Commit Graph

270 Commits

Author SHA1 Message Date
Thomas Munro c6c9474aaf Use condition variables to wait for checkpoints.
Previously we used a polling/sleeping loop to wait for checkpoints
to begin and end, which leads to up to a couple hundred milliseconds
of needless thumb-twiddling.  Use condition variables instead.

Author: Thomas Munro
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/CA%2BhUKGLY7sDe%2Bbg1K%3DbnEzOofGoo4bJHYh9%2BcDCXJepb6DQmLw%40mail.gmail.com
2019-03-14 10:59:33 +13:00
Magnus Hagander 6b9e875f72 Track block level checksum failures in pg_stat_database
This adds a column that counts how many checksum failures have occurred
on files belonging to a specific database. Both checksum failures
during normal backend processing and those created when a base backup
detects a checksum failure are counted.

Author: Magnus Hagander
Reviewed by: Julien Rouhaud
2019-03-09 10:47:30 -08:00
Peter Eisentraut 213eae9b8a doc: Add security information about pg_stat_activity
Add a basic note that some columns in pg_stat_activity and related
views are not visible to all users.

Discussion: https://www.postgresql.org/message-id/3018acd9-e5d8-1e85-5ed7-47276cd77569%402ndquadrant.com
2019-02-21 19:49:27 +01:00
Noah Misch 301de4f7d9 Fix CLogTruncationLock documentation.
Back-patch to v10, which introduced the lock.
2019-02-17 00:51:11 -08:00
Peter Eisentraut f60a0e9677 Add more columns to pg_stat_ssl
Add columns client_serial and issuer_dn to pg_stat_ssl.  These allow
uniquely identifying the client certificate.

Rename the existing column clientdn to client_dn, to make the naming
more consistent and easier to read.

Discussion: https://www.postgresql.org/message-id/flat/398754d8-6bb5-c5cf-e7b8-22e5f0983caf@2ndquadrant.com/
2019-02-01 00:33:47 +01:00
Michael Paquier 1707a0d2aa Remove configure switch --disable-strong-random
This removes a portion of infrastructure introduced by fe0a0b5 to allow
compilation of Postgres in environments where no strong random source is
available, meaning that there is no linking to OpenSSL and no
/dev/urandom (Windows having its own CryptoAPI).  No systems shipped
this century lack /dev/urandom, and the buildfarm is actually not
testing this switch at all, so just remove it.  This simplifies
particularly some backend code which included a fallback implementation
using shared memory, and removes a set of alternate regression output
files from pgcrypto.

Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
2019-01-01 20:05:51 +09:00
Michael Paquier 7fee252f6f Add timestamp of last received message from standby to pg_stat_replication
The timestamp generated by the standby at message transmission has been
included in the protocol since its introduction for both the status
update message and hot standby feedback message, but it has never
appeared in pg_stat_replication.  Seeing this timestamp does not matter
much with a cluster which has a lot of activity, but on a mostly-idle
cluster, this makes monitoring able to react faster than the configured
timeouts.

Author: MyungKyu LIM
Reviewed-by: Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/1657809367.407321.1533027417725.JavaMail.jboss@ep2ml404
2018-12-09 16:35:06 +09:00
Michael Paquier 99f9ccee51 Fix invalid value of synchronous_commit in description of flush_lag
"remote_flush" has never been a valid user-facing value, but "on" is.

Author: Maksim Milyutin
Discussion: https://postgr.es/m/27b3b80c-3615-2d76-02c5-44566b53136c@gmail.com
2018-12-05 10:02:47 +09:00
Amit Kapila 621a8ac5af Fix the omission in docs.
Commit 5373bc2a08 has added type for background workers but forgot to
update at one place in the documentation.

Reported-by: John Naylor
Author: John Naylor
Reviewed-by: Amit Kapila
Backpatch-through: 11
Discussion: https://postgr.es/m/CAJVSVGVmvgJ8Lq4WBxC3zV5wf0txdCqRSgkWVP+jaBF=HgWscA@mail.gmail.com
2018-11-15 10:56:49 +05:30
Michael Paquier 10074651e3 Add pg_promote function
This function is able to promote a standby with this new SQL-callable
function.  Execution access can be granted to non-superusers so that
failover tools can observe the principle of least privilege.

Catalog version is bumped.

Author: Laurenz Albe
Reviewed-by: Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/6e7c79b3ec916cf49742fb8849ed17cd87aed620.camel@cybertec.at
2018-10-25 09:46:00 +09:00
Michael Paquier 5ef037cf0b List wait events in alphabetical order
This changes the documentation, and the related structures so as
everything is consistent.

Some wait events were not listed alphabetically since their
introduction, others have been added rather randomly.  Keeping all those
entries in order helps in maintenance, and helps the user looking at the
documentation.

Author: Michael Paquier, Kuntal Ghosh
Discussion: https://postgr.es/m/20181024002539.GI1658@paquier.xyz
Backpatch-through: 10, only for the documentation part to avoid an ABI
breakage.
2018-10-24 17:02:37 +09:00
Michael Paquier cccf81d259 Fix table format in documentation for I/O wait events
This is an oversight from c55de5e.

Author: Julien Rouhaud
2018-07-09 10:46:27 +09:00
Michael Paquier c55de5e512 Add wait event for fsync of WAL segments
This has been visibly a forgotten spot in the first implementation of
wait events for I/O added by 249cf07, and what has been missing is a
fsync call for WAL segments which is a wrapper reacting on the value of
GUC wal_sync_method.

Reported-by: Konstantin Knizhnik
Author: Konstantin Knizhnik
Reviewed-by: Craig Ringer, Michael Paquier
Discussion: https://postgr.es/m/4a243897-0ad8-f471-aa40-242591f2476e@postgrespro.ru
2018-07-02 22:19:46 +09:00
Alvaro Herrera d3b10f0d64 Fix grammar
Reported-by: Pavlo Golub
Author: Michaël Paquier
Discussion: https://postgr.es/m/152741547.20180530101229@cybertec.at
2018-05-30 14:11:42 -04:00
Fujii Masao 9a895462d9 Enhance pg_stat_wal_receiver view to display host and port of sender server.
Previously there was no way in the standby side to find out the host and port
of the sender server that the walreceiver was currently connected to when
multiple hosts and ports were specified in primary_conninfo. For that purpose,
this patch adds sender_host and sender_port columns into pg_stat_wal_receiver
view. They report the host and port that the active replication connection
currently uses.

Bump catalog version.

Author: Haribabu Kommi
Reviewed-by: Michael Paquier and me

Discussion: https://postgr.es/m/CAJrrPGcV_aq8=cdqkFhVDJKEnDQ70yRTTdY9RODzMnXNrCz2Ow@mail.gmail.com
2018-03-31 07:51:22 +09:00
Robert Haas 73797b7884 Document LWTRANCHE_PARALLEL_HASH_JOIN.
Thomas Munro

Discussion: http://postgr.es/m/CAEepm=3g1hhbFzYkR_QT9RmBvsGX4UaeCtX-4Js8OOEMmFeaSQ@mail.gmail.com
2018-02-28 11:46:26 -05:00
Robert Haas 6614aaa699 doc: Fix grammar.
Michael Paquier

Discussion: http://postgr.es/m/20180209135327.GC29003@paquier.xyz
2018-02-27 14:41:10 -05:00
Robert Haas 9da0cc3528 Support parallel btree index builds.
To make this work, tuplesort.c and logtape.c must also support
parallelism, so this patch adds that infrastructure and then applies
it to the particular case of parallel btree index builds.  Testing
to date shows that this can often be 2-3x faster than a serial
index build.

The model for deciding how many workers to use is fairly primitive
at present, but it's better than not having the feature.  We can
refine it as we get more experience.

Peter Geoghegan with some help from Rushabh Lathia.  While Heikki
Linnakangas is not an author of this patch, he wrote other patches
without which this feature would not have been possible, and
therefore the release notes should possibly credit him as an author
of this feature.  Reviewed by Claudio Freire, Heikki Linnakangas,
Thomas Munro, Tels, Amit Kapila, me.

Discussion: http://postgr.es/m/CAM3SWZQKM=Pzc=CAHzRixKjp2eO5Q0Jg1SoFQqeXFQ647JiwqQ@mail.gmail.com
Discussion: http://postgr.es/m/CAH2-Wz=AxWqDoVvGU7dq856S4r6sJAj6DBn7VMtigkB33N5eyg@mail.gmail.com
2018-02-02 13:32:44 -05:00
Andres Freund 1804284042 Add parallel-aware hash joins.
Introduce parallel-aware hash joins that appear in EXPLAIN plans as Parallel
Hash Join with Parallel Hash.  While hash joins could already appear in
parallel queries, they were previously always parallel-oblivious and had a
partial subplan only on the outer side, meaning that the work of the inner
subplan was duplicated in every worker.

After this commit, the planner will consider using a partial subplan on the
inner side too, using the Parallel Hash node to divide the work over the
available CPU cores and combine its results in shared memory.  If the join
needs to be split into multiple batches in order to respect work_mem, then
workers process different batches as much as possible and then work together
on the remaining batches.

The advantages of a parallel-aware hash join over a parallel-oblivious hash
join used in a parallel query are that it:

 * avoids wasting memory on duplicated hash tables
 * avoids wasting disk space on duplicated batch files
 * divides the work of building the hash table over the CPUs

One disadvantage is that there is some communication between the participating
CPUs which might outweigh the benefits of parallelism in the case of small
hash tables.  This is avoided by the planner's existing reluctance to supply
partial plans for small scans, but it may be necessary to estimate
synchronization costs in future if that situation changes.  Another is that
outer batch 0 must be written to disk if multiple batches are required.

A potential future advantage of parallel-aware hash joins is that right and
full outer joins could be supported, since there is a single set of matched
bits for each hashtable, but that is not yet implemented.

A new GUC enable_parallel_hash is defined to control the feature, defaulting
to on.

Author: Thomas Munro
Reviewed-By: Andres Freund, Robert Haas
Tested-By: Rafia Sabih, Prabhat Sahu
Discussion:
    https://postgr.es/m/CAEepm=2W=cOkiZxcg6qiFQP-dHUe09aqTrEMM7yJDrHMhDv_RA@mail.gmail.com
    https://postgr.es/m/CAEepm=37HKyJ4U6XOLi=JgfSHM3o6B-GaeO-6hkOmneTDkH+Uw@mail.gmail.com
2017-12-21 00:43:41 -08:00
Robert Haas ab72716778 Support Parallel Append plan nodes.
When we create an Append node, we can spread out the workers over the
subplans instead of piling on to each subplan one at a time, which
should typically be a bit more efficient, both because the startup
cost of any plan executed entirely by one worker is paid only once and
also because of reduced contention.  We can also construct Append
plans using a mix of partial and non-partial subplans, which may allow
for parallelism in places that otherwise couldn't support it.
Unfortunately, this patch doesn't handle the important case of
parallelizing UNION ALL by running each branch in a separate worker;
the executor infrastructure is added here, but more planner work is
needed.

Amit Khandekar, Robert Haas, Amul Sul, reviewed and tested by
Ashutosh Bapat, Amit Langote, Rafia Sabih, Amit Kapila, and
Rajkumar Raghuwanshi.

Discussion: http://postgr.es/m/CAJ3gD9dy0K_E8r727heqXoBmWZ83HwLFwdcaSSmBQ1+S+vRuUQ@mail.gmail.com
2017-12-05 17:28:39 -05:00
Peter Eisentraut 3c49c6facb Convert documentation to DocBook XML
Since some preparation work had already been done, the only source
changes left were changing empty-element tags like <xref linkend="foo">
to <xref linkend="foo"/>, and changing the DOCTYPE.

The source files are still named *.sgml, but they are actually XML files
now.  Renaming could be considered later.

In the build system, the intermediate step to convert from SGML to XML
is removed.  Everything is build straight from the source files again.
The OpenSP (or the old SP) package is no longer needed.

The documentation toolchain instructions are updated and are much
simpler now.

Peter Eisentraut, Alexander Lakhin, Jürgen Purtz
2017-11-23 09:44:28 -05:00
Peter Eisentraut c29c578908 Don't use SGML empty tags
For DocBook XML compatibility, don't use SGML empty tags (</>) anymore,
replace by the full tag name.  Add a warning option to catch future
occurrences.

Alexander Lakhin, Jürgen Purtz
2017-10-17 15:10:33 -04:00
Alvaro Herrera 885cab5811 Document further existing locks as wait events
Reported-by: Jeremy Schneider
Author: Michael Paquier
Discussion: https://postgr.es/m/CA+fnDAZaPCwfY8Lp-pfLnUGFAXRu1VfLyRgdup-L-kwcBj8MqQ@mail.gmail.com
2017-09-22 13:37:28 +02:00
Peter Eisentraut be87b70b61 Sync process names between ps and pg_stat_activity
Remove gratuitous differences in the process names shown in
pg_stat_activity.backend_type and the ps output.

Reviewed-by: Takayuki Tsunakawa <tsunakawa.takay@jp.fujitsu.com>
2017-09-20 08:59:03 -04:00
Robert Haas baaf272ac9 Use group updates when setting transaction status in clog.
Commit 0e141c0fbb introduced a mechanism
to reduce contention on ProcArrayLock by having a single process clear
XIDs in the procArray on behalf of multiple processes, reducing the
need to hand the lock around.  A previous attempt to introduce a similar
mechanism for CLogControlLock in ccce90b398
crashed and burned, but the design problem which resulted in those
failures is believed to have been corrected in this version.

Amit Kapila, with some cosmetic changes by me.  See the previous commit
message for additional credits.

Discussion: http://postgr.es/m/CAA4eK1KudxzgWhuywY_X=yeSAhJMT4DwCjroV5Ay60xaeB2Eew@mail.gmail.com
2017-09-01 11:45:40 -04:00
Noah Misch e88928c50d Fix vertical spanning in table "wait_event Description".
Michael Paquier

Discussion: https://postgr.es/m/CAB7nPqQr3KEQvXeuUNYcm7tDK2Fb9oLUQ8DU0+y0RZEoN_1_gg@mail.gmail.com
2017-08-12 18:19:49 -07:00
Alvaro Herrera b2c95a3798 Fix replication origin-related race conditions
Similar to what was fixed in commit 9915de6c1c for replication slots,
but this time it's related to replication origins: DROP SUBSCRIPTION
attempts to drop the replication origin, but that fails if the
replication worker process hasn't yet marked it unused.  This causes
failures in the buildfarm:
ERROR:  could not drop replication origin with OID 1, in use by PID 34069

Like the aforementioned commit, fix by having the process running DROP
SUBSCRIPTION sleep until the worker marks the the replication origin
struct as free.  This uses a condition variable on each replication
origin shmem state struct, so that the session trying to drop can sleep
and expect to be awakened by the process keeping the origin open.

Also fix a SGML markup in the previous commit.

Discussion: https://postgr.es/m/20170808001433.rozlseaf4m2wkw3n@alvherre.pgsql
2017-08-08 16:07:46 -04:00
Alvaro Herrera 030273b7ea Fix inadequacies in recently added wait events
In commit 9915de6c1c, we introduced a new wait point for replication
slots and incorrectly labelled it as wait event PG_WAIT_LOCK.  That's
wrong, so invent an appropriate new wait event instead, and document it
properly.

While at it, fix numerous other problems in the vicinity:
- two different walreceiver wait events were being mixed up in a single
  wait event (which wasn't documented either); split it out so that they
  can be distinguished, and document the new events properly.

- ParallelBitmapPopulate was documented but didn't exist.

- ParallelBitmapScan was not documented (I think this should be called
  "ParallelBitmapScanInit" instead.)

- Logical replication wait events weren't documented

- various symbols had been added in dartboard order in various places.
  Put them in alphabetical order instead, as was originally intended.

Discussion: https://postgr.es/m/20170808181131.mu4fjepuh5m75cyq@alvherre.pgsql
2017-08-08 15:37:44 -04:00
Peter Eisentraut bbaf9e8f84 Documentation spell checking and markup improvements 2017-06-18 14:02:12 -04:00
Peter Eisentraut bf6e4c3c82 Trim trailing whitespace 2017-06-12 09:51:18 -04:00
Andres Freund c6c3334364 Prevent possibility of panics during shutdown checkpoint.
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and
throws a PANIC if so.  At that point, only walsenders are still
active, so one might think this could not happen, but walsenders can
also generate WAL, for instance in BASE_BACKUP and logical decoding
related commands (e.g. via hint bits).  So they can trigger this panic
if such a command is run while the shutdown checkpoint is being
written.

To fix this, divide the walsender shutdown into two phases.  First,
checkpointer, itself triggered by postmaster, sends a
PROCSIG_WALSND_INIT_STOPPING signal to all walsenders.  If the backend
is idle or runs an SQL query this causes the backend to shutdown, if
logical replication is in progress all existing WAL records are
processed followed by a shutdown.  Otherwise this causes the walsender
to switch to the "stopping" state. In this state, the walsender will
reject any further replication commands. The checkpointer begins the
shutdown checkpoint once all walsenders are confirmed as
stopping. When the shutdown checkpoint finishes, the postmaster sends
us SIGUSR2. This instructs walsender to send any outstanding WAL,
including the shutdown checkpoint record, wait for it to be replicated
to the standby, and then exit.

Author: Andres Freund, based on an earlier patch by Michael Paquier
Reported-By: Fujii Masao, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
Backpatch: 9.4, where logical decoding was introduced
2017-06-05 19:18:15 -07:00
Andres Freund 703f148e98 Revert "Prevent panic during shutdown checkpoint"
This reverts commit 086221cf6b, which
was made to master only.

The approach implemented in the above commit has some issues.  While
those could easily be fixed incrementally, doing so would make
backpatching considerably harder, so instead first revert this patch.

Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
2017-06-05 19:18:15 -07:00
Peter Eisentraut d496a65790 Standardize "WAL location" terminology
Other previously used terms were "WAL position" or "log position".
2017-05-12 13:51:27 -04:00
Peter Eisentraut c1a7f64b4a Replace "transaction log" with "write-ahead log"
This makes documentation and error messages match the renaming of "xlog"
to "wal" in APIs and file naming.
2017-05-12 11:52:43 -04:00
Tom Lane d10c626de4 Rename WAL-related functions and views to use "lsn" not "location".
Per discussion, "location" is a rather vague term that could refer to
multiple concepts.  "LSN" is an unambiguous term for WAL locations and
should be preferred.  Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position".  Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.

David Rowley, minor additional docs hacking by me

Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
2017-05-11 11:49:59 -04:00
Peter Eisentraut 086221cf6b Prevent panic during shutdown checkpoint
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and throws
a PANIC if so.  At that point, only walsenders are still active, so one
might think this could not happen, but walsenders can also generate WAL,
for instance in BASE_BACKUP and certain variants of
CREATE_REPLICATION_SLOT.  So they can trigger this panic if such a
command is run while the shutdown checkpoint is being written.

To fix this, divide the walsender shutdown into two phases.  First, the
postmaster sends a SIGUSR2 signal to all walsenders.  The walsenders
then put themselves into the "stopping" state.  In this state, they
reject any new commands.  (For simplicity, we reject all new commands,
so that in the future we do not have to track meticulously which
commands might generate WAL.)  The checkpointer waits for all walsenders
to reach this state before proceeding with the shutdown checkpoint.
After the shutdown checkpoint is done, the postmaster sends
SIGINT (previously unused) to the walsenders.  This triggers the
existing shutdown behavior of sending out the shutdown checkpoint record
and then terminating.

Author: Michael Paquier <michael.paquier@gmail.com>
Reported-by: Fujii Masao <masao.fujii@gmail.com>
2017-05-05 10:31:42 -04:00
Fujii Masao 7a3e8d7b50 Move pg_stat_progress_vacuum to the table of Dynamic Statistics Views in doc.
Previously the description about pg_stat_progress_vacuum was in the table
of "Collected Statistics Views" in the doc. But since it repors dynamic
information, i.e., the current progress of VACUUM, its description should be
in the table of "Dynamic Statistics Views".

Back-patch to 9.6 where pg_stat_progress_vacuum was added.

Author: Amit Langote
Discussion: http://postgr.es/m/7ab51b59-8d4d-6193-c60a-b75f222efb12@lab.ntt.co.jp
2017-04-13 12:09:14 +09:00
Peter Eisentraut 234811c21d doc: Add missing closing tag
Author: Erik Rijkers <er@xs4all.nl>
2017-04-07 18:30:13 -04:00
Robert Haas d4116a7719 Add ProcArrayGroupUpdate wait event.
Discussion: http://postgr.es/m/CA+TgmobgWHcXDcChX2+BqJDk2dkPVF85ZrJFhUyHHQmw8diTpA@mail.gmail.com
2017-04-07 13:41:47 -04:00
Robert Haas fc70a4b0df Show more processes in pg_stat_activity.
Previously, auxiliary processes and background workers not connected
to a database (such as the logical replication launcher) weren't
shown.  Include them, so that we can see the associated wait state
information.  Add a new column to identify the processes type, so that
people can filter them out easily using SQL if they wish.

Before this patch was written, there was discussion about whether we
should expose this information in a separate view, so as to avoid
contaminating pg_stat_activity with things people might not want to
see.  But putting everything in pg_stat_activity was a more popular
choice, so that's what the patch does.

Kuntal Ghosh, reviewed by Amit Langote and Michael Paquier.  Some
revisions and bug fixes by me.

Discussion: http://postgr.es/m/CA+TgmoYES5nhkEGw9nZXU8_FhA8XEm8NTm3-SO+3ML1B81Hkww@mail.gmail.com
2017-03-26 22:02:22 -04:00
Robert Haas ea42cc18c3 Track the oldest XID that can be safely looked up in CLOG.
This provides infrastructure for looking up arbitrary, user-supplied
XIDs without a risk of scary-looking failures from within the clog
module.  Normally, the oldest XID that can be safely looked up in CLOG
is the same as the oldest XID that can reused without causing
wraparound, and the latter is already tracked.  However, while
truncation is in progress, the values are different, so we must
keep track of them separately.

Craig Ringer, reviewed by Simon Riggs and by me.

Discussion: http://postgr.es/m/CAMsr+YHQiWNEi0daCTboS40T+V5s_+dst3PYv_8v2wNVH+Xx4g@mail.gmail.com
2017-03-23 14:26:31 -04:00
Simon Riggs 6912acc04f Replication lag tracking for walsenders
Adds write_lag, flush_lag and replay_lag cols to pg_stat_replication.

Implements a lag tracker module that reports the lag times based upon
measurements of the time taken for recent WAL to be written, flushed and
replayed and for the sender to hear about it. These times
represent the commit lag that was (or would have been) introduced by each
synchronous commit level, if the remote server was configured as a
synchronous standby.  For an asynchronous standby, the replay_lag column
approximates the delay before recent transactions became visible to queries.
If the standby server has entirely caught up with the sending server and
there is no more WAL activity, the most recently measured lag times will
continue to be displayed for a short time and then show NULL.

Physical replication lag tracking is automatic. Logical replication tracking
is possible but is the responsibility of the logical decoding plugin.
Tracking is a private module operating within each walsender individually,
with values reported to shared memory. Module not used outside of walsender.

Design and code is good enough now to commit - kudos to the author.
In many ways a difficult topic, with important and subtle behaviour so this
shoudl be expected to generate discussion and multiple open items: Test now!

Author: Thomas Munro, following designs by Fujii Masao and Simon Riggs
Review: Simon Riggs, Ian Barwick and Craig Ringer
2017-03-23 14:05:28 +00:00
Peter Eisentraut 7c4f52409a Logical replication support for initial data copy
Add functionality for a new subscription to copy the initial data in the
tables and then sync with the ongoing apply process.

For the copying, add a new internal COPY option to have the COPY source
data provided by a callback function.  The initial data copy works on
the subscriber by receiving COPY data from the publisher and then
providing it locally into a COPY that writes to the destination table.

A WAL receiver can now execute full SQL commands.  This is used here to
obtain information about tables and publications.

Several new options were added to CREATE and ALTER SUBSCRIPTION to
control whether and when initial table syncing happens.

Change pg_dump option --no-create-subscription-slots to
--no-subscription-connect and use the new CREATE SUBSCRIPTION
... NOCONNECT option for that.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Tested-by: Erik Rijkers <er@xs4all.nl>
2017-03-23 08:55:37 -04:00
Peter Eisentraut 164bdbe9c2 doc: Correct row count in table
The incorrect count causes FOP to error out.
2017-03-18 09:42:26 -04:00
Robert Haas 249cf070e3 Create and use wait events for read, write, and fsync operations.
Previous commits, notably 53be0b1add and
6f3bd98ebf, made it possible to see from
pg_stat_activity when a backend was stuck waiting for another backend,
but it's also fairly common for a backend to be stuck waiting for an
I/O.  Add wait events for those operations, too.

Rushabh Lathia, with further hacking by me.  Reviewed and tested by
Michael Paquier, Amit Kapila, Rajkumar Raghuwanshi, and Rahila Syed.

Discussion: http://postgr.es/m/CAGPqQf0LsYHXREPAZqYGVkDqHSyjf=KsD=k0GTVPAuzyThh-VQ@mail.gmail.com
2017-03-18 07:43:01 -04:00
Peter Eisentraut a47b38c9ee Spelling fixes
From: Josh Soref <jsoref@gmail.com>
2017-03-14 12:58:39 -04:00
Robert Haas f35742ccb7 Support parallel bitmap heap scans.
The index is scanned by a single process, but then all cooperating
processes can iterate jointly over the resulting set of heap blocks.
In the future, we might also want to support using a parallel bitmap
index scan to set up for a parallel bitmap heap scan, but that's a
job for another day.

Dilip Kumar, with some corrections and cosmetic changes by me.  The
larger patch set of which this is a part has been reviewed and tested
by (at least) Andres Freund, Amit Khandekar, Tushar Ahuja, Rafia
Sabih, Haribabu Kommi, Thomas Munro, and me.

Discussion: http://postgr.es/m/CAFiTN-uc4=0WxRGfCzs-xfkMYcSEWUC-Fon6thkJGjkh9i=13A@mail.gmail.com
2017-03-08 12:05:43 -05:00
Robert Haas 98e6e89040 tidbitmap: Support shared iteration.
When a shared iterator is used, each call to tbm_shared_iterate()
returns a result that has not yet been returned to any process
attached to the shared iterator.  In other words, each cooperating
processes gets a disjoint subset of the full result set, but all
results are returned exactly once.

This is infrastructure for parallel bitmap heap scan.

Dilip Kumar.  The larger patch set of which this is a part has been
reviewed and tested by (at least) Andres Freund, Amit Khandekar,
Tushar Ahuja, Rafia Sabih, Haribabu Kommi, and Thomas Munro.

Discussion: http://postgr.es/m/CAFiTN-uc4=0WxRGfCzs-xfkMYcSEWUC-Fon6thkJGjkh9i=13A@mail.gmail.com
2017-03-08 08:09:38 -05:00
Robert Haas 569174f1be btree: Support parallel index scans.
This isn't exposed to the optimizer or the executor yet; we'll add
support for those things in a separate patch.  But this puts the
basic mechanism in place: several processes can attach to a parallel
btree index scan, and each one will get a subset of the tuples that
would have been produced by a non-parallel scan.  Each index page
becomes the responsibility of a single worker, which then returns
all of the TIDs on that page.

Rahila Syed, Amit Kapila, Robert Haas, reviewed and tested by
Anastasia Lubennikova, Tushar Ahuja, and Haribabu Kommi.
2017-02-15 07:41:14 -05:00
Robert Haas 3f01fd4ca0 Rename dtrace probes for ongoing xlog -> wal conversion.
xlog-switch becomes wal-switch, and xlog-insert becomes wal-insert.
2017-02-09 16:40:19 -05:00
Peter Eisentraut 665d1fad99 Logical replication
- Add PUBLICATION catalogs and DDL
- Add SUBSCRIPTION catalog and DDL
- Define logical replication protocol and output plugin
- Add logical replication workers

From: Petr Jelinek <petr@2ndquadrant.com>
Reviewed-by: Steve Singer <steve@ssinger.info>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Erik Rijkers <er@xs4all.nl>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
2017-01-20 09:04:49 -05:00
Robert Haas e13029a5ce Provide a DSA area for all parallel queries.
This will allow future parallel query code to dynamically allocate
storage shared by all participants.

Thomas Munro, with assorted changes by me.
2016-12-19 17:11:46 -05:00
Fujii Masao 3901fd70cc Support quorum-based synchronous replication.
This feature is also known as "quorum commit" especially in discussion
on pgsql-hackers.

This commit adds the following new syntaxes into synchronous_standby_names
GUC. By using FIRST and ANY keywords, users can specify the method to
choose synchronous standbys from the listed servers.

  FIRST num_sync (standby_name [, ...])
  ANY num_sync (standby_name [, ...])

The keyword FIRST specifies a priority-based synchronous replication
which was available also in 9.6 or before. This method makes transaction
commits wait until their WAL records are replicated to num_sync
synchronous standbys chosen based on their priorities.

The keyword ANY specifies a quorum-based synchronous replication
and makes transaction commits wait until their WAL records are
replicated to *at least* num_sync listed standbys. In this method,
the values of sync_state.pg_stat_replication for the listed standbys
are reported as "quorum". The priority is still assigned to each standby,
but not used in this method.

The existing syntaxes having neither FIRST nor ANY keyword are still
supported. They are the same as new syntax with FIRST keyword, i.e.,
a priorirty-based synchronous replication.

Author: Masahiko Sawada
Reviewed-By: Michael Paquier, Amit Kapila and me
Discussion: <CAD21AoAACi9NeC_ecm+Vahm+MMA6nYh=Kqs3KB3np+MBOS_gZg@mail.gmail.com>

Many thanks to the various individuals who were involved in
discussing and developing this feature.
2016-12-19 21:15:30 +09:00
Robert Haas 3761fe3c20 Simplify LWLock tranche machinery by removing array_base/array_stride.
array_base and array_stride were added so that we could identify the
offset of an LWLock within a tranche, but this facility is only very
marginally used apart from the main tranche.  So, give every lock in
the main tranche its own tranche ID and get rid of array_base,
array_stride, and all that's attached.  For debugging facilities
(Trace_lwlocks and LWLOCK_STATS) print the pointer address of the
LWLock using %p instead of the offset.  This is arguably more useful,
and certainly a lot cheaper.  Drop the offset-within-tranche from
the information reported to dtrace and from one can't-happen message
inside lwlock.c.

The main user-visible impact of this change is that pg_stat_activity
will now report all waits for LWLocks as "LWLock" rather than
reporting some as "LWLockTranche" and others as "LWLockNamed".

The main motivation for this change is that the need to specify an
array_base and an array_stride is awkward for parallel query.  There
is only a very limited supply of tranche IDs so we can't just keep
allocating new ones, and if we try to use the same tranche IDs every
time then we run into trouble when multiple parallel contexts are
use simultaneously.  So if we didn't get rid of this mechanism we'd
have to make it even more complicated.  By simplifying it in this
way, we instead reduce the size of the generated code for lwlock.c
by about 5%.

Discussion: http://postgr.es/m/CA+TgmoYsFn6NUW1x0AZtupJGUAs1UDY4dJtCN47_Q6D0sP80PA@mail.gmail.com
2016-12-16 11:29:23 -05:00
Fujii Masao dfe530a092 Improve documentation about pg_stat_replication view.
Add the descriptions of possible values in "state" and "sync_state" columns
of pg_stat_replication view.

Author: Michael Paquier, slightly modified by me
Discussion: <CAB7nPqT7APWrvPFZrcjKEHoq4=g3z2ErxtTdojSf+sDALzuemA@mail.gmail.com>
2016-12-06 17:09:10 +09:00
Robert Haas e63d414988 Clarify that pg_stat_activity.query has a length limit.
There was always documentation of the GUC that controlled what the
limit actually was, but previously the documentation of the field
itself made no mention of that limit.

Ian Barwick
2016-12-02 08:59:20 -05:00
Robert Haas 6f3bd98ebf Extend framework from commit 53be0b1ad to report latch waits.
WaitLatch, WaitLatchOrSocket, and WaitEventSetWait now taken an
additional wait_event_info parameter; legal values are defined in
pgstat.h.  This makes it possible to uniquely identify every point in
the core code where we are waiting for a latch; extensions can pass
WAIT_EXTENSION.

Because latches were the major wait primitive not previously covered
by this patch, it is now possible to see information in
pg_stat_activity on a large number of important wait events not
previously addressed, such as ClientRead, ClientWrite, and SyncRep.

Unfortunately, many of the wait events added by this patch will fail
to appear in pg_stat_activity because they're only used in background
processes which don't currently appear in pg_stat_activity.  We should
fix this either by creating a separate view for such information, or
else by deciding to include them in pg_stat_activity after all.

Michael Paquier and Robert Haas, reviewed by Alexander Korotkov and
Thomas Munro.
2016-10-04 11:01:42 -04:00
Tom Lane da6c4f6ca8 Refer to OS X as "macOS", except for the port name which is still "darwin".
We weren't terribly consistent about whether to call Apple's OS "OS X"
or "Mac OS X", and the former is probably confusing to people who aren't
Apple users.  Now that Apple has rebranded it "macOS", follow their lead
to establish a consistent naming pattern.  Also, avoid the use of the
ancient project name "Darwin", except as the port code name which does not
seem desirable to change.  (In short, this patch touches documentation and
comments, but no actual code.)

I didn't touch contrib/start-scripts/osx/, either.  I suspect those are
obsolete and due for a rewrite, anyway.

I dithered about whether to apply this edit to old release notes, but
those were responsible for quite a lot of the inconsistencies, so I ended
up changing them too.  Anyway, Apple's being ahistorical about this,
so why shouldn't we be?
2016-09-25 15:40:57 -04:00
Kevin Grittner c93d8737be Add OldSnapshotTimeMapLock to wait_event table in docs.
Ashutosh Sharma with minor fixes by me.
2016-08-03 09:58:50 -05:00
Peter Eisentraut 0a4d67b16c doc: Remove slightly confusing xreflabels
It seems clearer to refer to these tables in the normal way.
2016-08-02 22:34:45 -04:00
Peter Eisentraut 5676da2d01 Documentation spell checking and markup improvements 2016-07-28 22:46:15 -04:00
Fujii Masao 60d50769b7 Rename pg_stat_wal_receiver.conn_info to conninfo.
Per discussion on pgsql-hackers, conninfo is better as the column name
because it's more commonly used in PostgreSQL.

Catalog version bumped due to the change of pg_proc.

Author: Michael Paquier
2016-07-07 12:59:39 +09:00
Alvaro Herrera 9ed551e0a4 Add conninfo to pg_stat_wal_receiver
Commit b1a9bad9e7 introduced a stats view to provide insight into the
running WAL receiver, but neglected to include the connection string in
it, as reported by Michaël Paquier.  This commit fixes that omission.
(Any security-sensitive information is not disclosed).

While at it, close the mild security hole that we were exposing the
password in the connection string in shared memory.  This isn't
user-accessible, but it still looks like a good idea to avoid having the
cleartext password in memory.

Author: Michaël Paquier, Álvaro Herrera
Review by: Vik Fearing

Discussion: https://www.postgresql.org/message-id/CAB7nPqStg4M561obo7ryZ5G+fUydG4v1Ajs1xZT1ujtu+woRag@mail.gmail.com
2016-06-29 16:57:17 -04:00
Simon Riggs 29424a9c66 Fix simple typo in monitoring docs 2016-06-07 15:21:01 +01:00
Tom Lane c311f78873 First-draft release notes for Postgres 9.6.
These are just of beta quality, but we're only at beta ... the section
about parallel query, in particular, could doubtless use more work.
2016-05-05 13:27:59 -04:00
Stephen Frost 1574783b4c Use GRANT system to manage access to sensitive functions
Now that pg_dump will properly dump out any ACL changes made to
functions which exist in pg_catalog, switch to using the GRANT system
to manage access to those functions.

This means removing 'if (!superuser()) ereport()' checks from the
functions themselves and then REVOKEing EXECUTE right from 'public' for
these functions in system_views.sql.

Reviews by Alexander Korotkov, Jose Luis Tallon
2016-04-06 21:45:32 -04:00
Fujii Masao 112a2d0615 Fix typo in docs.
Jeff Janes
2016-03-22 22:05:17 +09:00
Robert Haas 1c4f001b79 Fix typo.
Amit Langote
2016-03-16 11:38:30 -04:00
Robert Haas 2a90cb69e1 Fix typos.
Thomas Reiss
2016-03-15 16:28:17 -04:00
Robert Haas c16dc1aca5 Add simple VACUUM progress reporting.
There's a lot more that could be done here yet - in particular, this
reports only very coarse-grained information about the index vacuuming
phase - but even as it stands, the new pg_stat_progress_vacuum can
tell you quite a bit about what a long-running vacuum is actually
doing.

Amit Langote and Robert Haas, based on earlier work by Vinayak Pokale
and Rahila Syed.
2016-03-15 13:32:56 -04:00
Robert Haas 53be0b1add Provide much better wait information in pg_stat_activity.
When a process is waiting for a heavyweight lock, we will now indicate
the type of heavyweight lock for which it is waiting.  Also, you can
now see when a process is waiting for a lightweight lock - in which
case we will indicate the individual lock name or the tranche, as
appropriate - or for a buffer pin.

Amit Kapila, Ildus Kurbangaliev, reviewed by me.  Lots of helpful
discussion and suggestions by many others, including Alexander
Korotkov, Vladimir Borodin, and many others.
2016-03-10 12:44:09 -05:00
Alvaro Herrera b1a9bad9e7 pgstat: add WAL receiver status view & SRF
This new view provides insight into the state of a running WAL receiver
in a HOT standby node.
The information returned includes the PID of the WAL receiver process,
its status (stopped, starting, streaming, etc), start LSN and TLI, last
received LSN and TLI, timestamp of last message send and receipt, latest
end-of-WAL LSN and time, and the name of the slot (if any).

Access to the detailed data is only granted to superusers; others only
get the PID.

Author: Michael Paquier
Reviewer: Haribabu Kommi
2016-01-07 16:21:19 -03:00
Peter Eisentraut 19e7ca8938 doc: Add some markup 2015-12-12 11:31:28 -05:00
Magnus Hagander 9029f4b374 Add system view pg_stat_ssl
This view shows information about all connections, such as if the
connection is using SSL, which cipher is used, and which client
certificate (if any) is used.

Reviews by Alex Shulgin, Heikki Linnakangas, Andres Freund & Michael Paquier
2015-04-12 19:07:46 +02:00
Bruce Momjian 7e9ed623d9 docs: mention the optimizer can increase the index usage count
Report by Marko Tiikkaja
2015-03-19 22:38:15 -04:00
Peter Eisentraut 959df4b5fc doc: Remove link to outdated dtrace project on pgfoundry 2015-03-14 16:29:36 -04:00
Tom Lane 2fb7a75f37 Add pg_stat_get_snapshot_timestamp() to show statistics snapshot timestamp.
Per discussion, this could be useful for purposes such as programmatically
detecting a nonresponding stats collector.  We already have the timestamp
anyway, it's just a matter of providing a SQL-accessible function to fetch
it.

Matt Kelly, reviewed by Jim Nasby
2015-02-19 21:36:50 -05:00
Andres Freund 5ede3a3117 Document that pg_stat_*_tables.n_tup_upd includes n_tup_hot_upd.
Author: Peter Geoghegan
2014-12-04 23:55:19 +01:00
Magnus Hagander 386c9b7383 Restructure doc sections about statistics views
Break out the "dynamic statistics" views in the table from the
"collected statistics" ones. Could do with some more refactoring,
but this is a start.
2014-11-16 13:49:03 +01:00
Peter Eisentraut 220bb39dee doc: Reflect renaming of Mac OS X to OS X
bug #10528
2014-09-09 13:56:29 -04:00
Peter Eisentraut aa68872561 doc: Spell checking 2014-07-16 22:48:11 -04:00
Andres Freund 6647f59fd2 Fix typos in the cluster_name commit.
Thom Brown and Fujii Masao
2014-06-30 10:49:39 +02:00
Andres Freund 51adcaa0df Add cluster_name GUC which is included in process titles if set.
When running several postgres clusters on one OS instance it's often
inconveniently hard to identify which "postgres" process belongs to
which postgres instance.

Add the cluster_name GUC, whose value will be included as part of the
process titles if set. With that processes can more easily identified
using tools like 'ps'.

To avoid problems with encoding mismatches between postgresql.conf,
consoles, and individual databases replace non-ASCII chars in the name
with question marks. The length is limited to NAMEDATALEN to make it
less likely to truncate important information at the end of the
status.

Thomas Munro, with some adjustments by me and review by a host of people.
2014-06-29 14:15:09 +02:00
Fujii Masao c8c9c1f5a3 Add description of pg_stat directory into doc.
Back-patch to 9.3 where pg_stat directory was introduced.
2014-06-05 01:43:17 +09:00
Fujii Masao eb56812144 Fix incorrect column name in pg_stat_replication document.
Fabrízio de Royes Mello
2014-05-19 17:03:30 +09:00
Heikki Linnakangas 4a781f1e6c Fix typo, trance -> tranche, in docs.
Amit Langote
2014-04-23 13:00:08 +03:00
Robert Haas dd1a3bccca Show xid and xmin in pg_stat_activity and pg_stat_replication.
Christian Kruse, reviewed by Andres Freund and myself, with further
minor adjustments by me.
2014-02-25 12:34:04 -05:00
Robert Haas 6615e77439 Use pg_lsn data type in pg_stat_replication, too.
Michael Paquier, per a suggestion from Andres Freund
2014-02-24 10:38:45 -05:00
Bruce Momjian 637fab6e57 doc: mention statistics reset during crash recovery
Takayuki Tsunakawa
2014-01-31 21:28:15 -05:00
Fujii Masao 9132b189bf Add pg_stat_archiver statistics view.
This view shows the statistics about the WAL archiver process's activity.

Gabriele Bartolini, reviewed by Michael Paquier, refactored a bit by me.
2014-01-29 02:58:22 +09:00
Robert Haas ea9df812d8 Relax the requirement that all lwlocks be stored in a single array.
This makes it possible to store lwlocks as part of some other data
structure in the main shared memory segment, or in a dynamic shared
memory segment.  There is still a main LWLock array and this patch does
not move anything out of it, but it provides necessary infrastructure
for doing that in the future.

This change is likely to increase the size of LWLockPadded on some
platforms, especially 32-bit platforms where it was previously only
16 bytes.

Patch by me.  Review by Andres Freund and KaiGai Kohei.
2014-01-27 11:07:44 -05:00
Magnus Hagander c87ff71f37 Expose the estimation of number of changed tuples since last analyze
This value, now pg_stat_all_tables.n_mod_since_analyze, was already
tracked and used by autovacuum, but not exposed to the user.

Mark Kirkwood, review by Laurenz Albe
2013-07-05 15:10:15 +02:00
Fujii Masao 2ef085d0e6 Get rid of pg_class.reltoastidxid.
Treat TOAST index just the same as normal one and get the OID
of TOAST index from pg_index but not pg_class.reltoastidxid.
This change allows us to handle multiple TOAST indexes, and
which is required infrastructure for upcoming
REINDEX CONCURRENTLY feature.

Patch by Michael Paquier, reviewed by Andres Freund and me.
2013-07-04 03:24:09 +09:00
Peter Eisentraut 82b55c9769 doc: Update DTrace information
The old web site link no longer worked, and some information was
outdated.
2013-04-10 23:06:19 -04:00
Peter Eisentraut 79a457dca7 doc: Add pg_stat_reset and related functions to index 2012-12-15 00:30:53 -05:00
Peter Eisentraut 5baf6da717 Documentation spell and markup checking 2012-06-08 00:06:20 +03:00
Tom Lane f35ebd2aa1 Update example of process titles shown by "ps".
This example was quite old: it lacked the WAL writer and autovac launcher
as well as the more recently added checkpointer.  Linux "ps" seems to show
slightly different stuff now too.
2012-05-11 18:33:39 -04:00
Tom Lane 809e7e21af Converge all SQL-level statistics timing values to float8 milliseconds.
This patch adjusts the core statistics views to match the decision already
taken for pg_stat_statements, that values representing elapsed time should
be represented as float8 and measured in milliseconds.  By using float8,
we are no longer tied to a specific maximum precision of timing data.
(Internally, it's still microseconds, but we could now change that without
needing changes at the SQL level.)

The columns affected are
pg_stat_bgwriter.checkpoint_write_time
pg_stat_bgwriter.checkpoint_sync_time
pg_stat_database.blk_read_time
pg_stat_database.blk_write_time
pg_stat_user_functions.total_time
pg_stat_user_functions.self_time
pg_stat_xact_user_functions.total_time
pg_stat_xact_user_functions.self_time

The first four of these are new in 9.2, so there is no compatibility issue
from changing them.  The others require a release note comment that they
are now double precision (and can show a fractional part) rather than
bigint as before; also their underlying statistics functions now match
the column definitions, instead of returning bigint microseconds.
2012-04-30 14:03:33 -04:00
Tom Lane 1dd89eadcd Rename I/O timing statistics columns to blk_read_time and blk_write_time.
This seems more consistent with the pre-existing choices for names of
other statistics columns.  Rename assorted internal identifiers to match.
2012-04-29 18:13:33 -04:00
Tom Lane 309c64745e Rename track_iotiming GUC to track_io_timing.
This spelling seems significantly more readable to me.
2012-04-29 16:23:54 -04:00