when a function that returns a single tuple (not a setof tuple) returns
NULL. This seems to be the most consistent behavior. It would have
taken a bit less code to make it return an empty table (zero rows) but
ISTM a non-SETOF function ought always return exactly one row. Per
bug report from Ivan-Sun1.
was large enough to be batched and the tuples fell into a batch where
there were no inner tuples at all. Thanks to Xiaoyu Wang for finding a
test case that exposed this long-standing bug.
creating a new tuple. This is just for debugging sanity, though, since
nothing should be paying any attention to xmax when the HEAP_XMAX_INVALID
bit is set.
pg_subtrans --- what we need is the oldest xmin of any snapshot in use
in the current top transaction. Introduce a new variable TransactionXmin
to play this role. Fixes intermittent regression failure reported by
Neil Conway.
as per recent discussions. Invent SubTransactionIds that are managed like
CommandIds (ie, counter is reset at start of each top transaction), and
use these instead of TransactionIds to keep track of subtransaction status
in those modules that need it. This means that a subtransaction does not
need an XID unless it actually inserts/modifies rows in the database.
Accordingly, don't assign it an XID nor take a lock on the XID until it
tries to do that. This saves a lot of overhead for subtransactions that
are only used for error recovery (eg plpgsql exceptions). Also, arrange
to release a subtransaction's XID lock as soon as the subtransaction
exits, in both the commit and abort cases. This avoids holding many
unique locks after a long series of subtransactions. The price is some
additional overhead in XactLockTableWait, but that seems acceptable.
Finally, restructure the state machine in xact.c to have a more orthogonal
set of states for subtransactions.
mode see a fresh snapshot for each command in the function, rather than
using the latest interactive command's snapshot. Also, suppress fresh
snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE
functions, instead using the snapshot taken for the most closely nested
regular query. (This behavior is only sane for read-only functions, so
the patch also enforces that such functions contain only SELECT commands.)
As per my proposal of 6-Sep-2004; I note that I floated essentially the
same proposal on 19-Jun-2002, but that discussion tailed off without any
action. Since 8.0 seems like the right place to be taking possibly
nontrivial backwards compatibility hits, let's get it done now.
((Snapshot) NULL) can no longer be confused with a valid snapshot,
as per my recent suggestion. Define a macro InvalidSnapshot for 0.
Use InvalidSnapshot instead of SnapshotAny as the do-nothing special
case for heap_update and heap_delete crosschecks; this seems a little
cleaner even though the behavior is really the same.
rather than when returning to the idle loop. This makes no particular
difference for interactively-issued queries, but it makes a big difference
for queries issued within functions: trigger execution now occurs before
the calling function is allowed to proceed. This responds to numerous
complaints about nonintuitive behavior of foreign key checking, such as
http://archives.postgresql.org/pgsql-bugs/2004-09/msg00020.php, and
appears to be required by the SQL99 spec.
Also take the opportunity to simplify the data structures used for the
pending-trigger list, rename them for more clarity, and squeeze out a
bit of space.
status. In particular, I see no reason for deferredTriggerCheckState
to make an explicit entry to note that a particular trigger has its
default state --- that just clutters a list that should normally be
empty or very short. I have plans to revise this module much more
heavily, but this is a simple separable improvement.
Asserts would lead to a server core dump if an error occurred while
trying to abort a failed subtransaction (thereby leading to re-execution
of whatever parts of AbortSubTransaction had already run). This of course
does not prevent such an error from creating an infinite loop, but at
least we don't make the situation worse. Responds to an open item on
the subtransactions to-do list.
elog() emulation code always calls errstart with ERROR error level.
This means that a recursive error call triggered by elog would do
MemoryContextReset(ErrorContext), whether or not this was actually
appropriate. I'm surprised we haven't seen this in the field...
Messages of less than ERROR severity should never be promoted (this
fixes Gaetano Mendola's problem with a COMMERROR becoming a PANIC,
and is obvious in hindsight anyway). Do all promotion in errstart
not errfinish, to ensure that output decisions are made correctly;
the former coding could suppress logging of promoted errors, which
doesn't seem like a good idea. Eliminate some redundant code too.
use of already-freed strings, other silliness. Also fix reporting of
config file syntax errors so that it actually works reasonably well
(eg, points at the correct line). Use palloc instead of malloc for
temporary storage to reduce code clutter.
not supposed to (fixes problem with postmaster aborting due to mistaken
postgresql.conf change); don't call superuser() when not inside a
transaction (fixes coredump when, eg, try to set log_statement from
PGOPTIONS); some message style guidelines enforcement.
default tablespace --- they should always go in the database's default
tablespace. Adjust heap_create() API so that it is passed the relkind
to make this easier; should simplify any further tweaking of the same
sort.
to allow DBA to choose the form in which log filenames reflect the
current time. Also allow for truncating instead of appending to
pre-existing files --- this is convenient when the log filename pattern
rewrites the same names cyclically. Per Ed L.
during replay of CREATE DATABASE as well as the first time around.
Else it's possible that the copy operation will copy obsolete blocks.
We are still a long way from guaranteeing anything about using a
recently-written database as a CREATE template, but this seems needed
to ensure the existing behavior holds up during replay.
Fix TablespaceCreateDbspace() to be able to create a dummy directory
in place of a dropped tablespace's symlink. This eliminates the open
problem of a PANIC during WAL replay when a replayed action attempts
to touch a file in a since-deleted tablespace. It also makes for a
significant improvement in the usability of PITR replay.
a more tolerable limit on the number of subtransactions or deleted files
in COMMIT and ABORT records. Buy back the extra space by eliminating the
xl_xact_prev field, which isn't being used for anything and is rather
unlikely ever to be used for anything.
This does not force initdb, but you do need to do pg_resetxlog if you
want to upgrade an existing 8.0 installation without initdb.
Win32 WaitForMultipleObjects:
ret = WaitForMultipleObjects(win32_numChildren, win32_childHNDArray,
FALSE, 0);
Problem is 'win32_numChildren' could be more then 64 ( function supports
), problem basically arise ( kills postgres ) when you create more then
64 connections and terminate some of them sill leaving more then 64.
Claudio Natoli
>>GetLastError will
>>> give much more details than errno.
>>
>>How much more, really? That mapping table gave me the impression that
>>the win32 error codes aren't all that much more detailed than errno...
>
>The mapping table is not complete. My winerror.h from the SDK
>lists 2209
>error codes, whereas errno.h lists 42...
>
>I still don't think we'll get that much more stuff. Right now,
>the Win32
>code paths that actually use the more advanced functions already write
>out the error number in case something happens. We can keep doing that
>for the other paths (ereport the error *number* when the mapping does
>not have a match). The map to errno will catch almost all cases, I
>think. And in the corner cases we can do with just the number, and use
>"net helpmsg" to get the actual message when checking...
Here's an attempt on this. new file goes in backend/port/win32.
Magnus Hagander
so that we close and flush the doomed relation's relcache entry before
we start to delete the underlying catalog rows, rather than afterwards.
For awhile yesterday I thought that an unexpected relcache entry rebuild
partway through this sequence might explain the infrequent parallel
regression failures we were chasing. It doesn't, mainly because there's
no CommandCounterIncrement in the sequence and so the deletions aren't
"really" done yet. But it sure seems like trouble waiting to happen.
relcache entries. Also, change TransactionIdIsCurrentTransactionId()
so that if consulted during transaction abort, it will not say that
the aborted xact is still current. (It would be better to ensure that
it's never called at all during abort, but I'm not sure we can easily
guarantee that.) In combination, these fix a crash we have seen
occasionally during parallel regression tests of 8.0.
from being accepted after the outer right brace. Per report from
Markus Bertheau.
Also add regression test cases for this change, and for previous
recent array literal parser changes.
PROCLOCK structs in shared memory now have only a bitmask for held
locks, rather than counts (making them 40 bytes smaller, which is a
good thing). Multiple locks within a transaction are counted in the
local hash table instead, and we have provision for tracking which
ResourceOwner each count belongs to. Solves recently reported problem
with memory leakage within long transactions.
for every command executed within a transaction. For long transactions
this was a significant memory leak. Instead, we can delete a portal's
or subtransaction's ResourceOwner immediately, if we physically transfer
the information about its locks up to the parent owner. This does not
fully solve the leak problem; we need to do something about counting
multiple acquisitions of the same lock in order to fix it. But it's a
necessary step along the way.
ColLabel instead of just ColId --- that is, any keyword can appear after
a dot and it will be taken as an identifier. Fixes problems with names
that are okay as standalone function names but fail when qualified.
updates are no longer WAL-logged nor even fsync'd; we do not need to,
since after a crash no old pg_subtrans data is needed again. We truncate
pg_subtrans to RecentGlobalXmin at each checkpoint. slru.c's API is
refactored a little bit to separate out the necessary decisions.
RecentXmin (== MyProc->xmin). This ensures that it will be safe to
truncate pg_subtrans at RecentGlobalXmin, which should largely eliminate
any fear of bloat. Along the way, eliminate SubTransXidsHaveCommonAncestor,
which isn't really needed and could not give a trustworthy result anyway
under the lookback restriction.
In an unrelated but nearby change, #ifdef out GetUndoRecPtr, which has
been dead code since 2001 and seems unlikely to ever be resurrected.
>>'127.0.0.1/32' instead of '127.0.0.1 255.255.255.255'.
>>
>>
>
>Yeah, that's probably the path of least resistance. Note that the
>comments and possibly the SGML docs need to be adjusted to match,
>however, so it's not quite a one-liner.
Andrew Dunstan
> why does CVS tip still give me
>
> regression=# select extract(century from now());
> date_part
> -----------
> 20
> (1 row)
> [ ... looks in code ... ]
>
> Apparently it's because you fixed only timestamp_part, and not
> timestamptz_part. I'm not too sure about what timestamp_trunc or
> timestamptz_trunc should do, but they may be wrong as well.
Sigh... as usual, what is not tested does not work:-(
> Could we have a more complete patch?
Please find a submission attached. I hope it really fixes all decade,
century and millenium issues for extract and *_trunc functions on
interval
and other timestamp types. If someone could check that the results
are reasonnable, it would be great.
I indeed overlooked the fact that there were two functions. The patch
fixes the code so that both variants agree.
I added comments to interval extractions, because it relies on the C
division to have a negative remainder: -7/10 = 0 and remains -7.
As for *_trunc functions, I have chosen to put the first year of the
century or millennium: -100, 1, 101... 1001 2001 etc. Indeed, I don't
think it would make sense to put 2000 (last year of the 2nd millennium)
for rounding all years of the third millenium.
I also fixed the code so that all decades last 10 years and decade 199
means the 1990's.
I have added some tests that are relevant to deal with tricky cases. The
formula may be simplified, but all these cases must pass. Please keep
them.
Fabien Coelho
presence of dropped columns. Document the already-presumed fact that
eref aliases in relation RTEs are supposed to have entries for dropped
columns; cause the user alias structs to have such entries too, so that
there's always a one-to-one mapping to the underlying physical attnums.
Adjust expandRTE() and related code to handle the case where a column
that is part of a JOIN has been dropped. Generalize expandRTE()'s API
so that it can be used in a couple of places that formerly rolled their
own implementation of the same logic. Fix ruleutils.c to suppress
display of aliases for columns that were dropped since the rule was made.
value of 'start' could be past the end of the page, if the page was
split by some concurrent inserting process since we visited it. In
this situation the code could look at bogus entries and possibly find
a match (since after all those entries still contain what they had
before the split). This would lead to 'specified item offset is too large'
followed by 'PANIC: failed to add item to the page', as reported by Joe
Conway for scenarios involving heavy concurrent insertion activity.
to the physical layout of the rowtype, ie, there are dummy arguments
corresponding to any dropped columns in the rowtype. We formerly had a
couple of places that did it this way and several others that did not.
Fixes Gaetano Mendola's "cache lookup failed for type 0" bug of 5-Aug.
of XLogInsert had the same sort of checkpoint interlock problem as
RecordTransactionCommit, and indeed I found some. Btree index build
and ALTER TABLE SET TABLESPACE write data outside the friendly confines
of the buffer manager, and therefore they have to take their own
responsibility for checkpoint interlock. The easiest solution seems to
be to force smgrimmedsync at the end of the index build or table copy,
even when the operation is being WAL-logged. This is sufficient since
the new index or table will be of interest to no one if we don't get
as far as committing the current transaction.
therefore starting with GetCurrentTransactionId is wrong. Fixes
miscomputation of RecentGlobalXmin leading to bizarre behavior
reported by Gavin Sherry.
Neil Conway
Tom Lane
Peter Eisentraut
Bruce Momjian
Dennis Bjorklund
Joe Conway