Before, make check-world would create a new temporary installation for
each test suite, which is slow and wasteful. Instead, we now create one
test installation that is used by all test suites that are part of a
make run.
The management of the temporary installation is removed from pg_regress
and handled in the makefiles. This allows for better control, and
unifies the code with that of test suites not run through pg_regress.
review and msvc support by Michael Paquier <michael.paquier@gmail.com>
more review by Fabien Coelho <coelho@cri.ensmp.fr>
In support of this, have the MSVC build follow GNU make in preferring
GNUmakefile over Makefile when a directory contains both.
Michael Paquier, reviewed by MauMau.
I'm not sure why commit 1eb1dde049 seems
to have made this start to fail on Cygwin when it never did before ---
but nonetheless, the coding was pretty bogus, and unlike the way we
handle $(X) anywhere else. Per buildfarm.
Numerous flex and bison make rules have appeared in the source tree
over time, and they are all virtually identical, so we can replace
them by pattern rules with some variables for customization.
Users of pgxs will also be able to benefit from this.
There is no point in running this test when prepared transactions are disabled,
which is the default. New make targets that include the test are provided. This
will save some useless waste of cycles on buildfarm machines.
Backpatch to 9.1 where these tests were introduced.
This effectively reverts 7886cc73ad,
which was done under the impression that isolationtester needs libpq,
which it no longer does (and never really did).
It's not necessary and can only create confusion about which libpq
installation should be used.
Also remove some dead code from the makefile that was apparently
copied from elsewhere.
Per recommendation from Peter. Neither choice is bulletproof, but this
is the existing style and it does help prevent unexpected environment
variable substitution.
Apparently there is no buildfarm critter exercising this case after all,
because it fails in several places. With this patch, build, install,
check-world, and installcheck-world pass for me on OS X.
This doesn't work as expected because the isolationtester program requires
libpq to already be installed. While it works when you've already installed
libpq, having to already have done "make install" defeats most of the point
of a check with a temp installation. And there are weird corner cases if
the dynamic linker picks up an old libpq.so from system library directories.
Remove the target (or more precisely, make it print a helpful message) so
people don't expect the case to work.
Remove random system #includes in favor of using postgres_fe.h. (The
alternative to that is letting this module grow its own configuration
testing ability...)
Also fix the "make clean" target to actually clean things up.
Per local testing.
At least two recent commits have apparently imagined that a comment in
a Makefile stating that something would be included in the distribution
tarball was sufficient to make it so. They hadn't bothered to hook
into the upper maintainer-clean targets either. Per bug #5923 from
Charles Johnson, in which it emerged that the 9.1alpha4 tarballs are
short a few files that should be there.
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
Andrew Dunstan
Peter Eisentraut
Noah Misch
Bruce Momjian
Tom Lane
Alvaro Herrera
Heikki Linnakangas