As bug #15733 has proved, we are lacking coverage for partition tuple
routing with dropped attributes when involving three levels of
partitioning or more. There was only an active bug in this area for
v11, and HEAD is proving to handle those scenarios fine, still it lacked
some coverage for the previous problem.
Author: Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/15733-7692379e310b80ec@postgresql.org
pg_get_indexdef_worker carelessly fetched indoption entries even for
non-key index columns that don't have one. 99.999% of the time this
would be harmless, since the code wouldn't examine the value ... but
some fine day this will be a fetch off the end of memory, resulting
in SIGSEGV.
Detected through valgrind testing. Odd that the buildfarm's valgrind
critters haven't noticed.
The new command lists partitioned relations (tables and/or indexes),
possibly with their sizes, possibly including partitioned partitions;
their parents (if not top-level); if indexes show the tables they belong
to; and their descriptions.
While there are various possible improvements to this, having it in this
form is already a great improvement over not having any way to obtain
this report.
Author: Pavel Stěhule, with help from Mathias Brossard, Amit Langote and
Justin Pryzby.
Reviewed-by: Amit Langote, Mathias Brossard, Melanie Plageman,
Michaël Paquier, Álvaro Herrera
Before those commits, partitioning-related code in the executor could
assume that ModifyTableState.resultRelInfo[] contains only leaf partitions.
However, now a fully-pruned update results in a dummy ModifyTable that
references the root partitioned table, and that breaks some stuff.
In v11, this led to an assertion or core dump in the tuple routing code.
Fix by disabling tuple routing, since we don't need that anyway.
(I chose to do that in HEAD as well for safety, even though the problem
doesn't manifest in HEAD as it stands.)
In v10, this confused ExecInitModifyTable's decision about whether it
needed to close the root table. But we can get rid of that altogether
by being smarter about where to find the root table.
Note that since the referenced commits haven't shipped yet, this
isn't fixing any bug the field has seen.
Amit Langote, per a report from me
Discussion: https://postgr.es/m/20710.1554582479@sss.pgh.pa.us
This uses the same infrastructure that the CREATE INDEX progress
reporting uses. Add a column to pg_stat_progress_create_index to
report the OID of the index being worked on. This was not necessary
for CREATE INDEX, but it's useful for REINDEX.
Also edit the phase descriptions a bit to be more consistent with the
source code comments.
Discussion: https://www.postgresql.org/message-id/ef6a6757-c36a-9e81-123f-13b19e36b7d7%402ndquadrant.com
Fix some places where we might fail to do Py_DECREF() on a Python
object (thereby leaking it for the rest of the session). Almost
all of the risks were in error-recovery paths, which we don't really
expect to hit anyway. Hence, while this is definitely a bug fix,
it doesn't quite seem worth back-patching.
Nikita Glukhov, Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/28053a7d-10d8-fc23-b05c-b4749c873f63@postgrespro.ru
The foreign-key-checking loop in ATRewriteTables failed to ignore
relations without storage (e.g., partitioned tables), unlike the
initial loop. This accidentally worked as long as RI_Initial_Check
succeeded, which it does in most practical cases (including all the
ones exercised in the existing regression tests :-(). However, if
that failed, as for instance when there are permissions issues,
then we entered the slow fire-the-trigger-on-each-tuple path.
And that would try to read from the referencing relation, and fail
if it lacks storage.
A second problem, recently introduced in HEAD, was that this loop
had been broken by sloppy refactoring for the tableam API changes.
Repair both issues, and add a regression test case so we have some
coverage on this code path. Back-patch as needed to v11.
(It looks like this code could do with additional bulletproofing,
but let's get a working test case in place first.)
Hadi Moshayedi, Tom Lane, Andres Freund
Discussion: https://postgr.es/m/CAK=1=WrnNmBbe5D9sm3t0a6dnAq3cdbF1vXY816j1wsMqzC8bw@mail.gmail.com
Discussion: https://postgr.es/m/19030.1554574075@sss.pgh.pa.us
Discussion: https://postgr.es/m/20190325180405.jytoehuzkeozggxx%40alap3.anarazel.de
Similarly to the set of parameters for keepalive, a connection parameter
for libpq is added as well as a backend GUC, called tcp_user_timeout.
Increasing the TCP user timeout is useful to allow a connection to
survive extended periods without end-to-end connection, and decreasing
it allows application to fail faster. By default, the parameter is 0,
which makes the connection use the system default, and follows a logic
close to the keepalive parameters in its handling. When connecting
through a Unix-socket domain, the parameters have no effect.
Author: Ryohei Nagaura
Reviewed-by: Fabien Coelho, Robert Haas, Kyotaro Horiguchi, Kirk
Jamison, Mikalai Keida, Takayuki Tsunakawa, Andrei Yahorau
Discussion: https://postgr.es/m/EDA4195584F5064680D8130B1CA91C45367328@G01JPEXMBYT04
If we need ordered output from a scan of a partitioned table, but
the ordering matches the partition ordering, then we don't need to
use a MergeAppend to combine the pre-ordered per-partition scan
results: a plain Append will produce the same results. This
both saves useless comparison work inside the MergeAppend proper,
and allows us to start returning tuples after istarting up just
the first child node not all of them.
However, all is not peaches and cream, because if some of the
child nodes have high startup costs then there will be big
discontinuities in the tuples-returned-versus-elapsed-time curve.
The planner's cost model cannot handle that (yet, anyway).
If we model the Append's startup cost as being just the first
child's startup cost, we may drastically underestimate the cost
of fetching slightly more tuples than are available from the first
child. Since we've had bad experiences with over-optimistic choices
of "fast start" plans for ORDER BY LIMIT queries, that seems scary.
As a klugy workaround, set the startup cost estimate for an ordered
Append to be the sum of its children's startup costs (as MergeAppend
would). This doesn't really describe reality, but it's less likely
to cause a bad plan choice than an underestimated startup cost would.
In practice, the cases where we really care about this optimization
will have child plans that are IndexScans with zero startup cost,
so that the overly conservative estimate is still just zero.
David Rowley, reviewed by Julien Rouhaud and Antonin Houska
Discussion: https://postgr.es/m/CAKJS1f-hAqhPLRk_RaSFTgYxd=Tz5hA7kQ2h4-DhJufQk8TGuw@mail.gmail.com
This allows the user to create duplicates of existing replication slots,
either logical or physical, and even changing properties such as whether
they are temporary or the output plugin used.
There are multiple uses for this, such as initializing multiple replicas
using the slot for one base backup; when doing investigation of logical
replication issues; and to select a different output plugins.
Author: Masahiko Sawada
Reviewed-by: Michael Paquier, Andres Freund, Petr Jelinek
Discussion: https://postgr.es/m/CAD21AoAm7XX8y_tOPP6j4Nzzch12FvA1wPqiO690RCk+uYVstg@mail.gmail.com
Prior to v12, if you used a collation-sensitive regex feature in a
pattern handled by processSQLNamePattern() (for instance, \d '\\w+'
in psql), the behavior you got matched the database's default collation.
Since commit 586b98fdf you'd usually get C-collation behavior, because
the catalog "name"-type columns are now marked as COLLATE "C". Add
explicit COLLATE specifications to restore the prior behavior.
(Note for whoever writes the v12 release notes: the need for this shows
that while 586b98fdf preserved pre-v12 behavior of "name" columns for
simple comparison operators, it changed the behavior of regex operators
on those columns. Although this patch fixes it for pattern matches
generated by our own tools, user-written queries will still be affected.
So we'd better mention this issue as a compatibility item.)
Daniel Vérité
Discussion: https://postgr.es/m/701e51f0-0ec0-4e70-a365-1958d66dd8d2@manitou-mail.org
The limitations that it is not allowed to create/attach a foreign table
as a partition of an indexed partitioned table were not documented.
Reported-By: Stepan Yankevych
Author: Etsuro Fujita
Reviewed-By: Amit Langote
Backpatch-through: 11 where partitioned index was introduced
Discussion: https://postgr.es/m/1553869152.858391073.5f8m3n0x@frv53.fwdcdn.com
Rewrite get_attgenerated() to avoid compiler warning if the compiler
does not recognize that elog(ERROR) does not return.
Reported-by: David Rowley <david.rowley@2ndquadrant.com>
Commit 3eb77eba moved a _mdfd_getseg() call from mdsync() into a new
callback function mdsyncfiletag(), but didn't get the arguments quite
right. Without the EXTENSION_DONT_CHECK_SIZE flag we fail to open a
segment if lower-numbered segments have been truncated, and it wants
a block number rather than a segment number.
While comparing with the older coding, also remove an unnecessary
clobbering of errno, and adjust the code in mdunlinkfiletag() to
ressemble the original code from mdpostckpt() more closely instead
of using an unnecessary call to smgropen().
Author: Thomas Munro
Discussion: https://postgr.es/m/CA%2BhUKGL%2BYLUOA0eYiBXBfwW%2BbH5kFgh94%3DgQH0jHEJ-t5Y91wQ%40mail.gmail.com
There was some confusion over the format of the error message returned
from the server during GSSAPI startup; specifically, it was expected
that a length would be returned when, in reality, at this early stage in
the startup sequence, no length is returned from the server as part of
an error message.
Correct the client-side code for dealing with error messages sent by the
server during startup by simply reading what's available into our
buffer, after we've discovered it's an error message, and then reporting
back what was returned.
In passing, also add in documentation of the environment variable
PGGSSENCMODE which was missed previously, and adjust the code to look
for the PGGSSENCMODE variable (the environment variable change was
missed in the prior GSSMODE -> GSSENCMODE commit).
Error-handling issue discovered by Peter Eisentraut, the rest were items
discovered during testing of the error handling.
Since 11, it is possible to use a non-superuser role when using an
online source cluster with pg_rewind as long as the role has proper
permissions to execute on the source all the functions used by
pg_rewind, and the documentation stated that a superuser is necessary.
Let's add at the same time all the details needed to create such a
role.
A second confusion which comes a lot from users is that it is necessary
to issue a checkpoint on a freshly-promoted standby so as its control
file has up-to-date timeline information which is used by pg_rewind to
validate the operation. Let's document that properly. This is
back-patched down to 9.5 where pg_rewind has been introduced.
Author: Michael Paquier
Reviewed-by: Magnus Hagander
Discussion: https://postgr.es/m/CABUevEz5bpvbwVsYCaSMV80CBZ5-82nkMzbb+Bu=h1m=rLdn=g@mail.gmail.com
Backpatch-through: 9.5
Previously it was allowed to set default_table_access_method to an
empty string. That makes sense for default_tablespace, where that was
copied from, as it signals falling back to the database's default
tablespace. As there is no equivalent for table AMs, forbid that.
Also make sure to throw a usable error when creating a table using an
index AM, by using get_am_type_oid() to implement get_table_am_oid()
instead of a separate copy. Previously we'd error out only later, in
GetTableAmRoutine().
Thirdly remove GetTableAmRoutineByAmId() - it was only used in an
earlier version of 8586bf7ed8.
Add tests for the above (some for index AMs as well).
Commit c1afd175, which added support for rootdescend verification to
amcheck, added only minimal regression test coverage. Address this by
making sure that rootdescend verification is run on a multi-level index.
In passing, simplify some of the regression tests that exercise
multi-level nbtree page deletion.
Both issues spotted while rereviewing coverage of the nbtree patch
series using gcov.
This adds table_multi_insert(), and converts COPY FROM, the only user
of heap_multi_insert, to it.
A simple conversion of COPY FROM use slots would have yielded a
slowdown when inserting into a partitioned table for some
workloads. Different partitions might need different slots (both slot
types and their descriptors), and dropping / creating slots when
there's constant partition changes is measurable.
Thus instead revamp the COPY FROM buffering for partitioned tables to
allow to buffer inserts into multiple tables, flushing only when
limits are reached across all partition buffers. By only dropping
slots when there've been inserts into too many different partitions,
the aforementioned overhead is gone. By allowing larger batches, even
when there are frequent partition changes, we actuall speed such cases
up significantly.
By using slots COPY of very narrow rows into unlogged / temporary
might slow down very slightly (due to the indirect function calls).
Author: David Rowley, Andres Freund, Haribabu Kommi
Discussion:
https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.dehttps://postgr.es/m/20190327054923.t3epfuewxfqdt22e@alap3.anarazel.de
This is intended for use mostly in test scripts for external tools,
which could do without cross-PG-version variations in error message
wording. Of course, the SQLSTATE isn't guaranteed stable either, but
it should be more so than the error message text.
Note: there's a bit of an ABI change for libpq here, but it seems
OK because if somebody compiles against a newer version of libpq-fe.h,
and then tries to pass PQERRORS_SQLSTATE to PQsetErrorVerbosity()
of an older libpq library, it will be accepted and then act like
PQERRORS_DEFAULT, thanks to the way the tests in pqBuildErrorMessage3
have historically been phrased. That seems acceptable.
Didier Gautheron, reviewed by Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/CAJRYxuKyj4zA+JGVrtx8OWAuBfE-_wN4sUMK4H49EuPed=mOBw@mail.gmail.com
The previous convention that stdout was selected by default when nothing
is specified was just too error-prone.
After a suggestion from Andrew Gierth.
Author: Euler Taveira
Reviewed-by: Yoshikazu Imai, José Arthur Benetasso Villanova
Discussion: https://postgr.es/m/87sgwrmhdv.fsf@news-spur.riddles.org.uk
The assertions added by commit b04aeb0a0 exposed that there are some
code paths wherein the executor will try to open an index without
holding any lock on it. We do have some lock on the index's table,
so it seems likely that there's no fatal problem with this (for
instance, the index couldn't get dropped from under us). Still,
it's bad practice and we should fix it.
To do so, remove the optimizations in ExecInitIndexScan and friends
that tried to avoid taking a lock on an index belonging to a target
relation, and just take the lock always. In non-bug cases, this
will result in no additional shared-memory access, since we'll find
in the local lock table that we already have a lock of the desired
type; hence, no significant performance degradation should occur.
Also, adjust the planner and executor so that the type of lock taken
on an index is always identical to the type of lock taken for its table,
by relying on the recently added RangeTblEntry.rellockmode field.
This avoids some corner cases where that might not have been true
before (possibly resulting in extra locking overhead), and prevents
future maintenance issues from having multiple bits of logic that
all needed to be in sync. In addition, this change removes all core
calls to ExecRelationIsTargetRelation, which avoids a possible O(N^2)
startup penalty for queries with large numbers of target relations.
(We'd probably remove that function altogether, were it not that we
advertise it as something that FDWs might want to use.)
Also adjust some places in selfuncs.c to not take any lock on indexes
they are transiently opening, since we can assume that plancat.c
did that already.
In passing, change gin_clean_pending_list() to take RowExclusiveLock
not AccessShareLock on its target index. Although it's not clear that
that's actually a bug, it seemed very strange for a function that's
explicitly going to modify the index to use only AccessShareLock.
David Rowley, reviewed by Julien Rouhaud and Amit Langote,
a bit of further tweaking by me
Discussion: https://postgr.es/m/19465.1541636036@sss.pgh.pa.us
This commit adds a new reloption, vacuum_index_cleanup, which
controls whether index cleanup is performed for a particular
relation by default. It also adds a new option to the VACUUM
command, INDEX_CLEANUP, which can be used to override the
reloption. If neither the reloption nor the VACUUM option is
used, the default is true, as before.
Masahiko Sawada, reviewed and tested by Nathan Bossart, Alvaro
Herrera, Kyotaro Horiguchi, Darafei Praliaskouski, and me.
The wording of the documentation is mostly due to me.
Discussion: http://postgr.es/m/CAD21AoAt5R3DNUZSjOoXDUY=naYPUOuffVsRzuTYMz29yLzQCA@mail.gmail.com
_bt_check_unique() failed to invalidate binary search bounds in the
event of a live conflict following commit e5adcb78. This resulted in
problems after waiting for the conflicting xact to commit or abort. The
subsequent call to _bt_check_unique() would restore the initial binary
search bounds, rather than starting a new search. Fix by explicitly
invalidating bounds when it becomes clear that there is a live conflict
that insertion will have to wait to resolve.
Ashutosh Sharma, with a few additional tweaks by me.
Author: Ashutosh Sharma
Reported-By: Ashutosh Sharma
Diagnosed-By: Ashutosh Sharma
Discussion: https://postgr.es/m/CAE9k0PnQp-qr-UYKMSCzdC2FBzdE4wKP41hZrZvvP26dKLonLg@mail.gmail.com
The be_gssapi_get_* prototypes were put close to similar ones for SSL-
but a bit too close since that meant they ended up only being included
for SSL-enabled builds. Move those to be under ENABLE_GSS instead.
Pointed out by Tom.
Previously, md.c and checkpointer.c were tightly integrated so that
fsync calls could be handed off and processed in the background.
Introduce a system of callbacks and file tags, so that other modules
can hand off fsync work in the same way.
For now only md.c uses the new interface, but other users are being
proposed. Since there may be use cases that are not strictly SMGR
implementations, use a new function table for sync handlers rather
than extending the traditional SMGR one.
Instead of using a bitmapset of segment numbers for each RelFileNode
in the checkpointer's hash table, make the segment number part of the
key. This requires sending explicit "forget" requests for every
segment individually when relations are dropped, but suits the file
layout schemes of proposed future users better (ie sparse or high
segment numbers).
Author: Shawn Debnath and Thomas Munro
Reviewed-by: Thomas Munro, Andres Freund
Discussion: https://postgr.es/m/CAEepm=2gTANm=e3ARnJT=n0h8hf88wqmaZxk0JYkxw+b21fNrw@mail.gmail.com
Since file_fdw uses COPY internally, but COPY doesn't allow listing
generated columns in its column list, we need to make sure that we
don't add generated columns to the column lists internally generated
by file_fdw.
Reported-by: Erik Rijkers <er@xs4all.nl>
Buildfarm members idiacanthus and komodoensis, which share a host, both
executed this test in the same second. That failed. Back-patch to 9.6,
where the test first appeared.
Discussion: https://postgr.es/m/20190404020543.GA1319573@rfd.leadboat.com
c251336 has added some tests to check if a toast relation should be
empty or not, hardcoding the toast relation name when calling
pg_relation_size(). pg_class.reltoastrelid offers the same information,
so simplify the tests to use that.
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20190403065949.GH3298@paquier.xyz
This adds documentation about the user oriented parts of table access
methods (i.e. the default_table_access_method GUC and the USING clause
for CREATE TABLE etc), adds a basic chapter about the table access
method interface, and adds a note to storage.sgml that it's contents
don't necessarily apply for non-builtin AMs.
Author: Haribabu Kommi and Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
When $(MODULES) and $(MODULE_big) are empty, derive the database name
from the first element of $(REGRESS) instead of using a constant string.
When deriving the database name from $(MODULES), use its first element
instead of the entire list; the earlier approach would fail if any
multi-module directory had $(REGRESS) tests. Treat isolation suites and
src/pl correspondingly. Under USE_MODULE_DB=1, installcheck-world and
check-world no longer reuse any database name in a given postmaster.
Buildfarm members axolotl, mandrill and frogfish saw spurious "is being
accessed by other users" failures that would not have happened without
database name reuse. (The CountOtherDBBackends() 5s deadline expired
during DROP DATABASE; a backend for an earlier test suite had used the
same database name and had not yet exited.) Back-patch to 9.4 (all
supported versions), except bits pertaining to isolation suites.
Concept reviewed by Andrew Dunstan, Andres Freund and Tom Lane.
Discussion: https://postgr.es/m/20190401135213.GE891537@rfd.leadboat.com
postmaster startup scrutinizes any shared memory segment recorded in
postmaster.pid, exiting if that segment matches the current data
directory and has an attached process. When the postmaster.pid file was
missing, a starting postmaster used weaker checks. Change to use the
same checks in both scenarios. This increases the chance of a startup
failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1
postmaster.pid` && rm postmaster.pid && pg_ctl -w start". A postmaster
will no longer recycle segments pertaining to other data directories.
That's good for production, but it's bad for integration tests that
crash a postmaster and immediately delete its data directory. Such a
test now leaks a segment indefinitely. No "make check-world" test does
that. win32_shmem.c already avoided all these problems. In 9.6 and
later, enhance PostgresNode to facilitate testing. Back-patch to 9.4
(all supported versions).
Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI.
Discussion: https://postgr.es/m/20130911033341.GD225735@tornado.leadboat.com
Query planning is affected by a number of configuration options, and it
may be crucial to know which of those options were set to non-default
values. With this patch you can say EXPLAIN (SETTINGS ON) to include
that information in the query plan. Only options affecting planning,
with values different from the built-in default are printed.
This patch also adds auto_explain.log_settings option, providing the
same capability in auto_explain module.
Author: Tomas Vondra
Reviewed-by: Rafia Sabih, John Naylor
Discussion: https://postgr.es/m/e1791b4c-df9c-be02-edc5-7c8874944be0@2ndquadrant.com
This is useful to obtain a view of the different transaction types in an
application, regardless of the durations of the statements each runs.
Author: Adrien Nayrat
Reviewed-by: Masahiko Sawada, Hayato Kuroda, Andres Freund
Not required after nuking the zipfian thread-local cache.
Also add a comment about hazardous pointer punning in threadRun(),
and avoid using "thread" to refer to the threads array as a whole.
Fabien Coelho and Tom Lane, per suggestion from Alvaro Herrera
Discussion: https://postgr.es/m/alpine.DEB.2.21.1904032126060.7997@lancre
Commit ea4e1c0e8f resolved issues with memory alignment in serialized
pg_mcv_list values, but it required copying data to/from the varlena
buffer during serialization and deserialization. As the MCV lits may
be fairly large, the overhead (memory consumption, CPU usage) can get
rather significant too.
This change tweaks the serialization format so that the alignment is
correct with respect to the varlena value, and so the parts may be
accessed directly without copying the data.
Catversion bump, as it affects existing pg_statistic_ext data.
On both the frontend and backend, prepare for GSSAPI encryption
support by moving common code for error handling into a separate file.
Fix a TODO for handling multiple status messages in the process.
Eliminate the OIDs, which have not been needed for some time.
Add frontend and backend encryption support functions. Keep the
context initiation for authentication-only separate on both the
frontend and backend in order to avoid concerns about changing the
requested flags to include encryption support.
In postmaster, pull GSSAPI authorization checking into a shared
function. Also share the initiator name between the encryption and
non-encryption codepaths.
For HBA, add "hostgssenc" and "hostnogssenc" entries that behave
similarly to their SSL counterparts. "hostgssenc" requires either
"gss", "trust", or "reject" for its authentication.
Similarly, add a "gssencmode" parameter to libpq. Supported values are
"disable", "require", and "prefer". Notably, negotiation will only be
attempted if credentials can be acquired. Move credential acquisition
into its own function to support this behavior.
Add a simple pg_stat_gssapi view similar to pg_stat_ssl, for monitoring
if GSSAPI authentication was used, what principal was used, and if
encryption is being used on the connection.
Finally, add documentation for everything new, and update existing
documentation on connection security.
Thanks to Michael Paquier for the Windows fixes.
Author: Robbie Harwood, with changes to the read/write functions by me.
Reviewed in various forms and at different times by: Michael Paquier,
Andres Freund, David Steele.
Discussion: https://www.postgresql.org/message-id/flat/jlg1tgq1ktm.fsf@thriss.redhat.com
Previously, while primary keys could be made on partitioned tables, it
was not possible to define foreign keys that reference those primary
keys. Now it is possible to do that.
Author: Álvaro Herrera
Reviewed-by: Amit Langote, Jesper Pedersen
Discussion: https://postgr.es/m/20181102234158.735b3fevta63msbj@alvherre.pgsql
Instead of WAL-logging every modification during the build separately,
first build the index without any WAL-logging, and make a separate pass
through the index at the end, to write all pages to the WAL. This
significantly reduces the amount of WAL generated, and is usually also
faster, despite the extra I/O needed for the extra scan through the index.
WAL generated this way is also faster to replay.
For GiST, the LSN-NSN interlock makes this a little tricky. All pages must
be marked with a valid (i.e. non-zero) LSN, so that the parent-child
LSN-NSN interlock works correctly. We now use magic value 1 for that during
index build. Change the fake LSN counter to begin from 1000, so that 1 is
safely smaller than any real or fake LSN. 2 would've been enough for our
purposes, but let's reserve a bigger range, in case we need more special
values in the future.
Author: Anastasia Lubennikova, Andrey V. Lepikhov
Reviewed-by: Heikki Linnakangas, Dmitry Dolgov
Michael Paquier
Tom Lane
Alvaro Herrera
Peter Eisentraut
Thomas Munro
Robert Haas
Andres Freund
Etsuro Fujita
Noah Misch
Stephen Frost
Peter Geoghegan
Tomas Vondra
Heikki Linnakangas