sub-select contains a join alias reference that expands into an expression
containing another sub-select. Per yesterday's report from Merlin Moncure
and subsequent off-list investigation.
Back-patch to 7.4. Older versions didn't attempt to flatten sub-selects in
ways that would trigger this problem.
If such a Var appeared within a nested sub-select, we failed to translate it
correctly during pullup of the view, because the recursive call to
replace_rte_variables_mutator was looking for the wrong sublevels_up value.
Bug was introduced during the addition of the PlaceHolderVar mechanism.
Per bug #5514 from Marcos Castedo.
for sure ;-)). It now also optimizes more cases, such as %_%_. Improve
comments too. Per bug #5478.
In passing, also rename the TCHAR macro to GETCHAR, because pgindent is
messing with the formatting of the former (apparently it now thinks TCHAR
is a typedef name).
Back-patch to 8.3, where the bug was introduced.
being assigned to, in case the expression to be assigned is a FieldStore that
would need to modify that value. The need for this was foreseen some time
ago, but not implemented then because we did not have arrays of composites.
Now we do, but the point evidently got overlooked in that patch. Net result
is that updating a field of an array element doesn't work right, as
illustrated if you try the new regression test on an unpatched backend.
Noted while experimenting with EXPLAIN VERBOSE, which has also got some issues
in this area.
Backpatch to 8.3, where arrays of composites were introduced.
relations (they don't live in pg_toast). This caused an Assert failure in
assert-enabled builds. So far as I can see, in a non-assert build it would
only have messed up the checks for conflicting names, so a failure would be
quite improbable but perhaps not impossible.
peculiar variant of UNION ALL, and so wouldn't likely get written directly
as-is, it's possible for it to arise as a result of simplification of
less-obviously-silly queries. In particular, now that we can do flattening
of subqueries that have constant outputs and are underneath an outer join,
it's possible for the case to result from simplification of queries of the
type exhibited in bug #5263. Back-patch to 8.4 to avoid a functionality
regression for this type of query.
CREATE FOREIGN DATA WRAPPER. Arguably it wasn't a bug because the
documentation said that it's passed the catalog ID or zero, but surely
we should provide it when it's known. And there isn't currently any
scenario where it's not known, and I can't imagine having one in the
future either, so better remove the "or zero" escape hatch and always
pass a valid catalog ID. Backpatch to 8.4.
Martin Pihlak
presented with an UNKNOWN-type Var, which can happen in cases where an
unknown literal appeared in a subquery. While many such cases will fail
later on anyway in the planner, there are some cases where the planner is
able to flatten the query and replace the Var by the constant before it has
to coerce the union column to the final type. I had added this check in 8.4
to provide earlier/better error detection, but it causes a regression for
some cases that worked OK before. Fix by not making the check if the input
node is UNKNOWN type and not a Const or Param. If it isn't going to work,
it will fail anyway at plan time, with the only real loss being inability to
provide an error cursor. Per gripe from Britt Piehler.
In passing, rename a couple of variables to remove confusion from an
inner scope masking the same variable names in an outer scope.
we have to cope with the possibility that the declared result rowtype contains
dropped columns. This fails in 8.4, as per bug #5240.
While at it, be more paranoid about inserting binary coercions when inlining.
The pre-8.4 code did not really need to worry about that because it could not
inline at all in any case where an added coercion could change the behavior
of the function's statement. However, when inlining a SRF we allow sorting,
grouping, and set-ops such as UNION. In these cases, modifying one of the
targetlist entries that the sort/group/setop depends on could conceivably
change the behavior of the function's statement --- so don't inline when
such a case applies.
Partially revert the previous patch I installed and replace it with a more
general fix: any time a snapshot is pushed as Active, we need to ensure that it
will not be modified in the future. This means that if the same snapshot is
used as CurrentSnapshot, it needs to be copied separately. This affects
serializable transactions only, because CurrentSnapshot has already been copied
by RegisterSnapshot and so PushActiveSnapshot does not think it needs another
copy. However, CommandCounterIncrement would modify CurrentSnapshot, whereas
ActiveSnapshots must not have their command counters incremented.
I say "partially" because the regression test I added for the previous bug
has been kept.
(This restores 8.3 behavior, because before snapmgr.c existed, any snapshot set
as Active was copied.)
Per bug report from Stuart Bishop in
6bc73d4c0910042358k3d1adff3qa36f8df75198ecea@mail.gmail.com
inheritance parent tables are compared using equal(), instead of doing
strcmp() on the nodeToString representation. The old implementation was
always a tad cheesy, and it finally fails completely as of 8.4, now that the
node tree might contain syntax location information. equal() knows it's
supposed to ignore those fields, but strcmp() hardly can. Per recent
report from Scott Ribe.
The old coding was using a regular snapshot, referenced elsewhere, that was
subject to having its command counter updated. Fix by creating a private copy
of the snapshot exclusively for the cursor.
Backpatch to 8.4, which is when the bug was introduced during the snapshot
management rewrite.
The original coding correctly noted that these aren't just redundancies
(they're effectively X IS NOT NULL, assuming = is strict). However, they
got treated that way if X happened to be in a single-member EquivalenceClass
already, which could happen if there was an ORDER BY X clause, for instance.
The simplest and most reliable solution seems to be to not try to process
such clauses through the EquivalenceClass machinery; just throw them back
for traditional processing. The amount of work that'd be needed to be
smarter than that seems out of proportion to the benefit.
Per bug #5084 from Bernt Marius Johnsen, and analysis by Andrew Gierth.
In this case we generate two PathKey references to the expression (one for
DISTINCT and one for ORDER BY) and they really need to refer to the same
EquivalenceClass. However get_eclass_for_sort_expr was being overly paranoid
and creating two different EC's. Correct behavior is to use the SortGroupRef
index to decide whether two references to volatile expressions that are
equal() (ie textually equivalent) should be considered the same.
Backpatch to 8.4. Possibly this should be changed in 8.3 as well, but
I'll refrain in the absence of evidence of a visible failure in that branch.
Per bug #5049.
code was already okay with this, but the hack that obtained the output
column types of a recursive union in advance of doing real parse analysis
of the recursive union forgot to handle the case where there was an inner
WITH clause available to the non-recursive term. Best fix seems to be to
refactor so that we don't need the "throwaway" parse analysis step at all.
Instead, teach the transformSetOperationStmt code to set up the CTE's output
column information after it's processed the non-recursive term normally.
Per report from David Fetter.
that's generated for a whole-row Var referencing the subquery, when the
subquery is in the nullable side of an outer join. The previous coding
instead put PlaceHolderVars around the elements of the RowExpr. The effect
was that when the outer join made the subquery outputs go to null, the
whole-row Var produced ROW(NULL,NULL,...) rather than just NULL. There
are arguments afoot about whether those things ought to be semantically
indistinguishable, but for the moment they are not entirely so, and the
planner needs to take care that its machinations preserve the difference.
Per bug #5025.
Making this feasible required refactoring ResolveNew() to allow more caller
control over what is substituted for a Var. I chose to make ResolveNew()
a wrapper around a new general-purpose function replace_rte_variables().
I also fixed the ancient bogosity that ResolveNew might fail to set
a query's hasSubLinks field after inserting a SubLink in it. Although
all current callers make sure that happens anyway, we've had bugs of that
sort before, and it seemed like a good time to install a proper solution.
Back-patch to 8.4. The problem can be demonstrated clear back to 8.0,
but the fix would be too invasive in earlier branches; not to mention
that people may be depending on the subtly-incorrect behavior. The
8.4 series is new enough that fixing this probably won't cause complaints,
but it might in older branches. Also, 8.4 shows the incorrect behavior
in more cases than older branches do, because it is able to flatten
subqueries in more cases.
so that their elements are always taken as simple expressions over the
query's input columns. It originally seemed like a good idea to make them
act exactly like GROUP BY and ORDER BY, right down to the SQL92-era behavior
of accepting output column names or numbers. However, that was not such a
great idea, for two reasons:
1. It permits circular references, as exhibited in bug #5018: the output
column could be the one containing the window function itself. (We actually
had a regression test case illustrating this, but nobody thought twice about
how confusing that would be.)
2. It doesn't seem like a good idea for, eg, "lead(foo) OVER (ORDER BY foo)"
to potentially use two completely different meanings for "foo".
Accordingly, narrow down the behavior of window clauses to use only the
SQL99-compliant interpretation that the expressions are simple expressions.
that the sanity checking I added to create_mergejoin_plan() in 8.3 was a
few bricks shy of a load: the mergeclauses could reference pathkeys in a
noncanonical order such as x,y,x, not only cases like x,x,y which is all
that the code had allowed for. The odd cases only turn up when using
redundant clauses in an outer join condition, which is why no one had
noticed before.
the "cteParam" as a proxy for the possibility that the underlying CTE plan
depends on outer-level variables or Params, but that doesn't work very well
because it sometimes causes calling subqueries to be treated as SubPlans when
they could be InitPlans. This is inefficient and also causes the outright
failure exhibited in bug #4902. Instead, leave the cteParam out of it and
copy the underlying CTE plan's extParams directly. Per bug #4902 from
Marko Tiikkaja.
even when not in FM mode. This improves compatibility with Oracle and with
our pre-8.4 behavior, as per bug #4862.
Brendan Jurd
Add a couple of regression test cases for this. In passing, get rid of the
labeling of the individual test cases; doesn't seem to be good for anything
except causing extra work when inserting a test...
Tom Lane
This prevents autovacuum from reclaiming free space in them and causing
the test's output row order to change, which is causing intermittent
bogus failure reports in the buildfarm.
Backpatch to 8.3. The issue exists further back, but since autovacuum was
not on by default before 8.3, it's not a problem for buildfarm testing.
function returning setof record. This used to work, more or less
accidentally, but I had broken it while extending the code to allow
materialize-mode functions to be called in select lists. Add a regression
test case so it doesn't get broken again. Per gripe from Greg Davidson.
more consistent with other cases, by having an unlabeled integer field
be treated as a number of minutes or seconds respectively. These cases
are outside the spec (which insists on full "dd hh:mm" or "dd hh:mm:ss"
input respectively), so it's not much help to us in deciding what to do.
But with this change, it's uniformly the case that an unlabeled integer
will be considered as being a number of the interval's rightmost field.
The change also takes us back to the 8.3 behavior of throwing error
for certain ambiguous inputs such as INTERVAL '1 2' DAY TO MINUTE.
Per recent discussion.
grounds that they don't fit into the specified interval qualifier (typmod).
This behavior, while of long standing, is clearly wrong per spec --- for
example the value INTERVAL '999' SECOND means 999 seconds and should not be
reduced to less than 60 seconds.
In some cases there could be grounds to raise an error if higher-order field
values are not given as zero; for example '1 year 1 month'::INTERVAL MONTH
should arguably be taken as an error rather than equivalent to 13 months.
However our internal representation doesn't allow us to do that in a fashion
that would consistently reject all and only the cases that a strict reading
of the spec would suggest. Also, seeing that for example INTERVAL '13' MONTH
will print out as '1 year 1 mon', we have to be careful not to create a
situation where valid data will fail to dump and reload. The present patch
therefore takes the attitude of not throwing an error in any such case.
We might want to revisit that in future but it would take more redesign
than seems prudent in late beta.
Per a complaint from Sebastien Flaesch and subsequent discussion. While
at other times we might have just postponed such an issue to the next
development cycle, 8.4 already has changed the parsing of interval literals
quite a bit in an effort to accept all spec-compliant cases correctly.
This seems like a change that should be part of that rather than coming
along later.
this case is worth a special code path, but a special code path that gets
the boundary condition wrong is definitely no good. Per bug #4821 from
Andrew Gierth.
In passing, clean up some minor code formatting issues (excess parentheses
and blank lines in odd places).
Back-patch to 8.3, where the bug was introduced.
must be used for the new database, except when copying from template0.
This is the same rule that we now enforce for locale settings, and it has
the same motivation: databases other than template0 might contain data that
would be invalid according to a different setting. This represents another
step in a continuing process of locking down ways in which encoding violations
could occur inside the backend. Per discussion of a few days ago.
In passing, fix pre-existing breakage of mbregress.sh, and fix up a couple
of ereport() calls in dbcommands.c that failed to specify sqlstate codes.
aggregate function. By definition, such a sub-SELECT cannot reference any
variables of query levels between itself and the aggregate's semantic level
(else the aggregate would've been assigned to that lower level instead).
So the correct, most efficient implementation is to treat the sub-SELECT as
being a sub-select of that outer query level, not the level the aggregate
syntactically appears in. Not doing so also confuses the heck out of our
parameter-passing logic, as illustrated in bug report from Daniel Grace.
Fortunately, we were already copying the whole Aggref expression up to the
outer query level, so all that's needed is to delay SS_process_sublinks
processing of the sub-SELECT until control returns to the outer level.
This has been broken since we introduced spec-compliant treatment of
outer aggregates in 7.4; so patch all the way back.
documentation warnings against setting it nonzero unless active use of
prepared transactions is intended and a suitable transaction manager has been
installed. This should help to prevent the type of scenario we've seen
several times now where a prepared transaction is forgotten and eventually
causes severe maintenance problems (or even anti-wraparound shutdown).
The only real reason we had the default be nonzero in the first place was to
support regression testing of the feature. To still be able to do that,
tweak pg_regress to force a nonzero value during "make check". Since we
cannot force a nonzero value in "make installcheck", add a variant regression
test "expected" file that shows the results that will be obtained when
max_prepared_transactions is zero.
Also, extend the HINT messages for transaction wraparound warnings to mention
the possibility that old prepared transactions are causing the problem.
All per today's discussion.
more nearly matching the core SQL scanner. The user-visible effects are:
* Block comments (slash-star comments) now nest, as per SQL spec.
* In standard_conforming_strings mode, backslash as the last character of a
non-E string literal is now correctly taken as an ordinary character;
formerly it was misinterpreted as escaping the ending quote. (Since the
string also had to pass through the core scanner, this invariably led
to syntax errors.)
* Formerly, backslashes in the format string of RAISE were always treated as
quoting the next character, regardless of mode. Now, they are ordinary
characters with standard_conforming_strings on, while with it off, they
introduce the same set of escapes as in the core SQL scanner. Also,
escape_string_warning is now effective for RAISE format strings. These
changes make RAISE format strings work just like any other string literal.
This is implemented by copying and pasting a lot of logic from the core
scanner. It would be a good idea to look into getting rid of plpgsql's
scanner entirely in favor of using the core scanner. However, that involves
more change than I can justify making during beta --- in particular, the core
scanner would have to become re-entrant.
In passing, remove the kluge that made the plpgsql scanner emit T_FUNCTION or
T_TRIGGER as a made-up first token. That presumably had some value once upon
a time, but now it's just useless complication for both the scanner and the
grammar.
how this ought to behave for multi-dimensional arrays. Per discussion,
not having it at all seems better than having it with what might prove
to be the wrong behavior. We can always add it later when we have consensus
on the correct behavior.
by my patch of 2007-01-28 to use per-subtransaction ExprContexts/EStates:
since we re-prepared any expression tree when the current subtransaction ID
changed, we'd accumulate more and more leaked expression state trees in the
outermost subtransaction if the same function was executed at multiple levels
of subtransaction nesting. To fix, go back to the previous scheme where
there was only one EState per transaction for simple plpgsql expressions.
We really only need an ExprContext per subtransaction, not a whole EState,
so it's possible to keep prepared expression state trees in the one EState
throughout the transaction. This should be more efficient as well as not
leaking memory for cases involving lots of subtransactions.
The added regression test is the case that inspired the 2007-01-28 patch in
the first place, just to make sure we didn't go backwards. The current
memory leak complaint is unfortunately hard to test for in the regression
test framework, though manual testing shows it's fixed.
Although this is a pre-existing bug, I'm not back-patching because I'd like to
see this method get some field testing first. Consider back-patching if it
gets through 8.4beta unscathed.
interval_eq() considers equal. I'm not sure how that fundamental requirement
escaped us through multiple revisions of this hash function, but there it is;
it's been wrong since interval_hash was first written for PG 7.1.
Per bug #4748 from Roman Kononov.
Backpatch to all supported releases.
This patch changes the contents of hash indexes for interval columns. That's
no particular problem for PG 8.4, since we've broken on-disk compatibility
of hash indexes already; but it will require a migration warning note in
the next minor releases of all existing branches: "if you have any hash
indexes on columns of type interval, REINDEX them after updating".
TupleTableSlots. We have functions for retrieving a minimal tuple from a slot
after storing a regular tuple in it, or vice versa; but these were implemented
by converting the internal storage from one format to the other. The problem
with that is it invalidates any pass-by-reference Datums that were already
fetched from the slot, since they'll be pointing into the just-freed version
of the tuple. The known problem cases involve fetching both a whole-row
variable and a pass-by-reference value from a slot that is fed from a
tuplestore or tuplesort object. The added regression tests illustrate some
simple cases, but there may be other failure scenarios traceable to the same
bug. Note that the added tests probably only fail on unpatched code if it's
built with --enable-cassert; otherwise the bug leads to fetching from freed
memory, which will not have been overwritten without additional conditions.
Fix by allowing a slot to contain both formats simultaneously; which turns out
not to complicate the logic much at all, if anything it seems less contorted
than before.
Back-patch to 8.2, where minimal tuples were introduced.
noise words for the last twelve years, for compatibility with Berkeley-era
output formatting of the special INVALID values for those datatypes.
Considering that the datatypes themselves have been deprecated for awhile,
this is taking backwards compatibility a little far. Per gripe from Josh
Berkus.
by the planning process. This prevents the "failed to locate grouping columns"
error recently reported by Dickson Guedes. That happens because planning
replaces SubLinks by SubPlans in the subquery's targetlist, and exprTypmod()
is smarter about the former than the latter, causing the apparent type of
the subquery's output columns to change. This seems to be a deficiency we
should fix in exprTypmod(), but that will be a much more invasive patch
with possible side-effects elsewhere, so I'll do that only in HEAD.
Back-patch to 8.3. Arguably the lack of a copying step is broken/dangerous
all the way back, but in the absence of known problems I'll refrain from
making the older branches pay the extra cost. (The reason this particular
symptom didn't appear before is that exprTypmod() wasn't smart about SubLinks
either, until 8.3.)
