*before* acquiring shlock on buffer context. This way we should be
protected against conflicts with FlushRelationBuffers.
(Seems we never do excl lock and then StartBufferIO for the same
buffer, so there should be no deadlock here, - but we'd better
check this very soon).
O_SYNC, or O_DSYNC (as available on a given platform). Add GUC parameter
to control sync method.
Also, add defense to XLogWrite to prevent it from going nuts if passed
a target write position that's past the end of the buffers so far filled
by XLogInsert.
I'm not sure that it's really necessary to save insert events when there
are only after update or delete triggers, but certainly it's wrong for
COPY to behave differently from an INSERT query.
detect case that next page in log came from an older run than the prior
page. This avoids the necessity to re-zero the log after recovery from
a crash, which is good because we need not risk destroying valuable log
information.
This forces another initdb since yesterday :-(. Need to get that log
reset utility done...
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
tuples inserted/deleted/updated in a single transaction. On my machine,
this reduced the time to delete 80000 tuples in a foreign-key-referencing
table from ~15min to ~8sec.
of a counted input string. Marinos Yannikos' recent crash report turns
out to be due to applying pg_ascii2wchar_with_len to a TEXT object that
is smack up against the end of memory. This is the second just-barely-
reproducible bug report I have seen that traces to some bit of code
fetching one more byte than it is allowed to. Let's be more careful
out there, boys and girls.
While at it, I changed the code to not risk a similar crash when there
is a truncated multibyte character at the end of an input string. The
output in this case might not be the most reasonable output possible;
if anyone wants to improve it further, step right up...
succeeds or not. Revise rtree page split algorithm to take care about
making a feasible split --- ie, will the incoming tuple actually fit?
Failure to make a feasible split, combined with failure to notice the
failure, account for Jim Stone's recent bug report. I suspect that
hash and gist indices may have the same type of bug, but at least now
we'll get error messages rather than silent failures if so. Also clean
up rtree code to use Datum rather than char* where appropriate.
when user does another FETCH after reaching end of data, or another
FETCH backwards after reaching start. This is needed because some plan
nodes are not very robust about being called again after they've already
returned NULL; for example, MergeJoin will crash in some states but not
others. While the ideal approach would be for them all to handle this
correctly, it seems foolish to assume that no such bugs would creep in
again once cleaned up. Therefore, the most robust answer is to prevent
the situation from arising at all.
vacuum analyze on pg_type fails if bogus entries remain in pg_operator.
Here is a sample script to reproduce the problem.
drop table t1;
create table t1(i int);
drop function foo(t1,t1);
create function foo(t1,t1) returns bool as 'select true' language 'sql';
create operator = (
leftarg = t1,
rightarg = t1,
commutator = =,
procedure = foo
);
drop table t1;
vacuum analyze;
only if at least N other backends currently have open transactions. This
is not a great deal of intelligence about whether a delay might be
profitable ... but it beats no intelligence at all. Note that the default
COMMIT_DELAY is still zero --- this new code does nothing unless that
setting is changed.
Also, mark ENABLEFSYNC as a system-wide setting. It's no longer safe to
allow that to be set per-backend, since we may be relying on some other
backend's fsync to have synced the WAL log.
does not lead to a one-second delay, but to an immediate EINVAL failure.
This causes CHECKPOINT to crash with s_lock_stuck much too quickly :-(.
Fix by breaking down the requested wait div/mod 1e6.
> Is there one LOCKMETHODCTL for every backend? I thought there was only
> one of them.
>>
>> You're right, that line is erroneous; it should read
>>
>> size += MAX_LOCK_METHODS * MAXALIGN(sizeof(LOCKMETHODCTL));
>>
>> Not a significant error but it should be changed for clarity ...
in Turkish locale. Keywords are now checked under pure ASCII case-folding
rules ('A'-'Z'->'a'-'z' and nothing else). However, once a word is
determined not to be a keyword, it will be case-folded under the current
locale, same as before. See pghackers discussion 20-Feb-01.
Bruce Momjian
Vadim B. Mikheev
Tom Lane
Hiroshi Inoue
Peter Eisentraut
Tatsuo Ishii