VACUUM and ANALYZE update the target table's pg_class row in-place, that is
nontransactionally. This is OK, more or less, for the statistical columns,
which are mostly nontransactional anyhow. It's not so OK for the DDL hint
flags (relhasindex etc), which might get changed in response to
transactional changes that could still be rolled back. This isn't a
problem for VACUUM, since it can't be run inside a transaction block nor
in parallel with DDL on the table. However, we allow ANALYZE inside a
transaction block, so if the transaction had earlier removed the last
index, rule, or trigger from the table, and then we roll back the
transaction after ANALYZE, the table would be left in a corrupted state
with the hint flags not set though they should be.
To fix, suppress the hint-flag updates if we are InTransactionBlock().
This is safe enough because it's always OK to postpone hint maintenance
some more; the worst-case consequence is a few extra searches of pg_index
et al. There was discussion of instead using a transactional update,
but that would change the behavior in ways that are not all desirable:
in most scenarios we're better off keeping ANALYZE's statistical values
even if the ANALYZE itself rolls back. In any case we probably don't want
to change this behavior in back branches.
Per bug #11638 from Casey Shobe. This has been broken for a good long
time, so back-patch to all supported branches.
Tom Lane and Michael Paquier, initial diagnosis by Andres Freund
Since we taught btree to handle ScalarArrayOpExpr quals natively (commit
9e8da0f757), the planner has always included
ScalarArrayOpExpr quals in index conditions if possible. However, if the
qual is for a non-first index column, this could result in an inferior plan
because we can no longer take advantage of index ordering (cf. commit
807a40c551). It can be better to omit the
ScalarArrayOpExpr qual from the index condition and let it be done as a
filter, so that the output doesn't need to get sorted. Indeed, this is
true for the query introduced as a test case by the latter commit.
To fix, restructure get_index_paths and build_index_paths so that we
consider paths both with and without ScalarArrayOpExpr quals in non-first
index columns. Redesign the API of build_index_paths so that it reports
what it found, saving useless second or third calls.
Report and patch by Andrew Gierth (though rather heavily modified by me).
Back-patch to 9.2 where this code was introduced, since the issue can
result in significant performance regressions compared to plans produced
by 9.1 and earlier.
Perl 5.12 ships with a somewhat broken version of Test::Simple, so skip
the tests if that is found.
The relevant fix is
0.98 Wed, 23 Feb 2011 14:38:02 +1100
Bug Fixes
* subtest() should not fail if $? is non-zero. (Aaron Crane)
If an inline-able SQL function taking a composite argument is used in a
LATERAL subselect, and the composite argument is a lateral reference,
the planner could fail with "variable not found in subplan target list",
as seen in bug #11703 from Karl Bartel. (The outer function call used in
the bug report and in the committed regression test is not really necessary
to provoke the bug --- you can get it if you manually expand the outer
function into "LATERAL (SELECT inner_function(outer_relation))", too.)
The cause of this is that we generate the reltargetlist for the referenced
relation before doing eval_const_expressions() on the lateral sub-select's
expressions (cf find_lateral_references()), so what's scheduled to be
emitted by the referenced relation is a whole-row Var, not the simplified
single-column Var produced by optimizing the function's FieldSelect on the
whole-row Var. Then setrefs.c fails to match up that lateral reference to
what's available from the outer scan.
Preserving the FieldSelect optimization in such cases would require either
major planner restructuring (to recursively do expression simplification
on sub-selects much earlier) or some amazingly ugly kluge to change the
reltargetlist of a possibly-already-planned relation. It seems better
just to skip the optimization when the Var is from an upper query level;
the case is not so common that it's likely anyone will notice a few
wasted cycles.
AFAICT this problem only occurs for uplevel LATERAL references, so
back-patch to 9.3 where LATERAL was added.
Revert the output of the individual backslash commands that change print
settings back to the 9.3 way (not showing the command name in
parentheses). Implement \pset without arguments separately, showing all
settings with values in a table form.
Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time. But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation. Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.
To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone. For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time. However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.
The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970. The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.
While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.
This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib. Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.
This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time. We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.
In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
When determining whether one JSONB object contains another, it's okay to
make a quick exit if the first object has fewer pairs than the second:
because we de-duplicate keys within objects, it is impossible that the
first object has all the keys the second does. However, the code was
applying this rule to JSONB arrays as well, where it does *not* hold
because arrays can contain duplicate entries. The test was really in
the wrong place anyway; we should do it within JsonbDeepContains, where
it can be applied to nested objects not only top-level ones.
Report and test cases by Alexander Korotkov; fix by Peter Geoghegan and
Tom Lane.
As of commit a87c72915 (which later got backpatched as far as 9.1),
we're explicitly supporting the notion that append relations can be
nested; this can occur when UNION ALL constructs are nested, or when
a UNION ALL contains a table with inheritance children.
Bug #11457 from Nelson Page, as well as an earlier report from Elvis
Pranskevichus, showed that there were still nasty bugs associated with such
cases: in particular the EquivalenceClass mechanism could try to generate
"join" clauses connecting an appendrel child to some grandparent appendrel,
which would result in assertion failures or bogus plans.
Upon investigation I concluded that all current callers of
find_childrel_appendrelinfo() need to be fixed to explicitly consider
multiple levels of parent appendrels. The most complex fix was in
processing of "broken" EquivalenceClasses, which are ECs for which we have
been unable to generate all the derived equality clauses we would like to
because of missing cross-type equality operators in the underlying btree
operator family. That code path is more or less entirely untested by
the regression tests to date, because no standard opfamilies have such
holes in them. So I wrote a new regression test script to try to exercise
it a bit, which turned out to be quite a worthwhile activity as it exposed
existing bugs in all supported branches.
The present patch is essentially the same as far back as 9.2, which is
where parameterized paths were introduced. In 9.0 and 9.1, we only need
to back-patch a small fragment of commit 5b7b5518d, which fixes failure to
propagate out the original WHERE clauses when a broken EC contains constant
members. (The regression test case results show that these older branches
are noticeably stupider than 9.2+ in terms of the quality of the plans
generated; but we don't really care about plan quality in such cases,
only that the plan not be outright wrong. A more invasive fix in the
older branches would not be a good idea anyway from a plan-stability
standpoint.)
This function created new Vars with varno different from varnoold, which
is a condition that should never prevail before setrefs.c does the final
variable-renumbering pass. The created Vars could not be seen as equal()
to normal Vars, which among other things broke equivalence-class processing
for them. The consequences of this were indeed visible in the regression
tests, in the form of failure to propagate constants as one would expect.
I stumbled across it while poking at bug #11457 --- after intentionally
disabling join equivalence processing, the security-barrier regression
tests started falling over with fun errors like "could not find pathkey
item to sort", because of failure to match the corrupted Vars to normal
ones.
When the number of allowed iterations is limited (either a "?" quantifier
or a bound expression), the last sub-match has to reach to the end of the
target string. The previous coding here first tried the shortest possible
match (one character, usually) and then gave up and back-tracked if that
didn't work, typically leading to failure to match overall, as shown in
bug #11478 from Christoph Berg. The minimum change to fix that would be to
not decrement k before "goto backtrack"; but that would be a pretty stupid
solution, because we'd laboriously try each possible sub-match length
before finally discovering that only ending at the end can work. Instead,
force the sub-match endpoint limit up to the end for even the first
shortest() call if we cannot have any more sub-matches after this one.
Bug introduced in my rewrite that added the iterdissect logic, commit
173e29aa5d. The shortest-first search code
was too closely modeled on the longest-first code, which hasn't got this
issue since it tries a match reaching to the end to start with anyway.
Back-patch to all affected branches.
While withCheckOption exprs had been handled in many cases by
happenstance, they need to be handled during set_plan_references and
more specifically down in set_plan_refs for ModifyTable plan nodes.
This is to ensure that the opfuncid's are set for operators referenced
in the withCheckOption exprs.
Identified as an issue by Thom Brown
Patch by Dean Rasheed
Back-patch to 9.4, where withCheckOption was introduced.
The code for raising a NUMERIC value to an integer power wasn't very
careful about large powers. It got an outright wrong answer for an
exponent of INT_MIN, due to failure to consider overflow of the Abs(exp)
operation; which is fixable by using an unsigned rather than signed
exponent value after that point. Also, even though the number of
iterations of the power-computation loop is pretty limited, it's easy for
the repeated squarings to result in ridiculously enormous intermediate
values, which can take unreasonable amounts of time/memory to process,
or even overflow the internal "weight" field and so produce a wrong answer.
We can forestall misbehaviors of that sort by bailing out as soon as the
weight value exceeds what will fit in int16, since then the final answer
must overflow (if exp > 0) or underflow (if exp < 0) the packed numeric
format.
Per off-list report from Pavel Stehule. Back-patch to all supported
branches.
The code I added in commit f343a880d5 was
careless about preserving AND/OR flatness: it could create a structure with
an OR node directly underneath another one. That breaks an assumption
that's fairly important for planning efficiency, not to mention triggering
various Asserts (as reported by Benjamin Smith). Add a trifle more logic
to handle the case properly.
If SELECT FOR UPDATE NOWAIT tries to lock a tuple that is concurrently
being updated, it might fail to honor its NOWAIT specification and block
instead of raising an error.
Fix by adding a no-wait flag to EvalPlanQualFetch which it can pass down
to heap_lock_tuple; also use it in EvalPlanQualFetch itself to avoid
blocking while waiting for a concurrent transaction.
Authors: Craig Ringer and Thomas Munro, tweaked by Álvaro
http://www.postgresql.org/message-id/51FB6703.9090801@2ndquadrant.com
Per Thomas Munro in the course of his SKIP LOCKED feature submission,
who also provided one of the isolation test specs.
Backpatch to 9.4, because that's as far back as it applies without
conflicts (although the bug goes all the way back). To that branch also
backpatch Thomas Munro's new NOWAIT test cases, committed in master by
Heikki as commit 9ee16b49f0 .
Use SECURITY_LOCAL_USERID_CHANGE while building temporary tables;
only escalate to SECURITY_RESTRICTED_OPERATION while potentially
running user-supplied code. The more secure mode was preventing
temp table creation. Add regression tests to cover this problem.
This fixes Bug #11208 reported by Bruno Emanuel de Andrade Silva.
Backpatch to 9.4, where the bug was introduced.
Cause the path extraction operators to return their lefthand input,
not NULL, if the path array has no elements. This seems more consistent
since the case ought to correspond to applying the simple extraction
operator (->) zero times.
Cause other corner cases in field/element/path extraction to return NULL
rather than failing. This behavior is arguably more useful than throwing
an error, since it allows an expression index using these operators to be
built even when not all values in the column are suitable for the
extraction being indexed. Moreover, we already had multiple
inconsistencies between the path extraction operators and the simple
extraction operators, as well as inconsistencies between the JSON and
JSONB code paths. Adopt a uniform rule of returning NULL rather than
throwing an error when the JSON input does not have a structure that
permits the request to be satisfied.
Back-patch to 9.4. Update the release notes to list this as a behavior
change since 9.3.
As 'ALTER TABLESPACE .. MOVE ALL' really didn't change the tablespace
but instead changed objects inside tablespaces, it made sense to
rework the syntax and supporting functions to operate under the
'ALTER (TABLE|INDEX|MATERIALIZED VIEW)' syntax and to be in
tablecmds.c.
Pointed out by Alvaro, who also suggested the new syntax.
Back-patch to 9.4.
Cover some cases I omitted before, such as null and empty-string
elements in the path array. This exposes another inconsistency:
json_extract_path complains about empty path elements but
jsonb_extract_path does not.
jsonb's #> operator segfaulted (dereferencing a null pointer) if the RHS
was a zero-length array, as reported in bug #11207 from Justin Van Winkle.
json's #> operator returns NULL in such cases, so for the moment let's
make jsonb act likewise.
Also add a bunch of regression test queries memorializing the -> and #>
operators' behavior for this and other corner cases.
There is a good argument for changing some of these behaviors, as they
are not very consistent with each other, and throwing an error isn't
necessarily a desirable behavior for operators that are likely to be
used in indexes. However, everybody can agree that a core dump is the
Wrong Thing, and we need test cases even if we decide to change their
expected output later.
nice and we'll keep it in 9.5 but it'll take more time to iron out the
collateral damage on other queries and also on tools like
check_postgres.
revert dbe31616c9
revert 6513633b94
With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, PostgreSQL
backends can crash at exit. Raise a warning during "configure" based on
the compile-time OpenLDAP version number, and test the crash scenario in
the dblink test suite. Back-patch to 9.0 (all supported versions).
Unset environment variables that control message language, so that we
can compare some program output with expected strings. This is very
similar to what pg_regress does.
When a view has a function-returning-composite in FROM, and there are
some dropped columns in the underlying composite type, ruleutils.c
printed junk in the column alias list for the reconstructed FROM entry.
Before 9.3, this was prevented by doing get_rte_attribute_is_dropped
tests while printing the column alias list; but that solution is not
currently available to us for reasons I'll explain below. Instead,
check for empty-string entries in the alias list, which can only exist
if that column position had been dropped at the time the view was made.
(The parser fills in empty strings to preserve the invariant that the
aliases correspond to physical column positions.)
While this is sufficient to handle the case of columns dropped before
the view was made, we have still got issues with columns dropped after
the view was made. In particular, the view could contain Vars that
explicitly reference such columns! The dependency machinery really
ought to refuse the column drop attempt in such cases, as it would do
when trying to drop a table column that's explicitly referenced in
views. However, we currently neglect to store dependencies on columns
of composite types, and fixing that is likely to be too big to be
back-patchable (not to mention that existing views in existing databases
would not have the needed pg_depend entries anyway). So I'll leave that
for a separate patch.
Pre-9.3, ruleutils would print such Vars normally (with their original
column names) even though it suppressed their entries in the RTE's
column alias list. This is certainly bogus, since the printed view
definition would fail to reload, but at least it didn't crash. However,
as of 9.3 the printed column alias list is tightly tied to the names
printed for Vars; so we can't treat columns as dropped for one purpose
and not dropped for the other. This is why we can't just put back the
get_rte_attribute_is_dropped test: it results in an assertion failure
if the view in fact contains any Vars referencing the dropped column.
Once we've got dependencies preventing such cases, we'll probably want
to do it that way instead of relying on the empty-string test used here.
This fix turned up a very ancient bug in outfuncs/readfuncs, namely
that T_String nodes containing empty strings were not dumped/reloaded
correctly: the node was printed as "<>" which is read as a string
value of <>. Since (per SQL) we disallow empty-string identifiers,
such nodes don't occur normally, which is why we'd not noticed.
(Such nodes aren't used for literal constants, just identifiers.)
Per report from Marc Schablewski. Back-patch to 9.3 which is where
the rule printing behavior changed. The dangling-variable case is
broken all the way back, but that's not what his complaint is about.
ExecEvalWholeRowVar incorrectly supposed that it could "bless" the source
TupleTableSlot just once per query. But if the input is coming from an
Append (or, perhaps, other cases?) more than one slot might be returned
over the query run. This led to "record type has not been registered"
errors when a composite datum was extracted from a non-blessed slot.
This bug has been there a long time; I guess it escaped notice because when
dealing with subqueries the planner tends to expand whole-row Vars into
RowExprs, which don't have the same problem. It is possible to trigger
the problem in all active branches, though, as illustrated by the added
regression test.
While the x output of "select x from t group by x" can be presumed unique,
this does not hold for "select x, generate_series(1,10) from t group by x",
because we may expand the set-returning function after the grouping step.
(Perhaps that should be re-thought; but considering all the other oddities
involved with SRFs in targetlists, it seems unlikely we'll change it.)
Put a check in query_is_distinct_for() so it's not fooled by such cases.
Back-patch to all supported branches.
David Rowley
Creating the Unix-domain socket in the build directory can run into
name-length limitations. Therefore, create the socket file in the
default temporary directory of the operating system. Keep the temporary
data directory etc. in the build tree.
The "false" case was really quite useless since all it did was to throw
an error; a definition not helped in the least by making it the default.
Instead let's just have the "true" case, which emits nested objects and
arrays in JSON syntax. We might later want to provide the ability to
emit sub-objects in Postgres record or array syntax, but we'd be best off
to drive that off a check of the target field datatype, not a separate
argument.
For the functions newly added in 9.4, we can just remove the flag arguments
outright. We can't do that for json_populate_record[set], which already
existed in 9.3, but we can ignore the argument and always behave as if it
were "true". It helps that the flag arguments were optional and not
documented in any useful fashion anyway.
A WHERE clause applied to the output of a subquery with DISTINCT should
theoretically be applied only once per distinct row; but if we push it
into the subquery then it will be evaluated at each row before duplicate
elimination occurs. If the qual is volatile this can give rise to
observably wrong results, so don't do that.
While at it, refactor a little bit to allow subquery_is_pushdown_safe
to report more than one kind of restrictive condition without indefinitely
expanding its argument list.
Although this is a bug fix, it seems unwise to back-patch it into released
branches, since it might de-optimize plans for queries that aren't giving
any trouble in practice. So apply to 9.4 but not further back.
These should not have existed to begin with, but there was apparently some
misunderstanding of the purpose of the opr_sanity regression test item
that checks for operator implementation functions with their own comments.
The idea there is to check for unintentional violations of the rule that
operator implementation functions shouldn't be documented separately
.... but for these functions, that is in fact what we want, since the
variadic option is useful and not accessible via the operator syntax.
Get rid of the extra pg_proc entries and fix the regression test and
documentation to be explicit about what we're doing here.
Commit a87c729153 already fixed the bug this
is checking for, but the regression test case it added didn't cover this
scenario. Since we managed to miss the fact that there was a bug at all,
it seems like a good idea to propagate the extra test case forward to HEAD.
I noticed that the functions in jsonfuncs.c sometimes printed error
messages that claimed I'd called some other function. Investigation showed
that this was from repurposing code into "worker" functions without taking
much care as to whether it would mention the right SQL-level function if it
threw an error. Moreover, there was a weird mismash of messages that
contained a fixed function name, messages that used %s for a function name,
and messages that constructed a function name out of spare parts, like
"json%s_populate_record" (which, quite aside from being ugly as sin, wasn't
even sufficient to cover all the cases). This would put an undue burden on
our long-suffering translators. Standardize on inserting the SQL function
name with %s so as to reduce the number of translatable strings, and pass
function names around as needed to make sure we can report the right one.
Fix up some gratuitous variations in wording, too.
populate_recordset_object_start() improperly created a new hash table
(overwriting the link to the existing one) if called at nest levels
greater than one. This resulted in previous fields not appearing in
the final output, as reported by Matti Hameister in bug #10728.
In 9.4 the problem also affects json_to_recordset.
This perhaps missed detection earlier because the default behavior is to
throw an error for nested objects: you have to pass use_json_as_text = true
to see the problem.
In addition, fix query-lifespan leakage of the hashtable created by
json_populate_record(). This is pretty much the same problem recently
fixed in dblink: creating an intended-to-be-temporary context underneath
the executor's per-tuple context isn't enough to make it go away at the
end of the tuple cycle, because MemoryContextReset is not
MemoryContextResetAndDeleteChildren.
Michael Paquier and Tom Lane
Any OS user able to access the socket can connect as the bootstrap
superuser and proceed to execute arbitrary code as the OS user running
the test. Protect against that by placing the socket in a temporary,
mode-0700 subdirectory of /tmp. The pg_regress-based test suites and
the pg_upgrade test suite were vulnerable; the $(prove_check)-based test
suites were already secure. Back-patch to 8.4 (all supported versions).
The hazard remains wherever the temporary cluster accepts TCP
connections, notably on Windows.
As a convenient side effect, this lets testing proceed smoothly in
builds that override DEFAULT_PGSOCKET_DIR. Popular non-default values
like /var/run/postgresql are often unwritable to the build user.
Security: CVE-2014-0067
Since we commonly test pg_dump/pg_restore by seeing whether they can dump
and restore the regression test database, it behooves us to include some
large objects in that test scenario.
I tried to include a comment on one of these large objects to improve
the test scenario further ... but it turns out that pg_upgrade fails to
preserve comments on large objects, and its regression test notices
the discrepancy. So uncommenting that COMMENT is a TODO for later.
Robert Frost is no longer with us, but his copyrights still are, so
let's stop using "Stopping by Woods on a Snowy Evening" as test data
before somebody decides to sue us. Wordsworth is more safely dead.
Memorialize the expected output of the query that libpq has been using for
many years to get the OIDs of large-object support functions. Although
we really ought to change the way libpq does this, we must expect that
this query will remain in use in the field for the foreseeable future,
so until we're ready to break compatibility with old libpq versions
we'd better check the results stay the same. See the recent lo_create()
fiasco.
The previous naming broke the query that libpq's lo_initialize() uses
to collect the OIDs of the server-side functions it requires, because
that query effectively assumes that there is only one function named
lo_create in the pg_catalog schema (and likewise only one lo_open, etc).
While we should certainly make libpq more robust about this, the naive
query will remain in use in the field for the foreseeable future, so it
seems the only workable choice is to use a different name for the new
function. lo_from_bytea() won a small straw poll.
Back-patch into 9.4 where the new function was introduced.
