Commit Graph

34 Commits

Author SHA1 Message Date
Robert Haas
2e44770fa3 pgrowlocks: Use GetActiveSnapshot() rather than SnapshotNow.
Per discussion, it's desirable to eliminate all remaining uses of
SnapshotNow, because it has unpleasant semantics: race conditions
can result in seeing multiple versions of a concurrently updated
row, or none at all.  By using GetActiveSnapshot() here, callers
will see exactly those rows that would have been visible if the
invoking query had scanned the table using, for example, a SELECT
statement.

This is slightly different from the old behavior, because commits
that happen concurrently with the scan will not affect the results.
In REPEATABLE READ or SERIALIZABLE modes, where transaction
snapshots are used, commits that have happened since the start of
the transaction will also not affect the results.  It is hoped
that this minor incompatibility will be thought an improvement,
or at least no worse than what we did before.
2013-07-22 16:21:14 -04:00
Robert Haas
0518eceec3 Adjust HeapTupleSatisfies* routines to take a HeapTuple.
Previously, these functions took a HeapTupleHeader, but upcoming
patches for logical replication will introduce new a new snapshot
type under which the tuple's TID will be used to lookup (CMIN, CMAX)
for visibility determination purposes.  This makes that information
available.  Code churn is minimal since HeapTupleSatisfiesVisibility
took the HeapTuple anyway, and deferenced it before calling the
satisfies function.

Independently of logical replication, this allows t_tableOid and
t_self to be cross-checked via assertions in tqual.c.  This seems
like a useful way to make sure that all callers are setting these
values properly, which has been previously put forward as
desirable.

Andres Freund, reviewed by Álvaro Herrera
2013-07-22 13:38:44 -04:00
Fujii Masao
6f9e39bc99 Fix typo in update scripts for some contrib modules. 2013-07-19 04:13:01 +09:00
Bruce Momjian
9af4159fce pgindent run for release 9.3
This is the first run of the Perl-based pgindent script.  Also update
pgindent instructions.
2013-05-29 16:58:43 -04:00
Alvaro Herrera
77a3082fc5 pgrowlocks: fix bogus lock strength output
Per report from digoal@126.com
2013-01-31 19:15:35 -03:00
Alvaro Herrera
0ac5ad5134 Improve concurrency of foreign key locking
This patch introduces two additional lock modes for tuples: "SELECT FOR
KEY SHARE" and "SELECT FOR NO KEY UPDATE".  These don't block each
other, in contrast with already existing "SELECT FOR SHARE" and "SELECT
FOR UPDATE".  UPDATE commands that do not modify the values stored in
the columns that are part of the key of the tuple now grab a SELECT FOR
NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently
with tuple locks of the FOR KEY SHARE variety.

Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this
means the concurrency improvement applies to them, which is the whole
point of this patch.

The added tuple lock semantics require some rejiggering of the multixact
module, so that the locking level that each transaction is holding can
be stored alongside its Xid.  Also, multixacts now need to persist
across server restarts and crashes, because they can now represent not
only tuple locks, but also tuple updates.  This means we need more
careful tracking of lifetime of pg_multixact SLRU files; since they now
persist longer, we require more infrastructure to figure out when they
can be removed.  pg_upgrade also needs to be careful to copy
pg_multixact files over from the old server to the new, or at least part
of multixact.c state, depending on the versions of the old and new
servers.

Tuple time qualification rules (HeapTupleSatisfies routines) need to be
careful not to consider tuples with the "is multi" infomask bit set as
being only locked; they might need to look up MultiXact values (i.e.
possibly do pg_multixact I/O) to find out the Xid that updated a tuple,
whereas they previously were assured to only use information readily
available from the tuple header.  This is considered acceptable, because
the extra I/O would involve cases that would previously cause some
commands to block waiting for concurrent transactions to finish.

Another important change is the fact that locking tuples that have
previously been updated causes the future versions to be marked as
locked, too; this is essential for correctness of foreign key checks.
This causes additional WAL-logging, also (there was previously a single
WAL record for a locked tuple; now there are as many as updated copies
of the tuple there exist.)

With all this in place, contention related to tuples being checked by
foreign key rules should be much reduced.

As a bonus, the old behavior that a subtransaction grabbing a stronger
tuple lock than the parent (sub)transaction held on a given tuple and
later aborting caused the weaker lock to be lost, has been fixed.

Many new spec files were added for isolation tester framework, to ensure
overall behavior is sane.  There's probably room for several more tests.

There were several reviewers of this patch; in particular, Noah Misch
and Andres Freund spent considerable time in it.  Original idea for the
patch came from Simon Riggs, after a problem report by Joel Jacobson.
Most code is from me, with contributions from Marti Raudsepp, Alexander
Shulgin, Noah Misch and Andres Freund.

This patch was discussed in several pgsql-hackers threads; the most
important start at the following message-ids:
	AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com
	1290721684-sup-3951@alvh.no-ip.org
	1294953201-sup-2099@alvh.no-ip.org
	1320343602-sup-2290@alvh.no-ip.org
	1339690386-sup-8927@alvh.no-ip.org
	4FE5FF020200002500048A3D@gw.wicourts.gov
	4FEAB90A0200002500048B7D@gw.wicourts.gov
2013-01-23 12:04:59 -03:00
Tom Lane
458857cc9d Throw a useful error message if an extension script file is fed to psql.
We have seen one too many reports of people trying to use 9.1 extension
files in the old-fashioned way of sourcing them in psql.  Not only does
that usually not work (due to failure to substitute for MODULE_PATHNAME
and/or @extschema@), but if it did work they'd get a collection of loose
objects not an extension.  To prevent this, insert an \echo ... \quit
line that prints a suitable error message into each extension script file,
and teach commands/extension.c to ignore lines starting with \echo.
That should not only prevent any adverse consequences of loading a script
file the wrong way, but make it crystal clear to users that they need to
do it differently now.

Tom Lane, following an idea of Andrew Dunstan's.  Back-patch into 9.1
... there is not going to be much value in this if we wait till 9.2.
2011-10-12 15:45:03 -04:00
Bruce Momjian
6416a82a62 Remove unnecessary #include references, per pgrminclude script. 2011-09-01 10:04:27 -04:00
Alvaro Herrera
b93f5a5673 Move Trigger and TriggerDesc structs out of rel.h into a new reltrigger.h
This lets us stop including rel.h into execnodes.h, which is a widely
used header.
2011-07-04 14:35:58 -04:00
Tom Lane
029fac2264 Avoid use of CREATE OR REPLACE FUNCTION in extension installation files.
It was never terribly consistent to use OR REPLACE (because of the lack of
comparable functionality for data types, operators, etc), and
experimentation shows that it's now positively pernicious in the extension
world.  We really want a failure to occur if there are any conflicts, else
it's unclear what the extension-ownership state of the conflicted object
ought to be.  Most of the time, CREATE EXTENSION will fail anyway because
of conflicts on other object types, but an extension defining only
functions can succeed, with bad results.
2011-02-13 22:54:52 -05:00
Tom Lane
629b3af27d Convert contrib modules to use the extension facility.
This isn't fully tested as yet, in particular I'm not sure that the
"foo--unpackaged--1.0.sql" scripts are OK.  But it's time to get some
buildfarm cycles on it.

sepgsql is not converted to an extension, mainly because it seems to
require a very nonstandard installation process.

Dimitri Fontaine and Tom Lane
2011-02-13 22:54:49 -05:00
Magnus Hagander
fe9b36fd59 Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
Magnus Hagander
9f2e211386 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
Bruce Momjian
d747140279 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list
provided by Andrew.
2009-06-11 14:49:15 +00:00
Bruce Momjian
636edd553d Blank line Makefile cleanups. 2009-04-28 17:07:50 +00:00
Tatsuo Ishii
40e01e267d Remove outdated Japanese README files per discussion. 2009-01-06 13:43:31 +00:00
Alvaro Herrera
a3540b0f65 Improve our #include situation by moving pointer types away from the
corresponding struct definitions.  This allows other headers to avoid including
certain highly-loaded headers such as rel.h and relscan.h, instead using just
relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less
unnecessary dependencies.
2008-06-19 00:46:06 +00:00
Alvaro Herrera
f8c4d7db60 Restructure some header files a bit, in particular heapam.h, by removing some
unnecessary #include lines in it.  Also, move some tuple routine prototypes and
macros to htup.h, which allows removal of heapam.h inclusion from some .c
files.

For this to work, a new header file access/sysattr.h needed to be created,
initially containing attribute numbers of system columns, for pg_dump usage.

While at it, make contrib ltree, intarray and hstore header files more
consistent with our header style.
2008-05-12 00:00:54 +00:00
Alvaro Herrera
73b0300b2a Move the HTSU_Result enum definition into snapshot.h, to avoid including
tqual.h into heapam.h.  This makes all inclusion of tqual.h explicit.

I also sorted alphabetically the includes on some source files.
2008-03-26 21:10:39 +00:00
Tom Lane
895a94de6d Avoid incrementing the CommandCounter when CommandCounterIncrement is called
but no database changes have been made since the last CommandCounterIncrement.
This should result in a significant improvement in the number of "commands"
that can typically be performed within a transaction before hitting the 2^32
CommandId size limit.  In particular this buys back (and more) the possible
adverse consequences of my previous patch to fix plan caching behavior.

The implementation requires tracking whether the current CommandCounter
value has been "used" to mark any tuples.  CommandCounter values stored into
snapshots are presumed not to be used for this purpose.  This requires some
small executor changes, since the executor used to conflate the curcid of
the snapshot it was using with the command ID to mark output tuples with.
Separating these concepts allows some small simplifications in executor APIs.

Something for the TODO list: look into having CommandCounterIncrement not do
AcceptInvalidationMessages.  It seems fairly bogus to be doing it there,
but exactly where to do it instead isn't clear, and I'm disinclined to mess
with asynchronous behavior during late beta.
2007-11-30 21:22:54 +00:00
Bruce Momjian
33e2e02493 Add CVS version labels to all install/uninstall scripts. 2007-11-13 04:24:29 +00:00
Bruce Momjian
926bbab448 Make /contrib install/uninstall script consistent:
remove transactions
	use create or replace function
	make formatting consistent
	set search patch on first line

Add documentation on modifying *.sql to set the search patch, and
mention that major upgrades should still run the installation scripts.

Some of these issues were spotted by Tom today.
2007-11-11 03:25:35 +00:00
Bruce Momjian
541ff409cc Remove references to READMEs from /contrib Makefiles. 2007-11-10 23:59:52 +00:00
Bruce Momjian
c3c69ab4fd Move most /contrib README files into SGML. Some still need conversion
or will never be converted.
2007-11-10 23:30:46 +00:00
Tom Lane
89fefd9416 Reduce the permissions check needed to use pgrowlocks() to having
SELECT on the target table.  Per discussion.
2007-08-28 22:59:30 +00:00
Tom Lane
56f3fb3ba1 Restrict pgrowlocks function to superusers. (This might be too strict,
but no permissions check at all is certainly no good.)  Clean up usage
of some deprecated APIs.
2007-08-27 00:13:51 +00:00
Tom Lane
b09c248bdd Fix PGXS conventions so that extensions can be built against Postgres
installations whose pg_config program does not appear first in the PATH.
Per gripe from Eddie Stanley and subsequent discussions with Fabien Coelho
and others.
2007-06-26 22:05:04 +00:00
Tom Lane
72ec567a9a Simplify contrib Makefiles by removing unnecessary SRCS macro,
per Magnus.
2006-10-19 17:40:03 +00:00
Bruce Momjian
f99a569a2e pgindent run for 8.2. 2006-10-04 00:30:14 +00:00
Tom Lane
035599da01 uninstall script for pgrowlocks - Josh Drake 2006-09-30 18:08:32 +00:00
Bruce Momjian
66c15dfda1 Adjust /contrib for new include file contents. 2006-07-13 16:57:31 +00:00
Tom Lane
a0ffab351e Magic blocks don't do us any good unless we use 'em ... so install one
in every shared library.
2006-05-30 22:12:16 +00:00
Tatsuo Ishii
a34fd95977 Fix bug reported by Michael Fuhr on Sun, 23 Apr 2006 09:52:31 -0600
(pgsql-committers@postgresql.org).
2006-04-25 00:40:54 +00:00
Tatsuo Ishii
66126f9687 Add new contrib function pgrowlocks. See README.pgrowlocks for more details. 2006-04-23 01:12:58 +00:00