Commit Graph

3172 Commits

Author SHA1 Message Date
Magnus Hagander 32e33a7979 Fix typo in comment
Masahiko Sawada
2017-04-07 09:30:22 +02:00
Peter Eisentraut dc0400cc50 Fix compiler warning and add some more comments 2017-04-06 11:18:13 -04:00
Peter Eisentraut 3217327053 Identity columns
This is the SQL standard-conforming variant of PostgreSQL's serial
columns.  It fixes a few usability issues that serial columns have:

- CREATE TABLE / LIKE copies default but refers to same sequence
- cannot add/drop serialness with ALTER TABLE
- dropping default does not drop sequence
- need to grant separate privileges to sequence
- other slight weirdnesses because serial is some kind of special macro

Reviewed-by: Vitaly Burovoy <vitaly.burovoy@gmail.com>
2017-04-06 08:41:37 -04:00
Simon Riggs 68ea2b7f9b Reduce lock level for CREATE STATISTICS
In line with other lock reductions related to planning.

Simon Riggs
2017-04-05 18:22:32 -04:00
Simon Riggs 2686ee1b7c Collect and use multi-column dependency stats
Follow on patch in the multi-variate statistics patch series.

CREATE STATISTICS s1 WITH (dependencies) ON (a, b) FROM t;
ANALYZE;
will collect dependency stats on (a, b) and then use the measured
dependency in subsequent query planning.

Commit 7b504eb282 added
CREATE STATISTICS with n-distinct coefficients. These are now
specified using the mutually exclusive option WITH (ndistinct).

Author: Tomas Vondra, David Rowley
Reviewed-by: Kyotaro HORIGUCHI, Álvaro Herrera, Dean Rasheed, Robert Haas
and many other comments and contributions
Discussion: https://postgr.es/m/56f40b20-c464-fad2-ff39-06b668fac47c@2ndquadrant.com
2017-04-05 18:00:42 -04:00
Peter Eisentraut 60a0b2ec89 Adjust min/max values when changing sequence type
When changing the type of a sequence, adjust the min/max values of the
sequence if it looks like the previous values were the default values.
Previously, it would leave the old values in place, requiring manual
adjustments even in the usual/default cases.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Vitaly Burovoy <vitaly.burovoy@gmail.com>
2017-04-04 12:49:39 -04:00
Kevin Grittner 41bd155dd6 Fix two undocumented parameters to functions from ENR patch.
On ProcessUtility document the parameter, to match others.

On CreateCachedPlan drop the queryEnv parameter.  It was not
referenced within the function, and had been added on the
assumption that with some unknown future usage of QueryEnvironment
it might be useful to do something there.  We have avoided other
"just in case" implementation of unused paramters, so drop it here.

Per gripe from Tom Lane
2017-04-01 15:21:05 -05:00
Kevin Grittner 18ce3a4ab2 Add infrastructure to support EphemeralNamedRelation references.
A QueryEnvironment concept is added, which allows new types of
objects to be passed into queries from parsing on through
execution.  At this point, the only thing implemented is a
collection of EphemeralNamedRelation objects -- relations which
can be referenced by name in queries, but do not exist in the
catalogs.  The only type of ENR implemented is NamedTuplestore, but
provision is made to add more types fairly easily.

An ENR can carry its own TupleDesc or reference a relation in the
catalogs by relid.

Although these features can be used without SPI, convenience
functions are added to SPI so that ENRs can easily be used by code
run through SPI.

The initial use of all this is going to be transition tables in
AFTER triggers, but that will be added to each PL as a separate
commit.

An incidental effect of this patch is to produce a more informative
error message if an attempt is made to modify the contents of a CTE
from a referencing DML statement.  No tests previously covered that
possibility, so one is added.

Kevin Grittner and Thomas Munro
Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro
with valuable comments and suggestions from many others
2017-03-31 23:17:18 -05:00
Tom Lane 64d4da511c For foreign keys, check REFERENCES privilege only on the referenced table.
We were requiring that the user have REFERENCES permission on both the
referenced and referencing tables --- but this doesn't seem to have any
support in the SQL standard, which says only that you need REFERENCES
permission on the referenced table.  And ALTER TABLE ADD FOREIGN KEY has
already checked that you own the referencing table, so the check could
only fail if a table owner has revoked his own REFERENCES permission.
Moreover, the symmetric interpretation of this permission is unintuitive
and confusing, as per complaint from Paul Jungwirth.  So let's drop the
referencing-side check.

In passing, do a bit of wordsmithing on the GRANT reference page so that
all the privilege types are described in similar fashion.

Discussion: https://postgr.es/m/8940.1490906755@sss.pgh.pa.us
2017-03-31 18:11:30 -04:00
Peter Eisentraut 4cb824699e Cast result of copyObject() to correct type
copyObject() is declared to return void *, which allows easily assigning
the result independent of the input, but it loses all type checking.

If the compiler supports typeof or something similar, cast the result to
the input type.  This creates a greater amount of type safety.  In some
cases, where the result is assigned to a generic type such as Node * or
Expr *, new casts are now necessary, but in general casts are now
unnecessary in the normal case and indicate that something unusual is
happening.

Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
2017-03-28 21:59:23 -04:00
Simon Riggs ff539da316 Cleanup slots during drop database
Automatically drop all logical replication slots associated with a
database when the database is dropped. Previously we threw an ERROR
if a slot existed. Now we throw ERROR only if a slot is active in
the database being dropped.

Craig Ringer
2017-03-28 10:05:21 -04:00
Andrew Gierth b5635948ab Support hashed aggregation with grouping sets.
This extends the Aggregate node with two new features: HashAggregate
can now run multiple hashtables concurrently, and a new strategy
MixedAggregate populates hashtables while doing sorted grouping.

The planner will now attempt to save as many sorts as possible when
planning grouping sets queries, while not exceeding work_mem for the
estimated combined sizes of all hashtables used.  No SQL-level changes
are required.  There should be no user-visible impact other than the
new EXPLAIN output and possible changes to result ordering when ORDER
BY was not used (which affected a few regression tests).  The
enable_hashagg option is respected.

Author: Andrew Gierth
Reviewers: Mark Dilger, Andres Freund
Discussion: https://postgr.es/m/87vatszyhj.fsf@news-spur.riddles.org.uk
2017-03-27 04:20:54 +01:00
Tom Lane 9b95f2fa1e Use ExecPrepareExpr in place of ExecPrepareCheck where appropriate.
Change one more place where ExecInitCheck/ExecPrepareCheck's insistence
on getting implicit-AND-format quals wasn't really helpful, because the
caller had to do make_ands_implicit() for no reason that it cared about.
Using ExecPrepareExpr directly simplifies the code and saves cycles.

The only remaining use of these functions is to process
resultRelInfo->ri_PartitionCheck quals.  However, implicit-AND format
does seem to be what we want for that, so leave it alone.
2017-03-26 18:14:03 -04:00
Andres Freund b8d7f053c5 Faster expression evaluation and targetlist projection.
This replaces the old, recursive tree-walk based evaluation, with
non-recursive, opcode dispatch based, expression evaluation.
Projection is now implemented as part of expression evaluation.

This both leads to significant performance improvements, and makes
future just-in-time compilation of expressions easier.

The speed gains primarily come from:
- non-recursive implementation reduces stack usage / overhead
- simple sub-expressions are implemented with a single jump, without
  function calls
- sharing some state between different sub-expressions
- reduced amount of indirect/hard to predict memory accesses by laying
  out operation metadata sequentially; including the avoidance of
  nearly all of the previously used linked lists
- more code has been moved to expression initialization, avoiding
  constant re-checks at evaluation time

Future just-in-time compilation (JIT) has become easier, as
demonstrated by released patches intended to be merged in a later
release, for primarily two reasons: Firstly, due to a stricter split
between expression initialization and evaluation, less code has to be
handled by the JIT. Secondly, due to the non-recursive nature of the
generated "instructions", less performance-critical code-paths can
easily be shared between interpreted and compiled evaluation.

The new framework allows for significant future optimizations. E.g.:
- basic infrastructure for to later reduce the per executor-startup
  overhead of expression evaluation, by caching state in prepared
  statements.  That'd be helpful in OLTPish scenarios where
  initialization overhead is measurable.
- optimizing the generated "code". A number of proposals for potential
  work has already been made.
- optimizing the interpreter. Similarly a number of proposals have
  been made here too.

The move of logic into the expression initialization step leads to some
backward-incompatible changes:
- Function permission checks are now done during expression
  initialization, whereas previously they were done during
  execution. In edge cases this can lead to errors being raised that
  previously wouldn't have been, e.g. a NULL array being coerced to a
  different array type previously didn't perform checks.
- The set of domain constraints to be checked, is now evaluated once
  during expression initialization, previously it was re-built
  every time a domain check was evaluated. For normal queries this
  doesn't change much, but e.g. for plpgsql functions, which caches
  ExprStates, the old set could stick around longer.  The behavior
  around might still change.

Author: Andres Freund, with significant changes by Tom Lane,
	changes by Heikki Linnakangas
Reviewed-By: Tom Lane, Heikki Linnakangas
Discussion: https://postgr.es/m/20161206034955.bh33paeralxbtluv@alap3.anarazel.de
2017-03-25 14:52:06 -07:00
Peter Eisentraut e3920ac823 Add more subscription DDL tests
Add more tests for various variants of subscription DDL commands, based
on code coverage report.  Fix a small bug discovered by that.
2017-03-24 21:48:05 -04:00
Peter Eisentraut 176cbc2a25 Check that published table exists on subscriber
Author: Petr Jelinek <pjmodos@pjmodos.net>
2017-03-24 14:52:03 -04:00
Alvaro Herrera 8082bea2b0 Fix use-after-free bug
Detected by buildfarm member prion
2017-03-24 15:43:15 -03:00
Fujii Masao 70adf2fbe1 Make VACUUM VERBOSE report the number of skipped frozen pages.
Previously manual VACUUM did not report the number of skipped frozen
pages even when VERBOSE option is specified. But this information is
helpful to monitor the VACUUM activity, and also autovacuum reports that
number in the log file when the condition of log_autovacuum_min_duration
is met.

This commit changes VACUUM VERBOSE so that it reports the number
of frozen pages that it skips.

Author: Masahiko Sawada
Reviewed-by: Yugo Nagata and Jim Nasby

Discussion: http://postgr.es/m/CAD21AoDZQKCxo0L39Mrq08cONNkXQKXuh=2DP1Q8ebmt35SoaA@mail.gmail.com
2017-03-25 02:39:44 +09:00
Alvaro Herrera 7b504eb282 Implement multivariate n-distinct coefficients
Add support for explicitly declared statistic objects (CREATE
STATISTICS), allowing collection of statistics on more complex
combinations that individual table columns.  Companion commands DROP
STATISTICS and ALTER STATISTICS ... OWNER TO / SET SCHEMA / RENAME are
added too.  All this DDL has been designed so that more statistic types
can be added later on, such as multivariate most-common-values and
multivariate histograms between columns of a single table, leaving room
for permitting columns on multiple tables, too, as well as expressions.

This commit only adds support for collection of n-distinct coefficient
on user-specified sets of columns in a single table.  This is useful to
estimate number of distinct groups in GROUP BY and DISTINCT clauses;
estimation errors there can cause over-allocation of memory in hashed
aggregates, for instance, so it's a worthwhile problem to solve.  A new
special pseudo-type pg_ndistinct is used.

(num-distinct estimation was deemed sufficiently useful by itself that
this is worthwhile even if no further statistic types are added
immediately; so much so that another version of essentially the same
functionality was submitted by Kyotaro Horiguchi:
https://postgr.es/m/20150828.173334.114731693.horiguchi.kyotaro@lab.ntt.co.jp
though this commit does not use that code.)

Author: Tomas Vondra.  Some code rework by Álvaro.
Reviewed-by: Dean Rasheed, David Rowley, Kyotaro Horiguchi, Jeff Janes,
    Ideriha Takeshi
Discussion: https://postgr.es/m/543AFA15.4080608@fuzzy.cz
    https://postgr.es/m/20170320190220.ixlaueanxegqd5gr@alvherre.pgsql
2017-03-24 14:06:10 -03:00
Peter Eisentraut eccfef81e1 ICU support
Add a column collprovider to pg_collation that determines which library
provides the collation data.  The existing choices are default and libc,
and this adds an icu choice, which uses the ICU4C library.

The pg_locale_t type is changed to a union that contains the
provider-specific locale handles.  Users of locale information are
changed to look into that struct for the appropriate handle to use.

Also add a collversion column that records the version of the collation
when it is created, and check at run time whether it is still the same.
This detects potentially incompatible library upgrades that can corrupt
indexes and other structures.  This is currently only supported by
ICU-provided collations.

initdb initializes the default collation set as before from the `locale
-a` output but also adds all available ICU locales with a "-x-icu"
appended.

Currently, ICU-provided collations can only be explicitly named
collations.  The global database locales are still always libc-provided.

ICU support is enabled by configure --with-icu.

Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
2017-03-23 15:28:48 -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
Robert Haas 691b8d5928 Allow for parallel execution whenever ExecutorRun() is done only once.
Previously, it was unsafe to execute a plan in parallel if
ExecutorRun() might be called with a non-zero row count.  However,
it's quite easy to fix things up so that we can support that case,
provided that it is known that we will never call ExecutorRun() a
second time for the same QueryDesc.  Add infrastructure to signal
this, and cross-checks to make sure that a caller who claims this is
true doesn't later reneg.

While that pattern never happens with queries received directly from a
client -- there's no way to know whether multiple Execute messages
will be sent unless the first one requests all the rows -- it's pretty
common for queries originating from procedural languages, which often
limit the result to a single tuple or to a user-specified number of
tuples.

This commit doesn't actually enable parallelism in any additional
cases, because currently none of the places that would be able to
benefit from this infrastructure pass CURSOR_OPT_PARALLEL_OK in the
first place, but it makes it much more palatable to pass
CURSOR_OPT_PARALLEL_OK in places where we currently don't, because it
eliminates some cases where we'd end up having to run the parallel
plan serially.

Patch by me, based on some ideas from Rafia Sabih and corrected by
Rafia Sabih based on feedback from Dilip Kumar and myself.

Discussion: http://postgr.es/m/CA+TgmobXEhvHbJtWDuPZM9bVSLiTj-kShxQJ2uM5GPDze9fRYA@mail.gmail.com
2017-03-23 13:14:36 -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
Magnus Hagander 707576b571 Fix grammar in comment
Author: Emil Iggland
2017-03-23 10:14:42 +01:00
Simon Riggs af4b1a0869 Refactor GetOldestXmin() to use flags
Replace ignoreVacuum parameter with more flexible flags.

Author: Eiji Seki
Review: Haribabu Kommi
2017-03-22 16:51:01 +00:00
Peter Eisentraut 4cfc9484d4 Refine rules for altering publication owner
Previously, the new owner had to be a superuser.  The new rules are more
refined similar to other objects.

Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-03-22 11:19:30 -04:00
Simon Riggs 9b013dc238 Improve performance of replay of AccessExclusiveLocks
A hot standby replica keeps a list of Access Exclusive locks for a top
level transaction. These locks are released when the top level transaction
ends. Searching of this list is O(N^2), and each transaction had to pay the
price of searching this list for locks, even if it didn't take any AE
locks itself.

This patch optimizes this case by having the master server track which
transactions took AE locks, and passes that along to the standby server in
the commit/abort record. This allows the standby to only try to release
locks for transactions which actually took any, avoiding the majority of
the performance issue.

Refactor MyXactAccessedTempRel into MyXactFlags to allow minimal additional
cruft with this.

Analysis and initial patch by David Rowley
Author: David Rowley and Simon Riggs
2017-03-22 13:09:36 +00:00
Andrew Dunstan b6fb534f10 Add IF NOT EXISTS for CREATE SERVER and CREATE USER MAPPING
There is still some inconsistency with the error messages surrounding
foreign servers. Some use the word "foreign" and some don't. My
inclination is to remove all such uses of "foreign" on the basis that
the  CREATE/ALTER/DROP SERVER commands don't use the word. However, that
is left for another day. In this patch I have kept to the existing usage
in the affected commands, which omits "foreign".

Anastasia Lubennikova, reviewed by Arthur Zakirov and Ashtosh Bapat.

Discussion: http://postgr.es/m/7c2ab9b8-388a-1ce0-23a3-7acf2a0ed3c6@postgrespro.ru
2017-03-20 16:40:45 -04:00
Andrew Dunstan 839cb0649a Use a consistent error message style for user mappings.
User mappings are essentially anonymous, so messages referring to "user
mapping foo on server bar" are wrong, and inconsistent with other error
messages referring to user mappings. To be consistent with existing use,
use "user mapping for foo on server bar" instead.

I dropped the noise word "user" from the original suggestion to be
consistent with other uses.

Discussion: http://postgr.es/m/56c6f8ab-b2d6-f1fa-deb0-1d18cf67f7b9@2ndQuadrant.com
2017-03-20 16:01:45 -04:00
Tom Lane e3044f6184 Avoid use of already-closed relcache entry.
Oversight in commit 17f8ffa1e.  Per buildfarm member prion.
2017-03-18 18:43:06 -04:00
Tom Lane 17f8ffa1e3 Fix REFRESH MATERIALIZED VIEW to report activity to the stats collector.
The non-concurrent code path for REFRESH MATERIALIZED VIEW failed to
report its updates to the stats collector.  This is bad since it means
auto-analyze doesn't know there's any work to be done.  Adjust it to
report the refresh as a table truncate followed by insertion of an
appropriate number of rows.

Since a matview could contain more than INT_MAX rows, change the
signature of pgstat_count_heap_insert() to accept an int64 rowcount.
(The accumulator it's adding into is already int64, but existing
callers could not insert more than a small number of rows at once,
so the argument had been declared just "int n".)

This is surely a bug fix, but changing pgstat_count_heap_insert()'s API
seems too risky for the back branches.  Given the lack of previous
complaints, I'm not sure it's a big enough problem to justify a kluge
solution that would avoid that.  So, no back-patch, at least for now.

Jim Mlodgenski, adjusted a bit by me

Discussion: https://postgr.es/m/CAB_5SRchSz7-WmdO5szdiknG8Oj_GGqJytrk1KRd11yhcMs1KQ@mail.gmail.com
2017-03-18 17:49:39 -04:00
Robert Haas 88e66d193f Rename "pg_clog" directory to "pg_xact".
Names containing the letters "log" sometimes confuse users into
believing that only non-critical data is present.  It is hoped
this renaming will discourage ill-considered removals of transaction
status data.

Michael Paquier

Discussion: http://postgr.es/m/CA+Tgmoa9xFQyjRZupbdEFuwUerFTvC6HjZq1ud6GYragGDFFgA@mail.gmail.com
2017-03-17 09:48:38 -04:00
Andrew Gierth 1914c5ea7d Avoid having vacuum set reltuples to 0 on non-empty relations in the
presence of page pins, which leads to serious estimation errors in the
planner.  This particularly affects small heavily-accessed tables,
especially where locking (e.g. from FK constraints) forces frequent
vacuums for mxid cleanup.

Fix by keeping separate track of pages whose live tuples were actually
counted vs. pages that were only scanned for freezing purposes.  Thus,
reltuples can only be set to 0 if all pages of the relation were
actually counted.

Backpatch to all supported versions.

Per bug #14057 from Nicolas Baccelli, analyzed by me.

Discussion: https://postgr.es/m/20160331103739.8956.94469@wrigleys.postgresql.org
2017-03-16 22:28:03 +00:00
Peter Eisentraut eb4da3e380 Add option to control snapshot export to CREATE_REPLICATION_SLOT
We used to export snapshots unconditionally in CREATE_REPLICATION_SLOT
in the replication protocol, but several upcoming patches want more
control over what happens.

Suppress snapshot export in pg_recvlogical, which neither needs nor can
use the exported snapshot.  Since snapshot exporting can fail this
improves reliability.

This also paves the way for allowing the creation of replication slots
on standbys, which cannot export snapshots because they cannot allocate
new XIDs.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-03-14 17:34:22 -04:00
Robert Haas c11453ce0a hash: Add write-ahead logging support.
The warning about hash indexes not being write-ahead logged and their
use being discouraged has been removed.  "snapshot too old" is now
supported for tables with hash indexes.  Most importantly, barring
bugs, hash indexes will now be crash-safe and usable on standbys.

This commit doesn't yet add WAL consistency checking for hash
indexes, as we now have for other index types; a separate patch has
been submitted to cure that lack.

Amit Kapila, reviewed and slightly modified by me.  The larger patch
series of which this is a part has been reviewed and tested by Álvaro
Herrera, Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper
Pedersen.

Discussion: http://postgr.es/m/CAA4eK1JOBX=YU33631Qh-XivYXtPSALh514+jR8XeD7v+K3r_Q@mail.gmail.com
2017-03-14 13:27:02 -04:00
Peter Eisentraut f97a028d8e Spelling fixes in code comments
From: Josh Soref <jsoref@gmail.com>
2017-03-14 12:58:39 -04:00
Tom Lane 5ed6fff6b7 Make logging about multixact wraparound protection less chatty.
The original messaging design, introduced in commit 068cfadf9, seems too
chatty now that some time has elapsed since the bug fix; most installations
will be in good shape and don't really need a reminder about this on every
postmaster start.

Hence, arrange to suppress the "wraparound protections are now enabled"
message during startup (specifically, during the TrimMultiXact() call).
The message will still appear if protection becomes effective at some
later point.

Discussion: https://postgr.es/m/17211.1489189214@sss.pgh.pa.us
2017-03-14 12:47:53 -04:00
Noah Misch 3a0d473192 Use wrappers of PG_DETOAST_DATUM_PACKED() more.
This makes almost all core code follow the policy introduced in the
previous commit.  Specific decisions:

- Text search support functions with char* and length arguments, such as
  prsstart and lexize, may receive unaligned strings.  I doubt
  maintainers of non-core text search code will notice.

- Use plain VARDATA() on values detoasted or synthesized earlier in the
  same function.  Use VARDATA_ANY() on varlenas sourced outside the
  function, even if they happen to always have four-byte headers.  As an
  exception, retain the universal practice of using VARDATA() on return
  values of SendFunctionCall().

- Retain PG_GETARG_BYTEA_P() in pageinspect.  (Page images are too large
  for a one-byte header, so this misses no optimization.)  Sites that do
  not call get_page_from_raw() typically need the four-byte alignment.

- For now, do not change btree_gist.  Its use of four-byte headers in
  memory is partly entangled with storage of 4-byte headers inside
  GBT_VARKEY, on disk.

- For now, do not change gtrgm_consistent() or gtrgm_distance().  They
  incorporate the varlena header into a cache, and there are multiple
  credible implementation strategies to consider.
2017-03-12 19:35:34 -04:00
Peter Eisentraut cd603a4d6b Use SQL standard error code for nextval 2017-03-09 10:56:44 -05:00
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
Stephen Frost f9b1a0dd40 Expose explain's SUMMARY option
This exposes the existing explain summary option to users to allow them
to choose if they wish to have the planning time and totalled run time
included in the EXPLAIN result.  The existing default behavior is
retained if SUMMARY is not specified- running explain without analyze
will not print the summary lines (just the planning time, currently)
while running explain with analyze will include the summary lines (both
the planning time and the totalled execution time).

Users who wish to see the summary information for plain explain can now
use: EXPLAIN (SUMMARY ON) query;  Users who do not want to have the
summary printed for an analyze run can use:
EXPLAIN (ANALYZE ON, SUMMARY OFF) query;

With this, we can now also have EXPLAIN ANALYZE queries included in our
regression tests by using:
EXPLAIN (ANALYZE ON, TIMING OFF, SUMMARY off) query;

I went ahead and added an example of this, which will hopefully not make
the buildfarm complain.

Author: Ashutosh Bapat
Discussion: https://postgr.es/m/CAFjFpReE5z2h98U2Vuia8hcEkpRRwrauRjHmyE44hNv8-xk+XA@mail.gmail.com
2017-03-08 15:14:03 -05:00
Fujii Masao 4eafdcc276 Prevent logical rep workers with removed subscriptions from starting.
Any logical rep workers must have their subscription entries in
pg_subscription. To ensure this, we need to prevent the launcher
from starting new worker corresponding to the subscription that
DROP SUBSCRIPTION command is removing. To implement this,
previously LogicalRepLauncherLock was introduced and held until
the end of transaction running DROP SUBSCRIPTION. But using
LWLock for that purpose was not valid.

Instead, this commit changes DROP SUBSCRIPTION so that it takes
AccessExclusiveLock on pg_subscription, in order to ensure that
the launcher cannot see any subscriptions being removed. Also this
commit gets rid of LogicalRepLauncherLock.

Patch by me, reviewed by Petr Jelinek

Discussion: https://www.postgresql.org/message-id/CAHGQGwHPi8ky-yANFfe0sgmhKtsYcQLTnKx07bW9S7-Rn1746w@mail.gmail.com
2017-03-09 01:44:23 +09:00
Alvaro Herrera fcec6caafa Support XMLTABLE query expression
XMLTABLE is defined by the SQL/XML standard as a feature that allows
turning XML-formatted data into relational form, so that it can be used
as a <table primary> in the FROM clause of a query.

This new construct provides significant simplicity and performance
benefit for XML data processing; what in a client-side custom
implementation was reported to take 20 minutes can be executed in 400ms
using XMLTABLE.  (The same functionality was said to take 10 seconds
using nested PostgreSQL XPath function calls, and 5 seconds using
XMLReader under PL/Python).

The implemented syntax deviates slightly from what the standard
requires.  First, the standard indicates that the PASSING clause is
optional and that multiple XML input documents may be given to it; we
make it mandatory and accept a single document only.  Second, we don't
currently support a default namespace to be specified.

This implementation relies on a new executor node based on a hardcoded
method table.  (Because the grammar is fixed, there is no extensibility
in the current approach; further constructs can be implemented on top of
this such as JSON_TABLE, but they require changes to core code.)

Author: Pavel Stehule, Álvaro Herrera
Extensively reviewed by: Craig Ringer
Discussion: https://postgr.es/m/CAFj8pRAgfzMD-LoSmnMGybD0WsEznLHWap8DO79+-GTRAPR4qA@mail.gmail.com
2017-03-08 12:40:26 -03:00
Fujii Masao 77d21970ae Fix connection leak in DROP SUBSCRIPTION command, take 2.
Commit 898a792eb8 fixed the connection
leak issue, but it was an unreliable way of bugfix. This bugfix was
assuming that walrcv_command() subroutine cannot throw an error,
but it's untenable assumption. For example, if it will be changed
so that an error is thrown, connection leak issue will happen again.

This patch ensures that the connection is closed even when
walrcv_command() subroutine throws an error.

Patch by me, reviewed by Petr Jelinek and Michael Paquier

Discussion: https://www.postgresql.org/message-id/2058.1487704345@sss.pgh.pa.us
2017-03-08 23:43:38 +09:00
Robert Haas d88d06cd07 Fix relcache reference leak.
Reported by Kevin Grittner.  Faulty commit identified by Tom Lane.
Patch by Amit Langote, reviewed by Michael Paquier.

Discussion: http://postgr.es/m/CACjxUsOHbH1=99u8mGxmLHfy5hov4ENEpvM6=3ARjos7wG7rtQ@mail.gmail.com
2017-03-07 11:27:21 -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 a8df75b0a4 Avoid dangling pointer to relation name in RLS code path in DoCopy().
With RLS active, "COPY tab TO ..." failed under -DRELCACHE_FORCE_RELEASE,
and would sometimes fail without that, because it used the relation name
directly from the relcache as part of the parsetree it's building.  That
becomes a potentially-dangling pointer as soon as the relcache entry is
closed, a bit further down.  Typical symptom if the relcache entry chanced
to get cleared would be "relation does not exist" error with a garbage
relation name, or possibly a core dump; but if you were really truly
unlucky, the COPY might copy from the wrong table.

Per report from Andrew Dunstan that regression tests fail with
-DRELCACHE_FORCE_RELEASE.  The core tests now pass for me (but have
not tried "make check-world" yet).

Discussion: https://postgr.es/m/7b52f900-0579-cda9-ae2e-de5da17090e6@2ndQuadrant.com
2017-03-06 16:50:47 -05:00
Peter Eisentraut 2ca64c6f71 Replace LookupFuncNameTypeNames() with LookupFuncWithArgs()
The old function took function name and function argument list as
separate arguments.  Now that all function signatures are passed around
as ObjectWithArgs structs, this is no longer necessary and can be
replaced by a function that takes ObjectWithArgs directly.  Similarly
for aggregates and operators.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00
Peter Eisentraut 8b6d6cf853 Remove objname/objargs split for referring to objects
In simpler times, it might have worked to refer to all kinds of objects
by a list of name components and an optional argument list.  But this
doesn't work for all objects, which has resulted in a collection of
hacks to place various other nodes types into these fields, which have
to be unpacked at the other end.  This makes it also weird to represent
lists of such things in the grammar, because they would have to be lists
of singleton lists, to make the unpacking work consistently.  The other
problem is that keeping separate name and args fields makes it awkward
to deal with lists of functions.

Change that by dropping the objargs field and have objname, renamed to
object, be a generic Node, which can then be flexibly assigned and
managed using the normal Node mechanisms.  In many cases it will still
be a List of names, in some cases it will be a string Value, for types
it will be the existing Typename, for functions it will now use the
existing ObjectWithArgs node type.  Some of the more obscure object
types still use somewhat arbitrary nested lists.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00
Peter Eisentraut 550214a4ef Add operator_with_argtypes grammar rule
This makes the handling of operators similar to that of functions and
aggregates.

Rename node FuncWithArgs to ObjectWithArgs, to reflect the expanded use.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-06 13:31:47 -05:00