Commit 7d0f493f19 added infrastructure
to perform tests in assorted src/bin/ subdirectories, but forgot to
teach "make clean" to clean up the detritus the tests leave behind.
WAL records of hint bit updates is useful to tools that want to examine
which pages have been modified. In particular, this is required to make
the pg_rewind tool safe (without checksums).
This can also be used to test how much extra WAL-logging would occur if
you enabled checksums, without actually enabling them (which you can't
currently do without re-initdb'ing).
Sawada Masahiko, docs by Samrat Revagade. Reviewed by Dilip Kumar, with
further changes by me.
When wal_level=logical, we'll log columns from the old tuple as
configured by the REPLICA IDENTITY facility added in commit
07cacba983. This makes it possible
a properly-configured logical replication solution to correctly
follow table updates even if they change the chosen key columns,
or, with REPLICA IDENTITY FULL, even if the table has no key at
all. Note that updates which do not modify the replica identity
column won't log anything extra, making the choice of a good key
(i.e. one that will rarely be changed) important to performance
when wal_level=logical is configured.
Each insert, update, or delete to a catalog table will also log
the CMIN and/or CMAX values of stamped by the current transaction.
This is necessary because logical decoding will require access to
historical snapshots of the catalog in order to decode some data
types, and the CMIN/CMAX values that we may need in order to judge
row visibility may have been overwritten by the time we need them.
Andres Freund, reviewed in various versions by myself, Heikki
Linnakangas, KONDO Mitsumasa, and many others.
In 9.3, there's no particular limit on the number of bgworkers;
instead, we just count up the number that are actually registered,
and use that to set MaxBackends. However, that approach causes
problems for Hot Standby, which needs both MaxBackends and the
size of the lock table to be the same on the standby as on the
master, yet it may not be desirable to run the same bgworkers in
both places. 9.3 handles that by failing to notice the problem,
which will probably work fine in nearly all cases anyway, but is
not theoretically sound.
A further problem with simply counting the number of registered
workers is that new workers can't be registered without a
postmaster restart. This is inconvenient for administrators,
since bouncing the postmaster causes an interruption of service.
Moreover, there are a number of applications for background
processes where, by necessity, the background process must be
started on the fly (e.g. parallel query). While this patch
doesn't actually make it possible to register new background
workers after startup time, it's a necessary prerequisite.
Patch by me. Review by Michael Paquier.
Checksums are set immediately prior to flush out of shared buffers
and checked when pages are read in again. Hint bit setting will
require full page write when block is dirtied, which causes various
infrastructure changes. Extensive comments, docs and README.
WARNING message thrown if checksum fails on non-all zeroes page;
ERROR thrown but can be disabled with ignore_checksum_failure = on.
Feature enabled by an initdb option, since transition from option off
to option on is long and complex and has not yet been implemented.
Default is not to use checksums.
Checksum used is WAL CRC-32 truncated to 16-bits.
Simon Riggs, Jeff Davis, Greg Smith
Wide input and assistance from many community members. Thank you.
The reason this wasn't supported before was that GiST indexes need an
increasing sequence to detect concurrent page-splits. In a regular WAL-
logged GiST index, the LSN of the page-split record is used for that
purpose, and in a temporary index, we can get away with a backend-local
counter. Neither of those methods works for an unlogged relation.
To provide such an increasing sequence of numbers, create a "fake LSN"
counter that is saved and restored across shutdowns. On recovery, unlogged
relations are blown away, so the counter doesn't need to survive that
either.
Jeevan Chalke, based on discussions with Robert Haas, Tom Lane and me.
This isn't used for anything but a sanity check at the moment, but it could
be highly valuable for debugging purposes. It could also be used to recreate
timeline history by traversing WAL, which seems useful.
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.com1290721684-sup-3951@alvh.no-ip.org1294953201-sup-2099@alvh.no-ip.org1320343602-sup-2290@alvh.no-ip.org1339690386-sup-8927@alvh.no-ip.org4FE5FF020200002500048A3D@gw.wicourts.gov4FEAB90A0200002500048B7D@gw.wicourts.gov
This allows recovery to notice certain incorrect recovery scenarios.
If a server has recovered to point X on timeline 5, and you restart
recovery, it better be on timeline 5 when it reaches point X again, not on
some timeline with a higher ID. This can happen e.g if you a standby server
is shut down, a new timeline appears in the WAL archive, and the standby
server is restarted. It will try to follow the new timeline, which is wrong
because some WAL on the old timeline was already replayed before shutdown.
Requires an initdb (or at least pg_resetxlog), because this adds a field to
the control file.
This simplifies code that needs to do arithmetic on XLogRecPtrs.
To avoid changing on-disk format of data pages, the LSN on data pages is
still stored in the old format. That should keep pg_upgrade happy. However,
we have XLogRecPtrs embedded in the control file, and in the structs that
are sent over the replication protocol, so this changes breaks compatibility
of pg_basebackup and server. I didn't do anything about this in this patch,
per discussion on -hackers, the right thing to do would to be to change the
replication protocol to be architecture-independent, so that you could use
a newer version of pg_receivexlog, for example, against an older server
version.
Before, some places didn't document the short options (-? and -V),
some documented both, some documented nothing, and they were listed in
various orders. Now this is hopefully more consistent and complete.
This makes it much more convenient to build tools for Postgres that are
separately compiled and require a matching CRC implementation.
To prevent multiple copies of the CRC polynomial tables being introduced
into the postgres binaries, they are now included in the static library
libpgport that is mainly meant for replacement system functions. That
seems like a bit of a kludge, but there's no better place.
This cleans up building of the tools pg_controldata and pg_resetxlog,
which previously had to build their own copies of pg_crc.o.
In the future, external programs that need access to the CRC tables can
include the tables directly from the new header file pg_crc_tables.h.
Daniel Farina, reviewed by Abhijit Menon-Sen and Tom Lane
Base backup follows recommended procedure, plus goes to great
lengths to ensure that partial page writes are avoided.
Jun Ishizuka and Fujii Masao, with minor modifications
It currently doesn't make a difference, but it's inconsistent with
most other usage, and it might interfere with a future patch, so I'll
change it all in a separate commit.
Also, replace tabs with spaces for alignment.
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.
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.
archival or hot standby should be WAL-logged, instead of deducing that from
other options like archive_mode. This replaces recovery_connections GUC in
the primary, where it now has no effect, but it's still used in the standby
to enable/disable hot standby.
Remove the WAL-logging of "unlogged operations", like creating an index
without WAL-logging and fsyncing it at the end. Instead, we keep a copy of
the wal_mode setting and the settings that affect how much shared memory a
hot standby server needs to track master transactions (max_connections,
max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings
change, at server restart, write a WAL record noting the new settings and
update pg_control. This allows us to notice the change in those settings in
the standby at the right moment, they used to be included in checkpoint
records, but that meant that a changed value was not reflected in the
standby until the first checkpoint after the change.
Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to
the sequence it used to follow, before hot standby and subsequent patches
changed it to 0x9003.
recovery instead of reading the backup history file. This is more robust,
as it stops you from prematurely starting up an inconsisten cluster if the
backup history file is lost for some reason, or if the base backup was
never finished with pg_stop_backup().
This also paves the way for a simpler streaming replication patch, which
doesn't need to care about backup history files anymore.
The backup history file is still created and archived as before, but it's
not used by the system anymore. It's just for informational purposes now.
Bump PG_CONTROL_VERSION as the location of the backup startpoint is now
written to a new field in pg_control, and catversion because initdb is
required
Original patch by Fujii Masao per Simon's idea, with further fixes by me.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
XID) in checkpoint records. This eliminates the need to recompute the value
from scratch during database startup, which is one of the two remaining
reasons for the flatfile code to exist. It should also simplify life for
hot-standby operation.
To avoid bloating the checkpoint records unreasonably, I switched from
tracking the oldest database by name to tracking it by OID. This turns
out to save cycles in general (everywhere but the warning-generating
paths, which we hardly care about) and also helps us deal with the case
that the oldest database got dropped instead of being vacuumed. The prior
coding might go for a long time without updating the wrap limit in that case,
which is bad because it might result in a lot of useless autovacuum activity.
Update install-sh to that from Autoconf 2.63, plus our Darwin-specific
changes (which I simplified a bit). install-sh is now able to install
multiple files in one run, so we could simplify our makefiles sometime.
install-sh also now has a -d option to create directories, so we don't need
mkinstalldirs anymore.
Use AC_PROG_MKDIR_P in configure.in, so we can use mkdir -p when available
instead of install-sh -d. For consistency with the rest of the world,
the corresponding make variable has been renamed from $(mkinstalldirs) to
$(MKDIR_P).
ctype are now more like encoding, stored in new datcollate and datctype
columns in pg_database.
This is a stripped-down version of Radek Strnad's patch, with further
changes by me.
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.
inclusions in src/include/catalog/*.h files. The main idea here is to push
function declarations for src/backend/catalog/*.c files into separate headers,
rather than sticking them into the corresponding catalog definition file as
has been done in the past. This commit only carries out that idea fully for
pg_proc, pg_type and pg_conversion, but that's enough for the moment ---
if pg_list.h ever becomes unsafe for frontend code to include, we'll need
to work a bit more.
Zdenek Kotala
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.
duplicative -DFRONTEND flags from many Makefiles. We still need Makefile
control of the symbol in a few places that compile frontend-or-backend
src/port/ files, but it's a lot cleaner than before.
Hiroshi Saito
Add the latter to the values checked in pg_control, since it can't be changed
without invalidating toast table content. This commit in itself shouldn't
change any behavior, but it lays some necessary groundwork for experimentation
with these toast-control numbers.
Note: while TOAST_TUPLE_THRESHOLD can now be changed without initdb, some
thought still needs to be given to needs_toast_table() in toasting.c before
unleashing random changes.
in normal operation, and we can avoid rewriting pg_control at every log
segment switch if we don't insist that these values be valid. Reducing
the number of pg_control updates is a good idea for both performance and
reliability. It does make pg_resetxlog's life a bit harder, but that seems
a good tradeoff; and anyway the change to pg_resetxlog amounts to automating
something people formerly needed to do by hand, namely look at the existing
pg_xlog files to make sure the new WAL start point was past them.
In passing, change the wording of xlog.c's "database system was interrupted"
messages: describe the pg_control timestamp as "last known up at" rather than
implying it is the exact time of service interruption. With this change the
timestamp will generally be the time of the last checkpoint, which could be
many minutes before the failure; and we've already seen indications that
people tend to misinterpret the old wording.
initdb forced due to change in pg_control layout. Simon Riggs and Tom Lane
of the transaction ID counter. Nothing is done with the epoch except to
store it in checkpoint records, but this provides a foundation with which
add-on code can pretend that XIDs never wrap around. This is a severely
trimmed and rewritten version of the xxid patch submitted by Marko Kreen.
Per discussion, the epoch counter seems the only part of xxid that really
needs to be in the core server.
operation every so often. This improves the usefulness of PITR log
shipping for hot standby: formerly, if the standby server crashed, it
was necessary to restart it from the last base backup and replay all
the WAL since then. Now it will only need to reread about the same
amount of WAL as the master server would. The behavior might also
come in handy during a long PITR replay sequence. Simon Riggs,
with some editorialization by Tom Lane.
o remove many WIN32_CLIENT_ONLY defines
o add WIN32_ONLY_COMPILER define
o add 3rd argument to open() for portability
o add include/port/win32_msvc directory for
system includes
Magnus Hagander
used within WAL files. Historically this was the same as the data file
BLCKSZ, but there's no necessary connection, and it's possible that
performance gains might ensue from reducing XLOG_BLCKSZ. In any case
distinguishing two symbols should improve code clarity. This commit
does not actually change the page size, only provide the infrastructure
to make it possible to do so. initdb forced because of addition of a
field to pg_control.
Mark Wong, with some help from Simon Riggs and Tom Lane.
was created on a machine with alignment rules and floating-point format
similar to the current machine. Per recent discussion, this seems like
a good idea with the increasing prevalence of 32/64 bit environments.
transaction IDs, rather than like subtrans; in particular, the information
now survives a database restart. Per previous discussion, this is
essential for PITR log shipping and for 2PC.
Instead of a separate CRC on each backup block, include backup blocks
in their parent WAL record's CRC; this is important to ensure that the
backup block really goes with the WAL record, ie there was not a page
tear right at the start of the backup block. Implement a simple form
of compression of backup blocks: drop any run of zeroes starting at
pd_lower, so as not to store the unused 'hole' that commonly exists in
PG heap and index pages. Tweak PageRepairFragmentation and related
routines to ensure they keep the unused space zeroed, so that the above
compression method remains effective. All per recent discussions.
to eliminate unnecessary deadlocks. This commit adds SELECT ... FOR SHARE
paralleling SELECT ... FOR UPDATE. The implementation uses a new SLRU
data structure (managed much like pg_subtrans) to represent multiple-
transaction-ID sets. When more than one transaction is holding a shared
lock on a particular row, we create a MultiXactId representing that set
of transactions and store its ID in the row's XMAX. This scheme allows
an effectively unlimited number of row locks, just as we did before,
while not costing any extra overhead except when a shared lock actually
has to be shared. Still TODO: use the regular lock manager to control
the grant order when multiple backends are waiting for a row lock.
Alvaro Herrera and Tom Lane.
recovery more manageable. Also, undo recent change to add FILE_HEADER
and WASTED_SPACE records to XLOG; instead make the XLOG page header
variable-size with extra fields in the first page of an XLOG file.
This should fix the boundary-case bugs observed by Mark Kirkwood.
initdb forced due to change of XLOG representation.
environment variable processing to libpq.
The patch also adds code to our client apps so we set the environment
variable directly based on our binary location, unless it is already
set. This will allow our applications to emit proper locale messages
that are generated in libpq.
find_my_exec/find_other_exec(). Remove passing of progname to these
functions as they can find that out from argv[0], which they already
have.
Make get_progname return const char *, and update all progname variables
to be const char *.
wit: Add a header record to each WAL segment file so that it can be reliably
identified. Avoid splitting WAL records across segment files (this is not
strictly necessary, but makes it simpler to incorporate the header records).
Make WAL entries for file creation, deletion, and truncation (as foreseen but
never implemented by Vadim). Also, add support for making XLOG_SEG_SIZE
configurable at compile time, similarly to BLCKSZ. Fix a couple bugs I
introduced in WAL replay during recent smgr API changes. initdb is forced
due to changes in pg_control contents.
Tom Lane
Peter Eisentraut
Bruce Momjian
Fujii Masao
Heikki Linnakangas
Robert Haas
Simon Riggs
Alvaro Herrera
Magnus Hagander
Neil Conway
Dennis Bjorklund