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20827 commits

Author SHA1 Message Date
Simon Riggs
34a7ee82c4 Fix misleading DEBUG2 issued during RemoveOldXlogFiles() 2010-08-30 15:38:17 +00:00
Simon Riggs
4c5fb76c39 Truncate subtrans after each restartpoint.
Issue reported by Harald Kolb, patch by Fujii Masao, review by me.
2010-08-30 15:21:18 +00:00
Simon Riggs
7ab0236500 Teach GetOldestXmin() about KnownAssignedXids during recovery.
Very minor issue, though this is required for a later patch.
Reported by Heikki Linnakangas.
2010-08-30 15:20:31 +00:00
Heikki Linnakangas
e123939e8b Fix typo in comment. 2010-08-30 06:33:26 +00:00
Tom Lane
b39bec1ac4 Reduce PANIC to ERROR in some occasionally-reported btree failure cases.
This patch changes _bt_split() and _bt_pagedel() to throw a plain ERROR,
rather than PANIC, for several cases that are reported from the field
from time to time:
* right sibling's left-link doesn't match;
* PageAddItem failure during _bt_split();
* parent page's next child isn't right sibling during _bt_pagedel().
In addition the error messages for these cases have been made a bit
more verbose, with additional values included.

The original motivation for PANIC here was to capture core dumps for
subsequent analysis.  But with so many users whose platforms don't capture
core dumps by default, or who are unprepared to analyze them anyway, it's hard
to justify a forced database restart when we can fairly easily detect the
problems before we've reached the critical sections where PANIC would be
necessary.  It is not currently known whether the reports of these messages
indicate well-hidden bugs in Postgres, or are a result of storage-level
malfeasance; the latter possibility suggests that we ought to try to be more
robust even if there is a bug here that's ultimately found.

Backpatch to 8.2.  The code before that is sufficiently different that
it doesn't seem worth the trouble to back-port further.
2010-08-29 19:33:21 +00:00
Marc G. Fournier
ee48d27e34 tag rc1 ... final stretch ... 2010-08-27 03:04:41 +00:00
Tom Lane
d7a1feba67 Document the existence of the socket lock file under unix_socket_directory,
which is perhaps not a terribly good spot for it but there doesn't seem to be
a better place.  Also add a source-code comment pointing out a couple reasons
for having a separate lock file.  Per suggestion from Greg Smith.
2010-08-26 22:00:32 +00:00
Tom Lane
4ad4b95be2 Update time zone data files to tzdata release 2010l: DST law changes in
Egypt and Palestine.  Added new names for two Micronesian timezones:
Pacific/Chuuk is now preferred over Pacific/Truk (and the preferred
abbreviation is CHUT not TRUT) and Pacific/Pohnpei is preferred over
Pacific/Ponape.  Historical corrections for Finland.
2010-08-26 19:58:50 +00:00
Alvaro Herrera
2b9a93a21a Improve wording for privilege description on certain failure messages; the
original misleadingly suggests that only access is meant, causing confusion.
Per recent trouble report by Robert McGehee on pgsql-admin.
2010-08-26 19:49:41 +00:00
Alvaro Herrera
803250e97b Remove duplicate translatable phrase 2010-08-26 19:24:40 +00:00
Peter Eisentraut
d97ccb83ba Translation updates for 9.0rc1 2010-08-26 19:23:10 +00:00
Tom Lane
62275d55c4 Fix ExecMakeTableFunctionResult to verify that all rows returned by a SRF
returning "record" actually do have the same rowtype.  This is needed because
the parser can't realistically enforce that they will all have the same typmod,
as seen in a recent example from David Wheeler.

Back-patch to 8.0, which is as far back as we have the notion of RECORD
subtypes being distinguished by typmod.  Wheeler's example depends on
8.4-and-up features, but I suspect there may be ways to provoke similar
failures before 8.4.
2010-08-26 18:54:44 +00:00
Tom Lane
b5cf172d2c Improve hint message for ENOMEM failure from shmget().
It turns out that some platforms return ENOMEM for a request that violates
SHMALL, whereas we were assuming that ENOSPC would always be used for that.
Apparently the latter is a Linuxism while ENOMEM is the BSD tradition.
Extend the ENOMEM hint to suggest that raising SHMALL might be needed.
Per gripe from A.M.

Backpatch to 9.0, but not further, because this doesn't seem important
enough to warrant creating extra translation work in the stable branches.
(If it were, we'd have figured this out years ago.)
2010-08-25 20:10:59 +00:00
Peter Eisentraut
7bc59f7cec Catch null pointer returns from PyCObject_AsVoidPtr and PyCObject_FromVoidPtr
This is reproducibly possible in Python 2.7 if the user turned
PendingDeprecationWarning into an error, but it's theoretically also possible
in earlier versions in case of exceptional conditions.

backpatched to 8.0
2010-08-25 19:37:52 +00:00
Tom Lane
914a2f6e98 Marginal code cleanup for streaming replication.
There is no reason that proc.c should have to get involved in this dirty hack
for letting the postmaster know which children are walsenders.  Revert that
file to the way it was, and confine the kluge to pmsignal.c and postmaster.c.
2010-08-23 17:20:08 +00:00
Tom Lane
0804734d91 Use a non-locale-dependent definition of isspace() in array_in/array_out.
array_in discards unquoted leading and trailing whitespace in array values,
while array_out is careful to quote array elements that contain whitespace.
This is problematic when the definition of "whitespace" varies between
locales: array_in could drop characters that were meant to be part of the
value.  To avoid that, lock down "whitespace" to mean only the traditional
six ASCII space characters.

This change also works around a bug in OS X and some older BSD systems, in
which isspace() could return true for character fragments in UTF8 locales.
(There may be other places in PG where that bug could cause problems, but
this is the only one complained of so far; see recent report from Steven
Schlansker.)

Back-patch to 9.0, but not further.  Given the lack of previous reports
of trouble, changing this behavior in stable branches seems to offer
more risk of breaking applications than reward of avoiding problems.
2010-08-21 16:55:58 +00:00
Tom Lane
510034ac83 Improve parallel restore's ability to cope with selective restore (-L option).
The original coding tended to break down in the face of modified restore
orders, as shown in bug #5626 from Albert Ullrich, because it would flip over
into parallel-restore operation too soon.  That causes problems because we
don't have sufficient dependency information in dump archives to allow safe
parallel processing of SECTION_PRE_DATA items.  Even if we did, it's probably
undesirable to allow that to override the commanded restore order.

To fix the problem of omitted items causing unexpected changes in restore
order, tweak SortTocFromFile so that omitted items end up at the head of
the list not the tail.  This ensures that they'll be examined and their
dependencies will be marked satisfied before we get to any interesting
items.

In HEAD and 9.0, we can easily change restore_toc_entries_parallel so that
all SECTION_PRE_DATA items are guaranteed to be processed in the initial
serial-restore loop, and hence in commanded order.  Only DATA and POST_DATA
items are candidates for parallel processing.  For them there might be
variations from the commanded order because of parallelism, but we should
do it in a safe order thanks to dependencies.

In 8.4 it's much harder to make such a guarantee.  I settled for not
letting the initial loop break out into parallel processing mode if
it sees a DATA/POST_DATA item that's not to be restored; this at least
prevents a non-restorable item from causing premature exit from the loop.
This means that 8.4 will be more likely to fail given a badly-ordered -L
list than 9.x, but we don't really promise any such thing will work anyway.
2010-08-21 13:59:50 +00:00
Tom Lane
f333f69d19 Bring some sanity to the trace_recovery_messages code and docs.
Per gripe from Fujii Masao, though this is not exactly his proposed patch.
Categorize as DEVELOPER_OPTIONS and set context PGC_SIGHUP, as per Fujii,
but set the default to LOG because higher values aren't really sensible
(see the code for trace_recovery()).  Fix the documentation to agree with
the code and to try to explain what the variable actually does.  Get rid
of no-op calls trace_recovery(LOG), which accomplish nothing except to
demonstrate that this option confuses even its author.
2010-08-19 22:55:10 +00:00
Tom Lane
4a1989ffd5 Allow USING and INTO clauses of plpgsql's EXECUTE to appear in either order.
Aside from being more forgiving, this prevents a rather surprising misbehavior
when the "wrong" order was used: the old code didn't throw a syntax error,
but absorbed the INTO clause into the last USING expression, which then did
strange things downstream.

Intentionally not changing the documentation; we'll continue to advertise
only the "standard" clause order.

Backpatch to 8.4, where the USING clause was added to EXECUTE.
2010-08-19 18:58:04 +00:00
Tom Lane
f5c496b7f5 Keep exec_simple_check_plan() from thinking "SELECT foo INTO bar" is simple.
It's not clear if this situation can occur in plpgsql other than via the
EXECUTE USING case Heikki illustrated, which I will shortly close off.
However, ignoring the intoClause if it's there is surely wrong, so let's
patch it for safety.

Backpatch to 8.3, which is as far back as this code has a PlannedStmt
to deal with.  There might be another way to make an equivalent test
before that, but since this is just preventing hypothetical bugs,
I'm not going to obsess about it.
2010-08-19 18:10:56 +00:00
Tom Lane
3d7feba4b3 Be a bit less cavalier with both the code and the comment for UNKNOWN fix. 2010-08-19 17:31:50 +00:00
Heikki Linnakangas
cc46c4e862 Revert patch to coerce 'unknown' type parameters in the backend. As Tom
pointed out, it would need a 2nd pass after the whole query is processed to
correctly check that an unknown Param is coerced to the same target type
everywhere. Adding the 2nd pass would add a lot more code, which doesn't
seem worth the risk given that there isn't much of a use case for passing
unknown Params in the first place. The code would work without that check,
but it might be confusing and the behavior would be different from the
varparams case.

Instead, just coerce all unknown params in a PL/pgSQL USING clause to text.
That's simple, and is usually what users expect.

Revert the patch in CVS HEAD and master, and backpatch the new solution to
8.4. Unlike the previous solution, this applies easily to 8.4 too.
2010-08-19 16:54:48 +00:00
Tom Lane
67b4fcf806 Allocate local buffers in a context of their own, rather than dumping them
into TopMemoryContext.  This makes no functional difference, but makes it
easier to see what the space is being used for in MemoryContextStats dumps.
Per a recent example in which I was surprised by the size of TopMemoryContext.
2010-08-19 16:16:27 +00:00
Tom Lane
780a7dcb69 Fix possible corruption of AfterTriggerEventLists in subtransaction rollback.
afterTriggerInvokeEvents failed to adjust events->tailfree when truncating
the last chunk of an event list.  This could result in the data being
"de-truncated" by afterTriggerRestoreEventList during a subsequent
subtransaction abort.  Even that wouldn't kill us, because the re-added data
would just be events marked DONE --- unless the data had been partially
overwritten by new events.  Then we might crash, or in any case misbehave
(perhaps fire triggers twice, or fire triggers with the wrong event data).
Per bug #5622 from Thue Janus Kristensen.

Back-patch to 8.4 where the current trigger list representation was introduced.
2010-08-19 15:46:24 +00:00
Tom Lane
205fc921d7 Reset the per-output-tuple exprcontext each time through the main loop in
ExecModifyTable().  This avoids memory leakage when trigger functions leave
junk behind in that context (as they more or less must).  Problem and solution
identified by Dean Rasheed.

I'm a bit concerned about the longevity of this solution --- once a plan can
have multiple ModifyTable nodes, we are very possibly going to have to do
something different.  But it should hold up for 9.0.
2010-08-18 21:52:32 +00:00
Tom Lane
2eba69addc Fix failure of "ALTER TABLE t ADD COLUMN c serial" when done by non-owner.
The implicitly created sequence was created as owned by the current user,
who could be different from the table owner, eg if current user is a
superuser or some member of the table's owning role.  This caused sanity
checks in the SEQUENCE OWNED BY code to spit up.  Although possibly we
don't need those sanity checks, the safest fix seems to be to make sure
the implicit sequence is assigned the same owner role as the table has.
(We still do all permissions checks as the current user, however.)
Per report from Josh Berkus.

Back-patch to 9.0.  The bug goes back to the invention of SEQUENCE OWNED BY
in 8.2, but the fix requires an API change for DefineRelation(), which seems
to have potential for breaking third-party code if done in a minor release.
Given the lack of prior complaints, it's probably not worth fixing in the
stable branches.
2010-08-18 18:35:30 +00:00
Tom Lane
0321d031b5 Add missing handling of PlannedStmt.transientPlan in copyfuncs/outfuncs.
_outPlannedStmt is only debug support, so the omission there was not very
serious, but the omission in _copyPlannedStmt is a real bug.  The consequence
would be that a copied plan tree would never be marked as a transient plan,
so that we would forget we ought to replan it after some not-yet-ready index
becomes ready for use.  This might explain some past complaints about indexes
created with CREATE INDEX CONCURRENTLY not being used right away.  Problem
spotted by Yeb Havinga.

Back-patch to 8.3, where the field was added.
2010-08-18 15:22:00 +00:00
Heikki Linnakangas
dbc4669173 Coerce 'unknown' type parameters to the right type in the fixed-params
parse_analyze() function. That case occurs e.g with PL/pgSQL
EXECUTE ... USING 'stringconstant'.

The coercion with a CoerceViaIO node. The result is similar to the coercion
via input function performed for unknown constants in coerce_type(),
except that this happens at runtime.

Backpatch to 9.0. The issue is present in 8.4 as well, but the coerce param
hook infrastructure this patch relies on was introduced in 9.0. Given the
lack of user reports and harmlessness of the bug, it's not worth attempting
a different fix just for 8.4.
2010-08-18 12:20:22 +00:00
Michael Meskes
277633b7e8 Applied Zoltan's patch to fix a few memleaks in ecpg's pgtypeslib. 2010-08-17 11:06:26 +00:00
Tom Lane
c93b652c2d Arrange to fsync the contents of lockfiles (both postmaster.pid and the
socket lockfile) when writing them.  The lack of an fsync here may well
explain two different reports we've seen of corrupted lockfile contents,
which doesn't particularly bother the running server but can prevent a
new server from starting if the old one crashes.  Per suggestion from
Alvaro.

Back-patch to all supported versions.
2010-08-16 17:32:53 +00:00
Tom Lane
59ea02a108 Fix psql's copy of utf2ucs() to match the backend's copy exactly;
in particular, propagate a fix in the test to see whether a UTF8 character has
length 4 bytes.  This is likely of little real-world consequence because
5-or-more-byte UTF8 sequences are not supported by Postgres nor seen anywhere
in the wild, but still we may as well get it right.  Problem found by Joseph
Adams.

Bug is aboriginal, so back-patch all the way.
2010-08-16 00:06:24 +00:00
Tom Lane
a5955f4a65 Fix planner to make a reasonable assumption about the amount of memory space
used by array_agg(), string_agg(), and similar aggregate functions that use
"internal" as their transition datatype.  The previous coding thought this
took *no* extra space, since "internal" is pass-by-value; but actually these
aggregates typically consume a great deal of space.  Per bug #5608 from
Itagaki Takahiro, and fix suggestion from Hitoshi Harada.

Back-patch to 8.4, where array_agg was introduced.
2010-08-14 15:47:21 +00:00
Tom Lane
d2945deefb Fix Assert failure in PushOverrideSearchPath when trying to restore a search
path that specifies useTemp, but there is no active temp schema in the
current session.  (This can happen if the path was saved during a transaction
that created a temp schema and was later rolled back.)  For existing callers
it's sufficient to ignore the useTemp flag in this case, though we might
later want to offer an option to create a fresh temp schema.  So far as I can
tell this is just an Assert failure: in a non-assert build, the code would
push a zero onto the new search path, which is useless but not very harmful.
Per bug report from Heikki.

Back-patch to 8.3; prior versions don't have this code.
2010-08-13 16:27:18 +00:00
Robert Haas
361cadb224 Make RecordTransactionCommit() respect wal_level.
Since the only purpose of WAL-loggin SharedInvalidationMessages is to support
Hot Standby operation, they needn't be included when wal_level < hot_standby.

Back-patch to 9.0.

Review by Heikki Linnakanagas and Fujii Masao.
2010-08-13 15:45:17 +00:00
Tom Lane
e507a3ee7b Fix pg_restore to complain if any arguments remain after parsing the switches
and input file name, per bug #5617 from Leo Shklovskii.  Rearrange the
corresponding code in pg_dump and pg_dumpall so that all three programs
handle this in a consistent, straightforward fashion.

Back-patch to 9.0, but no further.  Although this is certainly a bug, it's
possible that people have scripts that will be broken by the added error
check, so it seems better not to change the behavior in stable branches.
2010-08-13 14:38:12 +00:00
Robert Haas
ed3ea3fa0c Correct sundry errors in Hot Standby-related comments.
Fujii Masao
2010-08-12 23:25:45 +00:00
Heikki Linnakangas
e286b85c90 The sanity check added to array_recv() wa a bit too tight; we must
continue to accept an empty array with dimension information. array_send()
can output such arrays.

Per report from Vladimir Shakhov.
2010-08-11 19:12:36 +00:00
Tom Lane
6d301d938f Fix incorrect logic in plpgsql for cleanup after evaluation of non-simple
expressions.  We need to deal with this when handling subscripts in an array
assignment, and also when catching an exception.  In an Assert-enabled build
these omissions led to Assert failures, but I think in a normal build the
only consequence would be short-term memory leakage; which may explain why
this wasn't reported from the field long ago.

Back-patch to all supported versions.  7.4 doesn't have exceptions, but
otherwise these bugs go all the way back.

Heikki Linnakangas and Tom Lane
2010-08-09 18:50:20 +00:00
Tom Lane
331c3c218b Add a very specific hint for the case that we're unable to locate a function
matching a call like f(x, ORDER BY y,z).  It could be that what the user
really wants is f(x,z ORDER BY y).  We now have pretty conclusive evidence
that many people won't understand this problem without concrete guidance,
so give it to them.  Per further discussion of the string_agg() problem.
2010-08-05 21:45:45 +00:00
Tom Lane
bdd538c571 Remove the single-argument form of string_agg(). It added nothing much in
functionality, while creating an ambiguity in usage with ORDER BY that at
least two people have already gotten seriously confused by.  Also, add an
opr_sanity test to check that we don't in future violate the newly minted
policy of not having built-in aggregates with the same name and different
numbers of parameters.  Per discussion of a complaint from Thom Brown.
2010-08-05 18:21:31 +00:00
Robert Haas
e4a5dc7b8e Fix inheritance count tracking in ALTER TABLE .. ADD CONSTRAINT.
Without this patch, constraints inherited by children of a parent
table which itself has multiple inheritance parents can end up with
the wrong coninhcount.  After dropping the constraint, the children
end up with a leftover copy of the constraint that is not dumped
and cannot be dropped.  There is a similar problem with ALTER TABLE
.. ADD COLUMN, but that looks significantly more difficult to
resolve, so I'm committing this fix separately.

Back-patch to 8.4, which is the first release that has coninhcount.

Report by Hank Enting.
2010-08-03 15:47:09 +00:00
Tom Lane
2f203642f8 Fix core dump in QTNodeCompare when tsquery_cmp() is applied to two empty
tsqueries.  CompareTSQ has to have a guard for the case rather than blindly
applying QTNodeCompare to random data past the end of the datums.  Also,
change QTNodeCompare to be a little less trusting: use an actual test rather
than just Assert'ing that the input is sane.  Problem encountered while
investigating another issue (I saw a core dump in autoanalyze on a table
containing multiple empty tsquery values).

Back-patch to all branches with tsquery support.

In HEAD, also fix some bizarre (though not outright wrong) coding in
tsq_mcontains().
2010-08-03 00:10:44 +00:00
Tom Lane
3e3ee1dfc3 Don't try to force use of -no-cpp-precomp on OS X. It's been five years
since Apple shipped a compiler that needed this switch, and there's
increasing interest in using other compilers that won't accept the switch
at all.  Better to let anybody who still needs the switch inject it via
CPPFLAGS.  Per gripe from Neil Conway.
2010-08-02 04:51:25 +00:00
Tom Lane
12dbe763f3 Fix an ancient typo that prevented the detection of conflicting fields when
interval input "invalid" was specified together with other fields.  Spotted
by Neil Conway with the help of a clang warning.  Although this has been
wrong since the interval code was written more than 10 years ago, it doesn't
affect anything beyond which error message you get for a wrong input, so not
worth back-patching very far.
2010-08-02 01:25:02 +00:00
Tom Lane
727117fe4e Back-patch fix for renaming asyncCommitLSN to asyncXactLSN.
AIUI this was supposed to go into 9.0 as well as HEAD.
2010-08-01 23:07:05 +00:00
Tom Lane
2fa68e2a35 Fix ANALYZE's ancient deficiency of not trying to collect stats for expression
indexes when the index column type (the opclass opckeytype) is different from
the expression's datatype.  When coded, this limitation wasn't worth worrying
about because we had no intelligence to speak of in stats collection for the
datatypes used by such opclasses.  However, now that there's non-toy
estimation capability for tsvector queries, it amounts to a bug that ANALYZE
fails to do this.

The fix changes struct VacAttrStats, and therefore constitutes an API break
for custom typanalyze functions.  Therefore we can't back-patch it into
released branches, but it was agreed that 9.0 isn't yet frozen hard enough
to make such a change unacceptable.  Ergo, back-patch to 9.0 but no further.
The API break had better be mentioned in 9.0 release notes.
2010-08-01 22:38:20 +00:00
Tom Lane
7354dbfa8c Fix an additional set of problems in GIN's handling of lossy page pointers.
Although the key-combining code claimed to work correctly if its input
contained both lossy and exact pointers for a single page in a single TID
stream, in fact this did not work, and could not work without pretty
fundamental redesign.  Modify keyGetItem so that it will not return such a
stream, by handling lossy-pointer cases a bit more explicitly than we did
before.

Per followup investigation of a gripe from Artur Dabrowski.
An example of a query that failed given his data set is
select count(*) from search_tab where
(to_tsvector('german', keywords ) @@ to_tsquery('german', 'ee:* | dd:*')) and
(to_tsvector('german', keywords ) @@ to_tsquery('german', 'aa:*'));

Back-patch to 8.4 where the lossy pointer code was introduced.
2010-08-01 19:16:47 +00:00
Tom Lane
538cb94db8 Rewrite the rbtree routines so that an RBNode is the first field of the
struct representing a tree entry, rather than being a separately allocated
piece of storage.  This API is at least as clean as the old one (if not
more so --- there were some bizarre choices in there) and it permits a
very substantial memory savings, on the order of 2X in ginbulk.c's usage.

Also, fix minor memory leaks in code called by ginEntryInsert, in
particular in ginInsertValue and entryFillRoot, as well as ginEntryInsert
itself.  These leaks resulted in the GIN index build context continuing
to bloat even after we'd filled it to maintenance_work_mem and started
to dump data out to the index.

In combination these fixes restore the GIN index build code to honoring
the maintenance_work_mem limit about as well as it did in 8.4.  Speed
seems on par with 8.4 too, maybe even a bit faster, for a non-pathological
case in which HEAD was formerly slower.

Back-patch to 9.0 so we don't have a performance regression from 8.4.
2010-08-01 02:12:51 +00:00
Tom Lane
c9e845f82a Tweak tsmatchsel() so that it examines the structure of the tsquery whenever
possible (ie, whenever the tsquery is a constant), even when no statistics
are available for the tsvector.  For example, foo @@ 'a & b'::tsquery
can be expected to be more selective than foo @@ 'a'::tsquery, whether
or not we know anything about foo.  We use DEFAULT_TS_MATCH_SEL as the assumed
selectivity of individual query terms when no stats are available, then
combine the terms according to the query's AND/OR structure as usual.

Per experimentation with Artur Dabrowski's example.  (The fact that there
are no stats available in that example is a problem in itself, but
nonetheless tsmatchsel should be smarter about the case.)

Back-patch to 8.4 to keep all versions of tsmatchsel() in sync.
2010-07-31 03:27:48 +00:00
Tom Lane
ed34833c57 Rewrite the key-combination logic in GIN's keyGetItem() and scanGetItem()
routines to make them behave better in the presence of "lossy" index pointers.
The previous coding was outright incorrect for some cases, as recently
reported by Artur Dabrowski: scanGetItem would fail to return index entries in
cases where one index key had multiple exact pointers on the same page as
another key had a lossy pointer.  Also, keyGetItem was extremely inefficient
for cases where a single index key generates multiple "entry" streams, such as
an @@ operator with a multiple-clause tsquery.  The presence of a lossy page
pointer in any one stream defeated its ability to use the opclass
consistentFn, resulting in probing many heap pages that didn't really need to
be visited.  In Artur's example case, a query like
	WHERE tsvector @@ to_tsquery('a & b')
was about 50X slower than the theoretically equivalent
	WHERE tsvector @@ to_tsquery('a') AND tsvector @@ to_tsquery('b')
The way that I chose to fix this was to have GIN call the consistentFn
twice with both TRUE and FALSE values for the in-doubt entry stream,
returning a hit if either call produces TRUE, but not if they both return
FALSE.  The code handles this for the case of a single in-doubt entry stream,
but punts (falling back to the stupid behavior) if there's more than one lossy
reference to the same page.  The idea could be scaled up to deal with multiple
lossy references, but I think that would probably be wasted complexity.  At
least to judge by Artur's example, such cases don't occur often enough to be
worth trying to optimize.

Back-patch to 8.4.  8.3 did not have lossy GIN index pointers, so not
subject to these problems.
2010-07-31 00:31:04 +00:00