Commit Graph

886 Commits

Author SHA1 Message Date
Peter Eisentraut 2eb4a831e5 Change TRUE/FALSE to true/false
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources.  The upper case spellings are only used
in some files/modules.  So standardize on the standard spellings.

The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.

In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-11-08 11:37:28 -05:00
Robert Haas 846fcc8516 Fix problems with the "role" GUC and parallel query.
Without this fix, dropping a role can sometimes result in parallel
query failures in sessions that have used "SET ROLE" to assume the
dropped role, even if that setting isn't active any more.

Report by Pavan Deolasee.  Patch by Amit Kapila, reviewed by me.

Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
2017-10-29 12:58:40 +05:30
Robert Haas f49842d1ee Basic partition-wise join functionality.
Instead of joining two partitioned tables in their entirety we can, if
it is an equi-join on the partition keys, join the matching partitions
individually.  This involves teaching the planner about "other join"
rels, which are related to regular join rels in the same way that
other member rels are related to baserels.  This can use significantly
more CPU time and memory than regular join planning, because there may
now be a set of "other" rels not only for every base relation but also
for every join relation.  In most practical cases, this probably
shouldn't be a problem, because (1) it's probably unusual to join many
tables each with many partitions using the partition keys for all
joins and (2) if you do that scenario then you probably have a big
enough machine to handle the increased memory cost of planning and (3)
the resulting plan is highly likely to be better, so what you spend in
planning you'll make up on the execution side.  All the same, for now,
turn this feature off by default.

Currently, we can only perform joins between two tables whose
partitioning schemes are absolutely identical.  It would be nice to
cope with other scenarios, such as extra partitions on one side or the
other with no match on the other side, but that will have to wait for
a future patch.

Ashutosh Bapat, reviewed and tested by Rajkumar Raghuwanshi, Amit
Langote, Rafia Sabih, Thomas Munro, Dilip Kumar, Antonin Houska, Amit
Khandekar, and by me.  A few final adjustments by me.

Discussion: http://postgr.es/m/CAFjFpRfQ8GrQvzp3jA2wnLqrHmaXna-urjm_UY9BqXj=EaDTSA@mail.gmail.com
Discussion: http://postgr.es/m/CAFjFpRcitjfrULr5jfuKWRPsGUX0LQ0k8-yG0Qw2+1LBGNpMdw@mail.gmail.com
2017-10-06 11:11:10 -04:00
Robert Haas 8b304b8b72 Remove replacement selection sort.
At the time replacement_sort_tuples was introduced, there were still
cases where replacement selection sort noticeably outperformed using
quicksort even for the first run.  However, those cases seem to have
evaporated as a result of further improvements made since that time
(and perhaps also advances in CPU technology).  So remove replacement
selection and the controlling GUC entirely.  This makes tuplesort.c
noticeably simpler and probably paves the way for further
optimizations someone might want to do later.

Peter Geoghegan, with review and testing by Tomas Vondra and me.

Discussion: https://postgr.es/m/CAH2-WzmmNjG_K0R9nqYwMq3zjyJJK+hCbiZYNGhAy-Zyjs64GQ@mail.gmail.com
2017-09-29 10:25:44 -04:00
Peter Eisentraut 0c5803b450 Refactor new file permission handling
The file handling functions from fd.c were called with a diverse mix of
notations for the file permissions when they were opening new files.
Almost all files created by the server should have the same permissions
set.  So change the API so that e.g. OpenTransientFile() automatically
uses the standard permissions set, and OpenTransientFilePerm() is a new
function that takes an explicit permissions set for the few cases where
it is needed.  This also saves an unnecessary argument for call sites
that are just opening an existing file.

While we're reviewing these APIs, get rid of the FileName typedef and
use the standard const char * for the file name and mode_t for the file
mode.  This makes these functions match other file handling functions
and removes an unnecessary layer of mysteriousness.  We can also get rid
of a few casts that way.

Author: David Steele <david@pgmasters.net>
2017-09-23 10:16:18 -04:00
Andres Freund fc49e24fa6 Make WAL segment size configurable at initdb time.
For performance reasons a larger segment size than the default 16MB
can be useful. A larger segment size has two main benefits: Firstly,
in setups using archiving, it makes it easier to write scripts that
can keep up with higher amounts of WAL, secondly, the WAL has to be
written and synced to disk less frequently.

But at the same time large segment size are disadvantageous for
smaller databases. So far the segment size had to be configured at
compile time, often making it unrealistic to choose one fitting to a
particularly load. Therefore change it to a initdb time setting.

This includes a breaking changes to the xlogreader.h API, which now
requires the current segment size to be configured.  For that and
similar reasons a number of binaries had to be taught how to recognize
the current segment size.

Author: Beena Emerson, editorialized by Andres Freund
Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael
    Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja
Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
2017-09-19 22:03:48 -07:00
Andres Freund 6e7baa3227 Introduce BYTES unit for GUCs.
This is already useful for track_activity_query_size, and will further
be used in a later commit making the WAL segment size configurable.

Author: Beena Emerson
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAOG9ApEu8bXVwBxkOO9J7ZpM76TASK_vFMEEiCEjwhMmSLiaqQ@mail.gmail.com
2017-09-12 12:13:12 -07:00
Peter Eisentraut 821fb8cdbf Message style fixes 2017-09-11 11:21:27 -04:00
Peter Eisentraut 1356f78ea9 Reduce excessive dereferencing of function pointers
It is equivalent in ANSI C to write (*funcptr) () and funcptr().  These
two styles have been applied inconsistently.  After discussion, we'll
use the more verbose style for plain function pointer variables, to make
it clear that it's a variable, and the shorter style when the function
pointer is in a struct (s.func() or s->func()), because then it's clear
that it's not a plain function name, and otherwise the excessive
punctuation makes some of those invocations hard to read.

Discussion: https://www.postgresql.org/message-id/f52c16db-14ed-757d-4b48-7ef360b1631d@2ndquadrant.com
2017-09-07 13:56:09 -04:00
Heikki Linnakangas c0a15e07cd Always use 2048 bit DH parameters for OpenSSL ephemeral DH ciphers.
1024 bits is considered weak these days, but OpenSSL always passes 1024 as
the key length to the tmp_dh callback. All the code to handle other key
lengths is, in fact, dead.

To remedy those issues:

* Only include hard-coded 2048-bit parameters.
* Set the parameters directly with SSL_CTX_set_tmp_dh(), without the
  callback
* The name of the file containing the DH parameters is now a GUC. This
  replaces the old hardcoded "dh1024.pem" filename. (The files for other
  key lengths, dh512.pem, dh2048.pem, etc. were never actually used.)

This is not a new problem, but it doesn't seem worth the risk and churn to
backport. If you care enough about the strength of the DH parameters on
old versions, you can create custom DH parameters, with as many bits as you
wish, and put them in the "dh1024.pem" file.

Per report by Nicolas Guini and Damian Quiroga. Reviewed by Michael Paquier.

Discussion: https://www.postgresql.org/message-id/CAMxBoUyjOOautVozN6ofzym828aNrDjuCcOTcCquxjwS-L2hGQ@mail.gmail.com
2017-07-31 22:36:09 +03:00
Tom Lane 382ceffdf7 Phase 3 of pgindent updates.
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.

By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis.  However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent.  That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.

This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.

This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.

Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 15:35:54 -04:00
Tom Lane c7b8998ebb Phase 2 of pgindent updates.
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.

Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code.  The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there.  BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs.  So the
net result is that in about half the cases, such comments are placed
one tab stop left of before.  This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.

Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.

This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.

Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 15:19:25 -04:00
Tom Lane e3860ffa4d Initial pgindent run with pg_bsd_indent version 2.0.
The new indent version includes numerous fixes thanks to Piotr Stefaniak.
The main changes visible in this commit are:

* Nicer formatting of function-pointer declarations.
* No longer unexpectedly removes spaces in expressions using casts,
  sizeof, or offsetof.
* No longer wants to add a space in "struct structname *varname", as
  well as some similar cases for const- or volatile-qualified pointers.
* Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely.
* Fixes bug where comments following declarations were sometimes placed
  with no space separating them from the code.
* Fixes some odd decisions for comments following case labels.
* Fixes some cases where comments following code were indented to less
  than the expected column 33.

On the less good side, it now tends to put more whitespace around typedef
names that are not listed in typedefs.list.  This might encourage us to
put more effort into typedef name collection; it's not really a bug in
indent itself.

There are more changes coming after this round, having to do with comment
indentation and alignment of lines appearing within parentheses.  I wanted
to limit the size of the diffs to something that could be reviewed without
one's eyes completely glazing over, so it seemed better to split up the
changes as much as practical.

Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 14:39:04 -04:00
Bruce Momjian a6fd7b7a5f Post-PG 10 beta1 pgindent run
perltidy run not included.
2017-05-17 16:31:56 -04:00
Heikki Linnakangas eb61136dc7 Remove support for password_encryption='off' / 'plain'.
Storing passwords in plaintext hasn't been a good idea for a very long
time, if ever. Now seems like a good time to finally forbid it, since we're
messing with this in PostgreSQL 10 anyway.

Remove the CREATE/ALTER USER UNENCRYPTED PASSSWORD 'foo' syntax, since
storing passwords unencrypted is no longer supported. ENCRYPTED PASSWORD
'foo' is still accepted, but ENCRYPTED is now just a noise-word, it does
the same as just PASSWORD 'foo'.

Likewise, remove the --unencrypted option from createuser, but accept
--encrypted as a no-op for backward compatibility. AFAICS, --encrypted was
a no-op even before this patch, because createuser encrypted the password
before sending it to the server even if --encrypted was not specified. It
added the ENCRYPTED keyword to the SQL command, but since the password was
already in encrypted form, it didn't make any difference. The documentation
was not clear on whether that was intended or not, but it's moot now.

Also, while password_encryption='on' is still accepted as an alias for
'md5', it is now marked as hidden, so that it is not listed as an accepted
value in error hints, for example. That's not directly related to removing
'plain', but it seems better this way.

Reviewed by Michael Paquier

Discussion: https://www.postgresql.org/message-id/16e9b768-fd78-0b12-cfc1-7b6b7f238fde@iki.fi
2017-05-08 11:26:07 +03:00
Magnus Hagander 34fc616738 Change hot_standby default value to 'on'
This goes together with the changes made to enable replication on the
sending side by default (wal_level, max_wal_senders etc) by making the
receiving stadby node also enable it by default.

Huong Dangminh
2017-05-02 11:12:30 +02:00
Heikki Linnakangas c727f120ff Rename "scram" to "scram-sha-256" in pg_hba.conf and password_encryption.
Per discussion, plain "scram" is confusing because we actually implement
SCRAM-SHA-256 rather than the original SCRAM that uses SHA-1 as the hash
algorithm. If we add support for SCRAM-SHA-512 or some other mechanism in
the SCRAM family in the future, that would become even more confusing.

Most of the internal files and functions still use just "scram" as a
shorthand for SCRMA-SHA-256, but I did change PASSWORD_TYPE_SCRAM to
PASSWORD_TYPE_SCRAM_SHA_256, as that could potentially be used by 3rd
party extensions that hook into the password-check hook.

Michael Paquier did this in an earlier version of the SCRAM patch set
already, but I didn't include that in the version that was committed.

Discussion: https://www.postgresql.org/message-id/fde71ff1-5858-90c8-99a9-1c2427e7bafb@iki.fi
2017-04-18 14:50:50 +03:00
Robert Haas 6599c9ac33 Add an Assert() to max_parallel_workers enforcement.
To prevent future bugs along the lines of the one corrected by commit
8ff518699f, or find any that remain
in the current code, add an Assert() that the difference between
parallel_register_count and parallel_terminate_count is in a sane
range.

Kuntal Ghosh, with considerable tidying-up by me, per a suggestion
from Neha Khatri.  Reviewed by Tomas Vondra.

Discussion: http://postgr.es/m/CAFO0U+-E8yzchwVnvn5BeRDPgX2z9vZUxQ8dxx9c0XFGBC7N1Q@mail.gmail.com
2017-04-11 13:03:44 -04:00
Fujii Masao ff7bce1743 Add max_sync_workers_per_subscription to postgresql.conf.sample.
This commit also does

- add REPLICATION_SUBSCRIBERS into config_group
- mark max_logical_replication_workers and max_sync_workers_per_subscription
  as REPLICATION_SUBSCRIBERS parameters
- move those parameters into "Subscribers" section in postgresql.conf.sample

Author: Masahiko Sawada, Petr Jelinek and me
Reported-by: Masahiko Sawada
Discussion: http://postgr.es/m/CAD21AoAonSCoa=v=87ZO3vhfUZA1k_E2XRNHTt=xioWGUa+0ug@mail.gmail.com
2017-04-12 00:10:54 +09:00
Tom Lane 8f0530f580 Improve castNode notation by introducing list-extraction-specific variants.
This extends the castNode() notation introduced by commit 5bcab1114 to
provide, in one step, extraction of a list cell's pointer and coercion to
a concrete node type.  For example, "lfirst_node(Foo, lc)" is the same
as "castNode(Foo, lfirst(lc))".  Almost half of the uses of castNode
that have appeared so far include a list extraction call, so this is
pretty widely useful, and it saves a few more keystrokes compared to the
old way.

As with the previous patch, back-patch the addition of these macros to
pg_list.h, so that the notation will be available when back-patching.

Patch by me, after an idea of Andrew Gierth's.

Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
2017-04-10 13:51:53 -04:00
Kevin Grittner c63172d60f Add GUCs for predicate lock promotion thresholds.
Defaults match the fixed behavior of prior releases, but now DBAs
have better options to tune serializable workloads.

It might be nice to be able to set this per relation, but that part
will need to wait for another release.

Author: Dagfinn Ilmari Mannsåker
2017-04-07 21:38:05 -05:00
Simon Riggs 9a3215026b Make min_wal_size/max_wal_size use MB internally
Previously they were defined using multiples of XLogSegSize.
Remove GUC_UNIT_XSEGS. Introduce GUC_UNIT_MB

Extracted from patch series on XLogSegSize infrastructure.

Beena Emerson
2017-04-04 18:00:01 -04:00
Simon Riggs 25fff40798 Default monitoring roles
Three nologin roles with non-overlapping privs are created by default
* pg_read_all_settings - read all GUCs.
* pg_read_all_stats - pg_stat_*, pg_database_size(), pg_tablespace_size()
* pg_stat_scan_tables - may lock/scan tables

Top level role - pg_monitor includes all of the above by default, plus others

Author: Dave Page
Reviewed-by: Stephen Frost, Robert Haas, Peter Eisentraut, Simon Riggs
2017-03-30 14:18:53 -04:00
Peter Eisentraut 3371e4d9b1 Change default of log_directory to 'log'
The previous default 'pg_log' might have indicated by its "pg_" prefix
that it is an internal system directory.  The new default is more in
line with the typical naming of directories with user-facing log files.
Together with the renaming of pg_clog and pg_xlog, this should clear up
that difference.

Author: Andreas Karlsson <andreas@proxel.se>
2017-03-27 10:34:33 -04:00
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 1e6de941e3 Change xlog to WAL in some error messages 2017-03-13 15:42:10 -04:00
Robert Haas 355d3993c5 Add a Gather Merge executor node.
Like Gather, we spawn multiple workers and run the same plan in each
one; however, Gather Merge is used when each worker produces the same
output ordering and we want to preserve that output ordering while
merging together the streams of tuples from various workers.  (In a
way, Gather Merge is like a hybrid of Gather and MergeAppend.)

This works out to a win if it saves us from having to perform an
expensive Sort.  In cases where only a small amount of data would need
to be sorted, it may actually be faster to use a regular Gather node
and then sort the results afterward, because Gather Merge sometimes
needs to wait synchronously for tuples whereas a pure Gather generally
doesn't.  But if this avoids an expensive sort then it's a win.

Rushabh Lathia, reviewed and tested by Amit Kapila, Thomas Munro,
and Neha Sharma, and reviewed and revised by me.

Discussion: http://postgr.es/m/CAGPqQf09oPX-cQRpBKS0Gq49Z+m6KBxgxd_p9gX8CKk_d75HoQ@mail.gmail.com
2017-03-09 07:49:29 -05:00
Heikki Linnakangas 818fd4a67d Support SCRAM-SHA-256 authentication (RFC 5802 and 7677).
This introduces a new generic SASL authentication method, similar to the
GSS and SSPI methods. The server first tells the client which SASL
authentication mechanism to use, and then the mechanism-specific SASL
messages are exchanged in AuthenticationSASLcontinue and PasswordMessage
messages. Only SCRAM-SHA-256 is supported at the moment, but this allows
adding more SASL mechanisms in the future, without changing the overall
protocol.

Support for channel binding, aka SCRAM-SHA-256-PLUS is left for later.

The SASLPrep algorithm, for pre-processing the password, is not yet
implemented. That could cause trouble, if you use a password with
non-ASCII characters, and a client library that does implement SASLprep.
That will hopefully be added later.

Authorization identities, as specified in the SCRAM-SHA-256 specification,
are ignored. SET SESSION AUTHORIZATION provides more or less the same
functionality, anyway.

If a user doesn't exist, perform a "mock" authentication, by constructing
an authentic-looking challenge on the fly. The challenge is derived from
a new system-wide random value, "mock authentication nonce", which is
created at initdb, and stored in the control file. We go through these
motions, in order to not give away the information on whether the user
exists, to unauthenticated users.

Bumps PG_CONTROL_VERSION, because of the new field in control file.

Patch by Michael Paquier and Heikki Linnakangas, reviewed at different
stages by Robert Haas, Stephen Frost, David Steele, Aleksander Alekseev,
and many others.

Discussion: https://www.postgresql.org/message-id/CAB7nPqRbR3GmFYdedCAhzukfKrgBLTLtMvENOmPrVWREsZkF8g%40mail.gmail.com
Discussion: https://www.postgresql.org/message-id/CAB7nPqSMXU35g%3DW9X74HVeQp0uvgJxvYOuA4A-A3M%2B0wfEBv-w%40mail.gmail.com
Discussion: https://www.postgresql.org/message-id/55192AFE.6080106@iki.fi
2017-03-07 14:25:40 +02:00
Tom Lane b9d092c962 Remove now-dead code for !HAVE_INT64_TIMESTAMP.
This is a basically mechanical removal of #ifdef HAVE_INT64_TIMESTAMP
tests and the negative-case controlled code.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
2017-02-23 14:04:43 -05:00
Peter Eisentraut 38d103763d Make more use of castNode() 2017-02-21 11:59:09 -05:00
Robert Haas 51ee6f3160 Replace min_parallel_relation_size with two new GUCs.
When min_parallel_relation_size was added, the only supported type
of parallel scan was a parallel sequential scan, but there are
pending patches for parallel index scan, parallel index-only scan,
and parallel bitmap heap scan.  Those patches introduce two new
types of complications: first, what's relevant is not really the
total size of the relation but the portion of it that we will scan;
and second, index pages and heap pages shouldn't necessarily be
treated in exactly the same way.  Typically, the number of index
pages will be quite small, but that doesn't necessarily mean that
a parallel index scan can't pay off.

Therefore, we introduce min_parallel_table_scan_size, which works
out a degree of parallelism for scans based on the number of table
pages that will be scanned (and which is therefore equivalent to
min_parallel_relation_size for parallel sequential scans) and also
min_parallel_index_scan_size which can be used to work out a degree
of parallelism based on the number of index pages that will be
scanned.

Amit Kapila and Robert Haas

Discussion: http://postgr.es/m/CAA4eK1KowGSYYVpd2qPpaPPA5R90r++QwDFbrRECTE9H_HvpOg@mail.gmail.com
Discussion: http://postgr.es/m/CAA4eK1+TnM4pXQbvn7OXqam+k_HZqb0ROZUMxOiL6DWJYCyYow@mail.gmail.com
2017-02-15 13:37:24 -05:00
Robert Haas 85c11324ca Rename user-facing tools with "xlog" in the name to say "wal".
This means pg_receivexlog because pg_receivewal, pg_resetxlog
becomes pg_resetwal, and pg_xlogdump becomes pg_waldump.
2017-02-09 16:23:46 -05:00
Robert Haas a507b86900 Add WAL consistency checking facility.
When the new GUC wal_consistency_checking is set to a non-empty value,
it triggers recording of additional full-page images, which are
compared on the standby against the results of applying the WAL record
(without regard to those full-page images).  Allowable differences
such as hints are masked out, and the resulting pages are compared;
any difference results in a FATAL error on the standby.

Kuntal Ghosh, based on earlier patches by Michael Paquier and Heikki
Linnakangas.  Extensively reviewed and revised by Michael Paquier and
by me, with additional reviews and comments from Amit Kapila, Álvaro
Herrera, Simon Riggs, and Peter Eisentraut.
2017-02-08 15:45:30 -05:00
Robert Haas 14ca9abfbe Increase upper bound for bgwriter_lru_maxpages.
There is no particularly good reason to limit this value to 1000,
so increase the limit to INT_MAX / 2, the same limit we use for
shared_buffers.  It's not clear how much practical effect larger
settings will have, but there seems no harm in letting people try it.

Jim Nasby, less a comment change I stripped out.

Discussion: http://postgr.es/m/f6e58a22-030b-eb8a-5457-f62fb08d701c@BlueTreble.com
2017-02-02 14:43:38 -05:00
Robert Haas d1ecd53947 Add a SHOW command to the replication command language.
This is useful infrastructure for an upcoming proposed patch to
allow the WAL segment size to be changed at initdb time; tools like
pg_basebackup need the ability to interrogate the server setting.
But it also doesn't seem like a bad thing to have independently of
that; it may find other uses in the future.

Robert Haas and Beena Emerson.  (The original patch here was by
Beena, but I rewrote it to such a degree that most of the code
being committed here is mine.)

Discussion: http://postgr.es/m/CA+TgmobNo4qz06wHEmy9DszAre3dYx-WNhHSCbU9SAwf+9Ft6g@mail.gmail.com
2017-01-24 17:04:12 -05:00
Peter Eisentraut f21a563d25 Move some things from builtins.h to new header files
This avoids that builtins.h has to include additional header files.
2017-01-20 20:29:53 -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
Magnus Hagander f6d6d2920d Change default values for backup and replication parameters
This changes the default values of the following parameters:

wal_level = replica
max_wal_senders = 10
max_replication_slots = 10

in order to make it possible to make a backup and set up simple
replication on the default settings, without requiring a system restart.

Discussion: https://postgr.es/m/CABUevEy4PR_EAvZEzsbF5s+V0eEvw7shJ2t-AUwbHOjT+yRb3A@mail.gmail.com

Reviewed by Peter Eisentraut. Benchmark help from Tomas Vondra.
2017-01-14 17:14:56 +01:00
Bruce Momjian 1d25779284 Update copyright via script for 2017 2017-01-03 13:48:53 -05:00
Tom Lane de41869b64 Allow SSL configuration to be updated at SIGHUP.
It is no longer necessary to restart the server to enable, disable,
or reconfigure SSL.  Instead, we just create a new SSL_CTX struct
(by re-reading all relevant files) whenever we get SIGHUP.  Testing
shows that this is fast enough that it shouldn't be a problem.

In conjunction with that, downgrade the logic that complains about
pg_hba.conf "hostssl" lines when SSL isn't active: now that's just
a warning condition not an error.

An issue that still needs to be addressed is what shall we do with
passphrase-protected server keys?  As this stands, the server would
demand the passphrase again on every SIGHUP, which is certainly
impractical.  But the case was only barely supported before, so that
does not seem a sufficient reason to hold up committing this patch.

Andreas Karlsson, reviewed by Michael Banck and Michael Paquier

Discussion: https://postgr.es/m/556A6E8A.9030400@proxel.se
2017-01-02 21:37:12 -05:00
Robert Haas e13486eba0 Remove sql_inheritance GUC.
This backward-compatibility GUC is long overdue for removal.

Discussion: http://postgr.es/m/CA+TgmoYe+EG7LdYX6pkcNxr4ygkP4+A=jm9o-CPXyOvRiCNwaQ@mail.gmail.com
2016-12-23 07:35:01 -05:00
Robert Haas 2b959d4957 Reduce the default for max_worker_processes back to 8.
Commit b460f5d669 -- at my suggestion --
increased the default value of max_worker_processes from 8 to 16, on
the theory that this would be harmless and convenient for users.
Unfortunately, this caused some buildfarm machines with low connection
limits to start failing, so apparently it's not harmless after all.
2016-12-05 10:53:21 -05:00
Robert Haas b460f5d669 Add max_parallel_workers GUC.
Increase the default value of the existing max_worker_processes GUC
from 8 to 16, and add a new max_parallel_workers GUC with a maximum
of 8.  This way, even if the maximum amount of parallel query is
happening, there is still room for background workers that do other
things, as originally envisioned when max_worker_processes was added.

Julien Rouhaud, reviewed by Amit Kapila and by revised by me.
2016-12-02 07:42:58 -05:00
Tom Lane dbdfd114f3 Bring some clarity to the defaults for the xxx_flush_after parameters.
Instead of confusingly stating platform-dependent defaults for these
parameters in the comments in postgresql.conf.sample (with the main
entry being a lie on Linux), teach initdb to install the correct
platform-dependent value in postgresql.conf, similarly to the way
we handle other platform-dependent defaults.  This won't do anything
for existing 9.6 installations, but since it's effectively only a
documentation improvement, that seems OK.

Since this requires initdb to have access to the default values,
move the #define's for those to pg_config_manual.h; the original
placement in bufmgr.h is unworkable because that file can't be
included by frontend programs.

Adjust the default value for wal_writer_flush_after so that it is 1MB
regardless of XLOG_BLCKSZ, conforming to what is stated in both the
SGML docs and postgresql.conf.  (We could alternatively make it scale
with XLOG_BLCKSZ, but I'm not sure I see the point.)

Copy-edit related SGML documentation.

Fabien Coelho and Tom Lane, per a gripe from Tomas Vondra.

Discussion: <30ebc6e3-8358-09cf-44a8-578252938424@2ndquadrant.com>
2016-11-25 18:36:10 -05:00
Tom Lane 13671b4b22 Code review for GUC serialization/deserialization code.
The serialization code dumped core for a string-valued GUC whose value
is NULL, which is a legal state.  The infrastructure isn't capable of
transmitting that state exactly, but fortunately, transmitting an empty
string instead should be close enough (compare, eg, commit e45e990e4).

The code potentially underestimated the space required to format a
real-valued variable, both because it made an unwarranted assumption that
%g output would never be longer than %e output, and because it didn't count
right even for %e format.  In practice this would pretty much always be
masked by overestimates for other variables, but it's still wrong.

Also fix boundary-case error in read_gucstate, incorrect handling of the
case where guc_sourcefile is non-NULL but zero length (not clear that can
happen, but if it did, this code would get totally confused), and
confusingly useless check for a NULL result from read_gucstate.

Andreas Seltenreich discovered the core dump; other issues noted while
reading nearby code.  Back-patch to 9.5 where this code was introduced.

Michael Paquier and Tom Lane

Discussion: <871sy78wno.fsf@credativ.de>
2016-11-19 14:26:19 -05:00
Robert Haas 60379f66c8 Fix mistake in XLOG_SEG_SIZE test.
The intent of the test is to check whether XLOG_SEG_SIZE is in a
particular range, but actually in one case it compares XLOG_BLCKSZ
by mistake.  Repair.

Commit 88e9823026 introduced this
faulty test.

Kuntal Ghosh, reviewed by Michael Paquier.
2016-11-08 12:12:19 -05:00
Robert Haas 7d3235ba42 By default, set log_line_prefix = '%m [%p] '.
This value might not be to everyone's taste; in particular, some
people might prefer %t to %m, and others may want %u, %d, or other
fields.  However, it's a vast improvement on the old default of ''.

Christoph Berg
2016-10-17 16:34:48 -04:00
Tom Lane 6bc811c992 Show a sensible value in pg_settings.unit for GUC_UNIT_XSEGS variables.
Commit 88e982302 invented GUC_UNIT_XSEGS for min_wal_size and max_wal_size,
but neglected to make it display sensibly in pg_settings.unit (by adding a
case to the switch in GetConfigOptionByNum).  Fix that, and adjust said
switch to throw a run-time error the next time somebody forgets.

In passing, avoid using a static buffer for the output string --- the rest
of this function pstrdup's from a local buffer, and I see no very good
reason why the units code should do it differently and less safely.

Per report from Otar Shavadze.  Back-patch to 9.5 where the new unit type
was added.

Report: <CAG-jOyA=iNFhN+yB4vfvqh688B7Tr5SArbYcFUAjZi=0Exp-Lg@mail.gmail.com>
2016-10-03 16:40:25 -04:00
Heikki Linnakangas babe05bc2b Turn password_encryption GUC into an enum.
This makes the parameter easier to extend, to support other password-based
authentication protocols than MD5. (SCRAM is being worked on.)

The GUC still accepts on/off as aliases for "md5" and "plain", although
we may want to remove those once we actually add support for another
password hash type.

Michael Paquier, reviewed by David Steele, with some further edits by me.

Discussion: <CAB7nPqSMXU35g=W9X74HVeQp0uvgJxvYOuA4A-A3M+0wfEBv-w@mail.gmail.com>
2016-09-28 12:22:44 +03:00
Tom Lane 5472ed3e9b Make min_parallel_relation_size's default value platform-independent.
The documentation states that the default value is 8MB, but this was
only true at BLCKSZ = 8kB, because the default was hard-coded as 1024.
Make the code match the docs by computing the default as 8MB/BLCKSZ.

Oversight in commit 75be66464, noted pursuant to a gripe from Peter E.

Discussion: <90634e20-097a-e4fd-67d5-fb2c42f0dd71@2ndquadrant.com>
2016-09-15 11:23:25 -04:00
Simon Riggs c3c0d7bd70 Raise max setting of checkpoint_timeout to 1d
Previously checkpoint_timeout was capped at 3600s
New max setting is 86400s = 24h = 1d

Discussion: 32558.1454471895@sss.pgh.pa.us
2016-09-11 23:26:18 +01:00
Magnus Hagander 0921554657 Disable update_process_title by default on Windows
The performance overhead of this can be significant on Windows, and most
people don't have the tools to view it anyway as Windows does not have
native support for process titles.

Discussion: <0A3221C70F24FB45833433255569204D1F5BE3E8@G01JPEXMBYT05>

Takayuki Tsunakawa
2016-08-17 10:43:16 +02:00
Peter Eisentraut c4d3a039f0 Change minimum max_worker_processes from 1 to 0
Setting it to 0 is probably not useful in practice, but it allows
testing of situations without available background worker slots.
2016-08-02 13:15:35 -04:00
Robert Haas d1f822e585 Clarify resource utilization of parallel query.
temp_file_limit is a per-process limit, not a per-session limit across
all cooperating parallel processes; change wording accordingly, per a
suggestion from Tom Lane.

Also, document under max_parallel_workers_per_gather the fact that each
process involved in a parallel query may use as many resources as a
separate session.  Caveat emptor.

Per a complaint from Peter Geoghegan.
2016-07-07 11:35:08 -04:00
Tom Lane 75be66464c Invent min_parallel_relation_size GUC to replace a hard-wired constant.
The main point of doing this is to allow the cutoff to be set very small,
even zero, to allow parallel-query behavior to be tested on relatively
small tables such as we typically use in the regression tests.  But it
might be of use to users too.  The number-of-workers scaling behavior in
create_plain_partial_paths() is pretty ad-hoc and subject to change, so
we won't expose anything about that, but the notion of not considering
parallel query at all for tables below size X seems reasonably stable.

Amit Kapila, per a suggestion from me

Discussion: <17170.1465830165@sss.pgh.pa.us>
2016-06-16 13:47:20 -04:00
Andres Freund 4bc0f165cb Change default of backend_flush_after GUC to 0 (disabled).
While beneficial, both for throughput and average/worst case latency, in
a significant number of workloads, there are other workloads in which
backend_flush_after can cause significant performance regressions in
comparison to < 9.6 releases. The regression is most likely when the hot
data set is bigger than shared buffers, but significantly smaller than
the operating system's page cache.

I personally think that the benefit of enabling backend flush control is
considerably bigger than the potential downsides, but a fair argument
can be made that not regressing is more important than improving
performance/latency. As the latter is the consensus, change the default
to 0.

The other settings introduced in 428b1d6b2 do not have the same
potential for regressions, so leave them enabled.

Benchmarks leading up to changing the default have been performed by
Mithun Cy, Ashutosh Sharma and Robert Haas.

Discussion: CAD__OuhPmc6XH=wYRm_+Q657yQE88DakN4=Ybh2oveFasHkoeA@mail.gmail.com
2016-06-10 15:31:11 -07:00
Robert Haas 4bc424b968 pgindent run for 9.6 2016-06-09 18:02:36 -04:00
Robert Haas c9ce4a1c61 Eliminate "parallel degree" terminology.
This terminology provoked widespread complaints.  So, instead, rename
the GUC max_parallel_degree to max_parallel_workers_per_gather
(leaving room for a possible future GUC max_parallel_workers that acts
as a system-wide limit), and rename the parallel_degree reloption to
parallel_workers.  Rename structure members to match.

These changes create a dump/restore hazard for users of PostgreSQL
9.6beta1 who have set the reloption (or applied the GUC using ALTER
USER or ALTER DATABASE).
2016-06-09 10:00:26 -04:00
Tom Lane 77ba610805 Revert "Use Foreign Key relationships to infer multi-column join selectivity".
This commit reverts 137805f89 as well as the associated commits 015e88942,
5306df283, and 68d704edb.  We found multiple bugs in this feature, and
there was concern about possible planner slowdown (though to be fair,
exhibiting a very large slowdown proved difficult).  The way forward
requires a considerable rewrite, which may or may not be possible to
accomplish in time for beta2.  In my judgment reviewing the rewrite will
be easier to accomplish starting from a clean slate, so let's temporarily
revert what's there now.  This also leaves us in a safe state if it turns
out to be necessary to postpone the rewrite to the next development cycle.

Discussion: <20160429102531.GA13701@huehner.biz>
2016-06-07 17:21:17 -04:00
Robert Haas c7ea68ff8d Limit maximum parallel degree to 1024.
This new limit affects both the max_parallel_degree GUC and the
parallel_degree reloption.  There may some day be a use case for using
more than 1024 CPUs for a single query, but that's surely not the case
right now.  Not only do not very many people have that many CPUs, but
the code hasn't been tested at that kind of scale and is very unlikely
to perform well, or even work at all, without a lot more work.  The
issue addressed by commit 06bd458cb8 is
probably just one problem of many.

The idea of a more reasonable limit here was suggested by Tom Lane;
the value of 1024 was suggested by Amit Kapila.
2016-05-06 14:50:54 -04:00
Tom Lane 4c804fbdfb Clean up parsing of synchronous_standby_names GUC variable.
Commit 989be0810d added a flex/bison lexer/parser to interpret
synchronous_standby_names.  It was done in a pretty crufty way, though,
making assorted end-use sites responsible for calling the parser at the
right times.  That was not only vulnerable to errors of omission, but made
it possible that lexer/parser errors occur at very undesirable times,
and created memory leakages even if there was no error.

Instead, perform the parsing once during check_synchronous_standby_names
and let guc.c manage the resulting data.  To do that, we have to flatten
the parsed representation into a single hunk of malloc'd memory, but that
is not very hard.

While at it, work a little harder on making useful error reports for
parsing problems; the previous code felt that "synchronous_standby_names
parser returned 1" was an appropriate user-facing error message.  (To
be fair, it did also log a syntax error message, but separately from the
GUC problem report, which is at best confusing.)  It had some outright
bugs in the face of invalid input, too.

I (tgl) also concluded that we need to restrict unquoted names in
synchronous_standby_names to be just SQL identifiers.  The previous coding
would accept darn near anything, which (1) makes the quoting convention
both nearly-unnecessary and formally ambiguous, (2) makes it very hard to
understand what is a syntax error and what is a creative interpretation of
the input as a standby name, and (3) makes it impossible to further extend
the syntax in future without a compatibility break.  I presume that we're
intending future extensions of the syntax, else this parsing infrastructure
is massive overkill, so (3) is an important objection.  Since we've taken
a compatibility hit for non-identifier names with this change anyway, we
might as well lock things down now and insist that users use double quotes
for standby names that aren't identifiers.

Kyotaro Horiguchi and Tom Lane
2016-04-27 17:55:25 -04:00
Robert Haas 77cd477c4b Enable parallel query by default.
Change max_parallel_degree default from 0 to 2.  It is possible that
this is not a good idea, or that we should go with 1 worker rather
than 2, but we won't find out without trying it.  Along the way,
reword the documentation for max_parallel_degree a little bit to
hopefully make it more clear.

Discussion: 20160420174631.3qjjhpwsvvx5bau5@alap3.anarazel.de
2016-04-26 08:35:58 -04:00
Andres Freund 8f91d87d43 Fix documentation & config inconsistencies around 428b1d6b2.
Several issues:
1) checkpoint_flush_after doc and code disagreed about the default
2) new GUCs were missing from postgresql.conf.sample
3) Outdated source-code comment about bgwriter_flush_after's default
4) Sub-optimal categories assigned to new GUCs
5) Docs suggested backend_flush_after is PGC_SIGHUP, but it's PGC_USERSET.
6) Spell out int as integer in the docs, as done elsewhere

Reported-By: Magnus Hagander, Fujii Masao
Discussion: CAHGQGwETyTG5VYQQ5C_srwxWX7RXvFcD3dKROhvAWWhoSBdmZw@mail.gmail.com
2016-04-24 12:26:55 -07:00
Kevin Grittner 848ef42bb8 Add the "snapshot too old" feature
This feature is controlled by a new old_snapshot_threshold GUC.  A
value of -1 disables the feature, and that is the default.  The
value of 0 is just intended for testing.  Above that it is the
number of minutes a snapshot can reach before pruning and vacuum
are allowed to remove dead tuples which the snapshot would
otherwise protect.  The xmin associated with a transaction ID does
still protect dead tuples.  A connection which is using an "old"
snapshot does not get an error unless it accesses a page modified
recently enough that it might not be able to produce accurate
results.

This is similar to the Oracle feature, and we use the same SQLSTATE
and error message for compatibility.
2016-04-08 14:36:30 -05:00
Robert Haas 0711803775 Use quicksort, not replacement selection, for external sorting.
We still use replacement selection for the first run of the sort only
and only when the number of tuples is relatively small.  Otherwise,
the first run, and subsequent runs in all cases, are produced using
quicksort.  This tends to be faster except perhaps for very small
amounts of working memory.

Peter Geoghegan, reviewed by Tomas Vondra, Jeff Janes, Mithun Cy,
Greg Stark, and me.
2016-04-08 02:36:26 -04:00
Simon Riggs 137805f89a Use Foreign Key relationships to infer multi-column join selectivity
In cases where joins use multiple columns we currently assess each join
separately causing gross mis-estimates for join cardinality.

This patch adds use of FK information for the first time into the
planner. When FKs are present and we have multi-column join information,
plan estimates will be drastically improved. Cases with multiple FKs
are handled, though partial matches are ignored currently.

Net effect is substantial performance improvements for joins in many
common cases. Additional planning time is isolated to cases that are
currently performing poorly, measured at 0.08 - 0.15 ms.

Please watch for planner performance regressions; circumstances seem
unlikely but the law of unintended consequences may apply somewhen.
Additional complex tests welcome to prove this before release.

Tests can be performed using SET enable_fkey_estimates = on | off
using scripts provided during Hackers discussions, message id:
552335D9.3090707@2ndquadrant.com

Authors: Tomas Vondra and David Rowley
Reviewed and tested by Simon Riggs, adding comments only
2016-04-08 02:51:09 +01:00
Fujii Masao 989be0810d Support multiple synchronous standby servers.
Previously synchronous replication offered only the ability to confirm
that all changes made by a transaction had been transferred to at most
one synchronous standby server.

This commit extends synchronous replication so that it supports multiple
synchronous standby servers. It enables users to consider one or more
standby servers as synchronous, and increase the level of transaction
durability by ensuring that transaction commits wait for replies from
all of those synchronous standbys.

Multiple synchronous standby servers are configured in
synchronous_standby_names which is extended to support new syntax of
'num_sync ( standby_name [ , ... ] )', where num_sync specifies
the number of synchronous standbys that transaction commits need to
wait for replies from and standby_name is the name of a standby
server.

The syntax of 'standby_name [ , ... ]' which was used in 9.5 or before
is also still supported. It's the same as new syntax with num_sync=1.

This commit doesn't include "quorum commit" feature which was discussed
in pgsql-hackers. Synchronous standbys are chosen based on their priorities.
synchronous_standby_names determines the priority of each standby for
being chosen as a synchronous standby. The standbys whose names appear
earlier in the list are given higher priority and will be considered as
synchronous. Other standby servers appearing later in this list
represent potential synchronous standbys.

The regression test for multiple synchronous standbys is not included
in this commit. It should come later.

Authors: Sawada Masahiko, Beena Emerson, Michael Paquier, Fujii Masao
Reviewed-By: Kyotaro Horiguchi, Amit Kapila, Robert Haas, Simon Riggs,
Amit Langote, Thomas Munro, Sameer Thakur, Suraj Kharage, Abhijit Menon-Sen,
Rajeev Rastogi

Many thanks to the various individuals who were involved in
discussing and developing this feature.
2016-04-06 17:18:25 +09:00
Tom Lane 99f3b5613b Disallow newlines in parameter values to be set in ALTER SYSTEM.
As noted by Julian Schauder in bug #14063, the configuration-file parser
doesn't support embedded newlines in string literals.  While there might
someday be a good reason to remove that restriction, there doesn't seem
to be one right now.  However, ALTER SYSTEM SET could accept strings
containing newlines, since many of the variable-specific value-checking
routines would just see a newline as whitespace.  This led to writing a
postgresql.auto.conf file that was broken and had to be removed manually.

Pending a reason to work harder, just throw an error if someone tries this.

In passing, fix several places in the ALTER SYSTEM logic that failed to
provide an errcode() for an ereport(), and thus would falsely log the
failure as an internal XX000 error.

Back-patch to 9.4 where ALTER SYSTEM was introduced.
2016-04-04 18:05:23 -04:00
Robert Haas 314cbfc5da Add new replication mode synchronous_commit = 'remote_apply'.
In this mode, the master waits for the transaction to be applied on
the remote side, not just written to disk.  That means that you can
count on a transaction started on the standby to see all commits
previously acknowledged by the master.

To make this work, the standby sends a reply after replaying each
commit record generated with synchronous_commit >= 'remote_apply'.
This introduces a small inefficiency: the extra replies will be sent
even by standbys that aren't the current synchronous standby.  But
previously-existing synchronous_commit levels make no attempt at all
to optimize which replies are sent based on what the primary cares
about, so this is no worse, and at least avoids any extra replies for
people not using the feature at all.

Thomas Munro, reviewed by Michael Paquier and by me.  Some additional
tweaks by me.
2016-03-29 21:29:49 -04:00
Robert Haas ae507d9222 Make max_parallel_degree PGC_USERSET.
It was intended to be this way all along, just like other planner
GUCs such as work_mem.  But I goofed.
2016-03-21 10:54:36 -04:00
Robert Haas 2d8a1e22b1 Various minor corrections of and improvements to comments.
Aleksander Alekseev
2016-03-18 09:38:59 -04:00
Peter Eisentraut fc201dfd95 Add syslog_split_messages parameter
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
2016-03-16 23:21:44 -04:00
Peter Eisentraut f4c454e9ba Add syslog_sequence_numbers parameter
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
2016-03-16 23:21:44 -04:00
Robert Haas c6dda1f48e Add idle_in_transaction_session_timeout.
Vik Fearing, reviewed by Stéphane Schildknecht and me, and revised
slightly by me.
2016-03-16 11:30:45 -04:00
Robert Haas 3aff33aa68 Fix typos.
Oskari Saarenmaa
2016-03-15 18:06:11 -04:00
Andres Freund 428b1d6b29 Allow to trigger kernel writeback after a configurable number of writes.
Currently writes to the main data files of postgres all go through the
OS page cache. This means that some operating systems can end up
collecting a large number of dirty buffers in their respective page
caches.  When these dirty buffers are flushed to storage rapidly, be it
because of fsync(), timeouts, or dirty ratios, latency for other reads
and writes can increase massively.  This is the primary reason for
regular massive stalls observed in real world scenarios and artificial
benchmarks; on rotating disks stalls on the order of hundreds of seconds
have been observed.

On linux it is possible to control this by reducing the global dirty
limits significantly, reducing the above problem. But global
configuration is rather problematic because it'll affect other
applications; also PostgreSQL itself doesn't always generally want this
behavior, e.g. for temporary files it's undesirable.

Several operating systems allow some control over the kernel page
cache. Linux has sync_file_range(2), several posix systems have msync(2)
and posix_fadvise(2). sync_file_range(2) is preferable because it
requires no special setup, whereas msync() requires the to-be-flushed
range to be mmap'ed. For the purpose of flushing dirty data
posix_fadvise(2) is the worst alternative, as flushing dirty data is
just a side-effect of POSIX_FADV_DONTNEED, which also removes the pages
from the page cache.  Thus the feature is enabled by default only on
linux, but can be enabled on all systems that have any of the above
APIs.

While desirable and likely possible this patch does not contain an
implementation for windows.

With the infrastructure added, writes made via checkpointer, bgwriter
and normal user backends can be flushed after a configurable number of
writes. Each of these sources of writes controlled by a separate GUC,
checkpointer_flush_after, bgwriter_flush_after and backend_flush_after
respectively; they're separate because the number of flushes that are
good are separate, and because the performance considerations of
controlled flushing for each of these are different.

A later patch will add checkpoint sorting - after that flushes from the
ckeckpoint will almost always be desirable. Bgwriter flushes are most of
the time going to be random, which are slow on lots of storage hardware.
Flushing in backends works well if the storage and bgwriter can keep up,
but if not it can have negative consequences.  This patch is likely to
have negative performance consequences without checkpoint sorting, but
unfortunately so has sorting without flush control.

Discussion: alpine.DEB.2.10.1506011320000.28433@sto
Author: Fabien Coelho and Andres Freund
2016-03-10 17:04:34 -08:00
Andres Freund 1d4a0ab19a Avoid unlikely data-loss scenarios due to rename() without fsync.
Renaming a file using rename(2) is not guaranteed to be durable in face
of crashes. Use the previously added durable_rename()/durable_link_or_rename()
in various places where we previously just renamed files.

Most of the changed call sites are arguably not critical, but it seems
better to err on the side of too much durability.  The most prominent
known case where the previously missing fsyncs could cause data loss is
crashes at the end of a checkpoint. After the actual checkpoint has been
performed, old WAL files are recycled. When they're filled, their
contents are fdatasynced, but we did not fsync the containing
directory. An OS/hardware crash in an unfortunate moment could then end
up leaving that file with its old name, but new content; WAL replay
would thus not replay it.

Reported-By: Tomas Vondra
Author: Michael Paquier, Tomas Vondra, Andres Freund
Discussion: 56583BDD.9060302@2ndquadrant.com
Backpatch: All supported branches
2016-03-09 18:53:53 -08:00
Andres Freund 7975c5e0a9 Allow the WAL writer to flush WAL at a reduced rate.
Commit 4de82f7d7 increased the WAL flush rate, mainly to increase the
likelihood that hint bits can be set quickly. More quickly set hint bits
can reduce contention around the clog et al.  But unfortunately the
increased flush rate can have a significant negative performance impact,
I have measured up to a factor of ~4.  The reason for this slowdown is
that if there are independent writes to the underlying devices, for
example because shared buffers is a lot smaller than the hot data set,
or because a checkpoint is ongoing, the fdatasync() calls force cache
flushes to be emitted to the storage.

This is achieved by flushing WAL only if the last flush was longer than
wal_writer_delay ago, or if more than wal_writer_flush_after (new GUC)
unflushed blocks are pending. Based on some tests the default for
wal_writer_delay is 1MB, which seems to work well both on SSD and
rotational media.

To avoid negative performance impact due to 4de82f7d7 an earlier
commit (db76b1e) made SetHintBits() more likely to succeed; preventing
performance regressions in the pgbench tests I performed.

Discussion: 20160118163908.GW10941@awork2.anarazel.de
2016-02-16 00:56:34 +01:00
Robert Haas 7c944bd903 Introduce a new GUC force_parallel_mode for testing purposes.
When force_parallel_mode = true, we enable the parallel mode restrictions
for all queries for which this is believed to be safe.  For the subset of
those queries believed to be safe to run entirely within a worker, we spin
up a worker and run the query there instead of running it in the
original process.  When force_parallel_mode = regress, make additional
changes to allow the regression tests to run cleanly even though parallel
workers have been injected under the hood.

Taken together, this facilitates both better user testing and better
regression testing of the parallelism code.

Robert Haas, with help from Amit Kapila and Rushabh Lathia.
2016-02-07 11:41:33 -05:00
Noah Misch f4aa3a18a2 Force certain "pljava" custom GUCs to be PGC_SUSET.
Future PL/Java versions will close CVE-2016-0766 by making these GUCs
PGC_SUSET.  This PostgreSQL change independently mitigates that PL/Java
vulnerability, helping sites that update PostgreSQL more frequently than
PL/Java.  Back-patch to 9.1 (all supported versions).
2016-02-05 20:22:51 -05:00
Peter Eisentraut f8003e07f9 Improve error message 2016-02-04 20:41:32 -05:00
Peter Eisentraut ac7238dc0f Improve error reporting when location specified by postgres -D does not exist
Previously, the first error seen would be that postgresql.conf does not
exist.  But for the case where the whole directory does not exist, give
an error message about that, together with a hint for how to create one.
2016-02-02 21:03:19 -05:00
Bruce Momjian ee94300446 Update copyright for 2016
Backpatch certain files through 9.1
2016-01-02 13:33:40 -05:00
Peter Eisentraut 5db837d3f2 Message improvements 2015-11-16 21:39:23 -05:00
Robert Haas 84ef9c596e Put back ssl_renegotiation_limit parameter, but only allow 0.
Per a report from Shay Rojansky, Npgsql sends ssl_renegotiation_limit=0
in the startup packet because it does not support renegotiation; other
clients which have not attempted to support renegotiation might well
behave similarly.  The recent removal of this parameter forces them to
break compatibility with either current PostgreSQL versions, or
previous ones.  Per discussion, the best solution is to accept the
parameter but only allow a value of 0.

Shay Rojansky, edited a little by me.
2015-10-20 09:56:04 -04:00
Peter Eisentraut 6390c8c654 Group cluster_name and update_process_title settings together 2015-10-04 12:29:36 -04:00
Robert Haas 3bd909b220 Add a Gather executor node.
A Gather executor node runs any number of copies of a plan in an equal
number of workers and merges all of the results into a single tuple
stream.  It can also run the plan itself, if the workers are
unavailable or haven't started up yet.  It is intended to work with
the Partial Seq Scan node which will be added in future commits.

It could also be used to implement parallel query of a different sort
by itself, without help from Partial Seq Scan, if the single_copy mode
is used.  In that mode, a worker executes the plan, and the parallel
leader does not, merely collecting the worker's results.  So, a Gather
node could be inserted into a plan to split the execution of that plan
across two processes.  Nested Gather nodes aren't currently supported,
but we might want to add support for that in the future.

There's nothing in the planner to actually generate Gather nodes yet,
so it's not quite time to break out the champagne.  But we're getting
close.

Amit Kapila.  Some designs suggestions were provided by me, and I also
reviewed the patch.  Single-copy mode, documentation, and other minor
changes also by me.
2015-09-30 19:23:36 -04:00
Andres Freund 020235a575 Lower *_freeze_max_age minimum values.
The old minimum values are rather large, making it time consuming to
test related behaviour. Additionally the current limits, especially for
multixacts, can be problematic in space-constrained systems. 10000000
multixacts can contain a lot of members.

Since there's no good reason for the current limits, lower them a good
bit. Setting them to 0 would be a bad idea, triggering endless vacuums,
so still retain a limit.

While at it fix autovacuum_multixact_freeze_max_age to refer to
multixact.c instead of varsup.c.

Reviewed-By: Robert Haas
Discussion: CA+TgmoYmQPHcrc3GSs7vwvrbTkbcGD9Gik=OztbDGGrovkkEzQ@mail.gmail.com
Backpatch: back to 9.0 (in parts)
2015-09-24 14:53:32 +02:00
Noah Misch 537bd178c7 Remove the row_security=force GUC value.
Every query of a single ENABLE ROW SECURITY table has two meanings, with
the row_security GUC selecting between them.  With row_security=force
available, every function author would have been advised to either set
the GUC locally or test both meanings.  Non-compliance would have
threatened reliability and, for SECURITY DEFINER functions, security.
Authors already face an obligation to account for search_path, and we
should not mimic that example.  With this change, only BYPASSRLS roles
need exercise the aforementioned care.  Back-patch to 9.5, where the
row_security GUC was introduced.

Since this narrows the domain of pg_db_role_setting.setconfig and
pg_proc.proconfig, one might bump catversion.  A row_security=force
setting in one of those columns will elicit a clear message, so don't.
2015-09-20 20:45:41 -04:00
Alvaro Herrera 1aba62ec63 Allow per-tablespace effective_io_concurrency
Per discussion, nowadays it is possible to have tablespaces that have
wildly different I/O characteristics from others.  Setting different
effective_io_concurrency parameters for those has been measured to
improve performance.

Author: Julien Rouhaud
Reviewed by: Andres Freund
2015-09-08 12:51:42 -03:00
Robert Haas 369342cf70 Cap wal_buffers to avoid a server crash when it's set very large.
It must be possible to multiply wal_buffers by XLOG_BLCKSZ without
overflowing int, or calculations in StartupXLOG will go badly wrong
and crash the server.  Avoid that by imposing a maximum value on
wal_buffers.  This will be just under 2GB, assuming the usual value
for XLOG_BLCKSZ.

Josh Berkus, per an analysis by Andrew Gierth.
2015-08-04 12:58:54 -04:00
Andres Freund 426746b930 Remove ssl renegotiation support.
While postgres' use of SSL renegotiation is a good idea in theory, it
turned out to not work well in practice. The specification and openssl's
implementation of it have lead to several security issues. Postgres' use
of renegotiation also had its share of bugs.

Additionally OpenSSL has a bunch of bugs around renegotiation, reported
and open for years, that regularly lead to connections breaking with
obscure error messages. We tried increasingly complex workarounds to get
around these bugs, but we didn't find anything complete.

Since these connection breakages often lead to hard to debug problems,
e.g. spuriously failing base backups and significant latency spikes when
synchronous replication is used, we have decided to change the default
setting for ssl renegotiation to 0 (disabled) in the released
backbranches and remove it entirely in 9.5 and master.

Author: Andres Freund
Discussion: 20150624144148.GQ4797@alap3.anarazel.de
Backpatch: 9.5 and master, 9.0-9.4 get a different patch
2015-07-28 22:06:31 +02:00
Fujii Masao c2e5f4d1c1 Make wal_compression PGC_SUSET rather than PGC_USERSET.
When enabling wal_compression, there is a risk to leak data similarly to
the BREACH and CRIME attacks on SSL where the compression ratio of
a full page image gives a hint of what is the existing data of this page.
This vulnerability is quite cumbersome to exploit in practice, but doable.

So this patch makes wal_compression PGC_SUSET in order to prevent
non-superusers from enabling it and exploiting the vulnerability while
DBA thinks the risk very seriously and disables it in postgresql.conf.

Back-patch to 9.5 where wal_compression was introduced.
2015-07-09 22:30:52 +09:00
Tom Lane 10fb48d66d Add an optional missing_ok argument to SQL function current_setting().
This allows convenient checking for existence of a GUC from SQL, which is
particularly useful when dealing with custom variables.

David Christensen, reviewed by Jeevan Chalke
2015-07-02 16:41:07 -04:00
Tom Lane 62d16c7fc5 Improve design and implementation of pg_file_settings view.
As first committed, this view reported on the file contents as they were
at the last SIGHUP event.  That's not as useful as reporting on the current
contents, and what's more, it didn't work right on Windows unless the
current session had serviced at least one SIGHUP.  Therefore, arrange to
re-read the files when pg_show_all_settings() is called.  This requires
only minor refactoring so that we can pass changeVal = false to
set_config_option() so that it won't actually apply any changes locally.

In addition, add error reporting so that errors that would prevent the
configuration files from being loaded, or would prevent individual settings
from being applied, are visible directly in the view.  This makes the view
usable for pre-testing whether edits made in the config files will have the
desired effect, before one actually issues a SIGHUP.

I also added an "applied" column so that it's easy to identify entries that
are superseded by later entries; this was the main use-case for the original
design, but it seemed unnecessarily hard to use for that.

Also fix a 9.4.1 regression that allowed multiple entries for a
PGC_POSTMASTER variable to cause bogus complaints in the postmaster log.
(The issue here was that commit bf007a27ac unintentionally reverted
3e3f65973a, which suppressed any duplicate entries within
ParseConfigFp.  However, since the original coding of the pg_file_settings
view depended on such suppression *not* happening, we couldn't have fixed
this issue now without first doing something with pg_file_settings.
Now we suppress duplicates by marking them "ignored" within
ProcessConfigFileInternal, which doesn't hide them in the view.)

Lesser changes include:

Drive the view directly off the ConfigVariable list, instead of making a
basically-equivalent second copy of the data.  There's no longer any need
to hang onto the data permanently, anyway.

Convert show_all_file_settings() to do its work in one call and return a
tuplestore; this avoids risks associated with assuming that the GUC state
will hold still over the course of query execution.  (I think there were
probably latent bugs here, though you might need something like a cursor
on the view to expose them.)

Arrange to run SIGHUP processing in a short-lived memory context, to
forestall process-lifespan memory leaks.  (There is one known leak in this
code, in ProcessConfigDirectory; it seems minor enough to not be worth
back-patching a specific fix for.)

Remove mistaken assignment to ConfigFileLineno that caused line counting
after an include_dir directive to be completely wrong.

Add missed failure check in AlterSystemSetConfigFile().  We don't really
expect ParseConfigFp() to fail, but that's not an excuse for not checking.
2015-06-28 18:06:14 -04:00
Fujii Masao 091c02a958 Fix alphabetization in catalogs.sgml.
System catalogs and views should be listed alphabetically
in catalog.sgml, but only pg_file_settings view not.

This patch also fixes typos in pg_file_settings comments.
2015-06-12 12:59:29 +09:00
Tom Lane da33a3894e Revert exporting of internal GUC variable "data_directory".
This undoes a poorly-thought-out choice in commit 970a18687f, namely
to export guc.c's internal variable data_directory.  The authoritative
variable so far as C code is concerned is DataDir; there is no reason for
anything except specific bits of GUC code to look at the GUC variable.

After yesterday's commits fixing the fsync-on-restart patch, the only
remaining misuse of data_directory was in AlterSystemSetConfigFile(),
which would be much better off just using a relative path anyhow: it's
less code and it doesn't break if the DBA moves the data directory of a
running system, which is a case we've taken some pains over in the past.

This is mostly cosmetic, so no need for a back-patch (and I'd be hesitant
to remove a global variable in stable branches anyway).
2015-05-29 11:57:33 -04:00
Bruce Momjian 807b9e0dff pgindent run for 9.5 2015-05-23 21:35:49 -04:00
Heikki Linnakangas ffd37740ee Add archive_mode='always' option.
In 'always' mode, the standby independently archives all files it receives
from the primary.

Original patch by Fujii Masao, docs and review by me.
2015-05-15 18:55:24 +03:00
Peter Eisentraut a486e35706 Add pg_settings.pending_restart column
with input from David G. Johnston, Robert Haas, Michael Paquier
2015-05-14 20:08:51 -04:00