Commit Graph

14985 Commits

Author SHA1 Message Date
Bruce Momjian 2a9f37243b docs: improve description of how to handle multiple databases
This is a redesign of the intro to the managing databases chapter.

Discussion: https://postgr.es/m/159586122762.680.1361378513036616007@wrigleys.postgresql.org

Author: David G. Johnston

Backpatch-through: 9.5
2020-08-21 20:23:09 -04:00
Bruce Momjian bfd78c0b41 docs: add COMMENT examples for new features, rename rtree
Reported-by: Jürgen Purtz

Discussion: https://postgr.es/m/15ec5428-d46a-1725-f38d-44986a977abb@purtz.de

Author: Jürgen Purtz

Backpatch-through: 11
2020-08-21 18:29:37 -04:00
Fujii Masao 9d701e624f Rework EXPLAIN for planner's buffer usage.
Commit ce77abe63c allowed EXPLAIN (BUFFERS) to report the information
on buffer usage during planning phase. However three issues were
reported regarding this feature.

(1) Previously, EXPLAIN option BUFFERS required ANALYZE. So the query
    had to be actually executed by specifying ANALYZE even when we
    want to see only the planner's buffer usage. This was inconvenient
    especially when the query was write one like DELETE.

(2) EXPLAIN included the planner's buffer usage in summary
    information. So SUMMARY option had to be enabled to report that.
    Also this format was confusing.

(3) The output structure for planning information was not consistent
    between TEXT format and the others. For example, "Planning" tag
    was output in JSON format, but not in TEXT format.

For (1), this commit allows us to perform EXPLAIN (BUFFERS) without
ANALYZE to report the planner's buffer usage.

For (2), this commit changed EXPLAIN output so that the planner's
buffer usage is reported before summary information.

For (3), this commit made the output structure for planning
information more consistent between the formats.

Back-patch to v13 where the planner's buffer usage was allowed to
be reported in EXPLAIN.

Reported-by: Pierre Giraud, David Rowley
Author: Fujii Masao
Reviewed-by: David Rowley, Julien Rouhaud, Pierre Giraud
Discussion: https://postgr.es/m/07b226e6-fa49-687f-b110-b7c37572f69e@dalibo.com
2020-08-21 20:48:59 +09:00
Alvaro Herrera 0784c33372
Revise REINDEX CONCURRENTLY recovery instructions
When the leftover invalid index is "ccold", there's no need to re-run
the command.  Reword the instructions to make that explicit.

Backpatch to 12, where REINDEX CONCURRENTLY appeared.

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://postgr.es/m/20200819211312.GA15497@alvherre.pgsql
2020-08-20 13:49:04 -04:00
Fujii Masao 3e98c0bafb Add pg_backend_memory_contexts system view.
This view displays the usages of all the memory contexts of the server
process attached to the current session. This information is useful to
investigate the cause of backend-local memory bloat.

This information can be also collected by calling
MemoryContextStats(TopMemoryContext) via a debugger. But this technique
cannot be uesd in some environments because no debugger is available there.
And it outputs lots of text messages and it's not easy to analyze them.
So, pg_backend_memory_contexts view allows us to access to backend-local
memory contexts information more easily.

Bump catalog version.

Author: Atsushi Torikoshi, Fujii Masao
Reviewed-by: Tatsuhito Kasahara, Andres Freund, Daniel Gustafsson, Robert Haas, Michael Paquier
Discussion: https://postgr.es/m/72a656e0f71d0860161e0b3f67e4d771@oss.nttdata.com
2020-08-19 15:34:43 +09:00
Michael Paquier adbe62d04b Add PL/Sample to src/test/modules/
PL/Sample is an example template of procedural-language handler.  This
can be used as a base to implement a custom PL, or as a facility to test
APIs dedicated to PLs.  Much more could be done in this module, like
adding a simple validator, but this is left as future work.

The documentation included originally some C code to understand the
basics of PL handler implementation, but it was outdated, and not really
helpful either if trying to implement a new procedural language,
particularly when it came to the integration of a PL installation with
CREATE EXTENSION.

Author: Mark Wong
Reviewed-by: Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/20200612172648.GA3327@2ndQuadrant.com
2020-08-18 11:10:50 +09:00
Tom Lane 22e75a341e Doc: fix description of UNION/CASE/etc type unification.
The description of what select_common_type() does was not terribly
accurate.  Improve it.

David Johnston and Tom Lane

Discussion: https://postgr.es/m/1019930.1597613200@sss.pgh.pa.us
2020-08-17 15:40:07 -04:00
Michael Paquier b4f16397af doc: Fix description about bgwriter and checkpoint in HA section
Since 806a2ae, the work of the bgwriter is split the checkpointer, but a
portion of the documentation did not get the message.

Author: Masahiko Sawada
Discussion: https://postgr.es/m/CA+fd4k6jXxjAtjMVC=wG3=QGpauZBtcgN3Jhw+oV7zXGKVLKzQ@mail.gmail.com
Backpatch-through: 9.5
2020-08-17 10:23:17 +09:00
Tom Lane db659a3416 Doc: various improvements for pg_basebackup reference page.
Put the -r option in the right section (it certainly isn't an
option controlling "the location and format of the output").

Clarify the behavior of the tablespace and waldir options
(that part per gripe from robert@interactive.co.uk).

Make a large number of small copy-editing fixes in text that
visibly wasn't written by native speakers, and try to avoid
grammatical inconsistencies between the descriptions of
the different options.

Back-patch to v13, since HEAD hasn't meaningfully diverged yet.

Discussion: https://postgr.es/m/159749418850.14322.216503677134569752@wrigleys.postgresql.org
2020-08-15 15:44:23 -04:00
Noah Misch 566372b3d6 Prevent concurrent SimpleLruTruncate() for any given SLRU.
The SimpleLruTruncate() header comment states the new coding rule.  To
achieve this, add locktype "frozenid" and two LWLocks.  This closes a
rare opportunity for data loss, which manifested as "apparent
wraparound" or "could not access status of transaction" errors.  Data
loss is more likely in pg_multixact, due to released branches' thin
margin between multiStopLimit and multiWrapLimit.  If a user's physical
replication primary logged ":  apparent wraparound" messages, the user
should rebuild standbys of that primary regardless of symptoms.  At less
risk is a cluster having emitted "not accepting commands" errors or
"must be vacuumed" warnings at some point.  One can test a cluster for
this data loss by running VACUUM FREEZE in every database.  Back-patch
to 9.5 (all supported versions).

Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
2020-08-15 10:15:53 -07:00
Tom Lane 0038f94387 Fix postmaster's behavior during smart shutdown.
Up to now, upon receipt of a SIGTERM ("smart shutdown" command), the
postmaster has immediately killed all "optional" background processes,
and subsequently refused to launch new ones while it's waiting for
foreground client processes to exit.  No doubt this seemed like an OK
policy at some point; but it's a pretty bad one now, because it makes
for a seriously degraded environment for the remaining clients:

* Parallel queries are killed, and new ones fail to launch. (And our
parallel-query infrastructure utterly fails to deal with the case
in a reasonable way --- it just hangs waiting for workers that are
not going to arrive.  There is more work needed in that area IMO.)

* Autovacuum ceases to function.  We can tolerate that for awhile,
but if bulk-update queries continue to run in the surviving client
sessions, there's eventually going to be a mess.  In the worst case
the system could reach a forced shutdown to prevent XID wraparound.

* The bgwriter and walwriter are also stopped immediately, likely
resulting in performance degradation.

Hence, let's rearrange things so that the only immediate change in
behavior is refusing to let in new normal connections.  Once the last
normal connection is gone, shut everything down as though we'd received
a "fast" shutdown.  To implement this, remove the PM_WAIT_BACKUP and
PM_WAIT_READONLY states, instead staying in PM_RUN or PM_HOT_STANDBY
while normal connections remain.  A subsidiary state variable tracks
whether or not we're letting in new connections in those states.

This also allows having just one copy of the logic for killing child
processes in smart and fast shutdown modes.  I moved that logic into
PostmasterStateMachine() by inventing a new state PM_STOP_BACKENDS.

Back-patch to 9.6 where parallel query was added.  In principle
this'd be a good idea in 9.5 as well, but the risk/reward ratio
is not as good there, since lack of autovacuum is not a problem
during typical uses of smart shutdown.

Per report from Bharath Rupireddy.

Patch by me, reviewed by Thomas Munro

Discussion: https://postgr.es/m/CALj2ACXAZ5vKxT9P7P89D87i3MDO9bfS+_bjMHgnWJs8uwUOOw@mail.gmail.com
2020-08-14 13:26:57 -04:00
Tom Lane a9306f10b9 Doc: improve examples for json_populate_record() and related functions.
Make these examples self-contained by providing declarations of the
user-defined row types they rely on.  There wasn't room to do this
in the old doc format, but now there is, and I think it makes the
examples a good bit less confusing.
2020-08-13 20:00:38 -04:00
Noah Misch cec57b1a0f Document clashes between logical replication and untrusted users.
Back-patch to v10, which introduced logical replication.

Security: CVE-2020-14349
2020-08-10 09:22:54 -07:00
Tom Lane 7eeb1d9861 Make contrib modules' installation scripts more secure.
Hostile objects located within the installation-time search_path could
capture references in an extension's installation or upgrade script.
If the extension is being installed with superuser privileges, this
opens the door to privilege escalation.  While such hazards have existed
all along, their urgency increases with the v13 "trusted extensions"
feature, because that lets a non-superuser control the installation path
for a superuser-privileged script.  Therefore, make a number of changes
to make such situations more secure:

* Tweak the construction of the installation-time search_path to ensure
that references to objects in pg_catalog can't be subverted; and
explicitly add pg_temp to the end of the path to prevent attacks using
temporary objects.

* Disable check_function_bodies within installation/upgrade scripts,
so that any security gaps in SQL-language or PL-language function bodies
cannot create a risk of unwanted installation-time code execution.

* Adjust lookup of type input/receive functions and join estimator
functions to complain if there are multiple candidate functions.  This
prevents capture of references to functions whose signature is not the
first one checked; and it's arguably more user-friendly anyway.

* Modify various contrib upgrade scripts to ensure that catalog
modification queries are executed with secure search paths.  (These
are in-place modifications with no extension version changes, since
it is the update process itself that is at issue, not the end result.)

Extensions that depend on other extensions cannot be made fully secure
by these methods alone; therefore, revert the "trusted" marking that
commit eb67623c9 applied to earthdistance and hstore_plperl, pending
some better solution to that set of issues.

Also add documentation around these issues, to help extension authors
write secure installation scripts.

Patch by me, following an observation by Andres Freund; thanks
to Noah Misch for review.

Security: CVE-2020-14350
2020-08-10 10:44:42 -04:00
Tom Lane 20e7e1fe31 Remove <@ from contrib/intarray's GiST operator classes.
Since commit efc77cf5f, an indexed query using <@ has required a
full-index scan, so that it actually performs worse than a plain seqscan
would do.  As I noted at the time, we'd be better off to not treat <@ as
being indexable by such indexes at all; and that's what this patch does.

It would have been difficult to remove these opclass members without
dropping the whole opclass before commit 9f9682783 fixed GiST opclass
member dependency rules, but now it's quite simple, so let's do it.

I left the existing support code in place for the time being, with
comments noting it's now unreachable.  At some point, perhaps we should
remove that code in favor of throwing an error telling people to upgrade
the extension version.

Discussion: https://postgr.es/m/2176979.1596389859@sss.pgh.pa.us
Discussion: https://postgr.es/m/458.1565114141@sss.pgh.pa.us
2020-08-08 17:26:29 -04:00
Amit Kapila 7259736a6e Implement streaming mode in ReorderBuffer.
Instead of serializing the transaction to disk after reaching the
logical_decoding_work_mem limit in memory, we consume the changes we have
in memory and invoke stream API methods added by commit 45fdc9738b.
However, sometimes if we have incomplete toast or speculative insert we
spill to the disk because we can't generate the complete tuple and stream.
And, as soon as we get the complete tuple we stream the transaction
including the serialized changes.

We can do this incremental processing thanks to having assignments
(associating subxact with toplevel xacts) in WAL right away, and
thanks to logging the invalidation messages at each command end. These
features are added by commits 0bead9af48 and c55040ccd0 respectively.

Now that we can stream in-progress transactions, the concurrent aborts
may cause failures when the output plugin consults catalogs (both system
and user-defined).

We handle such failures by returning ERRCODE_TRANSACTION_ROLLBACK
sqlerrcode from system table scan APIs to the backend or WALSender
decoding a specific uncommitted transaction. The decoding logic on the
receipt of such a sqlerrcode aborts the decoding of the current
transaction and continue with the decoding of other transactions.

We have ReorderBufferTXN pointer in each ReorderBufferChange by which we
know which xact it belongs to.  The output plugin can use this to decide
which changes to discard in case of stream_abort_cb (e.g. when a subxact
gets discarded).

We also provide a new option via SQL APIs to fetch the changes being
streamed.

Author: Dilip Kumar, Tomas Vondra, Amit Kapila, Nikhil Sontakke
Reviewed-by: Amit Kapila, Kuntal Ghosh, Ajin Cherian
Tested-by: Neha Sharma, Mahendra Singh Thalor and Ajin Cherian
Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
2020-08-08 07:47:06 +05:30
Bruce Momjian a677535247 doc: clarify "state" table reference in tutorial
Reported-by: Vyacheslav Shablistyy

Discussion: https://postgr.es/m/159586122762.680.1361378513036616007@wrigleys.postgresql.org

Backpatch-through: 9.5
2020-08-05 17:12:10 -04:00
Tom Lane eeb01e3122 Doc: fix obsolete info about allowed range of TZ offsets in timetz.
We've allowed UTC offsets up to +/- 15:59 since commit cd0ff9c0f, but
that commit forgot to fix the documentation about timetz.

Per bug #16571 from osdba.

Discussion: https://postgr.es/m/16571-eb7501598de78c8a@postgresql.org
2020-08-03 13:11:16 -04:00
Tom Lane 5f28b21eb3 Fix behavior of ecpg's "EXEC SQL elif name".
This ought to work much like C's "#elif defined(name)"; but the code
implemented it in a way equivalent to endif followed by ifdef, so that
it didn't matter whether any previous branch of the IF construct had
succeeded.  Fix that; add some test cases covering elif and nested IFs;
and improve the documentation, which also seemed a bit confused.

AFAICS the code has been like this since the feature was added in 1999
(commit b57b0e044).  So while it's surely wrong, there might be code
out there relying on the current behavior.  Hence, don't back-patch
into stable branches.  It seems all right to fix it in v13 though.

Per report from Ashutosh Sharma.  Reviewed by Ashutosh Sharma and
Michael Meskes.

Discussion: https://postgr.es/m/CAE9k0P=dQk9X0cU2tN49S7a9tv733-e1pVdpB1P-pWJ5PdTktg@mail.gmail.com
2020-08-03 09:46:12 -04:00
Michael Paquier b8fdee7d0c Add %P to log_line_prefix for parallel group leader
This is useful for monitoring purposes with log parsing.  Similarly to
pg_stat_activity, the leader's PID is shown only for active parallel
workers, minimizing the log footprint for the leaders as the equivalent
shared memory field is set as long as a backend is alive.

Author: Justin Pryzby
Reviewed-by: Álvaro Herrera, Michael Paquier, Julien Rouhaud, Tom Lane
Discussion: https://postgr.es/m/20200315111831.GA21492@telsasoft.com
2020-08-03 13:38:48 +09:00
Tom Lane 533020d050 Fix minor issues in psql's new \dAc and related commands.
The type-name pattern in \dAc and \dAf was matched only to the actual
pg_type.typname string, which is fairly user-unfriendly in cases where
that is not what's shown to the user by format_type (compare "_int4"
and "integer[]").  Make this code match what \dT does, i.e. match the
pattern against either typname or format_type() output.  Also fix its
broken handling of schema-name restrictions.  (IOW, make these
processSQLNamePattern calls match \dT's.)  While here, adjust
whitespace to make the query a little prettier in -E output, too.

Also improve some inaccuracies and shaky grammar in the related
documentation.

Noted while working on a patch for intarray's opclasses; I wondered
why I couldn't get a match to "integer*" for the input type name.
2020-08-02 17:00:26 -04:00
Noah Misch cd5e82256d Change XID and mxact limits to warn at 40M and stop at 3M.
We have edge-case bugs when assigning values in the last few dozen pages
before the wrap limit.  We may introduce similar bugs in the future.  At
default BLCKSZ, this makes such bugs unreachable outside of single-user
mode.  Also, when VACUUM began to consume mxacts, multiStopLimit did not
change to compensate.

pg_upgrade may fail on a cluster that was already printing "must be
vacuumed" warnings.  Follow the warning's instructions to clear the
warning, then run pg_upgrade again.  One can still, peacefully consume
98% of XIDs or mxacts, so DBAs need not change routine VACUUM settings.

Discussion: https://postgr.es/m/20200621083513.GA3074645@rfd.leadboat.com
2020-08-01 15:31:01 -07:00
Tom Lane 9f9682783b Invent "amadjustmembers" AM method for validating opclass members.
This allows AM-specific knowledge to be applied during creation of
pg_amop and pg_amproc entries.  Specifically, the AM knows better than
core code which entries to consider as required or optional.  Giving
the latter entries the appropriate sort of dependency allows them to
be dropped without taking out the whole opclass or opfamily; which
is something we'd like to have to correct obsolescent entries in
extensions.

This callback also opens the door to performing AM-specific validity
checks during opclass creation, rather than hoping than an opclass
developer will remember to test with "amvalidate".  For the most part
I've not actually added any such checks yet; that can happen in a
follow-on patch.  (Note that we shouldn't remove any tests from
"amvalidate", as those are still needed to cross-check manually
constructed entries in the initdb data.  So adding tests to
"amadjustmembers" will be somewhat duplicative, but it seems like
a good idea anyway.)

Patch by me, reviewed by Alexander Korotkov, Hamid Akhtar, and
Anastasia Lubennikova.

Discussion: https://postgr.es/m/4578.1565195302@sss.pgh.pa.us
2020-08-01 17:12:47 -04:00
Thomas Munro 84b1c63ad4 Preallocate some DSM space at startup.
Create an optional region in the main shared memory segment that can be
used to acquire and release "fast" DSM segments, and can benefit from
huge pages allocated at cluster startup time, if configured.  Fall back
to the existing mechanisms when that space is full.  The size is
controlled by a new GUC min_dynamic_shared_memory, defaulting to 0.

Main region DSM segments initially contain whatever garbage the memory
held last time they were used, rather than zeroes.  That change revealed
that DSA areas failed to initialize themselves correctly in memory that
wasn't zeroed first, so fix that problem.

Discussion: https://postgr.es/m/CA%2BhUKGLAE2QBv-WgGp%2BD9P_J-%3Dyne3zof9nfMaqq1h3EGHFXYQ%40mail.gmail.com
2020-07-31 17:49:58 +12:00
Tatsuo Ishii cab2556f3a Doc: fix high availability solutions comparison.
In "High Availability, Load Balancing, and Replication" chapter,
certain descriptions of Pgpool-II were not correct at this point.  It
does not need conflict resolution. Also "Multiple-Server Parallel
Query Execution" is not supported anymore.

Discussion: https://postgr.es/m/20200726.230128.53842489850344110.t-ishii%40sraoss.co.jp
Author: Tatsuo Ishii
Reviewed-by: Bruce Momjian
Backpatch-through: 9.5
2020-07-31 07:18:41 +09:00
Michael Paquier 903134fcc0 doc: Mention index references in pg_inherits
Partitioned indexes are also registered in pg_inherits, but the
description of this catalog did not reflect that.

Author: Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/87k0ynj35y.fsf@wibble.ilmari.org
Backpatch-through: 11
2020-07-30 15:48:44 +09:00
Peter Geoghegan d6c08e29e7 Add hash_mem_multiplier GUC.
Add a GUC that acts as a multiplier on work_mem.  It gets applied when
sizing executor node hash tables that were previously size constrained
using work_mem alone.

The new GUC can be used to preferentially give hash-based nodes more
memory than the generic work_mem limit.  It is intended to enable admin
tuning of the executor's memory usage.  Overall system throughput and
system responsiveness can be improved by giving hash-based executor
nodes more memory (especially over sort-based alternatives, which are
often much less sensitive to being memory constrained).

The default value for hash_mem_multiplier is 1.0, which is also the
minimum valid value.  This means that hash-based nodes continue to apply
work_mem in the traditional way by default.

hash_mem_multiplier is generally useful.  However, it is being added now
due to concerns about hash aggregate performance stability for users
that upgrade to Postgres 13 (which added disk-based hash aggregation in
commit 1f39bce0).  While the old hash aggregate behavior risked
out-of-memory errors, it is nevertheless likely that many users actually
benefited.  Hash agg's previous indifference to work_mem during query
execution was not just faster; it also accidentally made aggregation
resilient to grouping estimate problems (at least in cases where this
didn't create destabilizing memory pressure).

hash_mem_multiplier can provide a certain kind of continuity with the
behavior of Postgres 12 hash aggregates in cases where the planner
incorrectly estimates that all groups (plus related allocations) will
fit in work_mem/hash_mem.  This seems necessary because hash-based
aggregation is usually much slower when only a small fraction of all
groups can fit.  Even when it isn't possible to totally avoid hash
aggregates that spill, giving hash aggregation more memory will reliably
improve performance (the same cannot be said for external sort
operations, which appear to be almost unaffected by memory availability
provided it's at least possible to get a single merge pass).

The PostgreSQL 13 release notes should advise users that increasing
hash_mem_multiplier can help with performance regressions associated
with hash aggregation.  That can be taken care of by a later commit.

Author: Peter Geoghegan
Reviewed-By: Álvaro Herrera, Jeff Davis
Discussion: https://postgr.es/m/20200625203629.7m6yvut7eqblgmfo@alap3.anarazel.de
Discussion: https://postgr.es/m/CAH2-WzmD%2Bi1pG6rc1%2BCjc4V6EaFJ_qSuKCCHVnH%3DoruqD-zqow%40mail.gmail.com
Backpatch: 13-, where disk-based hash aggregation was introduced.
2020-07-29 14:14:58 -07:00
Peter Geoghegan f36e82072c Doc: Remove obsolete CREATE AGGREGATE note.
The planner is in fact willing to use hash aggregation when work_mem is
not set high enough for everything to fit in memory.  This has been the
case since commit 1f39bce0, which added disk-based hash aggregation.

There are a few remaining cases in which hash aggregation is avoided as
a matter of policy when the planner surmises that spilling will be
necessary.  For example, callers of choose_hashed_setop() still
conservatively avoid hash aggregation when spilling is anticipated.
That doesn't seem like a good enough reason to mention hash aggregation
in this context.

Backpatch: 13-, where disk-based hash aggregation was introduced.
2020-07-28 16:59:01 -07:00
David Rowley d7c8576ebe Doc: Improve documentation for pg_jit_available()
Per complaint from Scott Ribe. Based on wording suggestion from Tom Lane.

Discussion: https://postgr.es/m/1956E806-1468-4417-9A9D-235AE1D5FE1A@elevated-dev.com
Backpatch-through: 11, where pg_jit_available() was added
2020-07-28 22:52:03 +12:00
Amit Kapila 45fdc9738b Extend the logical decoding output plugin API with stream methods.
This adds seven methods to the output plugin API, adding support for
streaming changes of large in-progress transactions.

* stream_start
* stream_stop
* stream_abort
* stream_commit
* stream_change
* stream_message
* stream_truncate

Most of this is a simple extension of the existing methods, with
the semantic difference that the transaction (or subtransaction)
is incomplete and may be aborted later (which is something the
regular API does not really need to deal with).

This also extends the 'test_decoding' plugin, implementing these
new stream methods.

The stream_start/start_stop are used to demarcate a chunk of changes
streamed for a particular toplevel transaction.

This commit simply adds these new APIs and the upcoming patch to "allow
the streaming mode in ReorderBuffer" will use these APIs.

Author: Tomas Vondra, Dilip Kumar, Amit Kapila
Reviewed-by: Amit Kapila
Tested-by: Neha Sharma and Mahendra Singh Thalor
Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
2020-07-28 08:09:44 +05:30
Peter Geoghegan bcbf9446a2 Remove hashagg_avoid_disk_plan GUC.
Note: This GUC was originally named enable_hashagg_disk when it appeared
in commit 1f39bce0, which added disk-based hash aggregation.  It was
subsequently renamed in commit 92c58fd9.

Author: Peter Geoghegan
Reviewed-By: Jeff Davis, Álvaro Herrera
Discussion: https://postgr.es/m/9d9d1e1252a52ea1bad84ea40dbebfd54e672a0f.camel%40j-davis.com
Backpatch: 13-, where disk-based hash aggregation was introduced.
2020-07-27 17:53:19 -07:00
Michael Paquier 11a68e4b53 Tweak behavior of pg_stat_activity.leader_pid
The initial implementation of leader_pid in pg_stat_activity added by
b025f32 took the approach to strictly print what a PGPROC entry
includes.  In short, if a backend has been involved in parallel query at
least once, leader_pid would remain set as long as the backend is alive.
For a parallel group leader, this means that the field would always be
set after it participated at least once in parallel query, and after
more discussions this could be confusing if using for example a
connection pooler.

This commit changes the data printed so as leader_pid becomes always
NULL for a parallel group leader, showing up a non-NULL value only for
the parallel workers, and actually as long as a parallel query is
running as workers are shut down once the query has completed.

This does not change the definition of any catalog, so no catalog bump
is needed.  Per discussion with Justin Pryzby, Álvaro Herrera, Julien
Rouhaud and me.

Discussion: https://postgr.es/m/20200721035145.GB17300@paquier.xyz
Backpatch-through: 13
2020-07-26 16:32:11 +09:00
Peter Eisentraut 5733fa0fe4 doc: Document that ssl_ciphers does not affect TLS 1.3
TLS 1.3 uses a different way of specifying ciphers and a different
OpenSSL API.  PostgreSQL currently does not support setting those
ciphers.  For now, just document this.  In the future, support for
this might be added somehow.

Reviewed-by: Jonathan S. Katz <jkatz@postgresql.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2020-07-23 20:37:56 +02:00
Tom Lane a57d312a77 Support infinity and -infinity in the numeric data type.
Add infinities that behave the same as they do in the floating-point
data types.  Aside from any intrinsic usefulness these may have,
this closes an important gap in our ability to convert floating
values to numeric and/or replace float-based APIs with numeric.

The new values are represented by bit patterns that were formerly
not used (although old code probably would take them for NaNs).
So there shouldn't be any pg_upgrade hazard.

Patch by me, reviewed by Dean Rasheed and Andrew Gierth

Discussion: https://postgr.es/m/606717.1591924582@sss.pgh.pa.us
2020-07-22 19:19:44 -04:00
Alvaro Herrera 606c384598
Glossary: Add term "base backup"
Author: Jürgen Purtz <juergen@purtz.de>
Discussion: https://postgr.es/m/95f90a5d-7692-701d-2c0c-0c88eb5cea7d@purtz.de
2020-07-21 13:11:23 -04:00
Alvaro Herrera a0b2d583db
Minor glossary tweaks
Add "(process)" qualifier to two terms, remove self-reference in one
term.

Author: Jürgen Purtz <juergen@purtz.de>
Discussion: https://postgr.es/m/95f90a5d-7692-701d-2c0c-0c88eb5cea7d@purtz.de
2020-07-21 13:09:42 -04:00
Tom Lane fc032bed2f Be more careful about marking catalog columns NOT NULL by default.
The bug fixed in commit 72eab84a5 would not have occurred if initdb
had a less surprising rule about which columns should be marked
NOT NULL by default.  Let's make that rule be strictly that the
column must be fixed-width and its predecessors must be fixed-width
and NOT NULL, removing the hacky and unsafe exceptions for oidvector
and int2vector.

Since we do still want all existing oidvector and int2vector columns
to be marked NOT NULL, we have to put BKI_FORCE_NOT_NULL labels on
them.  But making this less magic and more documented seems like a
good idea, even if it's a shade more verbose.

I didn't bump catversion since the initial catalog contents are
not actually changed by this patch.  Note however that the
contents of postgres.bki do change, and feeding an old copy of
that to a new backend will produce wrong results.

Discussion: https://postgr.es/m/204760.1595181800@sss.pgh.pa.us
2020-07-21 13:03:48 -04:00
Tom Lane 3e66019f15 Assert that we don't insert nulls into attnotnull catalog columns.
The executor checks for this error, and so does the bootstrap catalog
loader, but we never checked for it in retail catalog manipulations.
The folly of that has now been exposed, so let's add assertions
checking it.  Checking in CatalogTupleInsert[WithInfo] and
CatalogTupleUpdate[WithInfo] should be enough to cover this.

Back-patch to v10; the aforesaid functions didn't exist before that,
and it didn't seem worth adapting the patch to the oldest branches.
But given the risk of JIT crashes, I think we certainly need this
as far back as v11.

Pre-v13, we have to explicitly exclude pg_subscription.subslotname
and pg_subscription_rel.srsublsn from the checks, since they are
mismarked.  (Even if we change our mind about applying BKI_FORCE_NULL
in the branch tips, it doesn't seem wise to have assertions that
would fire in existing databases.)

Discussion: https://postgr.es/m/298837.1595196283@sss.pgh.pa.us
2020-07-21 12:38:08 -04:00
Tom Lane 0fa0b487b5 Correctly mark pg_subscription_rel.srsublsn as nullable.
The code has always set this column to NULL when it's not valid,
but the catalog header's description failed to reflect that,
as did the SGML docs, as did some of the code.  To prevent future
coding errors of the same ilk, let's hide the field from C code
as though it were variable-length (which, in a sense, it is).

As with commit 72eab84a5, we can only fix this cleanly in HEAD
and v13; the problem extends further back but we'll need some
klugery in the released branches.

Discussion: https://postgr.es/m/367660.1595202498@sss.pgh.pa.us
2020-07-20 14:55:56 -04:00
Fujii Masao c3fe108c02 Rename wal_keep_segments to wal_keep_size.
max_slot_wal_keep_size that was added in v13 and wal_keep_segments are
the GUC parameters to specify how much WAL files to retain for
the standby servers. While max_slot_wal_keep_size accepts the number of
bytes of WAL files, wal_keep_segments accepts the number of WAL files.
This difference of setting units between those similar parameters could
be confusing to users.

To alleviate this situation, this commit renames wal_keep_segments to
wal_keep_size, and make users specify the WAL size in it instead of
the number of WAL files.

There was also the idea to rename max_slot_wal_keep_size to
max_slot_wal_keep_segments, in the discussion. But we have been moving
away from measuring in segments, for example, checkpoint_segments was
replaced by max_wal_size. So we concluded to rename wal_keep_segments
to wal_keep_size.

Back-patch to v13 where max_slot_wal_keep_size was added.

Author: Fujii Masao
Reviewed-by: Álvaro Herrera, Kyotaro Horiguchi, David Steele
Discussion: https://postgr.es/m/574b4ea3-e0f9-b175-ead2-ebea7faea855@oss.nttdata.com
2020-07-20 13:30:18 +09:00
Fujii Masao d05b172a76 Add generic_plans and custom_plans fields into pg_prepared_statements.
There was no easy way to find how many times generic and custom plans
have been executed for a prepared statement. This commit exposes those
numbers of times in pg_prepared_statements view.

Author: Atsushi Torikoshi, Kyotaro Horiguchi
Reviewed-by: Tatsuro Yamada, Masahiro Ikeda, Fujii Masao
Discussion: https://postgr.es/m/CACZ0uYHZ4M=NZpofH6JuPHeX=__5xcDELF8hT8_2T+R55w4RQw@mail.gmail.com
2020-07-20 11:55:50 +09:00
Tom Lane 72eab84a56 Correctly mark pg_subscription.subslotname as nullable.
Due to the layout of this catalog, subslotname has to be explicitly
marked BKI_FORCE_NULL, else initdb will default to the assumption
that it's non-nullable.  Since, in fact, CREATE/ALTER SUBSCRIPTION
will store null values there, the existing marking is just wrong,
and has been since this catalog was invented.

We haven't noticed because not much in the system actually depends
on attnotnull being truthful.  However, JIT'ed tuple deconstruction
does depend on that in some cases, allowing crashes or wrong answers
in queries that inspect pg_subscription.  Commit 9de77b545 quite
accidentally exposed this on the buildfarm members that force JIT
activation.

Back-patch to v13.  The problem goes further back, but we cannot
force initdb in released branches, so some klugier solution will
be needed there.  Before working on that, push this simple fix
to try to get the buildfarm back to green.

Discussion: https://postgr.es/m/4118109.1595096139@sss.pgh.pa.us
2020-07-19 12:37:23 -04:00
Tom Lane 9de77b5453 Allow logical replication to transfer data in binary format.
This patch adds a "binary" option to CREATE/ALTER SUBSCRIPTION.
When that's set, the publisher will send data using the data type's
typsend function if any, rather than typoutput.  This is generally
faster, if slightly less robust.

As committed, we won't try to transfer user-defined array or composite
types in binary, for fear that type OIDs won't match at the subscriber.
This might be changed later, but it seems like fit material for a
follow-on patch.

Dave Cramer, reviewed by Daniel Gustafsson, Petr Jelinek, and others;
adjusted some by me

Discussion: https://postgr.es/m/CADK3HH+R3xMn=8t3Ct+uD+qJ1KD=Hbif5NFMJ+d5DkoCzp6Vgw@mail.gmail.com
2020-07-18 12:44:51 -04:00
Michael Paquier 9add405014 doc: Refresh more URLs in the docs
This updates some URLs that are redirections, mostly to an equivalent
using https.  One URL referring to generalized partial indexes was
outdated.

Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20200717.121308.1369606287593685396.horikyota.ntt@gmail.com
Backpatch-through: 9.5
2020-07-18 22:43:35 +09:00
Michael Paquier b74d449a02 doc: Fix description of \copy for psql
The WHERE clause introduced by 31f3817 was not described.  While on it,
split the grammar of \copy FROM and TO into two distinct parts for
clarity as they support different set of options.

Author: Vignesh C
Discussion: https://postgr.es/m/CALDaNm3zWr=OmxeNqOqfT=uZTSdam_j-gkX94CL8eTNfgUtf6A@mail.gmail.com
Backpatch-through: 12
2020-07-18 10:42:41 +09:00
Tom Lane f009591d6e Cope with data-offset-less archive files during out-of-order restores.
pg_dump produces custom-format archive files that lack data offsets
when it is unable to seek its output.  Up to now that's been a hazard
for pg_restore.  But if pg_restore is able to seek in the archive
file, there is no reason to throw up our hands when asked to restore
data blocks out of order.  Instead, whenever we are searching for a
data block, record the locations of the blocks we passed over (that
is, fill in the missing data-offset fields in our in-memory copy of
the TOC data).  Then, when we hit a case that requires going
backwards, we can just seek back.

Also track the furthest point that we've searched to, and seek back
to there when beginning a search for a new data block.  This avoids
possible O(N^2) time consumption, by ensuring that each data block
is examined at most twice.  (On Unix systems, that's at most twice
per parallel-restore job; but since Windows uses threads here, the
threads can share block location knowledge, reducing the amount of
duplicated work.)

We can also improve the code a bit by using fseeko() to skip over
data blocks during the search.

This is all of some use even in simple restores, but it's really
significant for parallel pg_restore.  In that case, we require
seekability of the input already, and we will very probably need
to do out-of-order restores.

Back-patch to v12, as this fixes a regression introduced by commit
548e50976.  Before that, parallel restore avoided requesting
out-of-order restores, so it would work on a data-offset-less
archive.  Now it will again.

Ideally this patch would include some test coverage, but there are
other open bugs that need to be fixed before we can extend our
coverage of parallel restore very much.  Plan to revisit that later.

David Gilman and Tom Lane; reviewed by Justin Pryzby

Discussion: https://postgr.es/m/CALBH9DDuJ+scZc4MEvw5uO-=vRyR2=QF9+Yh=3hPEnKHWfS81A@mail.gmail.com
2020-07-17 13:04:05 -04:00
Thomas Munro d2bddc2500 Add huge_page_size setting for use on Linux.
This allows the huge page size to be set explicitly.  The default is 0,
meaning it will use the system default, as before.

Author: Odin Ugedal <odin@ugedal.com>
Discussion: https://postgr.es/m/20200608154639.20254-1-odin%40ugedal.com
2020-07-17 14:33:00 +12:00
Michael Paquier 2a10fdc430 Eliminate cache lookup errors in SQL functions for object addresses
When using the following functions, users could see various types of
errors of the type "cache lookup failed for OID XXX" with elog(), that
can only be used for internal errors:
* pg_describe_object()
* pg_identify_object()
* pg_identify_object_as_address()

The set of APIs managing object addresses for all object types are made
smarter by gaining a new argument "missing_ok" that allows any caller to
control if an error is raised or not on an undefined object.  The SQL
functions listed above are changed to handle the case where an object is
missing.

Regression tests are added for all object types for the cases where
these are undefined.  Before this commit, these cases failed with cache
lookup errors, and now they basically return NULL (minus the name of the
object type requested).

Author: Michael Paquier
Reviewed-by: Aleksander Alekseev, Dmitry Dolgov, Daniel Gustafsson,
Álvaro Herrera, Kyotaro Horiguchi
Discussion: https://postgr.es/m/CAB7nPqSZxrSmdHK-rny7z8mi=EAFXJ5J-0RbzDw6aus=wB5azQ@mail.gmail.com
2020-07-15 09:03:10 +09:00
Amit Kapila d973747281 Revert "Track statistics for spilling of changes from ReorderBuffer".
The stats with this commit was available only for WALSenders, however,
users might want to see for backends doing logical decoding via SQL API.
Then, users might want to reset and access these stats across server
restart which was not possible with the current patch.

List of commits reverted:

caa3c4242c   Don't call elog() while holding spinlock.
e641b2a995   Doc: Update the documentation for spilled transaction
statistics.
5883f5fe27   Fix unportable printf format introduced in commit 9290ad198.
9290ad198b   Track statistics for spilling of changes from ReorderBuffer.

Additionaly, remove the release notes entry for this feature.

Backpatch-through: 13, where it was introduced
Discussion: https://postgr.es/m/CA+fd4k5_pPAYRTDrO2PbtTOe0eHQpBvuqmCr8ic39uTNmR49Eg@mail.gmail.com
2020-07-13 08:53:23 +05:30
Michael Paquier b1e48bbe64 Include replication origins in SQL functions for commit timestamp
This includes two changes:
- Addition of a new function pg_xact_commit_timestamp_origin() able, for
a given transaction ID, to return the commit timestamp and replication
origin of this transaction.  An equivalent function existed in
pglogical.
- Addition of the replication origin to pg_last_committed_xact().

The commit timestamp manager includes already APIs able to return the
replication origin of a transaction on top of its commit timestamp, but
the code paths for replication origins were never stressed as those
functions have never looked for a replication origin, and the SQL
functions available have never included this information since their
introduction in 73c986a.

While on it, refactor a test of modules/commit_ts/ to use tstzrange() to
check that a transaction timestamp is within the wanted range, making
the test a bit easier to read.

Bump catalog version.

Author: Movead Li
Reviewed-by: Madan Kumar, Michael Paquier
Discussion: https://postgr.es/m/2020051116430836450630@highgo.ca
2020-07-12 20:47:15 +09:00