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
If we failed to get a background worker slot, the code just walked
away from the logicalrep-worker slot it already had, leaving that
looking like the worker is still starting up. This led to an indefinite
hang in subscription startup, as reported by Thomas Munro. We must
release the slot on failure.
Also fix a thinko: we must capture the worker slot's generation before
releasing LogicalRepWorkerLock the first time, else testing to see if
it's changed is pretty meaningless.
BTW, the CHECK_FOR_INTERRUPTS() in WaitForReplicationWorkerAttach is a
ticking time bomb, even without considering the possibility of elog(ERROR)
in one of the other functions it calls. Really, this entire business needs
a redesign with some actual thought about error recovery. But for now
I'm just band-aiding the case observed in testing.
Back-patch to v10 where this code was added.
Discussion: https://postgr.es/m/CAEepm=2bP3TBMFBArP6o20AZaRduWjMnjCjt22hSdnA-EvrtCw@mail.gmail.com
When ALTER SUBSCRIPTION DISABLE is run in the same transaction before
DROP SUBSCRIPTION, the latter will hang because workers will still be
running, not having seen the DISABLE committed, and DROP SUBSCRIPTION
will wait until the workers have vacated the replication origin slots.
Previously, DROP SUBSCRIPTION killed the logical replication workers
immediately only if it was going to drop the replication slot, otherwise
it scheduled the worker killing for the end of the transaction, as a
result of 7e174fa793. This, however,
causes the present problem. To fix, kill the workers immediately in all
cases. This covers all cases: A subscription that doesn't have a
replication slot must be disabled. It was either disabled in the same
transaction, or it was already disabled before the current transaction,
but then there shouldn't be any workers left and this won't make a
difference.
Reported-by: Arseny Sher <a.sher@postgrespro.ru>
Discussion: https://www.postgresql.org/message-id/flat/87mv6av84w.fsf%40ars-thinkpad
AfterTriggerEndQuery correctly notes that the query_stack could get
repalloc'd during a trigger firing, but it nonetheless passes the address
of a query_stack entry to afterTriggerInvokeEvents, so that if such a
repalloc occurs, afterTriggerInvokeEvents is already working with an
obsolete dangling pointer while it scans the rest of the events. Oops.
The only code at risk is its "delete_ok" cleanup code, so we can
prevent unsafe behavior by passing delete_ok = false instead of true.
However, that could have a significant performance penalty, because the
point of passing delete_ok = true is to not have to re-scan possibly
a large number of dead trigger events on the next time through the loop.
There's more than one way to skin that cat, though. What we can do is
delete all the "chunks" in the event list except the last one, since
we know all events in them must be dead. Deleting the chunks is work
we'd have had to do later in AfterTriggerEndQuery anyway, and it ends
up saving rescanning of just about the same events we'd have gotten
rid of with delete_ok = true.
In v10 and HEAD, we also have to be careful to mop up any per-table
after_trig_events pointers that would become dangling. This is slightly
annoying, but I don't think that normal use-cases will traverse this code
path often enough for it to be a performance problem.
It's pretty hard to hit this in practice because of the unlikelihood
of the query_stack getting resized at just the wrong time. Nonetheless,
it's definitely a live bug of ancient standing, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/2891.1505419542@sss.pgh.pa.us
Commit 0f79440fb introduced mechanism to keep AFTER STATEMENT triggers
from firing more than once per statement, which was formerly possible
if more than one FK enforcement action had to be applied to a given
table. Add a similar mechanism for BEFORE STATEMENT triggers, so that
we don't have the unexpected situation of firing BEFORE STATEMENT
triggers more often than AFTER STATEMENT.
As with the previous patch, back-patch to v10.
Discussion: https://postgr.es/m/22315.1505584992@sss.pgh.pa.us
The elements of RecordCacheArray are TupleDesc, not TupleDesc *.
Those are actually the same size, so that this error is harmless,
but it's still wrong --- and it might bite us someday, if TupleDesc
ever became a struct, say.
Per Coverity.
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
This code is unsafe, as proven by buildfarm failures, because it tries
to access shared memory that might already be gone. It's also unnecessary,
because we're about to exit the process anyway and so the record type cache
should never be accessed again. The idea was to lay some foundations for
someday recycling workers --- which would require attaching to a different
shared tupdesc registry --- but that will require considerably more
thought. In the meantime let's save some bytes by just removing the
nonfunctional code.
Problem identification, and proposal to fix by removing functionality
from the detach function, by Thomas Munro. I went a bit further by
removing the function altogether.
Discussion: https://postgr.es/m/E1dsguX-00056N-9x@gemulon.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
It's not necessary for such a small program, and it causes unnecessary
extra work to get the correct definition of bool, more so if we are
going to introduce stdbool.h later.
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>
With this change, the order of leaf partitions as returned by
RelationGetPartitionDispatchInfo should now be the same as the
order used by expand_inherited_rtentry. This will make it simpler
for future patches to match up the partition dispatch information
with the planner data structures. The new code is also, in my
opinion anyway, simpler and easier to understand.
Amit Langote, reviewed by Amit Khandekar. I also reviewed and
made a few cosmetic revisions.
Discussion: http://postgr.es/m/d98d4761-5071-1762-501e-0e15047c714b@lab.ntt.co.jp
Using ++ on a bool variable doesn't work well when stdbool.h is in use.
The original BSD code appears to use int here, so use that instead.
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>
During the development of d47cfef711 the CFI()s in ExecScan() were
moved back and forth, ending up in the wrong place. Thus queries that
largely spend their time in ExecScan(), and have neither projection
nor a qual, can't be cancelled in a timely manner.
Reported-By: Jeff Janes
Author: Andres Freund
Discussion: https://postgr.es/m/CAMkU=1weDXp8eLLPt9SO1LEUsJYYK9cScaGhLKpuN+WbYo9b5g@mail.gmail.com
Backpatch: 10, as d47cfef711
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.
Test queries added by commit 69835bc89 are giving unexpected results
on some smaller buildfarm critters. I think probably the seqscan
logic is kicking in to cause the scans to not start at the beginning
of the table. Add ORDER BY to make them be indexscans instead.
Per buildfarm member chipmunk.
Historically, the selectivity functions have simply not distinguished
< from <=, or > from >=, arguing that the fraction of the population that
satisfies the "=" aspect can be considered to be vanishingly small, if the
comparison value isn't any of the most-common-values for the variable.
(If it is, the code path that executes the operator against each MCV will
take care of things properly.) But that isn't really true unless we're
dealing with a continuum of variable values, and in practice we seldom are.
If "x = const" would estimate a nonzero number of rows for a given const
value, then it follows that we ought to estimate different numbers of rows
for "x < const" and "x <= const", even if the const is not one of the MCVs.
Handling this more honestly makes a significant difference in edge cases,
such as the estimate for a tight range (x BETWEEN y AND z where y and z
are close together).
Hence, split scalarltsel into scalarltsel/scalarlesel, and similarly
split scalargtsel into scalargtsel/scalargesel. Adjust <= and >=
operator definitions to reference the new selectivity functions.
Improve the core ineq_histogram_selectivity() function to make a
correction for equality. (Along the way, I learned quite a bit about
exactly why that function gives good answers, which I tried to memorialize
in improved comments.)
The corresponding join selectivity functions were, and remain, just stubs.
But I chose to split them similarly, to avoid confusion and to prevent the
need for doing this exercise again if someone ever makes them less stubby.
In passing, change ineq_histogram_selectivity's clamp for extreme
probability estimates so that it varies depending on the histogram
size, instead of being hardwired at 0.0001. With the default histogram
size of 100 entries, you still get the old clamp value, but bigger
histograms should allow us to put more faith in edge values.
Tom Lane, reviewed by Aleksander Alekseev and Kuntal Ghosh
Discussion: https://postgr.es/m/12232.1499140410@sss.pgh.pa.us
The previous error message when attempting to run a general SQL command
in a physical replication WAL sender was a bit sloppy.
Reported-by: Fujii Masao <masao.fujii@gmail.com>
Commit 83aaac41c6 introduced the use of
LDAP_NO_ATTRS to avoid requesting a dummy attribute when doing search+bind
LDAP authentication. It turns out that not all LDAP implementations define
that macro, but its value is fixed by the protocol so we can define it
ourselves if it's missing.
Author: Thomas Munro
Reported-By: Ashutosh Sharma
Discussion: https://postgr.es/m/CAE9k0Pm6FKCfPCiAr26-L_SMGOA7dT_k0%2B3pEbB8%2B-oT39xRpw%40mail.gmail.com
This patch adds ERROR, SQLSTATE, and ROW_COUNT, which are updated after
every query, as well as LAST_ERROR_MESSAGE and LAST_ERROR_SQLSTATE,
which are updated only when a query fails. The expected usage of these
is for scripting.
Fabien Coelho, reviewed by Pavel Stehule
Discussion: https://postgr.es/m/alpine.DEB.2.20.1704042158020.12290@lancre
Before, only filters of the form "(<ldapsearchattribute>=<user>)"
could be used to search an LDAP server. Introduce ldapsearchfilter
so that more general filters can be configured using patterns, like
"(|(uid=$username)(mail=$username))" and "(&(uid=$username)
(objectClass=posixAccount))". Also allow search filters to be included
in an LDAP URL.
Author: Thomas Munro
Reviewed-By: Peter Eisentraut, Mark Cave-Ayland, Magnus Hagander
Discussion: https://postgr.es/m/CAEepm=0XTkYvMci0WRubZcf_1am8=gP=7oJErpsUfRYcKF2gwg@mail.gmail.com
When copying from an active database tree, it's possible for files to be
deleted after we see them in a readdir() scan but before we can open them.
(Once we've got a file open, we don't expect any further errors from it
getting unlinked, though.) Tweak RecursiveCopy so it can cope with this
case, so as to avoid irreproducible test failures.
Back-patch to 9.6 where this code was added. In v10 and HEAD, also
remove unused "use RecursiveCopy" in one recovery test script.
Michael Paquier and Tom Lane
Discussion: https://postgr.es/m/24621.1504924323@sss.pgh.pa.us
This is primarily useful for making tests of this utility more
deterministic, to avoid the complexity of starting pg_receivewal as a
deamon in TAP tests.
While this is less useful than the equivalent pg_recvlogical option,
users can as well use it for example to enforce WAL streaming up to a
end-of-backup position, to save only a minimal amount of WAL.
Use this new option to stream WAL data in a deterministic way within a
new set of TAP tests.
Author: Michael Paquier <michael.paquier@gmail.com>
This allows the compiler/linker to move the static variables to a
read-only segment. Not all the signature changes are necessary, but
it seems better to apply const in a consistent manner.
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/20170910232154.asgml44ji2b7lv3d@alap3.anarazel.de
AFTER triggers using transition tables crashed if they were fired due
to a foreign key ON CASCADE update. This is because ExecEndModifyTable
flushes the transition tables, on the assumption that any trigger that
could need them was already fired during ExecutorFinish. Normally
that's true, because we don't allow transition-table-using triggers
to be deferred. However, foreign key CASCADE updates force any
triggers on the referencing table to be deferred to the outer query
level, by means of the EXEC_FLAG_SKIP_TRIGGERS flag. I don't recall
all the details of why it's like that and am pretty loath to redesign
it right now. Instead, just teach ExecEndModifyTable to skip destroying
the TransitionCaptureState when that flag is set. This will allow the
transition table data to survive until end of the current subtransaction.
This isn't a terribly satisfactory solution, because (1) we might be
leaking the transition tables for much longer than really necessary,
and (2) as things stand, an AFTER STATEMENT trigger will fire once per
RI updating query, ie once per row updated or deleted in the referenced
table. I suspect that is not per SQL spec. But redesigning this is a
research project that we're certainly not going to get done for v10.
So let's go with this hackish answer for now.
In passing, tweak AfterTriggerSaveEvent to not save the transition_capture
pointer into the event record for a deferrable trigger. This is not
necessary to fix the current bug, but it avoids letting dangling pointers
to long-gone transition tables persist in the trigger event queue. That's
at least a safety feature. It might also allow merging shared trigger
states in more cases than before.
I added a regression test that demonstrates the crash on unpatched code,
and also exposes the behavior of firing the AFTER STATEMENT triggers
once per row update.
Per bug #14808 from Philippe Beaudoin. Back-patch to v10.
Discussion: https://postgr.es/m/20170909064853.25630.12825@wrigleys.postgresql.org
This improves the regression tests' coverage of rbtree.c from pretty
awful (because some of the functions aren't used yet) to basically 100%.
Victor Drobny, reviewed by Aleksander Alekseev and myself
Discussion: https://postgr.es/m/c9d61310e16e75f8acaf6cb1c48b7b77@postgrespro.ru
This code isn't used, and there's no clear reason why anybody would ever
want to use it. These traversal mechanisms don't yield a visitation order
that is semantically meaningful for any external purpose, nor are they
any faster or simpler than the left-to-right or right-to-left traversals.
(In fact, some rough testing suggests they are slower :-(.) Moreover,
these mechanisms are impossible to test in any arm's-length fashion; doing
so requires knowledge of the red-black tree's internal implementation.
Hence, let's just jettison them.
Discussion: https://postgr.es/m/17735.1505003111@sss.pgh.pa.us
The previous coding of get_qual_for_list() was careful to copy everything
it was using from the input data structure. The new version missed
making a copy of pass-by-ref datum values that it's inserting into Consts.
This is not optional, however, as revealed by buildfarm failures on
machines running -DRELCACHE_FORCE_RELEASE: we're copying from a relcache
entry that could go away before the required lifespan of our output
expression. I'm pretty sure -DCLOBBER_CACHE_ALWAYS machines won't like
this either, but none of them have reported in yet.
map_partition_varattnos() failed to set its found_whole_row output
parameter if the given expression list was NIL. This seems to be
a pre-existing bug that chanced to be exposed by commit 6f6b99d13.
It might be unreachable in v10, but I have little faith in that
proposition, so back-patch.
Per buildfarm.
Tom Lane
Peter Eisentraut
Robert Haas
Alvaro Herrera
Andres Freund
Stephen Frost
Michael Meskes