we're at it, change four existing callers of qsort() to use
list_sort instead; previously, they all had local reinventions
of list_qsort, ie build-an-array-from-a-List-and-qsort-it.
(There are some other places where changing to list_sort perhaps
would be worthwhile, but they're less obviously wins.)

Discussion: https://postgr.es/m/29361.1563220190@sss.pgh.pa.us
2019-07-16 11:51:44 -04:00
Michael Paquier 0896ae561b Fix inconsistencies and typos in the tree
This is numbered take 7, and addresses a set of issues around:
- Fixes for typos and incorrect reference names.
- Removal of unneeded comments.
- Removal of unreferenced functions and structures.
- Fixes regarding variable name consistency.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/10bfd4ac-3e7c-40ab-2b2e-355ed15495e8@gmail.com
2019-07-16 13:23:53 +09:00
Tom Lane 1cff1b95ab Represent Lists as expansible arrays, not chains of cons-cells.
Originally, Postgres Lists were a more or less exact reimplementation of
Lisp lists, which consist of chains of separately-allocated cons cells,
each having a value and a next-cell link.  We'd hacked that once before
(commit d0b4399d8) to add a separate List header, but the data was still
in cons cells.  That makes some operations -- notably list_nth() -- O(N),
and it's bulky because of the next-cell pointers and per-cell palloc
overhead, and it's very cache-unfriendly if the cons cells end up
scattered around rather than being adjacent.

In this rewrite, we still have List headers, but the data is in a
resizable array of values, with no next-cell links.  Now we need at
most two palloc's per List, and often only one, since we can allocate
some values in the same palloc call as the List header.  (Of course,
extending an existing List may require repalloc's to enlarge the array.
But this involves just O(log N) allocations not O(N).)

Of course this is not without downsides.  The key difficulty is that
addition or deletion of a list entry may now cause other entries to
move, which it did not before.

For example, that breaks foreach() and sister macros, which historically
used a pointer to the current cons-cell as loop state.  We can repair
those macros transparently by making their actual loop state be an
integer list index; the exposed "ListCell *" pointer is no longer state
carried across loop iterations, but is just a derived value.  (In
practice, modern compilers can optimize things back to having just one
loop state value, at least for simple cases with inline loop bodies.)
In principle, this is a semantics change for cases where the loop body
inserts or deletes list entries ahead of the current loop index; but
I found no such cases in the Postgres code.

The change is not at all transparent for code that doesn't use foreach()
but chases lists "by hand" using lnext().  The largest share of such
code in the backend is in loops that were maintaining "prev" and "next"
variables in addition to the current-cell pointer, in order to delete
list cells efficiently using list_delete_cell().  However, we no longer
need a previous-cell pointer to delete a list cell efficiently.  Keeping
a next-cell pointer doesn't work, as explained above, but we can improve
matters by changing such code to use a regular foreach() loop and then
using the new macro foreach_delete_current() to delete the current cell.
(This macro knows how to update the associated foreach loop's state so
that no cells will be missed in the traversal.)

There remains a nontrivial risk of code assuming that a ListCell *
pointer will remain good over an operation that could now move the list
contents.  To help catch such errors, list.c can be compiled with a new
define symbol DEBUG_LIST_MEMORY_USAGE that forcibly moves list contents
whenever that could possibly happen.  This makes list operations
significantly more expensive so it's not normally turned on (though it
is on by default if USE_VALGRIND is on).

There are two notable API differences from the previous code:

* lnext() now requires the List's header pointer in addition to the
current cell's address.

* list_delete_cell() no longer requires a previous-cell argument.

These changes are somewhat unfortunate, but on the other hand code using
either function needs inspection to see if it is assuming anything
it shouldn't, so it's not all bad.

Programmers should be aware of these significant performance changes:

* list_nth() and related functions are now O(1); so there's no
major access-speed difference between a list and an array.

* Inserting or deleting a list element now takes time proportional to
the distance to the end of the list, due to moving the array elements.
(However, it typically *doesn't* require palloc or pfree, so except in
long lists it's probably still faster than before.)  Notably, lcons()
used to be about the same cost as lappend(), but that's no longer true
if the list is long.  Code that uses lcons() and list_delete_first()
to maintain a stack might usefully be rewritten to push and pop at the
end of the list rather than the beginning.

* There are now list_insert_nth...() and list_delete_nth...() functions
that add or remove a list cell identified by index.  These have the
data-movement penalty explained above, but there's no search penalty.

* list_concat() and variants now copy the second list's data into
storage belonging to the first list, so there is no longer any
sharing of cells between the input lists.  The second argument is
now declared "const List *" to reflect that it isn't changed.

This patch just does the minimum needed to get the new implementation
in place and fix bugs exposed by the regression tests.  As suggested
by the foregoing, there's a fair amount of followup work remaining to
do.

Also, the ENABLE_LIST_COMPAT macros are finally removed in this
commit.  Code using those should have been gone a dozen years ago.

Patch by me; thanks to David Rowley, Jesper Pedersen, and others
for review.

Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
2019-07-15 13:41:58 -04:00
Thomas Munro 67b9b3ca32 Provide XLogRecGetFullXid().
In order to be able to work with FullTransactionId values during replay
without increasing the size of the WAL, infer the epoch.  In general we
can't do that safely, but during replay we can because we know that
nextFullXid can't advance concurrently.

Prevent frontend code from seeing this new function, due to the above
restriction.  Perhaps in future it will be possible to extract the value
entirely from independent WAL records, and then this restriction can be
lifted.

Author: Thomas Munro, based on earlier code from Andres Freund
Discussion: https://postgr.es/m/CA%2BhUKG%2BmLmuDjMi6o1dxkKvGRL56Y2Rz%2BiXAcrZV03G9ZuFQ8Q%40mail.gmail.com
2019-07-15 17:04:29 +12:00
Peter Eisentraut 5925e55498 Add gen_random_uuid function
This adds a built-in function to generate UUIDs.

PostgreSQL hasn't had a built-in function to generate a UUID yet,
relying on external modules such as uuid-ossp and pgcrypto to provide
one.  Now that we have a strong random number generator built-in, we
can easily provide a version 4 (random) UUID generation function.

This patch takes the existing function gen_random_uuid() from pgcrypto
and makes it a built-in function.  The pgcrypto implementation now
internally redirects to the built-in one.

Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://www.postgresql.org/message-id/6a65610c-46fc-2323-6b78-e8086340a325@2ndquadrant.com
2019-07-14 14:30:27 +02:00
Alexander Korotkov 565f339000 Forgotten catversion bump
6254c55f81, c085e1c1cb and 075f0a880f all change system catalog.  But
catversion bump is missed in all of them.  So, do catversion bump now.

Also, I need mention patch reviewer Fabien Coelho, who has been missed in
commit messages of 6254c55f81, c085e1c1cb and 075f0a880f.
2019-07-14 15:22:21 +03:00
Alexander Korotkov 075f0a880f Add support for <-> (box, point) operator to SP-GiST box_ops
Opclass support functions already can handle this operator, just catalog
adjustment appears to be required.

Discussion: https://postgr.es/m/f71ba19d-d989-63b6-f04a-abf02ad9345d%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Tom Lane, Alexander Korotkov
2019-07-14 15:09:23 +03:00
Alexander Korotkov c085e1c1cb Add support for <-> (box, point) operator to GiST box_ops
Index-based calculation of this operator is exact.  So, signature of
gist_bbox_distance() function is changes so that caller is responsible for
setting *recheck flag.

Discussion: https://postgr.es/m/f71ba19d-d989-63b6-f04a-abf02ad9345d%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Tom Lane, Alexander Korotkov
2019-07-14 15:09:15 +03:00
Alexander Korotkov 6254c55f81 Add missing commutators for distance operators
Some of <-> operators between geometric types have their commutators missed.
This commit adds them.  The motivation is upcoming kNN support for some of those
operators.

Discussion: https://postgr.es/m/f71ba19d-d989-63b6-f04a-abf02ad9345d%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Tom Lane, Alexander Korotkov
2019-07-14 14:55:01 +03:00
Thomas Munro 1321509fa4 Introduce timed waits for condition variables.
Provide ConditionVariableTimedSleep(), like ConditionVariableSleep()
but with a timeout argument.

Author: Shawn Debnath
Reviewed-by: Kyotaro Horiguchi, Thomas Munro
Discussion: https://postgr.es/m/eeb06007ccfe46e399df6af18bfcd15a@EX13D05UWC002.ant.amazon.com
2019-07-13 13:51:05 +12:00
Amit Kapila bd56cd75d2 Fix few typos and minor wordsmithing in tableam comments.
Reported-by: Ashwin Agrawal
Author: Ashwin Agrawal
Reviewed-by: Amit Kapila
Backpatch-through: 12, where it was introduced
Discussion: https://postgr.es/m/CALfoeisgdZhYDrJOukaBzvXfJOK2FQ0szVMK7dzmcy6w93iDUA@mail.gmail.com
2019-07-10 07:52:51 +05:30
Robert Haas 554106b116 tableam: Provide helper functions for relation sizing.
Most block-based table AMs will need the exact same implementation of
the relation_size callback as the heap, and if they use a standard
page layout, they will likely need an implementation of the
relation_estimate_size callback that is very similar to that of the
heap.  Rearrange to facilitate code reuse.

Patch by me, reviewed by Michael Paquier, Daniel Gustafsson, and
Álvaro Herrera.

Discussion: http://postgr.es/m/CA+TgmoZ6DBPnP1E-vRpQZUJQijJFD54F+SR_pxGiAAS-MyrigA@mail.gmail.com
2019-07-08 14:51:53 -04:00
Michael Paquier 6b8548964b Fix inconsistencies in the code
This addresses a couple of issues in the code:
- Typos and inconsistencies in comments and function declarations.
- Removal of unreferenced function declarations.
- Removal of unnecessary compile flags.
- A cleanup error in regressplans.sh.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/0c991fdf-2670-1997-c027-772a420c4604@gmail.com
2019-07-08 13:15:09 +09:00
Michael Paquier d1a040543b Remove more unreferenced function declarations
Author: Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoDuAYsRb3Q9aobkFZ6DZMWxsyg4HOmgkwgeWNfSkTwGxw@mail.gmail.com
2019-07-07 09:58:33 +09:00
Tom Lane 79b94716e7 Remove unreferenced function declarations.
These seem to be leftovers from old patches, perhaps.

Masahiko Sawada

Discussion: https://postgr.es/m/CAD21AoDuAYsRb3Q9aobkFZ6DZMWxsyg4HOmgkwgeWNfSkTwGxw@mail.gmail.com
2019-07-05 19:28:45 -04:00
Tom Lane 0ab1a2e39b Remove dead encoding-conversion functions.
The code for conversions SQL_ASCII <-> MULE_INTERNAL and
SQL_ASCII <-> UTF8 was unreachable, because we long ago changed
the wrapper functions pg_do_encoding_conversion() et al so that
they have hard-wired behaviors for conversions involving SQL_ASCII.
(At least some of those fast paths date back to 2002, though it
looks like we may not have been totally consistent about this until
later.)  Given the lack of complaints, nobody is dissatisfied with
this state of affairs.  Hence, let's just remove the unreachable code.

Also, change CREATE CONVERSION so that it rejects attempts to
define such conversions.  Since we consider that SQL_ASCII represents
lack of knowledge about the encoding in use, such a conversion would
be semantically dubious even if it were reachable.

Adjust a couple of regression test cases that had randomly decided
to rely on these conversion functions rather than any other ones.

Discussion: https://postgr.es/m/41163.1559156593@sss.pgh.pa.us
2019-07-05 14:17:27 -04:00
Michael Paquier 313f87a171 Add min() and max() aggregates for pg_lsn
This is useful for monitoring, when it comes for example to calculations
of WAL retention with replication slots and delays with a set of
standbys.

Bump catalog version.

Author: Fabrízio de Royes Mello
Reviewed-by: Surafel Temesgen
Discussion: https://postgr.es/m/CAFcNs+oc8ZoHhowA4rR1GGCgG8QNgK_TOwPRVYQo5rYy8_PXzA@mail.gmail.com
2019-07-05 12:21:11 +09:00
Michael Paquier 8a810a177c Update hardcoded DH parameters to IANA standards
The source defining the current fallback and hardcoded DH parameters
has disappeared from the web a long time ago, and RFC 3526 defines the
most current Diffie-Hellman MODP groups, so update to those new values.

Author: Daniel Gustafsson
Reviewed-by: Peter Eisentraut, Michael Paquier
Discussion: https://postgr.es/m/5E60AC9A-CB10-4851-9EF2-7209490A164C@yesql.se
2019-07-05 10:47:32 +09:00
Tomas Vondra 08aa131c7a Simplify pg_mcv_list (de)serialization
The serialization format of multivariate MCV lists included alignment in
order to allow direct access to part of the serialized data, but despite
multiple fixes (see for example commits d85e0f366a and ea4e1c0e8f) this
proved to be problematic.

This commit abandons alignment in the serialized format, and just copies
everything during deserialization.  We now also track amount of memory
needed after deserialization (including alignment), which allows us to
deserialize the MCV list in a single pass.

Bump catversion, as this affects contents of pg_statistic_ext_data.

Backpatch to 12, where multi-column MCV lists were introduced.

Author: Tomas Vondra
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/2201.1561521148@sss.pgh.pa.us
2019-07-05 01:32:49 +02:00
Tomas Vondra 4d66285adc Fix pg_mcv_list_items() to produce text[]
The function pg_mcv_list_items() returns values stored in MCV items. The
items may contain columns with different data types, so the function was
generating text array-like representation, but in an ad-hoc way without
properly escaping various characters etc.

Fixed by simply building a text[] array, which also makes it easier to
use from queries etc.

Requires changes to pg_proc entry, so bump catversion.

Backpatch to 12, where multi-column MCV lists were introduced.

Author: Tomas Vondra
Reviewed-by: Dean Rasheed
Discussion: https://postgr.es/m/20190618205920.qtlzcu73whfpfqne@development
2019-07-05 01:32:46 +02:00
Peter Eisentraut 7b925e1270 Sync our Snowball stemmer dictionaries with current upstream
The main change is a new stemmer for Greek.  There are minor changes
in the Danish and French stemmers.

Author: Panagiotis Mavrogiorgos <pmav99@gmail.com>
2019-07-04 13:26:48 +02:00
Michael Paquier cfc40d384a Introduce safer encoding and decoding routines for base64.c
This is a follow-up refactoring after 09ec55b and b674211, which has
proved that the encoding and decoding routines used by SCRAM have a
poor interface when it comes to check after buffer overflows.  This adds
an extra argument in the shape of the length of the result buffer for
each routine, which is used for overflow checks when encoding or
decoding an input string.  The original idea comes from Tom Lane.

As a result of that, the encoding routine can now fail, so all its
callers are adjusted to generate proper error messages in case of
problems.

On failure, the result buffer gets zeroed.

Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20190623132535.GB1628@paquier.xyz
2019-07-04 16:08:09 +09:00
Tom Lane 615cebc94b Stamp HEAD as 13devel.
Let the hacking begin ...
2019-07-01 12:50:55 -04:00
Tom Lane 9e1c9f9594 pgindent run prior to branching v12.
pgperltidy and reformat-dat-files too, though the latter didn't
find anything to change.
2019-07-01 12:37:52 -04:00
Michael Paquier c74d49d41c Fix many typos and inconsistencies
Author: Alexander Lakhin
Discussion: https://postgr.es/m/af27d1b3-a128-9d62-46e0-88f424397f44@gmail.com
2019-07-01 10:00:23 +09:00
Noah Misch 459c3cdb4a Don't read fields of a misaligned ExpandedObjectHeader or AnyArrayType.
UBSan complains about this.  Instead, cast to a suitable type requiring
only 4-byte alignment.  DatumGetAnyArrayP() already assumes one can cast
between AnyArrayType and ArrayType, so this doesn't introduce a new
assumption.  Back-patch to 9.5, where AnyArrayType was introduced.

Reviewed by Tom Lane.

Discussion: https://postgr.es/m/20190629210334.GA1244217@rfd.leadboat.com
2019-06-30 17:34:17 -07:00
Peter Eisentraut 21f428ebde Don't call data type input functions in GUC check hooks
Instead of calling pg_lsn_in() in check_recovery_target_lsn and
timestamptz_in() in check_recovery_target_time, reorganize the
respective code so that we don't raise any errors in the check hooks.
The previous code tried to use PG_TRY/PG_CATCH to handle errors in a
way that is not safe, so now the code contains no ereport() calls and
can operate safely within the GUC error handling system.

Moreover, since the interpretation of the recovery_target_time string
may depend on the time zone, we cannot do the final processing of that
string until all the GUC processing is done.  Instead,
check_recovery_target_time() now does some parsing for syntax
checking, but the actual conversion to a timestamptz value is done
later in the recovery code that uses it.

Reported-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/20190611061115.njjwkagvxp4qujhp%40alap3.anarazel.de
2019-06-30 10:27:43 +02:00