BufFileSize() can't use off_t, because it's only 32 bits wide on
some systems. BufFile objects can have many 1GB segments so the
total size can exceed 2^31. The only known client of the function
is parallel CREATE INDEX, which was reported to fail when building
large indexes on Windows.
Though this is technically an ABI break on platforms with a 32 bit
off_t and we might normally avoid back-patching it, the function is
brand new and thus unlikely to have been discovered by extension
authors yet, and it's fairly thoroughly broken on those platforms
anyway, so just fix it.
Defect in 9da0cc35. Bug #15460. Back-patch to 11, where this
function landed.
Author: Thomas Munro
Reported-by: Paul van der Linden, Pavel Oskin
Reviewed-by: Peter Geoghegan
Discussion: https://postgr.es/m/15460-b6db80de822fa0ad%40postgresql.org
Discussion: https://postgr.es/m/CAHDGBJP_GsESbTt4P3FZA8kMUKuYxjg57XHF7NRBoKnR%3DCAR-g%40mail.gmail.com
This patch fixes several related cases in which pg_shdepend entries were
never made, or were lost, for references to roles appearing in the ACLs of
schemas and/or types. While that did no immediate harm, if a referenced
role were later dropped, the drop would be allowed and would leave a
dangling reference in the object's ACL. That still wasn't a big problem
for normal database usage, but it would cause obscure failures in
subsequent dump/reload or pg_upgrade attempts, taking the form of
attempts to grant privileges to all-numeric role names. (I think I've
seen field reports matching that symptom, but can't find any right now.)
Several cases are fixed here:
1. ALTER DOMAIN SET/DROP DEFAULT would lose the dependencies for any
existing ACL entries for the domain. This case is ancient, dating
back as far as we've had pg_shdepend tracking at all.
2. If a default type privilege applies, CREATE TYPE recorded the
ACL properly but forgot to install dependency entries for it.
This dates to the addition of default privileges for types in 9.2.
3. If a default schema privilege applies, CREATE SCHEMA recorded the
ACL properly but forgot to install dependency entries for it.
This dates to the addition of default privileges for schemas in v10
(commit ab89e465c).
Another somewhat-related problem is that when creating a relation
rowtype or implicit array type, TypeCreate would apply any available
default type privileges to that type, which we don't really want
since such an object isn't supposed to have privileges of its own.
(You can't, for example, drop such privileges once they've been added
to an array type.)
ab89e465c is also to blame for a race condition in the regression tests:
privileges.sql transiently installed globally-applicable default
privileges on schemas, which sometimes got absorbed into the ACLs of
schemas created by concurrent test scripts. This should have resulted
in failures when privileges.sql tried to drop the role holding such
privileges; but thanks to the bug fixed here, it instead led to dangling
ACLs in the final state of the regression database. We'd managed not to
notice that, but it became obvious in the wake of commit da906766c, which
allowed the race condition to occur in pg_upgrade tests.
To fix, add a function recordDependencyOnNewAcl to encapsulate what
callers of get_user_default_acl need to do; while the original call
sites got that right via ad-hoc code, none of the later-added ones
have. Also change GenerateTypeDependencies to generate these
dependencies, which requires adding the typacl to its parameter list.
(That might be annoying if there are any extensions calling that
function directly; but if there are, they're most likely buggy in the
same way as the core callers were, so they need work anyway.) While
I was at it, I changed GenerateTypeDependencies to accept most of its
parameters in the form of a Form_pg_type pointer, making its parameter
list a bit less unwieldy and mistake-prone.
The test race condition is fixed just by wrapping the addition and
removal of default privileges into a single transaction, so that that
state is never visible externally. We might eventually prefer to
separate out tests of default privileges into a script that runs by
itself, but that would be a bigger change and would make the tests
run slower overall.
Back-patch relevant parts to all supported branches.
Discussion: https://postgr.es/m/15719.1541725287@sss.pgh.pa.us
The original code to propagate NOT NULL and default expressions
specified when creating a partition was mostly copy-pasted from
typed-tables creation, but not being a great match it contained some
duplicity, inefficiency and bugs.
This commit fixes the bug that NOT NULL constraints declared in the
parent table would not be honored in the partition. One reported issue
that is not fixed is that a DEFAULT declared in the child is not used
when inserting through the parent. That would amount to a behavioral
change that's better not back-patched.
This rewrite makes the code simpler:
1. instead of checking for duplicate column names in its own block,
reuse the original one that already did that;
2. instead of concatenating the list of columns from parent and the one
declared in the partition and scanning the result to (incorrectly)
propagate defaults and not-null constraints, just scan the latter
searching the former for a match, and merging sensibly. This works
because we know the list in the parent is already correct and there can
only be one parent.
This rewrite makes ColumnDef->is_from_parent unused, so it's removed
on branch master; on released branches, it's kept as an unused field in
order not to cause ABI incompatibilities.
This commit also adds a test case for creating partitions with
collations mismatching that on the parent table, something that is
closely related to the code being patched. No code change is introduced
though, since that'd be a behavior change that could break some (broken)
working applications.
Amit Langote wrote a less invasive fix for the original
NOT NULL/defaults bug, but while I kept the tests he added, I ended up
not using his original code. Ashutosh Bapat reviewed Amit's fix. Amit
reviewed mine.
Author: Álvaro Herrera, Amit Langote
Reviewed-by: Ashutosh Bapat, Amit Langote
Reported-by: Jürgen Strobel (bug #15212)
Discussion: https://postgr.es/m/152746742177.1291.9847032632907407358@wrigleys.postgresql.org
The "rb" prefix is used by Ruby, so that our existing code results
in name collisions that break plruby. We discussed ways to prevent
that by adjusting dynamic linker options, but it seems that at best
we'd move the pain to other cases. Renaming to avoid the collision
is the only portable fix anyway. Fortunately, our rbtree code is
not (yet?) widely used --- in core, there's only a single usage
in GIN --- so it seems likely that we can get away with a rename.
I chose to do this basically as s/rb/rbt/g, except for places where
there already was a "t" after "rb". The patch could have been made
smaller by only touching linker-visible symbols, but it would have
resulted in oddly inconsistent-looking code. Better to make it look
like "rbt" was the plan all along.
Back-patch to v10. The rbtree.c code exists back to 9.5, but
rb_iterate() which is the actual immediate source of pain was added
in v10, so it seems like changing the names before that would have
more risk than benefit.
Per report from Pavel Raiskup.
Discussion: https://postgr.es/m/4738198.8KVIIDhgEB@nb.usersys.redhat.com
An array-type coercion appearing within a CASE that has a constant
(after const-folding) test expression was mangled by the planner, causing
all the elements of the resulting array to be equal to the coerced value
of the CASE's test expression. This is my oversight in commit c12d570fa:
that changed ArrayCoerceExpr to use a subexpression involving a
CaseTestExpr, and I didn't notice that eval_const_expressions needed an
adjustment to keep from folding such a CaseTestExpr to a constant when
it's inside a suitable CASE.
This is another in what's getting to be a depressingly long line of bugs
associated with misidentification of the referent of a CaseTestExpr.
We're overdue to redesign that mechanism; but any such fix is unlikely
to be back-patchable into v11. As a stopgap, fix eval_const_expressions
to do what it must here. Also add a bunch of comments pointing out the
restrictions and assumptions that are needed to make this work at all.
Also fix a related oversight: contain_context_dependent_node() was not
aware of the relationship of ArrayCoerceExpr to CaseTestExpr. That was
somewhat fail-soft, in that the outcome of a wrong answer would be to
prevent optimizations that could have been made, but let's fix it while
we're at it.
Per bug #15471 from Matt Williams. Back-patch to v11 where the faulty
logic came in.
Discussion: https://postgr.es/m/15471-1117f49271989bad@postgresql.org
We can allow this macro to accept either abbreviated or non-abbreviated
allocation parameters by making use of __VA_ARGS__. As noted by Andres
Freund, it's unlikely that any compiler would have __builtin_constant_p
but not __VA_ARGS__, so this gives up little or no error checking, and
it avoids a minor but annoying API break for extensions.
With this change, there is no reason for anybody to call
AllocSetContextCreateExtended directly, so in HEAD I renamed it to
AllocSetContextCreateInternal. It's probably too late for an ABI
break like that in 11, though.
Discussion: https://postgr.es/m/20181012170355.bhxi273skjt6sag4@alap3.anarazel.de
There was no code to handle foreign key constraints on partitioned
tables in the case of ALTER TABLE DETACH; and if you happened to ATTACH
a partition that already had an equivalent constraint, that one was
ignored and a new constraint was created. Adding this to the fact that
foreign key cloning reuses the constraint name on the partition instead
of generating a new name (as it probably should, to cater to SQL
standard rules about constraint naming within schemas), the result was a
pretty poor user experience -- the most visible failure was that just
detaching a partition and re-attaching it failed with an error such as
ERROR: duplicate key value violates unique constraint "pg_constraint_conrelid_contypid_conname_index"
DETAIL: Key (conrelid, contypid, conname)=(26702, 0, test_result_asset_id_fkey) already exists.
because it would try to create an identically-named constraint in the
partition. To make matters worse, if you tried to drop the constraint
in the now-independent partition, that would fail because the constraint
was still seen as dependent on the constraint in its former parent
partitioned table:
ERROR: cannot drop inherited constraint "test_result_asset_id_fkey" of relation "test_result_cbsystem_0001_0050_monthly_2018_09"
This fix attacks the problem from two angles: first, when the partition
is detached, the constraint is also marked as independent, so the drop
now works. Second, when the partition is re-attached, we scan existing
constraints searching for one matching the FK in the parent, and if one
exists, we link that one to the parent constraint. So we don't end up
with a duplicate -- and better yet, we don't need to scan the referenced
table to verify that the constraint holds.
To implement this I made a small change to previously planner-only
struct ForeignKeyCacheInfo to contain the constraint OID; also relcache
now maintains the list of FKs for partitioned tables too.
Backpatch to 11.
Reported-by: Michael Vitale (bug #15425)
Discussion: https://postgr.es/m/15425-2dbc9d2aa999f816@postgresql.org
Repeatedly rewriting a mapped catalog table with VACUUM FULL or
CLUSTER could cause logical decoding to fail with:
ERROR, "could not map filenode \"%s\" to relation OID"
To trigger the problem the rewritten catalog had to have live tuples
with toasted columns.
The problem was triggered as during catalog table rewrites the
heap_insert() check that prevents logical decoding information to be
emitted for system catalogs, failed to treat the new heap's toast table
as a system catalog (because the new heap is not recognized as a
catalog table via RelationIsLogicallyLogged()). The relmapper, in
contrast to the normal catalog contents, does not contain historical
information. After a single rewrite of a mapped table the new relation
is known to the relmapper, but if the table is rewritten twice before
logical decoding occurs, the relfilenode cannot be mapped to a
relation anymore. Which then leads us to error out. This only
happens for toast tables, because the main table contents aren't
re-inserted with heap_insert().
The fix is simple, add a new heap_insert() flag that prevents logical
decoding information from being emitted, and accept during decoding
that there might not be tuple data for toast tables.
Unfortunately that does not fix pre-existing logical decoding
errors. Doing so would require not throwing an error when a filenode
cannot be mapped to a relation during decoding, and that seems too
likely to hide bugs. If it's crucial to fix decoding for an existing
slot, temporarily changing the ERROR in ReorderBufferCommit() to a
WARNING appears to be the best fix.
Author: Andres Freund
Discussion: https://postgr.es/m/20180914021046.oi7dm4ra3ot2g2kt@alap3.anarazel.de
Backpatch: 9.4-, where logical decoding was introduced
Index DDL cascading on partitioned tables introduced a way for ALTER
TABLE to be called reentrantly. This caused an an important deficiency
in event trigger support to be exposed: on exiting the reentrant call,
the alter table state object was clobbered, causing a crash when the
outer alter table tries to finalize its processing. Fix the crash by
creating a stack of event trigger state objects. There are still ways
to cause things to misbehave (and probably other crashers) with more
elaborate tricks, but at least it now doesn't crash in the obvious
scenario.
Backpatch to 9.5, where DDL deparsing of event triggers was introduced.
Reported-by: Marco Slot
Authors: Michaël Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/CANNhMLCpi+HQ7M36uPfGbJZEQLyTy7XvX=5EFkpR-b1bo0uJew@mail.gmail.com
Previously, a worker process would establish values for these based on
its own start time. In v10 and up, this can trivially be shown to cause
misbehavior of transaction_timestamp(), timestamp_in(), and related
functions which are (perhaps unwisely?) marked parallel-safe. It seems
likely that other behaviors might diverge from what happens in the parent
as well.
It's not as trivial to demonstrate problems in 9.6 or 9.5, but I'm sure
it's still possible, so back-patch to all branches containing parallel
worker infrastructure.
In HEAD only, mark now() and statement_timestamp() as parallel-safe
(other affected functions already were). While in theory we could
still squeeze that change into v11, it doesn't seem important enough
to force a last-minute catversion bump.
Konstantin Knizhnik, whacked around a bit by me
Discussion: https://postgr.es/m/6406dbd2-5d37-4cb6-6eb2-9c44172c7e7c@postgrespro.ru
Historically we forbade datatype-specific comparison functions from
returning INT_MIN, so that it would be safe to invert the sort order
just by negating the comparison result. However, this was never
really safe for comparison functions that directly return the result
of memcmp(), strcmp(), etc, as POSIX doesn't place any such restriction
on those library functions. Buildfarm results show that at least on
recent Linux on s390x, memcmp() actually does return INT_MIN sometimes,
causing sort failures.
The agreed-on answer is to remove this restriction and fix relevant
call sites to not make such an assumption; code such as "res = -res"
should be replaced by "INVERT_COMPARE_RESULT(res)". The same is needed
in a few places that just directly negated the result of memcmp or
strcmp.
To help find places having this problem, I've also added a compile option
to nbtcompare.c that causes some of the commonly used comparators to
return INT_MIN/INT_MAX instead of their usual -1/+1. It'd likely be
a good idea to have at least one buildfarm member running with
"-DSTRESS_SORT_INT_MIN". That's far from a complete test of course,
but it should help to prevent fresh introductions of such bugs.
This is a longstanding portability hazard, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/20180928185215.ffoq2xrq5d3pafna@alap3.anarazel.de
I (Andres) was more than a bit hasty in committing 33001fd7a7072d48327
after last minute changes, leading to a number of problems (jit output
was only shown for JIT in parallel workers, and just EXPLAIN without
ANALYZE didn't work). Lukas luckily found these issues quickly.
Instead of combining instrumentation in in standard_ExecutorEnd(), do
so on demand in the new ExplainPrintJITSummary().
Also update a documentation example of the JIT output, changed in
52050ad8ebec8d831.
Author: Lukas Fittl, with minor changes by me
Discussion: https://postgr.es/m/CAP53PkxmgJht69pabxBXJBM+0oc6kf3KHMborLP7H2ouJ0CCtQ@mail.gmail.com
Backpatch: 11, where JIT compilation was introduced
The method we've traditionally used, of redeclaring strerror_r() to
see if the compiler complains of inconsistent declarations, turns out
not to work reliably because some compilers only report a warning,
not an error. Amazingly, this has gone undetected for years, even
though it certainly breaks our detection of whether strerror_r
succeeded.
Let's instead test whether the compiler will take the result of
strerror_r() as a switch() argument. It's possible this won't
work universally either, but it's the best idea I could come up with
on the spur of the moment.
Back-patch of commit 751f532b9. Buildfarm results indicate that only
icc-on-Linux actually has an issue here; perhaps the lack of field
reports indicates that people don't build PG for production that way.
Discussion: https://postgr.es/m/10877.1537993279@sss.pgh.pa.us
It failed if passed a nonexistent relation OID, or one that was a non-heap
relation, because of blindly applying heap_open to a user-supplied OID.
This is not OK behavior for a SQL-exposed function; we have a project
policy that we should return NULL in such cases. Moreover, since
pg_get_partition_constraintdef ought now to work on indexes, restricting
it to heaps is flat wrong anyway.
The underlying function generate_partition_qual() wasn't on board with
indexes having partition quals either, nor for that matter with rels
having relispartition set but yet null relpartbound. (One wonders
whether the person who wrote the function comment blocks claiming that
these functions allow a missing relpartbound had ever tested it.)
Fix by testing relispartition before opening the rel, and by using
relation_open not heap_open. (If any other relkinds ever grow the
ability to have relispartition set, the code will work with them
automatically.) Also, don't reject null relpartbound in
generate_partition_qual.
Back-patch to v11, and all but the null-relpartbound change to v10.
(It's not really necessary to change generate_partition_qual at all
in v10, but I thought s/heap_open/relation_open/ would be a good
idea anyway just to keep the code in sync with later branches.)
Per report from Justin Pryzby.
Discussion: https://postgr.es/m/20180927200020.GJ776@telsasoft.com
Previously, when using parallel query, EXPLAIN (ANALYZE)'s JIT
compilation timings did not include the overhead from doing so on the
workers. Fix that.
We do so by simply aggregating the cost of doing JIT compilation on
workers and the leader together. Arguably that's not quite accurate,
because the total time spend doing so is spent in parallel - but it's
hard to do much better. For additional detail, when VERBOSE is
specified, the stats for workers are displayed separately.
Author: Amit Khandekar and Andres Freund
Discussion: https://postgr.es/m/CAJ3gD9eLrz51RK_gTkod+71iDcjpB_N8eC6vU2AW-VicsAERpQ@mail.gmail.com
Backpatch: 11-
This reverts commit f02259fe93e75d5443a2fabe2f2f38b81924ab36, in the
v11 branch only.
The hack this required in initdb.c should probably have clued us that it
wasn't really ready, but we didn't get the hint. Subsequent developments
have made clear that it affected text-vs-binary behavior in a lot of
places, and there's no reason to think that any of those behavioral changes
are desirable. There's no time to fix this before 11beta4, so just revert
for the moment. We can keep working on this in HEAD, and maybe reconsider
a back-patch once we're satisfied things are stable.
(I take the blame for this fiasco, having encouraged Michael to back-patch
a change at the last possible moment before beta wrap.)
The system expects TABLEFUNC RTEs to have coltypes, coltypmods, and
colcollations lists, but outfuncs doesn't dump them and readfuncs doesn't
restore them. This doesn't cause obvious failures, because the only things
that look at those fields are expandRTE() and get_rte_attribute_type(),
which are mostly used during parse analysis, before anything would've
passed the parsetree through outfuncs/readfuncs. But expandRTE() is used
in build_physical_tlist(), which means that that function will return a
wrong answer for a TABLEFUNC RTE that came from a view. Very accidentally,
this doesn't cause serious problems, because what it will return is NIL
which callers will interpret as "couldn't build a physical tlist because
of dropped columns". So you still get a plan that works, though it's
marginally less efficient than it could be. There are also some other
expandRTE() calls associated with transformation of whole-row Vars in
the planner. I have been unable to exhibit misbehavior from that, and
it may be unreachable in any case that anyone would care about ... but
I'm not entirely convinced, so this seems like something we should back-
patch a fix for. Fortunately, we can fix it without forcing a change
of stored rules and a catversion bump, because we can just copy these
lists from the subsidiary TableFunc object.
readfuncs.c was also missing support for NamedTuplestoreScan plan nodes.
This accidentally fails to break parallel query because a query using
a named tuplestore would never be considered parallel-safe anyway.
However, project policy since parallel query came in is that all plan
node types should have outfuncs/readfuncs support, so this is clearly
an oversight that should be repaired.
Noted while fooling around with a patch to test outfuncs/readfuncs more
thoroughly. That exposed some other issues too, but these are the only
ones that seem worth back-patching.
Back-patch to v10 where both of these features came in.
Discussion: https://postgr.es/m/17114.1537138992@sss.pgh.pa.us
The original coding for XMLTABLE thought it could represent a default
namespace by a T_String Value node with a null string pointer. That's
not okay, though; in particular outfuncs.c/readfuncs.c are not on board
with such a representation, meaning you'll get a null pointer crash
if you try to store a view or rule containing this construct.
To fix, change the parsetree representation so that we have a NULL
list element, instead of a bogus Value node.
This isn't really a functional limitation since default XML namespaces
aren't yet implemented in the executor; you'd just get "DEFAULT
namespace is not supported" anyway. But crashes are not nice, so
back-patch to v10 where this syntax was added. Ordinarily we'd consider
a parsetree representation change to be un-backpatchable; but since
existing releases would crash on the way to storing such constructs,
there can't be any existing views/rules to be incompatible with.
Per report from Andrey Lepikhov.
Discussion: https://postgr.es/m/3690074f-abd2-56a9-144a-aa5545d7a291@postgrespro.ru
PostgreSQL uses a custom wrapper for open() and fopen() which is
concurrent-safe, allowing multiple processes to open and work on the
same file. This has a couple of advantages:
- pg_test_fsync does not handle O_DSYNC correctly otherwise, leading to
false claims that disks are unsafe.
- TAP tests can run into race conditions when a postmaster and pg_ctl
open postmaster.pid, fixing some random failures in the buildfam.
pg_upgrade is one frontend tool using workarounds to bypass file locking
issues with the log files it generates, however the interactions with
pg_ctl are proving to be tedious to get rid of, so this is left for
later.
Author: Laurenz Albe
Reviewed-by: Michael Paquier, Kuntal Ghosh
Discussion: https://postgr.es/m/1527846213.2475.31.camel@cybertec.at
Discussion: https://postgr.es/m/16922.1520722108@sss.pgh.pa.us
The EvalPlanQual machinery assumes that any initplans (that is,
uncorrelated sub-selects) used during an EPQ recheck would have already
been evaluated during the main query; this is implicit in the fact that
execPlan pointers are not copied into the EPQ estate's es_param_exec_vals.
But it's possible for that assumption to fail, if the initplan is only
reached conditionally. For example, a sub-select inside a CASE expression
could be reached during a recheck when it had not been previously, if the
CASE test depends on a column that was just updated.
This bug is old, appearing to date back to my rewrite of EvalPlanQual in
commit 9f2ee8f28, but was not detected until Kyle Samson reported a case.
To fix, force all not-yet-evaluated initplans used within the EPQ plan
subtree to be evaluated at the start of the recheck, before entering the
EPQ environment. This could be inefficient, if such an initplan is
expensive and goes unused again during the recheck --- but that's piling
one layer of improbability atop another. It doesn't seem worth adding
more complexity to prevent that, at least not in the back branches.
It was convenient to use the new-in-v11 ExecEvalParamExecParams function
to implement this, but I didn't like either its name or the specifics of
its API, so revise that.
Back-patch all the way. Rather than rewrite the patch to avoid depending
on bms_next_member() in the oldest branches, I chose to back-patch that
function into 9.4 and 9.3. (This isn't the first time back-patches have
needed that, and it exhausted my patience.) I also chose to back-patch
some test cases added by commits 71404af2a and 342a1ffa2 into 9.4 and 9.3,
so that the 9.x versions of eval-plan-qual.spec are all the same.
Andrew Gierth diagnosed the problem and contributed the added test cases,
though the actual code changes are by me.
Discussion: https://postgr.es/m/A033A40A-B234-4324-BE37-272279F7B627@tripadvisor.com
Allowing sub-select containing LIMIT/OFFSET in workers can lead to
inconsistent results at the top-level as there is no guarantee that the
row order will be fully deterministic. The fix is to prohibit pushing
LIMIT/OFFSET within sub-selects to workers.
Reported-by: Andrew Fletcher
Bug: 15324
Author: Amit Kapila
Reviewed-by: Dilip Kumar
Backpatch-through: 9.6
Discussion: https://postgr.es/m/153417684333.10284.11356259990921828616@wrigleys.postgresql.org
This patch removes two sources of interference between nominally
independent functions when one SPI-using function calls another,
perhaps without knowing that it does so.
Chapman Flack pointed out that xml.c's query_to_xml_internal() expects
SPI_tuptable and SPI_processed to stay valid across datatype output
function calls; but it's possible that such a call could involve
re-entrant use of SPI. It seems likely that there are similar hazards
elsewhere, if not in the core code then in third-party SPI users.
Previously SPI_finish() reset SPI's API globals to zeroes/nulls, which
would typically make for a crash in such a situation. Restoring them
to the values they had at SPI_connect() seems like a considerably more
useful behavior, and it still meets the design goal of not leaving any
dangling pointers to tuple tables of the function being exited.
Also, cause SPI_connect() to reset these variables to zeroes/nulls after
saving them. This prevents interference in the opposite direction: it's
possible that a SPI-using function that's only ever been tested standalone
contains assumptions that these variables start out as zeroes. That was
the case as long as you were the outermost SPI user, but not so much for
an inner user. Now it's consistent.
Report and fix suggestion by Chapman Flack, actual patch by me.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/9fa25bef-2e4f-1c32-22a4-3ad0723c4a17@anastigmatix.net
LockRelationOid and sibling routines supposed that, if our session already
holds the lock they were asked to acquire, they could skip calling
AcceptInvalidationMessages on the grounds that we must have already read
any remote sinval messages issued against the relation being locked.
This is normally true, but there's a critical special case where it's not:
processing inside AcceptInvalidationMessages might attempt to access system
relations, resulting in a recursive call to acquire a relation lock.
Hence, if the outer call had acquired that same system catalog lock, we'd
fall through, despite the possibility that there's an as-yet-unread sinval
message for that system catalog. This could, for example, result in
failure to access a system catalog or index that had just been processed
by VACUUM FULL. This is the explanation for buildfarm failures we've been
seeing intermittently for the past three months. The bug is far older
than that, but commits a54e1f158 et al added a new recursion case within
AcceptInvalidationMessages that is apparently easier to hit than any
previous case.
To fix this, we must not skip calling AcceptInvalidationMessages until
we have *finished* a call to it since acquiring a relation lock, not
merely acquired the lock. (There's already adequate logic inside
AcceptInvalidationMessages to deal with being called recursively.)
Fortunately, we can implement that at trivial cost, by adding a flag
to LOCALLOCK hashtable entries that tracks whether we know we have
completed such a call.
There is an API hazard added by this patch for external callers of
LockAcquire: if anything is testing for LOCKACQUIRE_ALREADY_HELD,
it might be fooled by the new return code LOCKACQUIRE_ALREADY_CLEAR
into thinking the lock wasn't already held. This should be a fail-soft
condition, though, unless something very bizarre is being done in
response to the test.
Also, I added an additional output argument to LockAcquireExtended,
assuming that that probably isn't called by any outside code given
the very limited usefulness of its additional functionality.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/12259.1532117714@sss.pgh.pa.us
The commit 620b49a1 changed the value of HASH_MAX_BITMAPS with the intent
to allow many non-unique values in hash indexes without worrying to reach
the limit of the number of overflow pages. At that time, this didn't
occur to us that it can overrun the block for smaller block sizes.
Choose the value of HASH_MAX_BITMAPS based on BLCKSZ such that it gives
the same answer as now for the cases where the overrun doesn't occur, and
some other sufficiently-value for the cases where an overrun currently
does occur. This allows us not to change the behavior in any case that
currently works, so there's really no reason for a HASH_VERSION bump.
Author: Dilip Kumar
Reviewed-by: Amit Kapila
Backpatch-through: 10
Discussion: https://postgr.es/m/CAA4eK1LtF4VmU4mx_+i72ff1MdNZ8XaJMGkt2HV8+uSWcn8t4A@mail.gmail.com
pg_get_object_address and pg_identify_object_as_address are supposed
to be inverses, but they disagreed as to the names of the arguments
representing the textual form of an object address. Moreover, the
documented argument names didn't agree with reality at all, either
for these functions or pg_identify_object.
In HEAD and v11, I think we can get away with renaming the input
arguments of pg_get_object_address to match the outputs of
pg_identify_object_as_address. In theory that might break queries
using named-argument notation to call pg_get_object_address, but
it seems really unlikely that anybody is doing that, or that they'd
have much trouble adjusting if they were. In older branches, we'll
just live with the lack of consistency.
Aside from fixing the documentation of these functions to match reality,
I couldn't resist the temptation to do some copy-editing.
Per complaint from Jean-Pierre Pelletier. Back-patch to 9.5 where these
functions were introduced. (Before v11, this is a documentation change
only.)
Discussion: https://postgr.es/m/CANGqjDnWH8wsTY_GzDUxbt4i=y-85SJreZin4Hm8uOqv1vzRQA@mail.gmail.com
It's been true for a long time that we expect names of table and domain
constraints to be unique among the constraints of that table or domain.
However, the enforcement of that has been pretty haphazard, and it missed
some corner cases such as creating a CHECK constraint and then an index
constraint of the same name (as per recent report from André Hänsel).
Also, due to the lack of an actual unique index enforcing this, duplicates
could be created through race conditions.
Moreover, the code that searches pg_constraint has been quite inconsistent
about how to handle duplicate names if one did occur: some places checked
and threw errors if there was more than one match, while others just
processed the first match they came to.
To fix, create a unique index on (conrelid, contypid, conname). Since
either conrelid or contypid is zero, this will separately enforce
uniqueness of constraint names among constraints of any one table and any
one domain. (If we ever implement SQL assertions, and put them into this
catalog, more thought might be needed. But it'd be at least as reasonable
to put them into a new catalog; having overloaded this one catalog with
two kinds of constraints was a mistake already IMO.) This index can replace
the existing non-unique index on conrelid, though we need to keep the one
on contypid for query performance reasons.
Having done that, we can simplify the logic in various places that either
coped with duplicates or neglected to, as well as potentially improve
lookup performance when searching for a constraint by name.
Also, as per our usual practice, install a preliminary check so that you
get something more friendly than a unique-index violation report in the
case complained of by André. And teach ChooseIndexName to avoid choosing
autogenerated names that would draw such a failure.
While it's not possible to make such a change in the back branches,
it doesn't seem quite too late to put this into v11, so do so.
Discussion: https://postgr.es/m/0c1001d4428f$0942b430$1bc81c90$@webkr.de
This column was added in commit 8224de4f42cc ("Indexes with INCLUDE
columns and their support in B-tree") to ease writing the ruleutils.c
supporting code for that feature, but it turns out to be unnecessary --
we can do the same thing with just one more syscache lookup.
Even the documentation for the new column being removed in this commit
is awkward.
Discussion: https://postgr.es/m/20180902165018.33otxftp3olgtu4t@alvherre.pgsql
When decoding a TRUNCATE record, the relids array was being allocated in
the main ReorderBuffer memory context, but not released with the change
resulting in a memory leak.
The array was also ignored when serializing/deserializing the change,
assuming all the information is stored in the change itself. So when
spilling the change to disk, we've only we have serialized only the
pointer to the relids array. Thanks to never releasing the array,
the pointer however remained valid even after loading the change back
to memory, preventing an actual crash.
This fixes both the memory leak and (de)serialization. The relids array
is still allocated in the main ReorderBuffer memory context (none of the
existing ones seems like a good match, and adding an extra context seems
like an overkill). The allocation is wrapped in a new ReorderBuffer API
functions, to keep the details within reorderbuffer.c, just like the
other ReorderBufferGet methods do.
Author: Tomas Vondra
Discussion: https://www.postgresql.org/message-id/flat/66175a41-9342-2845-652f-1bd4c3ee50aa%402ndquadrant.com
Backpatch: 11, where decoding of TRUNCATE was introduced
There's a project policy against using plain "char buf[BLCKSZ]" local
or static variables as page buffers; preferred style is to palloc or
malloc each buffer to ensure it is MAXALIGN'd. However, that policy's
been ignored in an increasing number of places. We've apparently got
away with it so far, probably because (a) relatively few people use
platforms on which misalignment causes core dumps and/or (b) the
variables chance to be sufficiently aligned anyway. But this is not
something to rely on. Moreover, even if we don't get a core dump,
we might be paying a lot of cycles for misaligned accesses.
To fix, invent new union types PGAlignedBlock and PGAlignedXLogBlock
that the compiler must allocate with sufficient alignment, and use
those in place of plain char arrays.
I used these types even for variables where there's no risk of a
misaligned access, since ensuring proper alignment should make
kernel data transfers faster. I also changed some places where
we had been palloc'ing short-lived buffers, for coding style
uniformity and to save palloc/pfree overhead.
Since this seems to be a live portability hazard (despite the lack
of field reports), back-patch to all supported versions.
Patch by me; thanks to Michael Paquier for review.
Discussion: https://postgr.es/m/1535618100.1286.3.camel@credativ.de
The previous definition was used in C++ mode, which causes problems
when using clang with libc++ (rather than libstdc++), due to bugs
therein. So just avoid in C++ mode.
A second problem is that depending on include order and implicit
includes the previous definition did not guarantee that the current
hack was effective by the time isinf was used, fix that by forcing
math.h to be included. This can cause clang using builds, or gcc
using ones with JIT enabled, to slow down noticably.
It's likely that we at some point want a better solution for the
performance problem, but while it's there it should better work.
Reported-By: Steven Winfield
Bug: #15270
Discussion: https://postgr.es/m/153116283147.1401.360416241833049560@wrigleys.postgresql.org
Author: Andres Freund
Backpatch: 11, like the previous commit.
In general, Postgres requires -fno-strict-aliasing with compilers that
implement C99 strict aliasing rules. There's little hope of getting
rid of that overall. But it seems like it would be a good idea if
storage/checksum_impl.h in particular didn't depend on it, because
that header is explicitly intended to be included by external programs.
We don't have a lot of control over the compiler switches that an
external program might use, as shown by Michael Banck's report of
failure in a privately-modified version of pg_verify_checksums.
Hence, switch to using a union in place of willy-nilly pointer casting
inside this file. I think this makes the code a bit more readable
anyway.
checksum_impl.h hasn't changed since it was introduced in 9.3,
so back-patch all the way.
Discussion: https://postgr.es/m/1535618100.1286.3.camel@credativ.de
Commit f49842d, which added support for partitionwise joins, built the
child's tlist by applying adjust_appendrel_attrs() to the parent's. So in
the case where the parent's included a whole-row Var for the parent, the
child's contained a ConvertRowtypeExpr. To cope with that, that commit
added code to the planner, such as setrefs.c, but some code paths still
assumed that the tlist for a scan (or join) rel would only include Vars
and PlaceHolderVars, which was true before that commit, causing errors:
* When creating an explicit sort node for an input path for a mergejoin
path for a child join, prepare_sort_from_pathkeys() threw the 'could not
find pathkey item to sort' error.
* When deparsing a relation participating in a pushed down child join as a
subquery in contrib/postgres_fdw, get_relation_column_alias_ids() threw
the 'unexpected expression in subquery output' error.
* When performing set_plan_references() on a local join plan generated by
contrib/postgres_fdw for EvalPlanQual support for a pushed down child
join, fix_join_expr() threw the 'variable not found in subplan target
lists' error.
To fix these, two approaches have been proposed: one by Ashutosh Bapat and
one by me. While the former keeps building the child's tlist with a
ConvertRowtypeExpr, the latter builds it with a whole-row Var for the
child not to violate the planner assumption, and tries to fix it up later,
But both approaches need more work, so refuse to generate partitionwise
join paths when whole-row Vars are involved, instead. We don't need to
handle ConvertRowtypeExprs in the child's tlists for now, so this commit
also removes the changes to the planner.
Previously, partitionwise join computed attr_needed data for each child
separately, and built the child join's tlist using that data, which also
required an extra step for adding PlaceHolderVars to that tlist, but it
would be more efficient to build it from the parent join's tlist through
the adjust_appendrel_attrs() transformation. So this commit builds that
list that way, and simplifies build_joinrel_tlist() and placeholder.c as
well as part of set_append_rel_size() to basically what they were before
partitionwise join went in.
Back-patch to PG11 where partitionwise join was introduced.
Report by Rajkumar Raghuwanshi. Analysis by Ashutosh Bapat, who also
provided some of regression tests. Patch by me, reviewed by Robert Haas.
Discussion: https://postgr.es/m/CAKcux6ktu-8tefLWtQuuZBYFaZA83vUzuRd7c1YHC-yEWyYFpg@mail.gmail.com
Historically, the term procedure was used as a synonym for function in
Postgres/PostgreSQL. Now we have procedures as separate objects from
functions, so we need to clean up the documentation to not mix those
terms.
In particular, mentions of "trigger procedures" are changed to "trigger
functions", and access method "support procedures" are changed to
"support functions". (The latter already used FUNCTION in the SQL
syntax anyway.) Also, the terminology in the SPI chapter has been
cleaned up.
A few tests, examples, and code comments are also adjusted to be
consistent with documentation changes, but not everything.
Reported-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
Previously, this code blindly followed the common coding pattern of
passing PQserverVersion(AH->connection) as the server-version parameter
of fmtQualifiedId. That works as long as we have a connection; but in
pg_restore with text output, we don't. Instead we got a zero from
PQserverVersion, which fmtQualifiedId interpreted as "server is too old to
have schemas", and so the name went unqualified. That still accidentally
managed to work in many cases, which is probably why this ancient bug went
undetected for so long. It only became obvious in the wake of the changes
to force dump/restore to execute with restricted search_path.
In HEAD/v11, let's deal with this by ripping out fmtQualifiedId's server-
version behavioral dependency, and just making it schema-qualify all the
time. We no longer support pg_dump from servers old enough to need the
ability to omit schema name, let alone restoring to them. (Also, the few
callers outside pg_dump already didn't work with pre-schema servers.)
In older branches, that's not an acceptable solution, so instead just
tweak the DISABLE/ENABLE TRIGGER logic to ensure it will schema-qualify
its output regardless of server version.
Per bug #15338 from Oleg somebody. Back-patch to all supported branches.
Discussion: https://postgr.es/m/153452458706.1316.5328079417086507743@wrigleys.postgresql.org
Commit dafa084, added in 10, made the removal of temporary orphaned
tables more aggressive. This commit makes an extra step into the
aggressiveness by adding a flag in each backend's MyProc which tracks
down any temporary namespace currently in use. The flag is set when the
namespace gets created and can be reset if the temporary namespace has
been created in a transaction or sub-transaction which is aborted. The
flag value assignment is assumed to be atomic, so this can be done in a
lock-less fashion like other flags already present in PGPROC like
databaseId or backendId, still the fact that the temporary namespace and
table created are still locked until the transaction creating those
commits acts as a barrier for other backends.
This new flag gets used by autovacuum to discard more aggressively
orphaned tables by additionally checking for the database a backend is
connected to as well as its temporary namespace in-use, removing
orphaned temporary relations even if a backend reuses the same slot as
one which created temporary relations in a past session.
The base idea of this patch comes from Robert Haas, has been written in
its first version by Tsunakawa Takayuki, then heavily reviewed by me.
Author: Tsunakawa Takayuki
Reviewed-by: Michael Paquier, Kyotaro Horiguchi, Andres Freund
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8A4DC6@G01JPEXMBYT05
Backpatch: 11-, as PGPROC gains a new flag and we don't want silent ABI
breakages on already released versions.
Multiple calls to XMLTABLE in a query (e.g. laterally applying it to a
table with an xml column, an important use-case) were leaking large
amounts of memory into the per-query context, blowing up memory usage.
Repair by reorganizing memory context usage in nodeTableFuncscan; use
the usual per-tuple context for row-by-row evaluations instead of
perValueCxt, and use the explicitly created context -- renamed from
perValueCxt to perTableCxt -- for arguments and state for each
individual table-generation operation.
Backpatch to PG10 where this code was introduced.
Original report by IRC user begriffs; analysis and patch by me.
Reviewed by Tom Lane and Pavel Stehule.
Discussion: https://postgr.es/m/153394403528.10284.7530399040974170549@wrigleys.postgresql.org
There are some problems with the tls-unique channel binding type. It's not
supported by all SSL libraries, and strictly speaking it's not defined for
TLS 1.3 at all, even though at least in OpenSSL, the functions used for it
still seem to work with TLS 1.3 connections. And since we had no
mechanism to negotiate what channel binding type to use, there would be
awkward interoperability issues if a server only supported some channel
binding types. tls-server-end-point seems feasible to support with any SSL
library, so let's just stick to that.
This removes the scram_channel_binding libpq option altogether, since there
is now only one supported channel binding type.
This also removes all the channel binding tests from the SSL test suite.
They were really just testing the scram_channel_binding option, which
is now gone. Channel binding is used if both client and server support it,
so it is used in the existing tests. It would be good to have some tests
specifically for channel binding, to make sure it really is used, and the
different combinations of a client and a server that support or doesn't
support it. The current set of settings we have make it hard to write such
tests, but I did test those things manually, by disabling
HAVE_BE_TLS_GET_CERTIFICATE_HASH and/or
HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH.
I also removed the SCRAM_CHANNEL_BINDING_TLS_END_POINT constant. This is a
matter of taste, but IMO it's more readable to just use the
"tls-server-end-point" string.
Refactor the checks on whether the SSL library supports the functions
needed for tls-server-end-point channel binding. Now the server won't
advertise, and the client won't choose, the SCRAM-SHA-256-PLUS variant, if
compiled with an OpenSSL version too old to support it.
In the passing, add some sanity checks to check that the chosen SASL
mechanism, SCRAM-SHA-256 or SCRAM-SHA-256-PLUS, matches whether the SCRAM
exchange used channel binding or not. For example, if the client selects
the non-channel-binding variant SCRAM-SHA-256, but in the SCRAM message
uses channel binding anyway. It's harmless from a security point of view,
I believe, and I'm not sure if there are some other conditions that would
cause the connection to fail, but it seems better to be strict about these
things and check explicitly.
Discussion: https://www.postgresql.org/message-id/ec787074-2305-c6f4-86aa-6902f98485a4%40iki.fi
When expanding an updatable view that is an INSERT's target, the rewriter
failed to rewrite Vars in the ON CONFLICT UPDATE clause. This accidentally
worked if the view was just "SELECT * FROM ...", as the transformation
would be a no-op in that case. With more complicated view targetlists,
this omission would often lead to "attribute ... has the wrong type" errors
or even crashes, as reported by Mario De Frutos Dieguez.
Fix by adding code to rewriteTargetView to fix up the data structure
correctly. The easiest way to update the exclRelTlist list is to rebuild
it from scratch looking at the new target relation, so factor the code
for that out of transformOnConflictClause to make it sharable.
In passing, avoid duplicate permissions checks against the EXCLUDED
pseudo-relation, and prevent useless view expansion of that relation's
dummy RTE. The latter is only known to happen (after this patch) in cases
where the query would fail later due to not having any INSTEAD OF triggers
for the view. But by exactly that token, it would create an unintended
and very poorly tested state of the query data structure, so it seems like
a good idea to prevent it from happening at all.
This has been broken since ON CONFLICT was introduced, so back-patch
to 9.5.
Dean Rasheed, based on an earlier patch by Amit Langote;
comment-kibitzing and back-patching by me
Discussion: https://postgr.es/m/CAFYwGJ0xfzy8jaK80hVN2eUWr6huce0RU8AgU04MGD00igqkTg@mail.gmail.com
