Until now, our Serializable mode has in fact been what's called Snapshot
Isolation, which allows some anomalies that could not occur in any
serialized ordering of the transactions. This patch fixes that using a
method called Serializable Snapshot Isolation, based on research papers by
Michael J. Cahill (see README-SSI for full references). In Serializable
Snapshot Isolation, transactions run like they do in Snapshot Isolation,
but a predicate lock manager observes the reads and writes performed and
aborts transactions if it detects that an anomaly might occur. This method
produces some false positives, ie. it sometimes aborts transactions even
though there is no anomaly.
To track reads we implement predicate locking, see storage/lmgr/predicate.c.
Whenever a tuple is read, a predicate lock is acquired on the tuple. Shared
memory is finite, so when a transaction takes many tuple-level locks on a
page, the locks are promoted to a single page-level lock, and further to a
single relation level lock if necessary. To lock key values with no matching
tuple, a sequential scan always takes a relation-level lock, and an index
scan acquires a page-level lock that covers the search key, whether or not
there are any matching keys at the moment.
A predicate lock doesn't conflict with any regular locks or with another
predicate locks in the normal sense. They're only used by the predicate lock
manager to detect the danger of anomalies. Only serializable transactions
participate in predicate locking, so there should be no extra overhead for
for other transactions.
Predicate locks can't be released at commit, but must be remembered until
all the transactions that overlapped with it have completed. That means that
we need to remember an unbounded amount of predicate locks, so we apply a
lossy but conservative method of tracking locks for committed transactions.
If we run short of shared memory, we overflow to a new "pg_serial" SLRU
pool.
We don't currently allow Serializable transactions in Hot Standby mode.
That would be hard, because even read-only transactions can cause anomalies
that wouldn't otherwise occur.
Serializable isolation mode now means the new fully serializable level.
Repeatable Read gives you the old Snapshot Isolation level that we have
always had.
Kevin Grittner and Dan Ports, reviewed by Jeff Davis, Heikki Linnakangas and
Anssi Kääriäinen
This fixes make distprep, and seems more robust in other ways as well.
Some special handling is required because errcodes.txt is needed by
some stuff in src/port, but just by src/backend as is the case for the
other generated headers.
While I'm at it, fix a few other things that were overlooked in the
original patch.
src/pl/plpgsql/src/plerrcodes.h, src/include/utils/errcodes.h, and a
big chunk of errcodes.sgml are now automatically generated from a single
file, src/backend/utils/errcodes.txt.
Jan Urbański, reviewed by Tom Lane.
This tool makes it possible to do the pg_start_backup/
copy files/pg_stop_backup step in a single command.
There are still some steps to be done before this is a
complete backup solution, such as the ability to stream
the required WAL logs, but it's still usable, and
could do with some buildfarm coverage.
In passing, make the checkpoint request optionally
fast instead of hardcoding it.
Magnus Hagander, reviewed by Fujii Masao and Dimitri Fontaine
Makes it easier to parse mainly the BASE_BACKUP command
with it's options, and avoids having to manually deal
with quoted identifiers in the label (previously broken),
and makes it easier to add new commands and options in
the future.
In passing, refactor the case statement in the walsender
to put each command in it's own function.
This is slower than the original coding but avoids the problem of
including files in an unpredictable order. Aside from being more
trustworthy, we can get rid of some exclusions that were formerly
made for what turn out to be ordering or re-inclusion problems.
I also modified it to include libpq's exported files in the check.
ecpg should be included as well, but I'm unclear on which ecpg .h
files are meant to be included by clients.
Replace for loops in makefiles with proper dependencies. Parallel
make can now span across directories. Also, make -k and make -q work
properly.
GNU make 3.80 or newer is now required.
Look only at the non-localized part of the output from "vcbuild /?",
which is used to determine the version of Visual Studio in use. Different
languages seem to localize different amounts of the string, but we assume
the part "Microsoft Visual C++" won't be modified.
1. Resurrect the behavior where old commits on master will have Branch:
labels for branches sprouted after the commit was made. I'm still
dubious about this mode, but if you want it, say --post-date or -p.
2. Annotate the Branch: labels with the release or branch in which the
commit was publicly released. For example, on a release branch you could
see
Branch: REL8_3_STABLE Release: REL8_3_2 [92c3a8004] 2008-03-29 00:15:37 +0000
showing that the fix was released in 8.3.2. Commits on master will
usually instead have notes like
Branch: master Release: REL8_4_BR [6fc9d4272] 2008-03-29 00:15:28 +0000
showing that this commit is ancestral to release branches 8.4 and later.
If no Release: marker appears, the commit hasn't yet made it into any
release.
3. Add support for release branches older than 7.4.
4. The implementation is improved by running git log on each branch only
back to where the branch sprouts from master. This saves a good deal
of time (about 50% of the runtime when generating the complete history).
We generate the post-date-mode tags via a direct understanding that
they should be applied to master commits made before the branch sprouted,
rather than backing into them via matching (which isn't any too
reliable when people used identical log messages for successive commits).
1. Don't assume there's only one candidate match; check them all and use the
one with the closest timestamp. Avoids funny output when someone makes
several successive commits with the same log message, as certain people
have been known to do.
2. When the same commit (with the same SHA1) is reachable from multiple
branch tips, don't report it for all the branches; instead report it only
for the first such branch. Given our development practices, this case
arises only for commits that occurred before a given branch split off from
master. The original coding blamed old commits on *all* the branches,
which isn't terribly useful; the new coding blames such a commit only on
master.
1. Don't forget the last (oldest) commit on the oldest branch.
2. When considering which commit to print next, if two alternatives have
the same "distortion" score (which is actually the normal case, since
generally the "distortion" is 0), then choose the later timestamp to
print first. I don't know where Robert got the idea to ignore timestamps
and sort by branch age, but it wasn't a good idea: the resulting ordering
of commits was just plain bizarre anywhere that some branches had many
fewer commits than others, which is the typical situation for us.
Avoid depending on Date::Calc, which isn't in a basic Perl installation,
when we can equally well use Time::Local which is. Also fix the parsing
of timestamps to take heed of the timezone. (It looks like cvs2git emitted
all commit timestamps with zone GMT, so this refinement might've looked
unnecessary when looking at converted data; but it's needed now.)
Fix parsing of message bodies so that blank lines that may or may not get
emitted by "git log" aren't confused with real data. This avoids strange
formatting of the oldest commit on a branch.
Check child-process exit status, so that we actually notice if "git log"
fails, and so that we don't accumulate zombie children.
This script is intended to substitute for cvs2cl in generating release
notes and scrutinizing what got back-patched to which branches.
Script by me. Support for --since by Alex Hunsaker.
wait until it is set. Latches can be used to reliably wait until a signal
arrives, which is hard otherwise because signals don't interrupt select()
on some platforms, and even when they do, there's race conditions.
On Unix, latches use the so called self-pipe trick under the covers to
implement the sleep until the latch is set, without race conditions. On
Windows, Windows events are used.
Use the new latch abstraction to sleep in walsender, so that as soon as
a transaction finishes, walsender is woken up to immediately send the WAL
to the standby. This reduces the latency between master and standby, which
is good.
Preliminary work by Fujii Masao. The latch implementation is by me, with
helpful comments from many people.
linking both executables and shared libraries, and we add on LDFLAGS_EX when
linking executables or LDFLAGS_SL when linking shared libraries. This
provides a significantly cleaner way of dealing with link-time switches than
the former behavior. Also, make sure that the various platform-specific
%.so: %.o rules incorporate LDFLAGS and LDFLAGS_SL; most of them missed that
before. (I did not add these variables for the platforms that invoke $(LD)
directly, however. It's not clear if we can do that safely, since for the
most part we assume these variables use CC command-line syntax.)
Per gripe from Aaron Swenson and subsequent investigation.
prefix, instead of assuming it will always be following the default layout.
All information we need is not available on Windows, but the number of
assumptions are at least fewer this way than before.
Based on suggestions from James William Pye.
and allow using config.pl to override the defaults. config.pl is removed from
the repository, so changes there will no longer show up when doing diff, and
will not prevent switching branches and such things.
config.pl would normally be used to override single values, but if an
old-style config.pl is read, it will override the entire default configuration,
making it backwards compatible.
symbols both using __declspec(dllexport) (via the PGDLLIMPORT macro) and using
full-dll-export. This works without warning on Win32, but not on Win64.
In passing, fix the fact that the framework could never deal with more than
one disbled linker warning - because MSVC wants commas between linker warnings,
and semicolons between compiler warnings...
pg_attribute, by having genbki.pl derive the information from the various
catalog header files. This greatly simplifies modification of the
"bootstrapped" catalogs.
This patch finally kills genbki.sh and Gen_fmgrtab.sh; we now rely entirely on
Perl scripts for those build steps. To avoid creating a Perl build dependency
where there was not one before, the output files generated by these scripts
are now treated as distprep targets, ie, they will be built and shipped in
tarballs. But you will need a reasonably modern Perl (probably at least
5.6) if you want to build from a CVS pull.
The changes to the MSVC build process are untested, and may well break ---
we'll soon find out from the buildfarm.
John Naylor, based on ideas from Robert Haas and others
directly. This was a lot of trouble, but should be worth it in terms of
not having to keep the plpgsql lexer in step with core anymore. In addition
the handling of keywords is significantly better-structured, allowing us to
de-reserve a number of words that plpgsql formerly treated as reserved.
hand-assigned rowtype OIDs, even when they are not "bootstrapped" catalogs
that have handmade type rows in pg_type.h. Give pg_database such an OID.
Restore the availability of C macros for the rowtype OIDs of the bootstrapped
catalogs. (These macros are now in the individual catalogs' .h files,
though, not in pg_type.h.)
This commit doesn't do anything especially useful by itself, but it's
necessary infrastructure for reverting some ill-considered changes in
relcache.c.
Test coverage support now covers the entire source tree, including
contrib, instead of just src/backend. In a related but independent
development, the commands make coverage and make coverage-html can be run
in any directory.
This turned out to be much easier than feared. Besides a few ad hoc fixes
to pass the make target down the tree, change all affected makefiles to
list their directories in the SUBDIRS variable, changed from variants like
DIRS and WANTED_DIRS. MSVC build fix was attempted as well.
and extend configure to test for it properly instead of hard-wiring
an assumption that everybody but Windows has the rand48 functions.
(We do cheat to the extent of assuming that probing for erand48 will do
for the entire rand48 family.)
erand48() is unused as of this commit, but a followon patch will cause
GEQO to depend on it.
Andres Freund, additional hacking by Tom
This alters various incidental uses of C++ key words to use other similar
identifiers, so that a C++ compiler won't choke outright. You still
(probably) need extern "C" { }; around the inclusion of backend headers.
based on a patch by Kurt Harriman <harriman@acm.org>
Also add a script cpluspluscheck to check for C++ compatibility in the
future. As of right now, this passes without error for me.
keyword lists in gram.y and kwlist.h. It checks that all lists are in
alphabetical order, and that all keywords present in gram.y are listed
in kwlist.h in the right category, and that all keywords in kwlist.h are
also in gram.y. What's still missing is to check that all keywords
defined with "%token <keyword>" in gram.y are present in one of the
keyword lists in gram.y.
Also, if linked against other versions than the default MSVCRT library
(for example the MSVC build which links against MSVCRT80), also update
the cache in the default MSVCRT at the same time.
This should fix the issues with setting LC_MESSAGES on the MSVC build.
Original patch from Hiroshi Inoue and Hiroshi Saito, much rewritten
by me.
the * character at the beginning of a pattern, and it does not match
subdomains.
Since this means we no longer need fnmatch, remove the imported implementation
from port, along with the autoconf check for it.
the postgres.bki file during build, because we want that file to be entirely
platform- and configuration-independent; else it can't safely be put into
/usr/share on multiarch machines. We can do the substitution during initdb,
instead. FLOAT4PASSBYVAL and FLOAT8PASSBYVAL are new breakage as of 8.4,
while the NAMEDATALEN hazard has been there all along but I guess no one
tripped over it. Noticed while trying to build "universal" OS X binaries.
in pg_proc. Also make it not emit duplicate extern declarations, and make it
a bit more bulletproof in some other small ways. Likewise fix the equally
hard-wired, and utterly undocumented, knowledge in the MSVC build scripts.
For testing purposes and perhaps other uses in future, pull out that portion
of the MSVC scripts into a standalone perl script equivalent to
Gen_fmgrtab.sh, and make it generate actually identical output, rather than
just more-or-less-the-same output.
Motivated by looking at Pavel's variadic function patch. Whether or not
that gets accepted, we can be sure that pg_proc's column set will change
again in the future; it's time to not have to deal with this gotcha.
"make all", and then reference them there during the actual tests. This
makes the handling of these files more parallel to that of regress.so,
and in particular simplifies use of the regression tests outside the
original build tree. The PGDG and Red Hat RPMs have been doing this via
patches for a very long time. Inclusion of the change in core was requested
by Jørgen Austvik of Sun, and I can't see any reason not to.
I attempted to fix the MSVC scripts for this too, but they may need
further tweaking ...
any hardcoding of those options. Along the way, reorder the expression used to
calculate RELSEG_SIZE to make it slightly clearer. For now wal_segsize is only
allowed to have a value of 1 on Windows - we can relax that when we get full
large file support in the backend.
where Datum is 8 bytes wide. Since this will break old-style C functions
(those still using version 0 calling convention) that have arguments or
results of these types, provide a configure option to disable it and retain
the old pass-by-reference behavior. Likewise, provide a configure option
to disable the recently-committed float4 pass-by-value change.
Zoltan Boszormenyi, plus configurability stuff by me.
data structures and backend internal APIs. This solves problems we've seen
recently with inconsistent layout of pg_control between machines that have
32-bit time_t and those that have already migrated to 64-bit time_t. Also,
we can get out from under the problem that Windows' Unix-API emulation is not
consistent about the width of time_t.
There are a few remaining places where local time_t variables are used to hold
the current or recent result of time(NULL). I didn't bother changing these
since they do not affect any cross-module APIs and surely all platforms will
have 64-bit time_t before overflow becomes an actual risk. time_t should
be avoided for anything visible to extension modules, however.
in .bat simply did not work, and it called them in the wrong order,
some several times, and some not at all. So this unrolls all subroutine
calls.
This should fix the issues with clean deleting the wrong files reported
by Dave Page.
While at it, add the "clean dist" option to act like "make distclean",
and no longer remove the flex/bison output files by default. This shuold
fix the problem reported by Pavel Golub in bug #3909.