Commit Graph

50 Commits

Author SHA1 Message Date
Bruce Momjian
4baaf863ec Update copyright for 2015
Backpatch certain files through 9.0
2015-01-06 11:43:47 -05:00
Bruce Momjian
7e04792a1c Update copyright for 2014
Update all files in head, and files COPYRIGHT and legal.sgml in all back
branches.
2014-01-07 16:05:30 -05:00
Bruce Momjian
bd61a623ac Update copyrights for 2013
Fully update git head, and update back branches in ./COPYRIGHT and
legal.sgml files.
2013-01-01 17:15:01 -05:00
Alvaro Herrera
c219d9b0a5 Split tuple struct defs from htup.h to htup_details.h
This reduces unnecessary exposure of other headers through htup.h, which
is very widely included by many files.

I have chosen to move the function prototypes to the new file as well,
because that means htup.h no longer needs to include tupdesc.h.  In
itself this doesn't have much effect in indirect inclusion of tupdesc.h
throughout the tree, because it's also required by execnodes.h; but it's
something to explore in the future, and it seemed best to do the htup.h
change now while I'm busy with it.
2012-08-30 16:52:35 -04:00
Bruce Momjian
927d61eeff Run pgindent on 9.2 source tree in preparation for first 9.3
commit-fest.
2012-06-10 15:20:04 -04:00
Bruce Momjian
e126958c2e Update copyright notices for year 2012. 2012-01-01 18:01:58 -05:00
Bruce Momjian
6416a82a62 Remove unnecessary #include references, per pgrminclude script. 2011-09-01 10:04:27 -04:00
Robert Haas
3cba8999b3 Create a "fast path" for acquiring weak relation locks.
When an AccessShareLock, RowShareLock, or RowExclusiveLock is requested
on an unshared database relation, and we can verify that no conflicting
locks can possibly be present, record the lock in a per-backend queue,
stored within the PGPROC, rather than in the primary lock table.  This
eliminates a great deal of contention on the lock manager LWLocks.

This patch also refactors the interface between GetLockStatusData() and
pg_lock_status() to be a bit more abstract, so that we don't rely so
heavily on the lock manager's internal representation details.  The new
fast path lock structures don't have a LOCK or PROCLOCK structure to
return, so we mustn't depend on that for purposes of listing outstanding
locks.

Review by Jeff Davis.
2011-07-18 00:49:28 -04:00
Robert Haas
a0e50e698b Include pid in pg_lock_status() results even for SIREAD locks.
Dan Ports
2011-04-04 13:23:43 -04:00
Itagaki Takahiro
62c7bd31c8 Add transaction-level advisory locks.
They share the same locking namespace with the existing session-level
advisory locks, but they are automatically released at the end of the
current transaction and cannot be released explicitly via unlock
functions.

Marko Tiikkaja, reviewed by me.
2011-02-18 14:05:12 +09:00
Heikki Linnakangas
dafaa3efb7 Implement genuine serializable isolation level.
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
2011-02-08 00:09:08 +02:00
Bruce Momjian
5d950e3b0c Stamp copyrights for year 2011. 2011-01-01 13:18:15 -05:00
Magnus Hagander
9f2e211386 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
Bruce Momjian
0239800893 Update copyright for the year 2010. 2010-01-02 16:58:17 +00:00
Bruce Momjian
511db38ace Update copyright for 2009. 2009-01-01 17:24:05 +00:00
Tom Lane
902d1cb35f Remove all uses of the deprecated functions heap_formtuple, heap_modifytuple,
and heap_deformtuple in favor of the newer functions heap_form_tuple et al
(which do the same things but use bool control flags instead of arbitrary
char values).  Eliminate the former duplicate coding of these functions,
reducing the deprecated functions to mere wrappers around the newer ones.
We can't get rid of them entirely because add-on modules probably still
contain many instances of the old coding style.

Kris Jurka
2008-11-02 01:45:28 +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
Tom Lane
220db7ccd8 Simplify and standardize conversions between TEXT datums and ordinary C
strings.  This patch introduces four support functions cstring_to_text,
cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and
two macros CStringGetTextDatum and TextDatumGetCString.  A number of
existing macros that provided variants on these themes were removed.

Most of the places that need to make such conversions now require just one
function or macro call, in place of the multiple notational layers that used
to be needed.  There are no longer any direct calls of textout or textin,
and we got most of the places that were using handmade conversions via
memcpy (there may be a few still lurking, though).

This commit doesn't make any serious effort to eliminate transient memory
leaks caused by detoasting toasted text objects before they reach
text_to_cstring.  We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few
places where it was easy, but much more could be done.

Brendan Jurd and Tom Lane
2008-03-25 22:42:46 +00:00
Tom Lane
da3df47c84 lmgr.c:DescribeLockTag was never taught about virtual xids, per Greg Stark.
Also a couple of minor tweaks to try to future-proof the code a bit better
against future locktag additions.
2008-01-08 23:18:51 +00:00
Bruce Momjian
9098ab9e32 Update copyrights in source tree to 2008. 2008-01-01 19:46:01 +00:00
Bruce Momjian
fdf5a5efb7 pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
Tom Lane
295e63983d Implement lazy XID allocation: transactions that do not modify any database
rows will normally never obtain an XID at all.  We already did things this way
for subtransactions, but this patch extends the concept to top-level
transactions.  In applications where there are lots of short read-only
transactions, this should improve performance noticeably; not so much from
removal of the actual XID-assignments, as from reduction of overhead that's
driven by the rate of XID consumption.  We add a concept of a "virtual
transaction ID" so that active transactions can be uniquely identified even
if they don't have a regular XID.  This is a much lighter-weight concept:
uniqueness of VXIDs is only guaranteed over the short term, and no on-disk
record is made about them.

Florian Pflug, with some editorialization by Tom.
2007-09-05 18:10:48 +00:00
Bruce Momjian
29dccf5fe0 Update CVS HEAD for 2007 copyright. Back branches are typically not
back-stamped for this.
2007-01-05 22:20:05 +00:00
Bruce Momjian
f99a569a2e pgindent run for 8.2. 2006-10-04 00:30:14 +00:00
Tom Lane
d40d34863e Fix pg_locks view to call advisory locks advisory locks, while preserving
backward compatibility for anyone using the old userlock code that's now
on pgfoundry --- locks from that code still show as 'userlock'.
2006-09-22 23:20:14 +00:00
Tom Lane
9b4cda0df6 Add built-in userlock manipulation functions to replace the former
contrib functionality.  Along the way, remove the USER_LOCKS configuration
symbol, since it no longer makes any sense to try to compile that out.
No user documentation yet ... mmoncure has promised to write some.
Thanks to Abhijit Menon-Sen for creating a first draft to work from.
2006-09-18 22:40:40 +00:00
Tom Lane
a794fb0681 Convert the lock manager to use the new dynahash.c support for partitioned
hash tables, instead of the previous kluge involving multiple hash tables.
This partially undoes my patch of last December.
2006-07-23 23:08:46 +00:00
Bruce Momjian
e0522505bd Remove 576 references of include files that were not needed. 2006-07-14 14:52:27 +00:00
Bruce Momjian
f2f5b05655 Update copyright for 2006. Update scripts. 2006-03-05 15:59:11 +00:00
Tom Lane
c599a247bb Simplify lock manager data structures by making a clear separation between
the data defining the semantics of a lock method (ie, conflict resolution
table and ancillary data, which is all constant) and the hash tables
storing the current state.  The only thing we give up by this is the
ability to use separate hashtables for different lock methods, but there
is no need for that anyway.  Put some extra fields into the LockMethod
definition structs to clean up some other uglinesses, like hard-wired
tests for DEFAULT_LOCKMETHOD and USER_LOCKMETHOD.  This commit doesn't
do anything about the performance issues we were discussing, but it clears
away some of the underbrush that's in the way of fixing that.
2005-12-09 01:22:04 +00:00
Bruce Momjian
1dc3498251 Standard pgindent run for 8.1. 2005-10-15 02:49:52 +00:00
Tom Lane
a8d1075f27 Add a time-of-preparation column to the pg_prepared_xacts view, per an
old suggestion by Oliver Jowett.  Also, add a transaction column to the
pg_locks view to show the xid of each transaction holding or awaiting
locks; this allows prepared transactions to be properly associated with
the locks they own.  There was already a column named 'transaction',
and I chose to rename it to 'transactionid' --- since this column is
new in the current devel cycle there should be no backwards compatibility
issue to worry about.
2005-06-18 19:33:42 +00:00
Tom Lane
a9c4c9cd52 Extend the pg_locks system view so that it can fully display all lock
types, as per recent discussion.
2005-05-17 21:46:11 +00:00
Tom Lane
3a694bb0a1 Restructure LOCKTAG as per discussions of a couple months ago.
Essentially, we shoehorn in a lockable-object-type field by taking
a byte away from the lockmethodid, which can surely fit in one byte
instead of two.  This allows less artificial definitions of all the
other fields of LOCKTAG; we can get rid of the special pg_xactlock
pseudo-relation, and also support locks on individual tuples and
general database objects (including shared objects).  None of those
possibilities are actually exploited just yet, however.

I removed pg_xactlock from pg_class, but did not force initdb for
that change.  At this point, relkind 's' (SPECIAL) is unused and
could be removed entirely.
2005-04-29 22:28:24 +00:00
Bruce Momjian
2daed8c5b3 Update copyrights that were missed. 2005-01-01 05:43:09 +00:00
Bruce Momjian
da9a8649d8 Update copyright to 2004. 2004-08-29 04:13:13 +00:00
Tom Lane
1785acebf2 Introduce local hash table for lock state, as per recent proposal.
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.
2004-08-27 17:07:42 +00:00
Tom Lane
375369acd1 Replace TupleTableSlot convention for whole-row variables and function
results with tuples as ordinary varlena Datums.  This commit does not
in itself do much for us, except eliminate the horrid memory leak
associated with evaluation of whole-row variables.  However, it lays the
groundwork for allowing composite types as table columns, and perhaps
some other useful features as well.  Per my proposal of a few days ago.
2004-04-01 21:28:47 +00:00
PostgreSQL Daemon
969685ad44 $Header: -> $PostgreSQL Changes ... 2003-11-29 19:52:15 +00:00
Tom Lane
2f9c859ea1 Fix some copyright notices that weren't updated. Improve copyright tool
so it won't miss 'em again.
2003-08-04 23:59:41 +00:00
Bruce Momjian
69c049cef4 Back out LOCKTAG changes by Rod Taylor, pending code review. Sorry. 2003-02-19 23:41:15 +00:00
Bruce Momjian
d0f3a7e9c4 - Modifies LOCKTAG to include a 'classId'. Relation receive a classId of
RelOid_pg_class, and transaction locks XactLockTableId. RelId is renamed
to objId.

- LockObject() and UnlockObject() functions created, and their use
sprinkled throughout the code to do descent locking for domains and
types. They accept lock modes AccessShare and AccessExclusive, as we
only really need a 'read' and 'write' lock at the moment.  Most locking
cases are held until the end of the transaction.

This fixes the cases Tom mentioned earlier in regards to locking with
Domains.  If the patch is good, I'll work on cleaning up issues with
other database objects that have this problem (most of them).

Rod Taylor
2003-02-19 04:02:54 +00:00
Bruce Momjian
32cc6cbe23 Rename 'holder' references to 'proclock' for PROCLOCK references, for
consistency.
2003-02-18 02:13:24 +00:00
Bruce Momjian
e50f52a074 pgindent run. 2002-09-04 20:31:48 +00:00
Tom Lane
c7a165adc6 Code review for HeapTupleHeader changes. Add version number to page headers
(overlaying low byte of page size) and add HEAP_HASOID bit to t_infomask,
per earlier discussion.  Simplify scheme for overlaying fields in tuple
header (no need for cmax to live in more than one place).  Don't try to
clear infomask status bits in tqual.c --- not safe to do it there.  Don't
try to force output table of a SELECT INTO to have OIDs, either.  Get rid
of unnecessarily complex three-state scheme for TupleDesc.tdhasoids, which
has already caused one recent failure.  Improve documentation.
2002-09-02 01:05:06 +00:00
Tom Lane
1bab464eb4 Code review for pg_locks feature. Make shmemoffset of PROCLOCK structs
available (else there's no way to interpret the list links).  Change
pg_locks view to show transaction ID locks separately from ordinary
relation locks.  Avoid showing N duplicate rows when the same lock is
held multiple times (seems unlikely that users care about exact hold
count).  Improve documentation.
2002-08-31 17:14:28 +00:00
Tom Lane
e4186762ff Adjust nodeFunctionscan.c to reset transient memory context between calls
to the table function, thus preventing memory leakage accumulation across
calls.  This means that SRFs need to be careful to distinguish permanent
and local storage; adjust code and documentation accordingly.  Patch by
Joe Conway, very minor tweaks by Tom Lane.
2002-08-29 17:14:33 +00:00
Tom Lane
64505ed58b Code review for standalone composite types, query-specified composite
types, SRFs.  Not happy with memory management yet, but I'll commit these
other changes.
2002-08-29 00:17:06 +00:00
Bruce Momjian
a77d34f0b8 This patch updates the lock listing code to use Joe Conway's new
anonymous return type SRF code. It gets rid of the superflous
'pg_locks_result' that Bruce/Tom had commented on. Otherwise, no
changes in functionality.

Neil Conway
2002-08-27 04:00:28 +00:00
Bruce Momjian
fc68e44062 Add lock file. 2002-08-17 13:11:43 +00:00