Commit Graph

2797 Commits

Author SHA1 Message Date
Andrew Dunstan f802c6ddba Enable transforms modules to build and run with Mingw builds.
These modules were all missing essential Windows scaffolding, including
resources files and descriptions, and links to the relevant library
import files. This latter item means that the modules can't be built
with pgxs on Windows, as we don't install the import files. If we ever
decide to install them this restriction could probably be removed.

Also, as with plperl we need to make sure that perl's CORE directory is
last on the include list, as on Windows it appears to contain some
headers with names that clash with names of some headers we include.
2015-05-03 09:10:47 -04:00
Peter Eisentraut e30a864963 hstore_plperl: Move port-specific parts to later in the makefile
PORTNAME isn't set until the global makefiles have been included.
2015-05-02 08:03:47 -04:00
Peter Eisentraut 0fd764647a Make hstore_plperl's build even more like plperl's
Combine the two places that set CPPFLAGS into one.  Also, some settings
should be restricted to Windows only.  More precisely, -Wno-comment is
a GCC-only option, but Windows in a makefile implies GCC at the moment.

Also, since -Wno-comment is more properly a preprocessor option, move it
to CPPFLAGS to simplify things a bit.
2015-05-01 22:16:58 -04:00
Andrew Dunstan 77477e745b Make hstore_plperl's build more like plperl's
This involves moving perl's CORE library to the end of the include list,
and adding other compilation settings that plperl uses. This won't
completely fix the breakage currently being seen by gcc builds on
Windows, but it will let the build get further, and should be wholly
benign, if not beneficial, on *nix.
2015-05-01 15:36:44 -04:00
Robert Haas 924bcf4f16 Create an infrastructure for parallel computation in PostgreSQL.
This does four basic things.  First, it provides convenience routines
to coordinate the startup and shutdown of parallel workers.  Second,
it synchronizes various pieces of state (e.g. GUCs, combo CID
mappings, transaction snapshot) from the parallel group leader to the
worker processes.  Third, it prohibits various operations that would
result in unsafe changes to that state while parallelism is active.
Finally, it propagates events that would result in an ErrorResponse,
NoticeResponse, or NotifyResponse message being sent to the client
from the parallel workers back to the master, from which they can then
be sent on to the client.

Robert Haas, Amit Kapila, Noah Misch, Rushabh Lathia, Jeevan Chalke.
Suggestions and review from Andres Freund, Heikki Linnakangas, Noah
Misch, Simon Riggs, Euler Taveira, and Jim Nasby.
2015-04-30 15:02:14 -04:00
Peter Eisentraut dbf2ec1a1c Fix parallel make risk with new check temp-install setup
The "check" target no longer needs to depend on "all", because it now
runs "install" directly, which in turn depends on "all".  Doing both
will cause problems with parallel make, because two builds will run next
to each other.

Also remove the redirection of the temp-install output into a log file.
This was appropriate when this was done from within pg_regress, but now
it's just a regular make run, and especially with the above changes this
will now take the place of running the "all" target before the test
suites.

problem report by Jeff Janes, patch in part by Michael Paquier
2015-04-29 20:34:22 -04:00
Andres Freund 5aa2350426 Introduce replication progress tracking infrastructure.
When implementing a replication solution ontop of logical decoding, two
related problems exist:
* How to safely keep track of replication progress
* How to change replication behavior, based on the origin of a row;
  e.g. to avoid loops in bi-directional replication setups

The solution to these problems, as implemented here, consist out of
three parts:

1) 'replication origins', which identify nodes in a replication setup.
2) 'replication progress tracking', which remembers, for each
   replication origin, how far replay has progressed in a efficient and
   crash safe manner.
3) The ability to filter out changes performed on the behest of a
   replication origin during logical decoding; this allows complex
   replication topologies. E.g. by filtering all replayed changes out.

Most of this could also be implemented in "userspace", e.g. by inserting
additional rows contain origin information, but that ends up being much
less efficient and more complicated.  We don't want to require various
replication solutions to reimplement logic for this independently. The
infrastructure is intended to be generic enough to be reusable.

This infrastructure also replaces the 'nodeid' infrastructure of commit
timestamps. It is intended to provide all the former capabilities,
except that there's only 2^16 different origins; but now they integrate
with logical decoding. Additionally more functionality is accessible via
SQL.  Since the commit timestamp infrastructure has also been introduced
in 9.5 (commit 73c986add) changing the API is not a problem.

For now the number of origins for which the replication progress can be
tracked simultaneously is determined by the max_replication_slots
GUC. That GUC is not a perfect match to configure this, but there
doesn't seem to be sufficient reason to introduce a separate new one.

Bumps both catversion and wal page magic.

Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer
Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer
Discussion: 20150216002155.GI15326@awork2.anarazel.de,
    20140923182422.GA15776@alap3.anarazel.de,
    20131114172632.GE7522@alap2.anarazel.de
2015-04-29 19:30:53 +02:00
Peter Eisentraut f95425478a Fix hstore_plperl regression tests on some platforms
On some platforms, plperl and plperlu cannot be loaded at the same
time.  So split the test into two separate test files.
2015-04-26 16:13:58 -04:00
Peter Eisentraut cac7658205 Add transforms feature
This provides a mechanism for specifying conversions between SQL data
types and procedural languages.  As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.

reviews by Pavel Stěhule and Andres Freund
2015-04-26 10:33:14 -04:00
Tom Lane f320cbb615 Fix typo in linux startup script.
Missed a "$" in what was meant to be a variable substitution.  Careless
mistake in commit f23425fa95.
2015-04-26 09:43:15 -04:00
Peter Eisentraut dcae5facca Improve speed of make check-world
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>
2015-04-23 08:59:52 -04:00
Stephen Frost 4ccc5bd28e Pull in tableoid for inheiritance with rowMarks
As noted by Etsuro Fujita [1] and Dean Rasheed[2],
cb1ca4d800 changed ExecBuildAuxRowMark()
to always look for the tableoid in the target list, but didn't also
change preprocess_targetlist() to always include the tableoid.  This
resulted in errors with soon-to-be-added RLS with inheritance tests,
and errors when using inheritance with foreign tables.

Authors: Etsuro Fujita and Dean Rasheed (independently)

Minor word-smithing on the comments by me.

[1] 552CF0B6.8010006@lab.ntt.co.jp
[2] CAEZATCVmFUfUOwwhnBTcgi6AquyjQ0-1fyKd0T3xBWJvn+xsFA@mail.gmail.com
2015-04-22 11:29:35 -04:00
Andres Freund cef939c347 Rename pg_replication_slot's new active_in to active_pid.
In d811c037ce active_in was added but discussion since showed that
active_pid is preferred as a name.

Discussion: CAMsr+YFKgZca5_7_ouaMWxA5PneJC9LNViPzpDHusaPhU9pA7g@mail.gmail.com
2015-04-22 09:43:40 +02:00
Peter Eisentraut b0a738f428 Move pg_xlogdump from contrib/ to src/bin/
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-21 19:03:49 -04:00
Andres Freund d811c037ce Add 'active_in' column to pg_replication_slots.
Right now it is visible whether a replication slot is active in any
session, but not in which.  Adding the active_in column, containing the
pid of the backend having acquired the slot, makes it much easier to
associate pg_replication_slots entries with the corresponding
pg_stat_replication/pg_stat_activity row.

This should have been done from the start, but I (Andres) dropped the
ball there somehow.

Author: Craig Ringer, revised by me Discussion:
CAMsr+YFKgZca5_7_ouaMWxA5PneJC9LNViPzpDHusaPhU9pA7g@mail.gmail.com
2015-04-21 11:51:06 +02:00
Peter Eisentraut 528c2e44ab Move pg_test_timing from contrib/ to src/bin/
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-20 21:30:12 -04:00
Peter Eisentraut 00882d9e5c Move pg_test_fsync from contrib/ to src/bin/
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-19 22:20:49 -04:00
Peter Eisentraut 9fa8b0ee90 Move pg_upgrade from contrib/ to src/bin/
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-14 19:26:38 -04:00
Peter Eisentraut 30982be4e5 Integrate pg_upgrade_support module into backend
Previously, these functions were created in a schema "binary_upgrade",
which was deleted after pg_upgrade was finished.  Because we don't want
to keep that schema around permanently, move them to pg_catalog but
rename them with a binary_upgrade_... prefix.

The provided functions are only small wrappers around global variables
that were added specifically for pg_upgrade use, so keeping the module
separate does not create any modularity.

The functions still check that they are only called in binary upgrade
mode, so it is not possible to call these during normal operation.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-14 19:26:37 -04:00
Heikki Linnakangas 4f700bcd20 Reorganize our CRC source files again.
Now that we use CRC-32C in WAL and the control file, the "traditional" and
"legacy" CRC-32 variants are not used in any frontend programs anymore.
Move the code for those back from src/common to src/backend/utils/hash.

Also move the slicing-by-8 implementation (back) to src/port. This is in
preparation for next patch that will add another implementation that uses
Intel SSE 4.2 instructions to calculate CRC-32C, where available.
2015-04-14 17:03:42 +03:00
Peter Eisentraut 81134af3ec Move pgbench from contrib/ to src/bin/
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-13 13:07:16 -04:00
Peter Eisentraut 83aca89f7c Move pg_archivecleanup from contrib/ to src/bin/
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2015-04-11 23:29:18 -04:00
Alvaro Herrera 27846f02c1 Optimize locking a tuple already locked by another subxact
Locking and updating the same tuple repeatedly led to some strange
multixacts being created which had several subtransactions of the same
parent transaction holding locks of the same strength.  However,
once a subxact of the current transaction holds a lock of a given
strength, it's not necessary to acquire the same lock again.  This made
some coding patterns much slower than required.

The fix is twofold.  First we change HeapTupleSatisfiesUpdate to return
HeapTupleBeingUpdated for the case where the current transaction is
already a single-xid locker for the given tuple; it used to return
HeapTupleMayBeUpdated for that case.  The new logic is simpler, and the
change to pgrowlocks is a testament to that: previously we needed to
check for the single-xid locker separately in a very ugly way.  That
test is simpler now.

As fallout from the HTSU change, some of its callers need to be amended
so that tuple-locked-by-own-transaction is taken into account in the
BeingUpdated case rather than the MayBeUpdated case.  For many of them
there is no difference; but heap_delete() and heap_update now check
explicitely and do not grab tuple lock in that case.

The HTSU change also means that routine MultiXactHasRunningRemoteMembers
introduced in commit 11ac4c73cb is no longer necessary and can be
removed; the case that used to require it is now handled naturally as
result of the changes to heap_delete and heap_update.

The second part of the fix to the performance issue is to adjust
heap_lock_tuple to avoid the slowness:

1. Previously we checked for the case that our own transaction already
held a strong enough lock and returned MayBeUpdated, but only in the
multixact case.  Now we do it for the plain Xid case as well, which
saves having to LockTuple.

2. If the current transaction is the only locker of the tuple (but with
a lock not as strong as what we need; otherwise it would have been
caught in the check mentioned above), we can skip sleeping on the
multixact, and instead go straight to create an updated multixact with
the additional lock strength.

3. Most importantly, make sure that both the single-xid-locker case and
the multixact-locker case optimization are applied always.  We do this
by checking both in a single place, rather than them appearing in two
separate portions of the routine -- something that is made possible by
the HeapTupleSatisfiesUpdate API change.  Previously we would only check
for the single-xid case when HTSU returned MayBeUpdated, and only
checked for the multixact case when HTSU returned BeingUpdated.  This
was at odds with what HTSU actually returned in one case: if our own
transaction was locker in a multixact, it returned MayBeUpdated, so the
optimization never applied.  This is what led to the large multixacts in
the first place.

Per bug report #8470 by Oskari Saarenmaa.
2015-04-10 13:47:15 -03:00
Robert Haas e41beea0dd Improve pgbench error reporting.
This would have been worth doing on general principle anyway, but the
recent addition of an expression syntax to pgbench makes it an even
better idea than it would have been otherwise.

Fabien Coelho
2015-04-02 16:26:49 -04:00
Andres Freund 62e2a8dc2c Define integer limits independently from the system definitions.
In 83ff1618 we defined integer limits iff they're not provided by the
system. That turns out not to be the greatest idea because there's
different ways some datatypes can be represented. E.g. on OSX PG's 64bit
datatype will be a 'long int', but OSX unconditionally uses 'long
long'. That disparity then can lead to warnings, e.g. around printf
formats.

One way to fix that would be to back int64 using stdint.h's
int64_t. While a good idea it's not that easy to implement. We would
e.g. need to include stdint.h in our external headers, which we don't
today. Also computing the correct int64 printf formats in that case is
nontrivial.

Instead simply prefix the integer limits with PG_ and define them
unconditionally. I've adjusted all the references to them in code, but
not the ones in comments; the latter seems unnecessary to me.

Discussion: 20150331141423.GK4878@alap3.anarazel.de
2015-04-02 17:43:35 +02:00
Bruce Momjian a0efc71453 pg_upgrade: call 'postgres' binary to get data directory location
This matches the binary 'pg_ctl' calls.  Previously we called the
'postmaster'.

Report by Christoph Berg
2015-04-01 18:25:45 -04:00
Bruce Momjian 0cf16b44cb btree_gin: properly call DirectFunctionCall1()
Previously we called DirectFunctionCall3() with dummy arguments.  Fixed
version of previous patch.

Report by Jon Nelson
2015-03-31 10:26:45 -04:00
Heikki Linnakangas 1d0db8de04 Remove spurious semicolons.
Petr Jelinek
2015-03-31 15:12:27 +03:00
Andrew Dunstan fa1e5afa8a Run pg_upgrade and pg_resetxlog with restricted token on Windows
As with initdb these programs need to run with a restricted token, and
if they don't pg_upgrade will fail when run as a user with Adminstrator
privileges.

Backpatch to all live branches. On the development branch the code is
reorganized so that the restricted token code is now in a single
location. On the stable bramches a less invasive change is made by
simply copying the relevant code to pg_upgrade.c and pg_resetxlog.c.

Patches and bug report from Muhammad Asif Naeem, reviewed by Michael
Paquier, slightly edited by me.
2015-03-30 17:07:52 -04:00
Tom Lane 542320c2bd Be more careful about printing constants in ruleutils.c.
The previous coding in get_const_expr() tried to avoid quoting integer,
float, and numeric literals if at all possible.  While that looks nice,
it means that dumped expressions might re-parse to something that's
semantically equivalent but not the exact same parsetree; for example
a FLOAT8 constant would re-parse as a NUMERIC constant with a cast to
FLOAT8.  Though the result would be the same after constant-folding,
this is problematic in certain contexts.  In particular, Jeff Davis
pointed out that this could cause unexpected failures in ALTER INHERIT
operations because of child tables having not-exactly-equivalent CHECK
expressions.  Therefore, favor correctness over legibility and dump
such constants in quotes except in the limited cases where they'll
be interpreted as the same type even without any casting.

This results in assorted small changes in the regression test outputs,
and will affect display of user-defined views and rules similarly.
The odds of that causing problems in the field seem non-negligible;
given the lack of previous complaints, it seems best not to change
this in the back branches.
2015-03-30 14:59:49 -04:00
Tom Lane e9dd03c03a Minor code cleanups in pgbench expression support.
Get rid of unnecessary expr_yylex declaration (we haven't supported
flex 2.5.4 in a long time, and even if we still did, the declaration in
pgbench.h makes this one unnecessary and inappropriate).  Fix copyright
dates, improve some layout choices, etc.
2015-03-29 13:06:59 -04:00
Tom Lane 2c33e0fbce Better fix for misuse of Float8GetDatumFast().
We can use that macro as long as we put the value into a local variable.
Commit 735cd6128 was not wrong on its own terms, but I think this way
looks nicer, and it should save a few cycles on 32-bit machines.
2015-03-28 13:56:37 -04:00
Andrew Dunstan cfe12763c3 Use standard librart sqrt function in pg_stat_statements
The stddev calculation included a faster but unportable sqrt function.
This is not worth the extra effort, and won't work everywhere. If the
standard library function is good enough for the SQL function it
should be good enough here too.
2015-03-28 09:22:51 -04:00
Heikki Linnakangas e09b48316c Add index-only scan support to btree_gist.
inet, cidr, and timetz indexes still cannot support index-only scans,
because they don't store the original unmodified value in the index, but a
derived approximate value.
2015-03-27 23:35:16 +02:00
Andrew Dunstan 735cd6128a Fix portability issues with stddev in pg_stat_statements
Stddev is calculated on the fly, and the code in commit 717f709532 was
using Float8GetDatumFast() inappropriately to convert the result to a
Datum. Mea culpa. It now uses Float8GetDatum().
2015-03-27 17:29:59 -04:00
Andrew Dunstan 717f709532 Add stats for min, max, mean, stddev times to pg_stat_statements.
The new fields are min_time, max_time, mean_time and stddev_time.

Based on an original patch from Mitsumasa KONDO, modified by me. Reviewed by Petr Jelínek.
2015-03-27 15:43:22 -04:00
Heikki Linnakangas 8816af65e4 Minor refactoring of btree_gist code.
The gbt_var_key_copy function was doing two different things depending on
the boolean argument. Seems cleaner to have two separate functions.

Remove unused argument from gbt_num_compress.
2015-03-26 23:10:10 +02:00
Tom Lane 785941cdc3 Tweak __attribute__-wrapping macros for better pgindent results.
This improves on commit bbfd7edae5 by
making two simple changes:

* pg_attribute_noreturn now takes parentheses, ie pg_attribute_noreturn().
Likewise pg_attribute_unused(), pg_attribute_packed().  This reduces
pgindent's tendency to misformat declarations involving them.

* attributes are now always attached to function declarations, not
definitions.  Previously some places were taking creative shortcuts,
which were not merely candidates for bad misformatting by pgindent
but often were outright wrong anyway.  (It does little good to put a
noreturn annotation where callers can't see it.)  In any case, if
we would like to believe that these macros can be used with non-gcc
compilers, we should avoid gratuitous variance in usage patterns.

I also went through and manually improved the formatting of a lot of
declarations, and got rid of excessively repetitive (and now obsolete
anyway) comments informing the reader what pg_attribute_printf is for.
2015-03-26 14:03:25 -04:00
Andres Freund 83ff1618bc Centralize definition of integer limits.
Several submitted and even committed patches have run into the problem
that C89, our baseline, does not provide minimum/maximum values for
various integer datatypes. C99's stdint.h does, but we can't rely on
it.

Several parts of the code defined limits locally, so instead centralize
the definitions to c.h.

This patch also changes the more obvious usages of literal limit values;
there's more places that could be changed, but it's less clear whether
it's beneficial to change those.

Author: Andrew Gierth
Discussion: 87619tc5wc.fsf@news-spur.riddles.org.uk
2015-03-25 22:39:42 +01:00
Bruce Momjian 11226e3817 Revert commit 843cd0bfe6
Report by Tom Lane
2015-03-24 22:35:05 -04:00
Bruce Momjian 843cd0bfe6 btree_gin: properly call DirectFunctionCall1()
Previously we called DirectFunctionCall3() with dummy arguments.

Patch by Jon Nelson
2015-03-24 20:53:29 -04:00
Tom Lane cb1ca4d800 Allow foreign tables to participate in inheritance.
Foreign tables can now be inheritance children, or parents.  Much of the
system was already ready for this, but we had to fix a few things of
course, mostly in the area of planner and executor handling of row locks.

As side effects of this, allow foreign tables to have NOT VALID CHECK
constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to
accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS.  Continuing to
disallow these things would've required bizarre and inconsistent special
cases in inheritance behavior.  Since foreign tables don't enforce CHECK
constraints anyway, a NOT VALID one is a complete no-op, but that doesn't
mean we shouldn't allow it.  And it's possible that some FDWs might have
use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops
for most.

An additional change in support of this is that when a ModifyTable node
has multiple target tables, they will all now be explicitly identified
in EXPLAIN output, for example:

 Update on pt1  (cost=0.00..321.05 rows=3541 width=46)
   Update on pt1
   Foreign Update on ft1
   Foreign Update on ft2
   Update on child3
   ->  Seq Scan on pt1  (cost=0.00..0.00 rows=1 width=46)
   ->  Foreign Scan on ft1  (cost=100.00..148.03 rows=1170 width=46)
   ->  Foreign Scan on ft2  (cost=100.00..148.03 rows=1170 width=46)
   ->  Seq Scan on child3  (cost=0.00..25.00 rows=1200 width=46)

This was done mainly to provide an unambiguous place to attach "Remote SQL"
fields, but it is useful for inherited updates even when no foreign tables
are involved.

Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro
Horiguchi, some additional hacking by me
2015-03-22 13:53:21 -04:00
Tom Lane 8d1f239003 Replace insertion sort in contrib/intarray with qsort().
It's all very well to claim that a simplistic sort is fast in easy
cases, but O(N^2) in the worst case is not good ... especially if the
worst case is as easy to hit as "descending order input".  Replace that
bit with our standard qsort.

Per bug #12866 from Maksym Boguk.  Back-patch to all active branches.
2015-03-15 23:22:03 -04:00
Tom Lane 7b8b8a4331 Improve representation of PlanRowMark.
This patch fixes two inadequacies of the PlanRowMark representation.

First, that the original LockingClauseStrength isn't stored (and cannot be
inferred for foreign tables, which always get ROW_MARK_COPY).  Since some
PlanRowMarks are created out of whole cloth and don't actually have an
ancestral RowMarkClause, this requires adding a dummy LCS_NONE value to
enum LockingClauseStrength, which is fairly annoying but the alternatives
seem worse.  This fix allows getting rid of the use of get_parse_rowmark()
in FDWs (as per the discussion around commits 462bd95705 and
8ec8760fc8), and it simplifies some things elsewhere.

Second, that the representation assumed that all child tables in an
inheritance hierarchy would use the same RowMarkType.  That's true today
but will soon not be true.  We add an "allMarkTypes" field that identifies
the union of mark types used in all a parent table's children, and use
that where appropriate (currently, only in preprocess_targetlist()).

In passing fix a couple of minor infelicities left over from the SKIP
LOCKED patch, notably that _outPlanRowMark still thought waitPolicy
is a bool.

Catversion bump is required because the numeric values of enum
LockingClauseStrength can appear in on-disk rules.

Extracted from a much larger patch to support foreign table inheritance;
it seemed worth breaking this out, since it's a separable concern.

Shigeru Hanada and Etsuro Fujita, somewhat modified by me
2015-03-15 18:41:47 -04:00
Robert Haas e96b7c6b9f sepgsql: Improve error message when unsupported object type is labeled.
KaiGai Kohei, reviewed by Álvaro Herrera and myself
2015-03-11 12:12:10 -04:00
Andres Freund bbfd7edae5 Add macros wrapping all usage of gcc's __attribute__.
Until now __attribute__() was defined to be empty for all compilers but
gcc. That's problematic because it prevents using it in other compilers;
which is necessary e.g. for atomics portability.  It's also just
generally dubious to do so in a header as widely included as c.h.

Instead add pg_attribute_format_arg, pg_attribute_printf,
pg_attribute_noreturn macros which are implemented in the compilers that
understand them. Also add pg_attribute_noreturn and pg_attribute_packed,
but don't provide fallbacks, since they can affect functionality.

This means that external code that, possibly unwittingly, relied on
__attribute__ defined to be empty on !gcc compilers may now run into
warnings or errors on those compilers. But there shouldn't be many
occurances of that and it's hard to work around...

Discussion: 54B58BA3.8040302@ohmu.fi
Author: Oskari Saarenmaa, with some minor changes by me.
2015-03-11 14:30:01 +01:00
Fujii Masao 57aa5b2bb1 Add GUC to enable compression of full page images stored in WAL.
When newly-added GUC parameter, wal_compression, is on, the PostgreSQL server
compresses a full page image written to WAL when full_page_writes is on or
during a base backup. A compressed page image will be decompressed during WAL
replay. Turning this parameter on can reduce the WAL volume without increasing
the risk of unrecoverable data corruption, but at the cost of some extra CPU
spent on the compression during WAL logging and on the decompression during
WAL replay.

This commit changes the WAL format (so bumping WAL version number) so that
the one-byte flag indicating whether a full page image is compressed or not is
included in its header information. This means that the commit increases the
WAL volume one-byte per a full page image even if WAL compression is not used
at all. We can save that one-byte by borrowing one-bit from the existing field
like hole_offset in the header and using it as the flag, for example. But which
would reduce the code readability and the extensibility of the feature.
Per discussion, it's not worth paying those prices to save only one-byte, so we
decided to add the one-byte flag to the header.

This commit doesn't introduce any new compression algorithm like lz4.
Currently a full page image is compressed using the existing PGLZ algorithm.
Per discussion, we decided to use it at least in the first version of the
feature because there were no performance reports showing that its compression
ratio is unacceptably lower than that of other algorithm. Of course,
in the future, it's worth considering the support of other compression
algorithm for the better compression.

Rahila Syed and Michael Paquier, reviewed in various versions by myself,
Andres Freund, Robert Haas, Abhijit Menon-Sen and many others.
2015-03-11 15:52:24 +09:00
Alvaro Herrera e491bd2ee3 Move BRIN page type to page's last two bytes
... which is the usual convention among AMs, so that pg_filedump and
similar utilities can tell apart pages of different AMs.  It was also
the intent of the original code, but I failed to realize that alignment
considerations would move the whole thing to the previous-to-last word
in the page.

The new definition of the associated macro makes surrounding code a bit
leaner, too.

Per note from Heikki at
http://www.postgresql.org/message-id/546A16EF.9070005@vmware.com
2015-03-10 12:27:15 -03:00
Heikki Linnakangas f1fd515b39 Move WAL-related definitions from dbcommands.h to separate header file.
This makes it easier to write frontend programs that needs to understand
the WAL record format of CREATE/DROP DATABASE. dbcommands.h cannot easily
be #included in a frontend program, because it pulls in other header files
that need backend stuff, but the new dbcommands_xlog.h header file has
fewer dependencies.
2015-03-09 15:50:49 +02:00
Alvaro Herrera c6ee39bc85 Fix contrib/file_fdw's expected file
I forgot to update it on yesterday's cf34e373fc.
2015-03-06 11:47:09 -03:00