As things stand now, channel binding data is fetched from OpenSSL and
saved into the SCRAM exchange context for any SSL connection attempted
for a SCRAM authentication, resulting in data fetched but not used if no
channel binding is used or if a different channel binding type is used
than what the data is here for.
Refactor the code in such a way that binding data is fetched from the
SSL stack only when a specific channel binding is used for both the
frontend and the backend. In order to achieve that, save the libpq
connection context directly in the SCRAM exchange state, and add a
dependency to SSL in the low-level SCRAM routines.
This makes the interface in charge of initializing the SCRAM context
cleaner as all its data comes from either PGconn* (for frontend) or
Port* (for the backend).
Author: Michael Paquier <michael.paquier@gmail.com>
- Remove unnecessary #include mistakenly added in execnodes.h.
- Fix mistake in comment in choose_next_subplan_for_leader.
- Adjust row estimates in cost_append for a possibly-different
parallel divisor.
- Clamp row estimates in cost_append after operations that may
not produce integers.
Amit Kapila, with cosmetic adjustments by me.
Discussion: http://postgr.es/m/CAA4eK1+qcbeai3coPpRW=GFCzFeLUsuY4T-AKHqMjxpEGZBPQg@mail.gmail.com
While ldaptls=1 provides an RFC 4513 conforming way to do LDAP
authentication with TLS encryption, there was an earlier de facto
standard way to do LDAP over SSL called LDAPS. Even though it's not
enshrined in a standard, it's still widely used and sometimes required
by organizations' network policies. There seems to be no reason not to
support it when available in the client library. Therefore, add support
when using OpenLDAP 2.4+ or Windows. It can be configured with
ldapscheme=ldaps or ldapurl=ldaps://...
Add tests for both ways of requesting LDAPS and a test for the
pre-existing ldaptls=1. Modify the 001_auth.pl test for "diagnostic
messages", which was previously relying on the server rejecting
ldaptls=1.
Author: Thomas Munro
Reviewed-By: Peter Eisentraut
Discussion: https://postgr.es/m/CAEepm=1s+pA-LZUjQ-9GQz0Z4rX_eK=DFXAF1nBQ+ROPimuOYQ@mail.gmail.com
Previously aggregate transition values for hash and other forms of
aggregation (i.e. sort and no group by) were represented
differently. Hash based aggregation used a grouping set indexed array
pointing to an array of transition values, whereas other forms of
aggregation used one flattened array with the index being computed out
of grouping set and transition offsets.
That made upcoming changes hard, so represent both as grouping set
indexed array of per-group data.
As a nice side-effect this also makes aggregation slightly faster,
because computing offsets with `transno + (setno * numTrans)` turns
out not to be that cheap (too big for x86 lea for example).
Author: Andres Freund
Discussion: https://postgr.es/m/20171128003121.nmxbm2ounxzb6n2t@alap3.anarazel.de
The previous coding relied (without any documentation) on the data[]
member of HashMemoryChunkData being at a MAXALIGN'ed offset. If it
was not, the tuples would not be maxaligned either, leading to failures
on alignment-picky machines. While there seems to be no live bug on any
platform we support, this is clearly pretty fragile: any addition to or
rearrangement of the fields in HashMemoryChunkData could break it.
Let's remove the hazard by getting rid of the data[] member and instead
using pointer arithmetic with an explicitly maxalign'ed offset.
Discussion: https://postgr.es/m/14483.1514938129@sss.pgh.pa.us
The original idea was that we could use an isNull-style bool array
directly as a GinNullCategory array. However, the existing code already
acknowledges that that doesn't really work, because of the possibility
that bool as currently defined can have arbitrary bit patterns for true
values. So it has to loop through the nullFlags array to set each bool
value to an acceptable value. But if we are looping through the whole
array anyway, we might as well build a proper GinNullCategory array
instead and abandon the type casting. That makes the code much safer in
case bool is ever changed to something else.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
In a race case, EXPLAIN ANALYZE could fail to display correct nbatch
and size information. Refactor so that participants report only on
batches they worked on rather than trying to report on all of them,
and teach explain.c to consider the HashInstrumentation object from
all participants instead of picking the first one it can find. This
should fix an occasional build farm failure in the "join" regression
test.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/30219.1514428346%40sss.pgh.pa.us
This reduces code duplication a bit, but the primary benefit that it
makes JITing expression evaluation easier. When doing so we can't, as
previously done in the interpreted case, really change opcode without
recompiling. Nor dow we just carry around unnecessary branches to
avoid re-checking over and over.
As a minor side-effect this makes ExecEvalStepOp() O(log(N)) rather
than O(N).
Author: Andres Freund
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de
Polygon opclass uses compress method feature of SP-GiST added earlier. For now
it's a single operator class which uses this feature. SP-GiST actually indexes
a bounding boxes of input polygons, so part of supported operations are lossy.
Opclass uses most methods of corresponding opclass over boxes of SP-GiST and
treats bounding boxes as point in 4D-space.
Bump catalog version.
Authors: Nikita Glukhov, Alexander Korotkov with minor editorization by me
Reviewed-By: all authors + Darafei Praliaskouski
Discussion: https://www.postgresql.org/message-id/flat/54907069.1030506@sigaev.ru
This patch does three interrelated things:
* Create a new expression execution step type EEOP_PARAM_CALLBACK
and add the infrastructure needed for add-on modules to generate that.
As discussed, the best control mechanism for that seems to be to add
another hook function to ParamListInfo, which will be called by
ExecInitExpr if it's supplied and a PARAM_EXTERN Param is found.
For stand-alone expressions, we add a new entry point to allow the
ParamListInfo to be specified directly, since it can't be retrieved
from the parent plan node's EState.
* Redesign the API for the ParamListInfo paramFetch hook so that the
ParamExternData array can be entirely virtual. This also lets us get rid
of ParamListInfo.paramMask, instead leaving it to the paramFetch hook to
decide which param IDs should be accessible or not. plpgsql_param_fetch
was already doing the identical masking check, so having callers do it too
seemed redundant. While I was at it, I added a "speculative" flag to
paramFetch that the planner can specify as TRUE to avoid unwanted failures.
This solves an ancient problem for plpgsql that it couldn't provide values
of non-DTYPE_VAR variables to the planner for fear of triggering premature
"record not assigned yet" or "field not found" errors during planning.
* Rework plpgsql to get rid of the need for "unshared" parameter lists,
by dint of turning the single ParamListInfo per estate into a nearly
read-only data structure that doesn't instantiate any per-variable data.
Instead, the paramFetch hook controls access to per-variable data and can
make the right decisions on the fly, replacing the cases that we used to
need multiple ParamListInfos for. This might perhaps have been a
performance loss on its own, but by using a paramCompile hook we can
bypass plpgsql_param_fetch entirely during normal query execution.
(It's now only called when, eg, we copy the ParamListInfo into a cursor
portal. copyParamList() or SerializeParamList() effectively instantiate
the virtual parameter array as a simple physical array without a
paramFetch hook, which is what we want in those cases.) This allows
reverting most of commit 6c82d8d1f, though I kept the cosmetic
code-consolidation aspects of that (eg the assign_simple_var function).
Performance testing shows this to be at worst a break-even change,
and it can provide wins ranging up to 20% in test cases involving
accesses to fields of "record" variables. The fact that values of
such variables can now be exposed to the planner might produce wins
in some situations, too, but I've not pursued that angle.
In passing, remove the "parent" pointer from the arguments to
ExecInitExprRec and related functions, instead storing that pointer in a
transient field in ExprState. The ParamListInfo pointer for a stand-alone
expression is handled the same way; we'd otherwise have had to add
yet another recursively-passed-down argument in expression compilation.
Discussion: https://postgr.es/m/32589.1513706441@sss.pgh.pa.us
Introduce parallel-aware hash joins that appear in EXPLAIN plans as Parallel
Hash Join with Parallel Hash. While hash joins could already appear in
parallel queries, they were previously always parallel-oblivious and had a
partial subplan only on the outer side, meaning that the work of the inner
subplan was duplicated in every worker.
After this commit, the planner will consider using a partial subplan on the
inner side too, using the Parallel Hash node to divide the work over the
available CPU cores and combine its results in shared memory. If the join
needs to be split into multiple batches in order to respect work_mem, then
workers process different batches as much as possible and then work together
on the remaining batches.
The advantages of a parallel-aware hash join over a parallel-oblivious hash
join used in a parallel query are that it:
* avoids wasting memory on duplicated hash tables
* avoids wasting disk space on duplicated batch files
* divides the work of building the hash table over the CPUs
One disadvantage is that there is some communication between the participating
CPUs which might outweigh the benefits of parallelism in the case of small
hash tables. This is avoided by the planner's existing reluctance to supply
partial plans for small scans, but it may be necessary to estimate
synchronization costs in future if that situation changes. Another is that
outer batch 0 must be written to disk if multiple batches are required.
A potential future advantage of parallel-aware hash joins is that right and
full outer joins could be supported, since there is a single set of matched
bits for each hashtable, but that is not yet implemented.
A new GUC enable_parallel_hash is defined to control the feature, defaulting
to on.
Author: Thomas Munro
Reviewed-By: Andres Freund, Robert Haas
Tested-By: Rafia Sabih, Prabhat Sahu
Discussion:
https://postgr.es/m/CAEepm=2W=cOkiZxcg6qiFQP-dHUe09aqTrEMM7yJDrHMhDv_RA@mail.gmail.comhttps://postgr.es/m/CAEepm=37HKyJ4U6XOLi=JgfSHM3o6B-GaeO-6hkOmneTDkH+Uw@mail.gmail.com
When a Gather or Gather Merge node is started and stopped multiple
times, accumulate instrumentation data only once, at the end, instead
of after each execution, to avoid recording inflated totals.
Commit 778e78ae9f, the previous attempt
at a fix, instead reset the state after every execution, which worked
for the general instrumentation data but had problems for the additional
instrumentation specific to Sort and Hash nodes.
Report by hubert depesz lubaczewski. Analysis and fix by Amit Kapila,
following a design proposal from Thomas Munro, with a comment tweak
by me.
Discussion: http://postgr.es/m/20171127175631.GA405@depesz.com
SharedTuplestore allows multiple participants to write into it and
then read the tuples back from it in parallel. Each reader receives
partial results.
For now it always uses disk files, but other buffering policies and
other kinds of scans (ie each reader receives complete results) may be
useful in future.
The upcoming parallel hash join feature will use this facility.
Author: Thomas Munro
Reviewed-By: Peter Geoghegan, Andres Freund, Robert Haas
Discussion: https://postgr.es/m/CAEepm=2W=cOkiZxcg6qiFQP-dHUe09aqTrEMM7yJDrHMhDv_RA@mail.gmail.com
Mechanism names for SCRAM and channel binding names have been included
in scram.h by the libpq frontend code, and this header references a set
of routines which are only used by the backend. scram-common.h is on
the contrary usable by both the backend and libpq, so getting those
names from there seems more reasonable.
Author: Michael Paquier <michael.paquier@gmail.com>
The previous commit has shown that the sanity checks around freezing
aren't strong enough. Strengthening them seems especially important
because the existance of the bug has caused corruption that we don't
want to make even worse during future vacuum cycles.
The errors are emitted with ereport rather than elog, despite being
"should never happen" messages, so a proper error code is emitted. To
avoid superflous translations, mark messages as internal.
Author: Andres Freund and Alvaro Herrera
Reviewed-By: Alvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
Backpatch: 9.3-
In order for executor nodes to be able to change their ExecProcNode function
after ExecInitNode() has finished, provide ExecSetExecProcNode(). This allows
any wrappers functions that only execProcnode.c knows about to be reinstalled.
The motivation for wanting to change ExecProcNode after ExecInitNode() has
finished is that it is not known until later whether parallel query is
available, so if a parallel variant is to be installed then ExecInitNode()
is too soon to decide.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=09rr65VN+cAV5FgyM_z=D77Xy8Fuc9CDDDYbq3pQUezg@mail.gmail.com
Sometimes it is useful to be able to insist that the compiler inline a
function that its normal cost analysis would not normally choose to inline.
This can be useful for instantiating different variants of a function that
remove branches of code by constant folding.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=09rr65VN+cAV5FgyM_z=D77Xy8Fuc9CDDDYbq3pQUezg@mail.gmail.com
This patch makes a number of interrelated changes to reduce the overhead
involved in creating/deleting memory contexts. The key ideas are:
* Include the AllocSetContext header of an aset.c context in its first
malloc request, rather than allocating it separately in TopMemoryContext.
This means that we now always create an initial or "keeper" block in an
aset, even if it never receives any allocation requests.
* Create freelists in which we can save and recycle recently-destroyed
asets (this idea is due to Robert Haas).
* In the common case where the name of a context is a constant string,
just store a pointer to it in the context header, rather than copying
the string.
The first change eliminates a palloc/pfree cycle per context, and
also avoids bloat in TopMemoryContext, at the price that creating
a context now involves a malloc/free cycle even if the context never
receives any allocations. That would be a loser for some common
usage patterns, but recycling short-lived contexts via the freelist
eliminates that pain.
Avoiding copying constant strings not only saves strlen() and strcpy()
overhead, but is an essential part of the freelist optimization because
it makes the context header size constant. Currently we make no
attempt to use the freelist for contexts with non-constant names.
(Perhaps someday we'll need to think harder about that, but in current
usage, most contexts with custom names are long-lived anyway.)
The freelist management in this initial commit is pretty simplistic,
and we might want to refine it later --- but in common workloads that
will never matter because the freelists will never get full anyway.
To create a context with a non-constant name, one is now required to
call AllocSetContextCreateExtended and specify the MEMCONTEXT_COPY_NAME
option. AllocSetContextCreate becomes a wrapper macro, and it includes
a test that will complain about non-string-literal context name
parameters on gcc and similar compilers.
An unfortunate side effect of making AllocSetContextCreate a macro is
that one is now *required* to use the size parameter abstraction macros
(ALLOCSET_DEFAULT_SIZES and friends) with it; the pre-9.6 habit of
writing out individual size parameters no longer works unless you
switch to AllocSetContextCreateExtended.
Internally to the memory-context-related modules, the context creation
APIs are simplified, removing the rather baroque original design whereby
a context-type module called mcxt.c which then called back into the
context-type module. That saved a bit of code duplication, but not much,
and it prevented context-type modules from exercising control over the
allocation of context headers.
In passing, I converted the test-and-elog validation of aset size
parameters into Asserts to save a few more cycles. The original thought
was that callers might compute size parameters on the fly, but in practice
nobody does that, so it's useless to expend cycles on checking those
numbers in production builds.
Also, mark the memory context method-pointer structs "const",
just for cleanliness.
Discussion: https://postgr.es/m/2264.1512870796@sss.pgh.pa.us
It's not easy to get signed integer overflow checks correct and
fast. Therefore abstract the necessary infrastructure into a common
header providing addition, subtraction and multiplication for 16, 32,
64 bit signed integers.
The new macros aren't yet used, but a followup commit will convert
several open coded overflow checks.
Author: Andres Freund, with some code stolen from Greg Stark
Reviewed-By: Robert Haas
Discussion: https://postgr.es/m/20171024103954.ztmatprlglz3rwke@alap3.anarazel.de
When we create an Append node, we can spread out the workers over the
subplans instead of piling on to each subplan one at a time, which
should typically be a bit more efficient, both because the startup
cost of any plan executed entirely by one worker is paid only once and
also because of reduced contention. We can also construct Append
plans using a mix of partial and non-partial subplans, which may allow
for parallelism in places that otherwise couldn't support it.
Unfortunately, this patch doesn't handle the important case of
parallelizing UNION ALL by running each branch in a separate worker;
the executor infrastructure is added here, but more planner work is
needed.
Amit Khandekar, Robert Haas, Amul Sul, reviewed and tested by
Ashutosh Bapat, Amit Langote, Rafia Sabih, Amit Kapila, and
Rajkumar Raghuwanshi.
Discussion: http://postgr.es/m/CAJ3gD9dy0K_E8r727heqXoBmWZ83HwLFwdcaSSmBQ1+S+vRuUQ@mail.gmail.com
If a hash join appears in a parallel query, there may be no hash table
available for explain.c to inspect even though a hash table may have
been built in other processes. This could happen either because
parallel_leader_participation was set to off or because the leader
happened to hit the end of the outer relation immediately (even though
the complete relation is not empty) and decided not to build the hash
table.
Commit bf11e7ee introduced a way for workers to exchange
instrumentation via the DSM segment for Sort nodes even though they
are not parallel-aware. This commit does the same for Hash nodes, so
that explain.c has a way to find instrumentation data from an
arbitrary participant that actually built the hash table.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm%3D3DUQC2-z252N55eOcZBer6DPdM%3DFzrxH9dZc5vYLsjaA%40mail.gmail.com
do_pg_start_backup() expects its callers to pass in an open DIR pointer
for the pg_tblspc directory, but there's no apparent advantage in that.
It complicates the callers without adding any flexibility, and there's no
robustness advantage, since we surely have to be prepared for errors during
the scan of pg_tblspc anyway. In fact, by holding an extra kernel resource
during operations like the preliminary checkpoint, we might be making
things a fraction more failure-prone not less. Hence, remove that argument
and open the directory just for the duration of the actual scan.
Discussion: https://postgr.es/m/28752.1512413887@sss.pgh.pa.us
This patch fixes a couple of low-probability bugs that could lead to
reporting an irrelevant errno value (and hence possibly a wrong SQLSTATE)
concerning directory-open or file-open failures. It also fixes places
where we took shortcuts in reporting such errors, either by using elog
instead of ereport or by using ereport but forgetting to specify an
errcode. And it eliminates a lot of just plain redundant error-handling
code.
In service of all this, export fd.c's formerly-static function
ReadDirExtended, so that external callers can make use of the coding
pattern
dir = AllocateDir(path);
while ((de = ReadDirExtended(dir, path, LOG)) != NULL)
if they'd like to treat directory-open failures as mere LOG conditions
rather than errors. Also fix FreeDir to be a no-op if we reach it
with dir == NULL, as such a coding pattern would cause.
Then, remove code at many call sites that was throwing an error or log
message for AllocateDir failure, as ReadDir or ReadDirExtended can handle
that job just fine. Aside from being a net code savings, this gets rid of
a lot of not-quite-up-to-snuff reports, as mentioned above. (In some
places these changes result in replacing a custom error message such as
"could not open tablespace directory" with more generic wording "could not
open directory", but it was agreed that the custom wording buys little as
long as we report the directory name.) In some other call sites where we
can't just remove code, change the error reports to be fully
project-style-compliant.
Also reorder code in restoreTwoPhaseData that was acquiring a lock
between AllocateDir and ReadDir; in the unlikely but surely not
impossible case that LWLockAcquire changes errno, AllocateDir failures
would be misreported. There is no great value in opening the directory
before acquiring TwoPhaseStateLock, so just do it in the other order.
Also fix CheckXLogRemoved to guarantee that it preserves errno,
as quite a number of call sites are implicitly assuming. (Again,
it's unlikely but I think not impossible that errno could change
during a SpinLockAcquire. If so, this function was broken for its
own purposes as well as breaking callers.)
And change a few places that were using not-per-project-style messages,
such as "could not read directory" when "could not open directory" is
more correct.
Back-patch the exporting of ReadDirExtended, in case we have occasion
to back-patch some fix that makes use of it; it's not needed right now
but surely making it global is pretty harmless. Also back-patch the
restoreTwoPhaseData and CheckXLogRemoved fixes. The rest of this is
essentially cosmetic and need not get back-patched.
Michael Paquier, with a bit of additional work by me
Discussion: https://postgr.es/m/CAB7nPqRpOCxjiirHmebEFhXVTK7V5Jvw4bz82p7Oimtsm3TyZA@mail.gmail.com
This adds a new object type "procedure" that is similar to a function
but does not have a return type and is invoked by the new CALL statement
instead of SELECT or similar. This implementation is aligned with the
SQL standard and compatible with or similar to other SQL implementations.
This commit adds new commands CALL, CREATE/ALTER/DROP PROCEDURE, as well
as ALTER/DROP ROUTINE that can refer to either a function or a
procedure (or an aggregate function, as an extension to SQL). There is
also support for procedures in various utility commands such as COMMENT
and GRANT, as well as support in pg_dump and psql. Support for defining
procedures is available in all the languages supplied by the core
distribution.
While this commit is mainly syntax sugar around existing functionality,
future features will rely on having procedures as a separate object
type.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Provide support for dynamic or static parties of processes to wait for
all processes to reach point in the code before continuing.
This is similar to the mechanism of the same name in POSIX threads and
MPI, though has explicit phasing and dynamic party support like the
Java core library's Phaser.
This will be used by an upcoming patch adding support for parallel
hash joins.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=2_y7oi01OjA_wLvYcWMc9_d=LaoxrY3eiROCZkB_qakA@mail.gmail.com
This will be used by pending patches to improve partition pruning.
Amit Langote and Kyotaro Horiguchi, per a suggestion from David
Rowley. Review and testing of the larger patch set of which this is a
part by Ashutosh Bapat, David Rowley, Dilip Kumar, Jesper Pedersen,
Rajkumar Raghuwanshi, Beena Emerson, Amul Sul, and Kyotaro Horiguchi.
Discussion: http://postgr.es/m/098b9c71-1915-1a2a-8d52-1a7a50ce79e8@lab.ntt.co.jp
rewriteTargetListUD's processing is dependent on the relkind of the query's
target table. That was fine at the time it was made to act that way, even
for queries on inheritance trees, because all tables in an inheritance tree
would necessarily be plain tables. However, the 9.5 feature addition
allowing some members of an inheritance tree to be foreign tables broke the
assumption that rewriteTargetListUD's output tlist could be applied to all
child tables with nothing more than column-number mapping. This led to
visible failures if foreign child tables had row-level triggers, and would
also break in cases where child tables belonged to FDWs that used methods
other than CTID for row identification.
To fix, delay running rewriteTargetListUD until after the planner has
expanded inheritance, so that it is applied separately to the (already
mapped) tlist for each child table. We can conveniently call it from
preprocess_targetlist. Refactor associated code slightly to avoid the
need to heap_open the target relation multiple times during
preprocess_targetlist. (The APIs remain a bit ugly, particularly around
the point of which steps scribble on parse->targetList and which don't.
But avoiding such scribbling would require a change in FDW callback APIs,
which is more pain than it's worth.)
Also fix ExecModifyTable to ensure that "tupleid" is reset to NULL when
we transition from rows providing a CTID to rows that don't. (That's
really an independent bug, but it manifests in much the same cases.)
Add a regression test checking one manifestation of this problem, which
was that row-level triggers on a foreign child table did not work right.
Back-patch to 9.5 where the problem was introduced.
Etsuro Fujita, reviewed by Ildus Kurbangaliev and Ashutosh Bapat
Discussion: https://postgr.es/m/20170514150525.0346ba72@postgrespro.ru
Originally, we palloc'd this buffer just barely big enough to hold the
largest xlog record seen so far. It turns out that that can result in
valgrind complaints, because some compilers will emit code that assumes
it can safely fetch padding bytes at the end of a struct, and those
padding bytes were unallocated so far as aset.c was concerned. We can
fix that by MAXALIGN'ing the palloc request size, ensuring that it is big
enough to include any possible padding that might've been omitted from
the on-disk record.
An additional objection to the original coding is that it could result in
many repeated palloc cycles, in the worst case where we see a series of
gradually larger xlog records. We can ameliorate that cheaply by
imposing a minimum buffer size that's large enough for most xlog records.
BLCKSZ/2 was chosen after a bit of discussion.
In passing, remove an obsolete comment in struct xl_heap_new_cid that the
combocid field is free due to alignment considerations. Perhaps that was
true at some point, but it's not now.
Back-patch to 9.5 where this code came in.
Discussion: https://postgr.es/m/E1eHa4J-0006hI-Q8@gemulon.postgresql.org
Commit 11e264517 removed BufFile's isTemp flag, thereby eliminating
the possibility of resurrecting BufFileCreate(). But it left that
function in place, as well as a bunch of comments describing how things
worked for the non-temp-file case. At best, that's now a source of
confusion. So remove the long-since-commented-out function and change
relevant comments.
I (tgl) wanted to rename BufFileCreateTemp() to BufFileCreate(), but
that seems not to be the consensus position, so leave it as-is.
In passing, fix commit f0828b2fc's failure to update BufFileSeek's
comment to match the change of its argument type from long to off_t.
(I think that might actually have been intentional at the time, but
now that 64-bit off_t is nearly universal, it looks anachronistic.)
Thomas Munro and Tom Lane
Discussion: https://postgr.es/m/E1eFVyl-0008J1-RO@gemulon.postgresql.org
It's most often the case that the target list for the Gather (Merge)
node matches the target list supplied by the underlying plan node;
when this is so, we can avoid the overhead of projecting.
This depends on commit f455e1125e for
proper functioning.
Idea by Andres Freund. Patch by me. Review by Amit Kapila.
Discussion: http://postgr.es/m/CA+TgmoZ0ZL=cesZFq8c9NnfK6bqy-wwUd3_74iYGodYrSoQ7Fw@mail.gmail.com
Add new style of memory allocator, known as Generational
appropriate for use in cases where memory is allocated
and then freed in roughly oldest first order (FIFO).
Use new allocator for logical decoding’s reorderbuffer
to significantly reduce memory usage and improve performance.
Author: Tomas Vondra
Reviewed-by: Simon Riggs
This is the basic feature set using OpenSSL to support the feature. In
order to allow the frontend and the backend to fetch the sent and
expected TLS Finished messages, a PG-like API is added to be able to
make the interface pluggable for other SSL implementations.
This commit also adds a infrastructure to facilitate the addition of
future channel binding types as well as libpq parameters to control the
SASL mechanism names and channel binding names. Those will be added by
upcoming commits.
Some tests are added to the SSL test suite to test SCRAM authentication
with channel binding.
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
It appears that proargmodes should always be set for variadic
functions, but satifies_hash_partition had it as NULL. In addition to
fixing the problem, add a regression test to guard against future
mistakes of this type.
Previously, executor nodes running in parallel worker processes didn't
have access to the dsm_segment object used for parallel execution. In
order to support resource management based on DSM segment lifetime,
they need that. So create a ParallelWorkerContext object to hold it
and pass it to all InitializeWorker functions.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=2W=cOkiZxcg6qiFQP-dHUe09aqTrEMM7yJDrHMhDv_RA@mail.gmail.com
Experimentation with modern MinGW (specifically the 5.0.2 version packaged
for Fedora 26) shows that its version of sys/stat.h *does* provide S_IRGRP
and friends, contrary to the expectation of win32_port.h. This results in
an astonishing number of compiler warnings, and perhaps in incorrect code
--- I'm not sure if the nonzero values supplied by MinGW's header actually
do anything. Hence, adjust win32_port.h to only define these macros if
<sys/stat.h> doesn't.
This might be worth back-patching, but given the lack of complaints so
far, I'm not too excited about it.
Fix PL/Python so that it can handle domains over composite, and so that
it enforces domain constraints correctly in other cases that were not
always done properly before. Notably, it didn't do arrays of domains
right (oversight in commit c12d570fa), and it failed to enforce domain
constraints when returning a composite type containing a domain field,
and if a transform function is being used for a domain's base type then
it failed to enforce domain constraints on the result. Also, in many
places it missed checking domain constraints on null values, because
the plpy_typeio code simply wasn't called for Py_None.
Rather than try to band-aid these problems, I made a significant
refactoring of the plpy_typeio logic. The existing design of recursing
for array and composite members is extended to also treat domains as
containers requiring recursion, and the APIs for the module are cleaned
up and simplified.
The patch also modifies plpy_typeio to rely on the typcache more than
it did before (which was pretty much not at all). This reduces the
need for repetitive lookups, and lets us get rid of an ad-hoc scheme
for detecting changes in composite types. I added a couple of small
features to typcache to help with that.
Although some of this is fixing bugs that long predate v11, I don't
think we should risk a back-patch: it's a significant amount of code
churn, and there've been no complaints from the field about the bugs.
Tom Lane, reviewed by Anthony Bykov
Discussion: https://postgr.es/m/24449.1509393613@sss.pgh.pa.us
The pending list must (for correctness) always be cleaned up by vacuum, and
should (for the avoidance of surprising behavior) always be cleaned up
by an explicit call to gin_clean_pending_list, but cleanup is optional
when inserting. The old logic got this backward: cleanup was forced
if (stats == NULL), but that's going to be *false* when vacuuming and
*true* for inserts.
Masahiko Sawada, reviewed by me.
Discussion: http://postgr.es/m/CAD21AoBLUSyiYKnTYtSAbC+F=XDjiaBrOUEGK+zUXdQ8owfPKw@mail.gmail.com
If a PARAM_EXEC parameter is used below a Gather (Merge) but the InitPlan
that computes it is attached to or above the Gather (Merge), force the
value to be computed before starting parallelism and pass it down to all
workers. This allows us to use parallelism in cases where it previously
would have had to be rejected as unsafe. We do - in this case - lose the
optimization that the value is only computed if it's actually used. An
alternative strategy would be to have the first worker that needs the value
compute it, but one downside of that approach is that we'd then need to
select a parallel-safe path to compute the parameter value; it couldn't for
example contain a Gather (Merge) node. At some point in the future, we
might want to consider both approaches.
Independent of that consideration, there is a great deal more work that
could be done to make more kinds of PARAM_EXEC parameters parallel-safe.
This infrastructure could be used to allow a Gather (Merge) on the inner
side of a nested loop (although that's not a very appealing plan) and
cases where the InitPlan is attached below the Gather (Merge) could be
addressed as well using various techniques. But this is a good start.
Amit Kapila, reviewed and revised by me. Reviewing and testing from
Kuntal Ghosh, Haribabu Kommi, and Tushar Ahuja.
Discussion: http://postgr.es/m/CAA4eK1LV0Y1AUV4cUCdC+sYOx0Z0-8NAJ2Pd9=UKsbQ5Sr7+JQ@mail.gmail.com
Commit 0fb54de9a thought that this was only needed in VS2015 and later,
but buildfarm member woodlouse shows that at least VS2013 whines as
well. Let's just define it regardless of MSVC version; it should be
harmless enough in older releases.
Also, in the wake of ed9b3606d, it seems better to put it in win32_port.h
where <winsock2.h> is included.
Since this is only suppressing a pedantic compiler warning, I don't
feel a need for a back-patch.
Discussion: https://postgr.es/m/20124.1510850225@sss.pgh.pa.us
It's become apparent during testing that there are problems with at
least the testing regime. I don't think we should have it without a
working test regime, and the difficulties might indicate implementation
problems anyway, so I'm backing out the whole thing until that's sorted
out.
This reverts commits 74594849989f92cd8ce3a
This continues the work of commit 91aec93e6 by getting rid of a lot of
Windows-specific funny business in "section 0". Instead of including
pg_config_os.h in different places depending on platform, let's
standardize on putting it before the system headers, and in consequence
reduce win32.h to just what has to appear before the system headers or
the body of c.h (the latter category seems to include only PGDLLIMPORT
and PGDLLEXPORT). The rest of what was in win32.h is moved to a new
sub-include of port.h, win32_port.h. Some of what was in port.h seems
to better belong there too.
It's possible that I missed some declaration ordering dependency that
needs to be preserved, but hopefully the buildfarm will find that
out in short order.
Unlike the previous commit, no back-patch, since this is just cleanup
not a prerequisite for a bug fix.
Discussion: https://postgr.es/m/29650.1510761080@sss.pgh.pa.us
Code should be using true and false. Existing code can be changed to
those in a backward compatible way.
The definitions in the ecpg header files are left around to avoid
upsetting those users unnecessarily.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Some code is moved from partition.c, which has grown very quickly lately;
splitting the executor parts out might help to keep it from getting
totally out of control. Other code is moved from execMain.c. All is
moved to a new file execPartition.c. get_partition_for_tuple now has
a new interface that more clearly separates executor concerns from
generic concerns.
Amit Langote. A slight comment tweak by me.
Discussion: http://postgr.es/m/1f0985f8-3b61-8bc4-4350-baa6d804cb6d@lab.ntt.co.jp
Our initial work with int128 neglected alignment considerations, an
oversight that came back to bite us in bug #14897 from Vincent Lachenal.
It is unsurprising that int128 might have a 16-byte alignment requirement;
what's slightly more surprising is that even notoriously lax Intel chips
sometimes enforce that.
Raising MAXALIGN seems out of the question: the costs in wasted disk and
memory space would be significant, and there would also be an on-disk
compatibility break. Nor does it seem very practical to try to allow some
data structures to have more-than-MAXALIGN alignment requirement, as we'd
have to push knowledge of that throughout various code that copies data
structures around.
The only way out of the box is to make type int128 conform to the system's
alignment assumptions. Fortunately, gcc supports that via its
__attribute__(aligned()) pragma; and since we don't currently support
int128 on non-gcc-workalike compilers, we shouldn't be losing any platform
support this way.
Although we could have just done pg_attribute_aligned(MAXIMUM_ALIGNOF) and
called it a day, I did a little bit of extra work to make the code more
portable than that: it will also support int128 on compilers without
__attribute__(aligned()), if the native alignment of their 128-bit-int
type is no more than that of int64.
Add a regression test case that exercises the one known instance of the
problem, in parallel aggregation over a bigint column.
This will need to be back-patched, along with the preparatory commit
91aec93e6. But let's see what the buildfarm makes of it first.
Discussion: https://postgr.es/m/20171110185747.31519.28038@wrigleys.postgresql.org
Generalize section 1 to handle stuff that is principally about the
compiler (not libraries), such as attributes, and collect stuff there
that had been dropped into various other parts of c.h. Also, push
all the gettext macros into section 8, so that section 0 is really
just inclusions rather than inclusions and random other stuff.
The primary goal here is to get pg_attribute_aligned() defined before
section 3, so that we can use it with int128. But this seems like good
cleanup anyway.
This patch just moves macro definitions around, and shouldn't result
in any changes in generated code. But I'll push it out separately
to see if the buildfarm agrees.
Discussion: https://postgr.es/m/20171110185747.31519.28038@wrigleys.postgresql.org
Instead of passing large swaths of boolean arguments, define some flags
that can be used in a bitmask. This makes it easier not only to figure
out what each call site is doing, but also to add some new flags.
The flags are split in two -- one set for index_create directly and
another for constraints. index_create() itself receives both, and then
passes down the latter to index_constraint_create(), which can also be
called standalone.
Discussion: https://postgr.es/m/20171023151251.j75uoe27gajdjmlm@alvherre.pgsql
Reviewed-by: Simon Riggs
Up until now, we only tracked the number of parameters, which was
sufficient to allocate an array of Datums of the appropriate size,
but not sufficient to, for example, know how to serialize a Datum
stored in one of those slots. An upcoming patch wants to do that,
so add this tracking to make it possible.
Patch by me, reviewed by Tom Lane and Amit Kapila.
Discussion: http://postgr.es/m/CA+TgmoYqpxDKn8koHdW8BEKk8FMUL0=e8m2Qe=M+r0UBjr3tuQ@mail.gmail.com
Hash partitioning is useful when you want to partition a growing data
set evenly. This can be useful to keep table sizes reasonable, which
makes maintenance operations such as VACUUM faster, or to enable
partition-wise join.
At present, we still depend on constraint exclusion for partitioning
pruning, and the shape of the partition constraints for hash
partitioning is such that that doesn't work. Work is underway to fix
that, which should both improve performance and make partitioning
pruning work with hash partitioning.
Amul Sul, reviewed and tested by Dilip Kumar, Ashutosh Bapat, Yugo
Nagata, Rajkumar Raghuwanshi, Jesper Pedersen, and by me. A few
final tweaks also by me.
Discussion: http://postgr.es/m/CAAJ_b96fhpJAP=ALbETmeLk1Uni_GFZD938zgenhF49qgDTjaQ@mail.gmail.com
Up to now, ACL checks for large objects happened at the level of
the SQL-callable functions, which led to CVE-2017-7548 because of a
missing check. Push them down to be enforced in inv_api.c as much
as possible, in hopes of preventing future bugs. This does have the
effect of moving read and write permission errors to happen at lo_open
time not loread or lowrite time, but that seems acceptable.
Michael Paquier and Tom Lane
Discussion: https://postgr.es/m/CAB7nPqRHmNOYbETnc_2EjsuzSM00Z+BWKv9sy6tnvSd5gWT_JA@mail.gmail.com
While it's generally unwise to give permissions on these functions to
anyone but a superuser, we've been moving away from hard-wired permission
checks inside functions in favor of using the SQL permission system to
control access. Bring lo_import() and lo_export() into compliance with
that approach.
In particular, this removes the manual configuration option
ALLOW_DANGEROUS_LO_FUNCTIONS. That dates back to 1999 (commit 4cd4a54c8);
it's unlikely anyone has used it in many years. Moreover, if you really
want such behavior, now you can get it with GRANT ... TO PUBLIC instead.
Michael Paquier
Discussion: https://postgr.es/m/CAB7nPqRHmNOYbETnc_2EjsuzSM00Z+BWKv9sy6tnvSd5gWT_JA@mail.gmail.com
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources. The upper case spellings are only used
in some files/modules. So standardize on the standard spellings.
The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.
In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Previously server reserved WAL for last two checkpoints,
which used too much disk space for small servers.
Bumps PG_CONTROL_VERSION
Author: Simon Riggs <simon@2ndQuadrant.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Add docs to explain this for other backup mechanisms
Author: David Steele <david@pgmasters.net>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndQuadrant.com> et al
The update path of an INSERT ... ON CONFLICT DO UPDATE requires SELECT
permission on the columns of the arbiter index, but it failed to check
for that in the case of an arbiter specified by constraint name.
In addition, for a table with row level security enabled, it failed to
check updated rows against the table's SELECT policies when the update
path was taken (regardless of how the arbiter index was specified).
Backpatch to 9.5 where ON CONFLICT DO UPDATE and RLS were introduced.
Security: CVE-2017-15099
For some reason, we have never accounted for either the evaluation cost
or the selectivity of filter conditions attached to Agg and Group nodes
(which, in practice, are always conditions from a HAVING clause).
Applying our regular selectivity logic to post-grouping conditions is a
bit bogus, but it's surely better than taking the selectivity as 1.0.
Perhaps someday the extended-statistics mechanism can be taught to provide
statistics that would help us in getting non-default estimates here.
Per a gripe from Benjamin Coutu. This is surely a bug fix, but I'm
hesitant to back-patch because of the prospect of destabilizing existing
plan choices. Given that it took us this long to notice the bug, it's
probably not hurting too many people in the field.
Discussion: https://postgr.es/m/20968.1509486337@sss.pgh.pa.us
It turns out we misdiagnosed what the real problem was. Revert the
previous changes, because they may have worse consequences going
forward. A better fix is forthcoming.
The simplistic test case is kept, though disabled.
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
If we don't have to return any columns from heap tuples, and there's
no need to recheck qual conditions, and the heap page is all-visible,
then we can skip fetching the heap page altogether.
Skip prefetching pages too, when possible, on the assumption that the
recheck flag will remain the same from one page to the next. While that
assumption is hardly bulletproof, it seems like a good bet most of the
time, and better than prefetching pages we don't need.
This commit installs the executor infrastructure, but doesn't change
any planner cost estimates, thus possibly causing bitmap scans to
not be chosen in cases where this change renders them the best choice.
I (tgl) am not entirely convinced that we need to account for this
behavior in the planner, because I think typically the bitmap scan would
get chosen anyway if it's the best bet. In any case the submitted patch
took way too many shortcuts, resulting in too many clearly-bad choices,
to be committable.
Alexander Kuzmenkov, reviewed by Alexey Chernyshov, and whacked around
rather heavily by me.
Discussion: https://postgr.es/m/239a8955-c0fc-f506-026d-c837e86c827b@postgrespro.ru
It's possible for dropping a column, or altering its type, to require
changes in domain CHECK constraint expressions; but the code was
previously only expecting to find dependent table CHECK constraints.
Make the necessary adjustments.
This is a fairly old oversight, but it's a lot easier to encounter
the problem in the context of domains over composite types than it
was before. Given the lack of field complaints, I'm not going to
bother with a back-patch, though I'd be willing to reconsider that
decision if someone does complain.
Patch by me, reviewed by Michael Paquier
Discussion: https://postgr.es/m/30656.1509128130@sss.pgh.pa.us
Without this fix, dropping a role can sometimes result in parallel
query failures in sessions that have used "SET ROLE" to assume the
dropped role, even if that setting isn't active any more.
Report by Pavan Deolasee. Patch by Amit Kapila, reviewed by me.
Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
If we try to run a parallel plan in serial mode because, for example,
it's going to be scanned via a cursor, but for some reason we're
already in parallel mode (for example because an outer query is
running in parallel), we'd incorrectly try to launch workers.
Fix by adding a flag to the EState, so that we can be certain that
ExecutePlan() and ExecGather()/ExecGatherMerge() will have the same
idea about whether we are executing serially or in parallel.
Report and fix by Amit Kapila with help from Kuntal Ghosh. A few
tweaks by me.
Discussion: http://postgr.es/m/CAA4eK1+_BuZrmVCeua5Eqnm4Co9DAXdM5HPAOE2J19ePbR912Q@mail.gmail.com
This is the last major omission in our domains feature: you can now
make a domain over anything that's not a pseudotype.
The major complication from an implementation standpoint is that places
that might be creating tuples of a domain type now need to be prepared
to apply domain_check(). It seems better that unprepared code fail
with an error like "<type> is not composite" than that it silently fail
to apply domain constraints. Therefore, relevant infrastructure like
get_func_result_type() and lookup_rowtype_tupdesc() has been adjusted
to treat domain-over-composite as a distinct case that unprepared code
won't recognize, rather than just transparently treating it the same
as plain composite. This isn't a 100% solution to the possibility of
overlooked domain checks, but it catches most places.
In passing, improve typcache.c's support for domains (it can now cache
the identity of a domain's base type), and rewrite the argument handling
logic in jsonfuncs.c's populate_record[set]_worker to reduce duplicative
per-call lookups.
I believe this is code-complete so far as the core and contrib code go.
The PLs need varying amounts of work, which will be tackled in followup
patches.
Discussion: https://postgr.es/m/4206.1499798337@sss.pgh.pa.us
This is epecially useful in the case or "VARIADIC ANY" functions. The
caller can get the artguments and types regardless of whether or not and
explicit VARIADIC array argument has been used. The function also
provides an option to convert arguments on type "unknown" to to "text".
Michael Paquier and me, reviewed by Tom Lane.
Backpatch to 9.4 in order to support the following json bug fix.
The built-in OSAs all share the same transition function, so they can
share transition state as long as the final functions cooperate to not
do the sort step more than once. To avoid running the tuplesort object
in randomAccess mode unnecessarily, add a bit of infrastructure to
nodeAgg.c to let the aggregate functions find out whether the transition
state is actually being shared or not.
This doesn't work for the hypothetical aggregates, since those inject
a hypothetical row that isn't traceable to the shared input state.
So they remain marked aggfinalmodify = 'w'.
Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
An aggregate's input expression(s) are not supposed to be evaluated
at all for a row where its FILTER test fails ... but commit 8ed3f11bb
overlooked that requirement. Reshuffle so that aggregates having a
filter clause evaluate their arguments separately from those without.
This still gets the benefit of doing only one ExecProject in the
common case of multiple Aggrefs, none of which have filters.
While at it, arrange for filter clauses to be included in the common
ExecProject evaluation, thus perhaps buying a little bit even when
there are filters.
Back-patch to v10 where the bug was introduced.
Discussion: https://postgr.es/m/30065.1508161354@sss.pgh.pa.us
Up to now, there's been hard-wired assumptions that normal aggregates'
final functions never modify their transition states, while ordered-set
aggregates' final functions always do. This has always been a bit
limiting, and in particular it's getting in the way of improving the
built-in ordered-set aggregates to allow merging of transition states.
Therefore, let's introduce catalog and CREATE AGGREGATE infrastructure
that lets the finalfn's behavior be declared explicitly.
There are now three possibilities for the finalfn behavior: it's purely
read-only, it trashes the transition state irrecoverably, or it changes
the state in such a way that no more transfn calls are possible but the
state can still be passed to other, compatible finalfns. There are no
examples of this third case today, but we'll shortly make the built-in
OSAs act like that.
This change allows user-defined aggregates to explicitly disclaim support
for use as window functions, and/or to prevent transition state merging,
if their implementations cannot handle that. While it was previously
possible to handle the window case with a run-time error check, there was
not any way to prevent transition state merging, which in retrospect is
something commit 804163bc2 should have provided for. But better late
than never.
In passing, split out pg_aggregate.c's extern function declarations into
a new header file pg_aggregate_fn.h, similarly to what we've done for
some other catalog headers, so that pg_aggregate.h itself can be safe
for frontend files to include. This lets pg_dump use the symbolic
names for relevant constants.
Discussion: https://postgr.es/m/4834.1507849699@sss.pgh.pa.us
The following are the individual improvements:
1) Avoidance of FunctionCallInfo based function calls, replaced by
more efficient functions with a native C argument interface.
2) Don't extract columns from a cache entry's tuple whenever matching
entries - instead store them as a Datum array. This also allows to
get rid of having to build dummy tuples for negative & list
entries, and of a hack for dealing with cstring vs. text weirdness.
3) Reorder members of catcache.h struct, so imortant entries are more
likely to be on one cacheline.
4) Allowing the compiler to specialize critical SearchCatCache for a
specific number of attributes allows to unroll loops and avoid
other nkeys dependant initialization.
5) Only initializing the ScanKey when necessary, i.e. catcache misses,
greatly reduces cache unnecessary cpu cache misses.
6) Split of the cache-miss case from the hash lookup, reducing stack
allocations etc in the common case.
7) CatCTup and their corresponding heaptuple are allocated in one
piece.
This results in making cache lookups themselves roughly three times as
fast - full-system benchmarks obviously improve less than that.
I've also evaluated further techniques:
- replace open coded hash with simplehash - the list walk right now
shows up in profiles. Unfortunately it's not easy to do so safely as
an entry's memory location can change at various times, which
doesn't work well with the refcounting and cache invalidation.
- Cacheline-aligning CatCTup entries - helps some with performance,
but the win isn't big and the code for it is ugly, because the
tuples have to be freed as well.
- add more proper functions, rather than macros for
SearchSysCacheCopyN etc., but right now they don't show up in
profiles.
The reason the macro wrapper for syscache.c/h have to be changed,
rather than just catcache, is that doing otherwise would require
exposing the SysCache array to the outside. That might be a good idea
anyway, but it's for another day.
Author: Andres Freund
Reviewed-By: Robert Haas
Discussion: https://postgr.es/m/20170914061207.zxotvyopetm7lrrp@alap3.anarazel.de
Forcing a function not to be inlined can be useful if it's the
slow-path of a performance critical function, or should be visible in
profiles to allow for proper cost attribution.
Author: Andres Freund
Discussion: https://postgr.es/m/20170914061207.zxotvyopetm7lrrp@alap3.anarazel.de
In each of the pq_writeintN functions, the three uses of sizeof() should
surely all be consistent. I started out to make them all sizeof(ni),
but on reflection let's make them sizeof(typename) instead. That's more
like our usual style elsewhere, and it's just barely possible that the
failures buildfarm member hornet has shown since 4c119fbcd went in are
caused by the compiler getting confused about sizeof() a parameter that
it's optimizing away.
In passing, improve a couple of comments.
Discussion: https://postgr.es/m/E1e2RML-0002do-Lc@gemulon.postgresql.org
Unfortunately using 'restrict' plainly causes problems with MSVC,
which supports restrict only as '__restrict'. Defining 'restrict' to
'__restrict' unfortunately causes a conflict with MSVC's usage of
__declspec(restrict) in headers.
Therefore define pg_restrict to the appropriate keyword instead, and
replace existing usages.
This replaces the temporary workaround introduced in 36b4b91ba0.
Author: Andres Freund
Discussion: https://postgr.es/m/2656.1507830907@sss.pgh.pa.us
The previous convention doesn't lend itself to creating ResultRelInfos
lazily, as we already do in ExecGetTriggerResultRel. This patch
doesn't make anything lazier than before, but the pending patch for
UPDATE tuple routing proposes to do so (and there might be other
opportunities as well).
Amit Khandekar with some adjustments by me.
Discussion: http://postgr.es/m/CA+TgmoYPVP9Lyf6vUFA5DwxS4c--x6LOj2y36BsJaYtp62eXPQ@mail.gmail.com
If we merge the transition calculations for two different aggregates,
it's reasonable to assume that the transition function should not care
which of those Aggref structs it gets from AggGetAggref(). It is not
reasonable to make the same assumption about an aggregate final function,
however. Commit 804163bc2 broke this, as it will pass whichever Aggref
was first associated with the transition state in both cases.
This doesn't create an observable bug so far as the core system is
concerned, because the only existing uses of AggGetAggref() are in
ordered-set aggregates that happen to not pay attention to anything
but the input properties of the Aggref; and besides that, we disabled
sharing of transition calculations for OSAs yesterday. Nonetheless,
if some third-party code were using AggGetAggref() in a normal aggregate,
they would be entitled to call this a bug. Hence, back-patch the fix
to 9.6 where the problem was introduced.
In passing, improve some of the comments about transition state sharing.
Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
It appears some versions of msvc use __declspec(restrict) in stdlib.h
and subsidiary headers. Including those after defining 'restrict' to
'__restrict' doesn't work. Try to get the buildfarm green to see
whether there's further problems, by including stdlib.h just before
said define.
Apparently MSVC requires a * before a restrict in a variable
declaration, even if the adorned type already is a pointer, just via
typedef.
As reported by buildfarm animal woodlouse.
Author: Andres Freund
Discussion: https://postgr.es/m/20171012001320.4putagiruuehtvb6@alap3.anarazel.de
There's three categories of changes leading to better performance:
- Splitting the per-attribute part of SendRowDescriptionMessage into a
v2 and a v3 version allows avoiding branches for every attribute.
- Preallocating the size of the buffer to be big enough for all
attributes and then using pq_write* avoids unnecessary buffer
size checks & resizing.
- Reusing a persistently allocated StringInfo for all
SendRowDescriptionMessage() invocations avoids repeated allocations
& reallocations.
Author: Andres Freund
Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
This takes advantage of the infrastructure introduced by commit
81c5e46c49 to greatly reduce the
likelihood that two different queries will end up with the same query
ID. It's still possible, of course, but whereas before it the chances
of a collision reached 25% around 50,000 queries, it will now take
more than 3 billion queries.
Backward incompatibility: Because the type exposed at the SQL level is
int8, users may now see negative query IDs in the pg_stat_statements
view (and also, query IDs more than 4 billion, which was the old
limit).
Patch by me, reviewed by Michael Paquier and Peter Geoghegan.
Discussion: http://postgr.es/m/CA+TgmobG_Kp4cBKFmsznUAaM1GWW6hhRNiZC0KjRMOOeYnz5Yw@mail.gmail.com
There's three prongs to achieve greater efficiency here:
1) Allow reusing a stringbuffer across pq_beginmessage/endmessage,
with the new pq_beginmessage_reuse/endmessage_reuse. This can be
beneficial both because it avoids allocating the initial buffer,
and because it's more likely to already have an correctly sized
buffer.
2) Replacing pq_sendint() with pq_sendint$width() inline
functions. Previously unnecessary and unpredictable branches in
pq_sendint() were needed. Additionally the replacement functions
are implemented more efficiently. pq_sendint is now deprecated, a
separate commit will convert all in-tree callers.
3) Add pq_writeint$width(), pq_writestring(). These rely on sufficient
space in the StringInfo's buffer, avoiding individual space checks
& potential individual resizing. To allow this to be used for
strings, expose mbutil.c's MAX_CONVERSION_GROWTH.
Followup commits will make use of these facilities.
Author: Andres Freund
Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
In a lot of the places having appendBinaryStringInfo() maintain a
trailing NUL byte wasn't actually meaningful, e.g. when appending an
integer which can contain 0 in one of its bytes.
Removing this yields some small speedup, but more importantly will be
more consistent when providing faster variants of pq_sendint etc.
Author: Andres Freund
Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
Will be used in later commits improving performance for a few key
routines where information about aliasing allows for significantly
better code generation.
This allows to use the C99 'restrict' keyword without breaking C89, or
for that matter C++, compilers. If not supported it's defined to be
empty.
Author: Andres Freund
Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
Up to now async.c has used TransactionIdIsInProgress() to detect whether
a notify message's source transaction is still running. However, that
function has a quick-exit path that reports that XIDs before RecentXmin
are no longer running. If a listening backend is doing nothing but
listening, and not running any queries, there is nothing that will advance
its value of RecentXmin. Once 2 billion transactions elapse, the
RecentXmin check causes active transactions to be reported as not running.
If they aren't committed yet according to CLOG, async.c decides they
aborted and discards their messages. The timing for that is a bit tight
but it can happen when multiple backends are sending notifies concurrently.
The net symptom therefore is that a sufficiently-long-surviving
listen-only backend starts to miss some fraction of NOTIFY traffic,
but only under heavy load.
The only function that updates RecentXmin is GetSnapshotData().
A brute-force fix would therefore be to take a snapshot before
processing incoming notify messages. But that would add cycles,
as well as contention for the ProcArrayLock. We can be smarter:
having taken the snapshot, let's use that to check for running
XIDs, and not call TransactionIdIsInProgress() at all. In this
way we reduce the number of ProcArrayLock acquisitions from one
per message to one per notify interrupt; that's the same under
light load but should be a benefit under heavy load. Light testing
says that this change is a wash performance-wise for normal loads.
I looked around for other callers of TransactionIdIsInProgress()
that might be at similar risk, and didn't find any; all of them
are inside transactions that presumably have already taken a
snapshot.
Problem report and diagnosis by Marko Tiikkaja, patch by me.
Back-patch to all supported branches, since it's been like this
since 9.0.
Discussion: https://postgr.es/m/20170926182935.14128.65278@wrigleys.postgresql.org
The previous placement of the fallback implementation in libpgcommon
was problematic, because libpqport functions need strnlen
functionality.
Move replacement into libpgport. Provide strnlen() under its posix
name, instead of pg_strnlen(). Fix stupid configure bug, executing the
test only when compiled with threading support.
Author: Andres Freund
Discussion: https://postgr.es/m/E1e1gR2-0005fB-SI@gemulon.postgresql.org
Previously nodeProjectSet only released memory once per input tuple,
rather than once per returned tuple. If the computation of an
individual returned tuple requires a lot of memory, that can lead to
problems.
Instead change things so that the expression context can be reset once
per output tuple, which requires a new memory context to store SRF
arguments in.
This is a longstanding issue, but was hard to fix before 9.6, due to
the way tSRFs where evaluated. But it's fairly easy to fix now. We
could backpatch this into 10, but given there've been fewc omplaints
that doesn't seem worth the risk so far.
Reported-By: Lucas Fairchild
Author: Andres Freund, per discussion with Tom Lane
Discussion: https://postgr.es/m/4514.1507318623@sss.pgh.pa.us
If the operator is a strict btree equality operator, and X isn't volatile,
then the clause must yield true for any non-null value of X, or null if X
is null. At top level of a WHERE clause, we can ignore the distinction
between false and null results, so it's valid to simplify the clause to
"X IS NOT NULL". This is a useful improvement mainly because we'll get
a far better selectivity estimate in most cases.
Because such cases seldom arise in well-written queries, it is unappetizing
to expend a lot of planner cycles looking for them ... but it turns out
that there's a place we can shoehorn this in practically for free, because
equivclass.c already has to detect and reject candidate equivalences of the
form X = X. That doesn't catch every place that it would be valid to
simplify to X IS NOT NULL, but it catches the typical case. Working harder
doesn't seem justified.
Patch by me, reviewed by Petr Jelinek
Discussion: https://postgr.es/m/CAMjNa7cC4X9YR-vAJS-jSYCajhRDvJQnN7m2sLH1wLh-_Z2bsw@mail.gmail.com
The logical decoding functions do BeginInternalSubTransaction and
RollbackAndReleaseCurrentSubTransaction to clean up after themselves.
It turns out that AtEOSubXact_SPI has an unrecognized assumption that
we always need to cancel the active SPI operation in the SPI context
that surrounds the subtransaction (if there is one). That's true
when the RollbackAndReleaseCurrentSubTransaction call is coming from
the SPI-using function itself, but not when it's happening inside
some unrelated function invoked by a SPI query. In practice the
affected callers are the various PLs.
To fix, record the current subtransaction ID when we begin a SPI
operation, and clean up only if that ID is the subtransaction being
canceled.
Also, remove AtEOSubXact_SPI's assertion that it must have cleaned
up the surrounding SPI context's active tuptable. That's proven
wrong by the same test case.
Also clarify (or, if you prefer, reinterpret) the calling conventions
for _SPI_begin_call and _SPI_end_call. The memory context cleanup
in the latter means that these have always had the flavor of a matched
resource-management pair, but they weren't documented that way before.
Per report from Ben Chobot.
Back-patch to 9.4 where logical decoding came in. In principle,
the SPI changes should go all the way back, since the problem dates
back to commit 7ec1c5a86. But given the lack of field complaints
it seems few people are using internal subtransactions in this way.
So I don't feel a need to take any risks in 9.2/9.3.
Discussion: https://postgr.es/m/73FBA179-C68C-4540-9473-71E865408B15@silentmedia.com
When some tuple versions in an update chain are frozen due to them being
older than freeze_min_age, the xmax/xmin trail can become broken. This
breaks HOT (and probably other things). A subsequent VACUUM can break
things in more serious ways, such as leaving orphan heap-only tuples
whose root HOT redirect items were removed. This can be seen because
index creation (or REINDEX) complain like
ERROR: XX000: failed to find parent tuple for heap-only tuple at (0,7) in table "t"
Because of relfrozenxid contraints, we cannot avoid the freezing of the
early tuples, so we must cope with the results: whenever we see an Xmin
of FrozenTransactionId, consider it a match for whatever the previous
Xmax value was.
This problem seems to have appeared in 9.3 with multixact changes,
though strictly speaking it seems unrelated.
Since 9.4 we have commit 37484ad2a "Change the way we mark tuples as
frozen", so the fix is simple: just compare the raw Xmin (still stored
in the tuple header, since freezing merely set an infomask bit) to the
Xmax. But in 9.3 we rewrite the Xmin value to FrozenTransactionId, so
the original value is lost and we have nothing to compare the Xmax with.
To cope with that case we need to compare the Xmin with FrozenXid,
assume it's a match, and hope for the best. Sadly, since you can
pg_upgrade a 9.3 instance containing half-frozen pages to newer
releases, we need to keep the old check in newer versions too, which
seems a bit brittle; I hope we can somehow get rid of that.
I didn't optimize the new function for performance. The new coding is
probably a bit slower than before, since there is a function call rather
than a straight comparison, but I'd rather have it work correctly than
be fast but wrong.
This is a followup after 20b6552242 fixed a few related problems.
Apparently, in 9.6 and up there are more ways to get into trouble, but
in 9.3 - 9.5 I cannot reproduce a problem anymore with this patch, so
there must be a separate bug.
Reported-by: Peter Geoghegan
Diagnosed-by: Peter Geoghegan, Michael Paquier, Daniel Wood,
Yi Wen Wong, Álvaro
Discussion: https://postgr.es/m/CAH2-Wznm4rCrhFAiwKPWTpEw2bXDtgROZK7jWWGucXeH3D1fmA@mail.gmail.com
Instead of joining two partitioned tables in their entirety we can, if
it is an equi-join on the partition keys, join the matching partitions
individually. This involves teaching the planner about "other join"
rels, which are related to regular join rels in the same way that
other member rels are related to baserels. This can use significantly
more CPU time and memory than regular join planning, because there may
now be a set of "other" rels not only for every base relation but also
for every join relation. In most practical cases, this probably
shouldn't be a problem, because (1) it's probably unusual to join many
tables each with many partitions using the partition keys for all
joins and (2) if you do that scenario then you probably have a big
enough machine to handle the increased memory cost of planning and (3)
the resulting plan is highly likely to be better, so what you spend in
planning you'll make up on the execution side. All the same, for now,
turn this feature off by default.
Currently, we can only perform joins between two tables whose
partitioning schemes are absolutely identical. It would be nice to
cope with other scenarios, such as extra partitions on one side or the
other with no match on the other side, but that will have to wait for
a future patch.
Ashutosh Bapat, reviewed and tested by Rajkumar Raghuwanshi, Amit
Langote, Rafia Sabih, Thomas Munro, Dilip Kumar, Antonin Houska, Amit
Khandekar, and by me. A few final adjustments by me.
Discussion: http://postgr.es/m/CAFjFpRfQ8GrQvzp3jA2wnLqrHmaXna-urjm_UY9BqXj=EaDTSA@mail.gmail.com
Discussion: http://postgr.es/m/CAFjFpRcitjfrULr5jfuKWRPsGUX0LQ0k8-yG0Qw2+1LBGNpMdw@mail.gmail.com
Turns out we have enough functions that the binary search is quite
noticeable in profiles.
Thus have Gen_fmgrtab.pl build a new mapping from a builtin function's
oid to an index in the existing fmgr_builtins array. That keeps the
additional memory usage at a reasonable amount.
Author: Andres Freund, with input from Tom Lane
Discussion: https://postgr.es/m/20170914065128.a5sk7z4xde5uy3ei@alap3.anarazel.de
Not much to say about this; does what it says on the tin.
However, formerly, if there was a column list then the ANALYZE action was
implied; now it must be specified, or you get an error. This is because
it would otherwise be a bit unclear what the user meant if some tables
have column lists and some don't.
Nathan Bossart, reviewed by Michael Paquier and Masahiko Sawada, with some
editorialization by me
Discussion: https://postgr.es/m/E061A8E3-5E3D-494D-94F0-E8A9B312BBFC@amazon.com
Commit 597a87ccc introduced a latch pointer variable to replace use
of a long-lived shared latch in the shared WalRcvData structure.
This was not well thought out, because there are now hazards of the
pointer variable changing while it's being inspected by another
process. This could obviously lead to a core dump in code like
if (WalRcv->latch)
SetLatch(WalRcv->latch);
and there's a more remote risk of a torn read, if we have any
platforms where reading/writing a pointer is not atomic.
An actual problem would occur only if the walreceiver process
exits (gracefully) while the startup process is trying to
signal it, but that seems well within the realm of possibility.
To fix, treat the pointer variable (not the referenced latch)
as being protected by the WalRcv->mutex spinlock. There
remains a race condition that we could apply SetLatch to a
process latch that no longer belongs to the walreceiver, but
I believe that's harmless: at worst it'd cause an extra wakeup
of the next process to use that PGPROC structure.
Back-patch to v10 where the faulty code was added.
Discussion: https://postgr.es/m/22735.1507048202@sss.pgh.pa.us
Allowing arrays with a domain type as their element type was left un-done
in the original domain patch, but not for any very good reason. This
omission leads to such surprising results as array_agg() not working on
a domain column, because the parser can't identify a suitable output type
for the polymorphic aggregate.
In order to fix this, first clean up the APIs of coerce_to_domain() and
some internal functions in parse_coerce.c so that we consistently pass
around a CoercionContext along with CoercionForm. Previously, we sometimes
passed an "isExplicit" boolean flag instead, which is strictly less
information; and coerce_to_domain() didn't even get that, but instead had
to reverse-engineer isExplicit from CoercionForm. That's contrary to the
documentation in primnodes.h that says that CoercionForm only affects
display and not semantics. I don't think this change fixes any live bugs,
but it makes things more consistent. The main reason for doing it though
is that now build_coercion_expression() receives ccontext, which it needs
in order to be able to recursively invoke coerce_to_target_type().
Next, reimplement ArrayCoerceExpr so that the node does not directly know
any details of what has to be done to the individual array elements while
performing the array coercion. Instead, the per-element processing is
represented by a sub-expression whose input is a source array element and
whose output is a target array element. This simplifies life in
parse_coerce.c, because it can build that sub-expression by a recursive
invocation of coerce_to_target_type(). The executor now handles the
per-element processing as a compiled expression instead of hard-wired code.
The main advantage of this is that we can use a single ArrayCoerceExpr to
handle as many as three successive steps per element: base type conversion,
typmod coercion, and domain constraint checking. The old code used two
stacked ArrayCoerceExprs to handle type + typmod coercion, which was pretty
inefficient, and adding yet another array deconstruction to do domain
constraint checking seemed very unappetizing.
In the case where we just need a single, very simple coercion function,
doing this straightforwardly leads to a noticeable increase in the
per-array-element runtime cost. Hence, add an additional shortcut evalfunc
in execExprInterp.c that skips unnecessary overhead for that specific form
of expression. The runtime speed of simple cases is within 1% or so of
where it was before, while cases that previously required two levels of
array processing are significantly faster.
Finally, create an implicit array type for every domain type, as we do for
base types, enums, etc. Everything except the array-coercion case seems
to just work without further effort.
Tom Lane, reviewed by Andrew Dunstan
Discussion: https://postgr.es/m/9852.1499791473@sss.pgh.pa.us
Upcoming patches are going to address performance issues that involve
slow system provided ntohs/htons etc. To address that expand
pg_bswap.h to provide pg_ntoh{16,32,64}, pg_hton{16,32,64} and
optimize their respective implementations by using compiler intrinsics
for gcc compatible compilers and msvc. Fall back to manual
implementations using shifts etc otherwise.
Additionally remove multiple evaluation hazards from the existing
BSWAP32/64 macros, by replacing them with inline functions when
necessary. In the course of that the naming scheme is changed to
pg_bswap16/32/64.
Author: Andres Freund
Discussion: https://postgr.es/m/20170927172019.gheidqy6xvlxb325@alap3.anarazel.de
Add bgw_type field to background worker structure. It is intended to be
set to the same value for all workers of the same type, so they can be
grouped in pg_stat_activity, for example.
The backend_type column in pg_stat_activity now shows bgw_type for a
background worker. The ps listing also no longer calls out that a
process is a background worker but just show the bgw_type. That way,
being a background worker is more of an implementation detail now that
is not shown to the user. However, most log messages still refer to
'background worker "%s"'; otherwise constructing sensible and
translatable log messages would become tricky.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
At the time replacement_sort_tuples was introduced, there were still
cases where replacement selection sort noticeably outperformed using
quicksort even for the first run. However, those cases seem to have
evaporated as a result of further improvements made since that time
(and perhaps also advances in CPU technology). So remove replacement
selection and the controlling GUC entirely. This makes tuplesort.c
noticeably simpler and probably paves the way for further
optimizations someone might want to do later.
Peter Geoghegan, with review and testing by Tomas Vondra and me.
Discussion: https://postgr.es/m/CAH2-WzmmNjG_K0R9nqYwMq3zjyJJK+hCbiZYNGhAy-Zyjs64GQ@mail.gmail.com
This reverts commit 15bc038f9, along with the followon commits 1635e80d3
and 984c92074 that tried to clean up the problems exposed by bug #14825.
The result was incomplete because it failed to address parallel-query
requirements. With 10.0 release so close upon us, now does not seem like
the time to be adding more code to fix that. I hope we can un-revert this
code and add the missing parallel query support during the v11 cycle.
Back-patch to v10.
Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
Commit 15bc038f9 allowed ALTER TYPE ADD VALUE to be executed inside
transaction blocks, by disallowing the use of the added value later
in the same transaction, except under limited circumstances. However,
the test for "limited circumstances" was heuristic and could reject
references to enum values that were created during CREATE TYPE AS ENUM,
not just later. This breaks the use-case of restoring pg_dump scripts
in a single transaction, as reported in bug #14825 from Balazs Szilfai.
We can improve this by keeping a "blacklist" table of enum value OIDs
created by ALTER TYPE ADD VALUE during the current transaction. Any
visible-but-uncommitted value whose OID is not in the blacklist must
have been created by CREATE TYPE AS ENUM, and can be used safely
because it could not have a lifespan shorter than its parent enum type.
This change also removes the restriction that a renamed enum value
can't be used before being committed (unless it was on the blacklist).
Andrew Dunstan, with cosmetic improvements by me.
Back-patch to v10.
Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
This was intended as infrastructure for weakening VACUUM's locking
requirements, similar to what was done for btree indexes in commit
2ed5b87f96. However, for hash indexes,
it seems that the improvements which are possible are actually
extremely marginal. Furthermore, performing the LSN cross-check will
end up skipping cleanup far more often than is necessary; we only care
about page modifications due to a VACUUM, but the LSN check will fail
if ANY modification has occurred. So, rather than pressing forward
with that "optimization", just rip the LSN field out.
Patch by me, reviewed by Ashutosh Sharma and Amit Kapila
Discussion: http://postgr.es/m/CAA4eK1JxqqcuC5Un7YLQVhOYSZBS+t=3xqZuEkt5RyquyuxpwQ@mail.gmail.com
On Linux, shared memory segments created with shm_open() are backed by
swap files created in tmpfs. If the swap file needs to be extended,
but there's no tmpfs space left, you get a very unfriendly SIGBUS trap.
To avoid this, force allocation of the full request size when we create
the segment. This adds a few cycles, but none that we wouldn't expend
later anyway, assuming the request isn't hugely bigger than the actual
need.
Make this code #ifdef __linux__, because (a) there's not currently a
reason to think the same problem exists on other platforms, and (b)
applying posix_fallocate() to an FD created by shm_open() isn't very
portable anyway.
Back-patch to 9.4 where the DSM code came in.
Thomas Munro, per a bug report from Amul Sul
Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
The file handling functions from fd.c were called with a diverse mix of
notations for the file permissions when they were opening new files.
Almost all files created by the server should have the same permissions
set. So change the API so that e.g. OpenTransientFile() automatically
uses the standard permissions set, and OpenTransientFilePerm() is a new
function that takes an explicit permissions set for the few cases where
it is needed. This also saves an unnecessary argument for call sites
that are just opening an existing file.
While we're reviewing these APIs, get rid of the FileName typedef and
use the standard const char * for the file name and mode_t for the file
mode. This makes these functions match other file handling functions
and removes an unnecessary layer of mysteriousness. We can also get rid
of a few casts that way.
Author: David Steele <david@pgmasters.net>
Commit 09cb5c0e7d added a similar
optimization to btree back in 2006, but nobody bothered to implement
the same thing for hash indexes, probably because they weren't
WAL-logged and had lots of other performance problems as well. As
with the corresponding btree case, this eliminates the problem of
potentially needing to refind our position within the page, and cuts
down on pin/unpin traffic as well.
Ashutosh Sharma, reviewed by Alexander Korotkov, Jesper Pedersen,
Amit Kapila, and me. Some final edits to comments and README by
me.
Discussion: http://postgr.es/m/CAE9k0Pm3KTx93K8_5j6VMzG4h5F+SyknxUwXrN-zqSZ9X8ZS3w@mail.gmail.com
These functions are required by SUS v2, which is our minimum baseline
for Unix platforms, and are present on all interesting Windows versions
as well. Even our oldest buildfarm members have them. Thus, we were not
testing the "!USE_WIDE_UPPER_LOWER" code paths, which explains why the bug
fixed in commit e6023ee7f escaped detection. Per discussion, there seems
to be no more real-world value in maintaining this option. Hence, remove
the configure-time tests for wcstombs() and towlower(), remove the
USE_WIDE_UPPER_LOWER symbol, and remove all the !USE_WIDE_UPPER_LOWER code.
There's not actually all that much of the latter, but simplifying the #if
nests is a win in itself.
Discussion: https://postgr.es/m/20170921052928.GA188913@rfd.leadboat.com
"\if :{?variable_name}" will be translated to "\if TRUE" if the variable
exists and "\if FALSE" otherwise. Thus it will be possible to execute code
conditionally on the existence of the variable, regardless of its value.
Fabien Coelho, with some review by Robins Tharakan and some light text
editing by me.
Discussion: https://postgr.es/m/alpine.DEB.2.20.1708260835520.3627@lancre
This is not used for anything yet, but it is necessary infrastructure
for partition-wise join and for partition pruning without constraint
exclusion.
Ashutosh Bapat, reviewed by Amit Langote and with quite a few changes,
mostly cosmetic, by me. Additional review and testing of this patch
series by Antonin Houska, Amit Khandekar, Rafia Sabih, Rajkumar
Raghuwanshi, Thomas Munro, and Dilip Kumar.
Discussion: http://postgr.es/m/CAFjFpRfneFG3H+F6BaiXemMrKF+FY-POpx3Ocy+RiH3yBmXSNw@mail.gmail.com
For performance reasons a larger segment size than the default 16MB
can be useful. A larger segment size has two main benefits: Firstly,
in setups using archiving, it makes it easier to write scripts that
can keep up with higher amounts of WAL, secondly, the WAL has to be
written and synced to disk less frequently.
But at the same time large segment size are disadvantageous for
smaller databases. So far the segment size had to be configured at
compile time, often making it unrealistic to choose one fitting to a
particularly load. Therefore change it to a initdb time setting.
This includes a breaking changes to the xlogreader.h API, which now
requires the current segment size to be configured. For that and
similar reasons a number of binaries had to be taught how to recognize
the current segment size.
Author: Beena Emerson, editorialized by Andres Freund
Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael
Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja
Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
The preceding patch allowed us to remove useless GiST support functions.
This patch actually does that for all the no-op cases in the core GiST
code. This buys us whatever performance gain is to be had, and more
importantly exercises the preceding patch.
There remain no-op functions in the contrib GiST opclasses, but those
will take more work to remove.
Discussion: https://postgr.es/m/CAJEAwVELVx9gYscpE=Be6iJxvdW5unZ_LkcAaVNSeOwvdwtD=A@mail.gmail.com
The use of strnlen rather than strlen was just paranoia. Instead of
giving up on the paranoia, just implement the safeguard
differently. And add a comment explaining why we're careful.
Author: Andres Freund
Discussion: https://postgr.es/m/E1duOkJ-0001Mc-U5@gemulon.postgresql.org
Previously multi-byte aware truncation was done on every
pgstat_report_activity() call - proving to be a bottleneck for
workloads with long query strings that execute quickly.
Instead move the truncation to the read side, which commonly is
executed far less frequently. That's possible because all server
encodings allow to determine the length of a multi-byte string from
the first byte.
Rename PgBackendStatus.st_activity to st_activity_raw so existing
extension users of the field break - their code has to be adjusted to
use pgstat_clip_activity().
Author: Andres Freund
Tested-By: Khuntal Ghosh
Reviewed-By: Robert Haas, Tom Lane
Discussion: https://postgr.es/m/20170912071948.pa7igbpkkkviecpz@alap3.anarazel.de
The bug was caused by not re-reading the control file during crash
recovery restarts, which lead to an attempt to pfree() shared memory
contents. The fix is to re-read the control file, which seems good
anyway.
It's unclear as of this moment, whether we want to keep the
refactoring introduced in the commit referenced above, or come up with
an alternative approach. But fixing the bug in the mean time seems
like a good idea regardless.
A followup commit will introduce regression test coverage for crash
restarts.
Reported-By: Tom Lane
Discussion: https://postgr.es/m/14134.1505572349@sss.pgh.pa.us
Make the btree page-flags test macros (P_ISLEAF and friends) return clean
boolean values, rather than values that might not fit in a bool. Use them
in a few places that were randomly referencing the flag bits directly.
In passing, change access/nbtree/'s only direct use of BUFFER_LOCK_SHARE to
BT_READ. (Some think we should go the other way, but as long as we have
BT_READ/BT_WRITE, let's use them consistently.)
Masahiko Sawada, reviewed by Doug Doole
Discussion: https://postgr.es/m/CAD21AoBmWPeN=WBB5Jvyz_Nt3rmW1ebUyAnk3ZbJP3RMXALJog@mail.gmail.com
By project convention, these names should include "P" when dealing with a
pointer type; that is, if the result of a GETARG macro is of type FOO *,
it should be called PG_GETARG_FOO_P not just PG_GETARG_FOO. Some newer
types such as JSONB and ranges had not followed the convention, and a
number of contrib modules hadn't gotten that memo either. Rename the
offending macros to improve consistency.
In passing, fix a few places that thought PG_DETOAST_DATUM() returns
a Datum; it does not, it returns "struct varlena *". Applying
DatumGetPointer to that happens not to cause any bad effects today,
but it's formally wrong. Also, adjust an ltree macro that was designed
without any thought for what pgindent would do with it.
This is all cosmetic and shouldn't have any impact on generated code.
Mark Dilger, some further tweaks by me
Discussion: https://postgr.es/m/EA5676F4-766F-4F38-8348-ECC7DB427C6A@gmail.com
The standard says that all changes of the same kind (insert, update, or
delete) caused in one table by a single SQL statement should be reported
in a single transition table; and by that, they mean to include foreign key
enforcement actions cascading from the statement's direct effects. It's
also reasonable to conclude that if the standard had wCTEs, they would say
that effects of wCTEs applying to the same table as each other or the outer
statement should be merged into one transition table. We weren't doing it
like that.
Hence, arrange to merge tuples from multiple update actions into a single
transition table as much as we can. There is a problem, which is that if
the firing of FK enforcement triggers and after-row triggers with
transition tables is interspersed, we might need to report more tuples
after some triggers have already seen the transition table. It seems like
a bad idea for the transition table to be mutable between trigger calls.
There's no good way around this without a major redesign of the FK logic,
so for now, resolve it by opening a new transition table each time this
happens.
Also, ensure that AFTER STATEMENT triggers fire just once per statement,
or once per transition table when we're forced to make more than one.
Previous versions of Postgres have allowed each FK enforcement query
to cause an additional firing of the AFTER STATEMENT triggers for the
referencing table, but that's certainly not per spec. (We're still
doing multiple firings of BEFORE STATEMENT triggers, though; is that
something worth changing?)
Also, forbid using transition tables with column-specific UPDATE triggers.
The spec requires such transition tables to show only the tuples for which
the UPDATE trigger would have fired, which means maintaining multiple
transition tables or else somehow filtering the contents at readout.
Maybe someday we'll bother to support that option, but it looks like a
lot of trouble for a marginal feature.
The transition tables are now managed by the AfterTriggers data structures,
rather than being directly the responsibility of ModifyTable nodes. This
removes a subtransaction-lifespan memory leak introduced by my previous
band-aid patch 3c4359521.
In passing, refactor the AfterTriggers data structures to reduce the
management overhead for them, by using arrays of structs rather than
several parallel arrays for per-query-level and per-subtransaction state.
I failed to resist the temptation to do some copy-editing on the SGML
docs about triggers, above and beyond merely documenting the effects
of this patch.
Back-patch to v10, because we don't want the semantics of transition
tables to change post-release.
Patch by me, with help and review from Thomas Munro.
Discussion: https://postgr.es/m/20170909064853.25630.12825@wrigleys.postgresql.org
Tuples can have type RECORDOID and a typmod number that identifies a blessed
TupleDesc in a backend-private cache. To support the sharing of such tuples
through shared memory and temporary files, provide a typmod registry in
shared memory.
To achieve that, introduce per-session DSM segments, created on demand when a
backend first runs a parallel query. The per-session DSM segment has a
table-of-contents just like the per-query DSM segment, and initially the
contents are a shared record typmod registry and a DSA area to provide the
space it needs to grow.
State relating to the current session is accessed via a Session object
reached through global variable CurrentSession that may require significant
redesign further down the road as we figure out what else needs to be shared
or remodelled.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
Previously we read the control file in multiple places. But soon the
segment size will be configurable and stored in the control file, and
that needs to be available earlier than it currently is needed.
Instead of adding yet another place where it's read, refactor things
so there's a single processing of the control file during startup (in
EXEC_BACKEND that's every individual backend's startup).
Author: Andres Freund
Discussion: http://postgr.es/m/20170913092828.aozd3gvvmw67gmyc@alap3.anarazel.de
Flattening the partitioning hierarchy at this stage makes various
desirable optimizations difficult. The original use case for this
patch was partition-wise join, which wants to match up the partitions
in one partitioning hierarchy with those in another such hierarchy.
However, it now seems that it will also be useful in making partition
pruning work using the PartitionDesc rather than constraint exclusion,
because with a flattened expansion, we have no easy way to figure out
which PartitionDescs apply to which leaf tables in a multi-level
partition hierarchy.
As it turns out, we end up creating both rte->inh and !rte->inh RTEs
for each intermediate partitioned table, just as we previously did for
the root table. This seems unnecessary since the partitioned tables
have no storage and are not scanned. We might want to go back and
rejigger things so that no partitioned tables (including the parent)
need !rte->inh RTEs, but that seems to require some adjustments not
related to the core purpose of this patch.
Ashutosh Bapat, reviewed by me and by Amit Langote. Some final
adjustments by me.
Discussion: http://postgr.es/m/CAFjFpRd=1venqLL7oGU=C1dEkuvk2DJgvF+7uKbnPHaum1mvHQ@mail.gmail.com
The order in which GRANTs are output is important as GRANTs which have
been GRANT'd by individuals via WITH GRANT OPTION GRANTs have to come
after the GRANT which included the WITH GRANT OPTION. This happens
naturally in the backend during normal operation as we only change
existing ACLs in-place, only add new ACLs to the end, and when removing
an ACL we remove any which depend on it also.
Also, adjust the comments in acl.h to make this clear.
Unfortunately, the updates to pg_dump to handle initial privileges
involved pulling apart ACLs and then combining them back together and
could end up putting them back together in an invalid order, leading to
dumps which wouldn't restore.
Fix this by adjusting the queries used by pg_dump to ensure that the
ACLs are rebuilt in the same order in which they were originally.
Back-patch to 9.6 where the changes for initial privileges were done.
Peter Eisentraut
Robert Haas
Bruce Momjian
Andres Freund
Tom Lane
Alvaro Herrera
Teodor Sigaev
Simon Riggs
Andrew Dunstan
Dean Rasheed
Stephen Frost