Commit Graph

1786 Commits

Author SHA1 Message Date
Robert Haas
b2e4399baa Code review for make_partition_op_expr.
It's better to use the actual keynum here rather than 0, because
someday someone might try to make list partitioning work with
multiple partitioning columns.

Jeevan Ladhe

Discussion: http://postgr.es/m/CAOgcT0M6-mx+dSX47JGJuJP1CKr4XssBFVmKNETt0OZYWpFr+w@mail.gmail.com
2017-05-17 14:31:48 -04:00
Robert Haas
236d6d462d Remove redundant has_null member from PartitionBoundInfoData.
Jeevan Ladhe, with some changes by me.

Discussion: http://postgr.es/m/CAOgcT0NZ_30-pjBpW2OgneV1ammArHkZDZ8B_KFC3q+_Xb2H9A@mail.gmail.com
2017-05-17 12:50:01 -04:00
Tom Lane
c079673dcb Preventive maintenance in advance of pgindent run.
Reformat various places in which pgindent will make a mess, and
fix a few small violations of coding style that I happened to notice
while perusing the diffs from a pgindent dry run.

There is one actual bug fix here: the need-to-enlarge-the-buffer code
path in icu_convert_case was obviously broken.  Perhaps it's unreachable
in our usage?  Or maybe this is just sadly undertested.
2017-05-16 20:36:35 -04:00
Tom Lane
ddd243584a Fix leakage of memory context header in find_all_inheritors().
Commit 827d6f977 contained the same misunderstanding of hash_create's API
as commit 090010f2e.  As in 5d00b764c, remove the unnecessary layer of
memory context.  (This bug is less significant than the other one, since
the extra context would be under a relatively short-lived context, but
it's still a bug.)
2017-05-16 19:33:31 -04:00
Robert Haas
edbe2a2936 Attempt to fix compiler warning.
Per a report from Tom Lane, newer versions of gcc apparently think
that partexprs_item_saved can be used uninitialized.  Try to convince
them otherwise.
2017-05-14 20:59:28 -04:00
Tom Lane
e84c019598 Fix maintenance hazards caused by ill-considered use of default: cases.
Remove default cases from assorted switches over ObjectClass and some
related enum types, so that we'll get compiler warnings when someone
adds a new enum value without accounting for it in all these places.

In passing, re-order some switch cases as needed to match the declaration
of enum ObjectClass.  OK, that's just neatnik-ism, but I dislike code
that looks like it was assembled with the help of a dartboard.

Discussion: https://postgr.es/m/20170512221010.nglatgt5azzdxjlj@alvherre.pgsql
2017-05-14 13:32:59 -04:00
Tom Lane
f04c9a6146 Standardize terminology for pg_statistic_ext entries.
Consistently refer to such an entry as a "statistics object", not just
"statistics" or "extended statistics".  Previously we had a mismash of
terms, accompanied by utter confusion as to whether the term was
singular or plural.  That's not only grating (at least to the ear of
a native English speaker) but could be outright misleading, eg in error
messages that seemed to be referring to multiple objects where only one
could be meant.

This commit fixes the code and a lot of comments (though I may have
missed a few).  I also renamed two new SQL functions,
pg_get_statisticsextdef -> pg_get_statisticsobjdef
pg_statistic_ext_is_visible -> pg_statistics_obj_is_visible
to conform better with this terminology.

I have not touched the SGML docs other than fixing those function
names; the docs certainly need work but it seems like a separable task.

Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
2017-05-14 10:55:01 -04:00
Robert Haas
1848b73d45 Teach \d+ to show partitioning constraints.
The fact that we didn't have this in the first place is likely why
the problem fixed by f8bffe9e6d
escaped detection.

Patch by Amit Langote, reviewed and slightly adjusted by me.

Discussion: http://postgr.es/m/CA+TgmoYWnV2GMnYLG-Czsix-E1WGAbo4D+0tx7t9NdfYBDMFsA@mail.gmail.com
2017-05-13 12:04:53 -04:00
Robert Haas
f8bffe9e6d Fix multi-column range partitioning constraints.
The old logic was just plain wrong.

Report by Olaf Gawenda.  Patch by Amit Langote, reviewed by
Beena Emerson and by me.  Minor adjustments by me also.
2017-05-13 11:36:41 -04:00
Alvaro Herrera
d99d58cdc8 Complete tab completion for DROP STATISTICS
Tab-completing DROP STATISTICS would only work if you started writing
the schema name containing the statistics object, because the visibility
clause was missing.  To add it, we need to add SQL-callable support for
testing visibility of a statistics object, like all other object types
already have.

Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
2017-05-13 01:05:48 -03:00
Alvaro Herrera
5e2af609e1 getObjectDescription: support extended statistics
This was missed in 7b504eb282.

Remove the "default:" clause in the switch, to avoid this problem in the
future.  Other switches involving the same enum should probably be
changed in the same way, but are not touched by this patch.

Discussion: https://postgr.es/m/20170512204800.iqt2uwyx3c32j45r@alvherre.pgsql
2017-05-12 19:22:50 -03:00
Tom Lane
928c4de309 Fix dependencies for extended statistics objects.
A stats object ought to have a dependency on each individual column
it reads, not the entire table.  Doing this honestly lets us get rid
of the hard-wired logic in RemoveStatisticsExt, which seems to have
been misguidedly modeled on RemoveStatistics; and it will be far easier
to extend to multiple tables later.

Also, add overlooked dependency on owner, and make the dependency on
schema be NORMAL like every other such dependency.

There remains some unfinished work here, which is to allow statistics
objects to be extension members.  That takes more effort than just
adding the dependency call, though, so I left it out for now.

initdb forced because this changes the set of pg_depend records that
should exist for a statistics object.

Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
2017-05-12 16:26:31 -04:00
Tom Lane
d10c626de4 Rename WAL-related functions and views to use "lsn" not "location".
Per discussion, "location" is a rather vague term that could refer to
multiple concepts.  "LSN" is an unambiguous term for WAL locations and
should be preferred.  Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position".  Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.

David Rowley, minor additional docs hacking by me

Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
2017-05-11 11:49:59 -04:00
Peter Eisentraut
013c1178fd Remove the NODROP SLOT option from DROP SUBSCRIPTION
It turned out this approach had problems, because a DROP command should
not have any options other than CASCADE and RESTRICT.  Instead, always
attempt to drop the slot if there is one configured, but also add an
ALTER SUBSCRIPTION action to set the slot to NONE.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/29431.1493730652@sss.pgh.pa.us
2017-05-09 10:20:42 -04:00
Noah Misch
3eefc51053 Match pg_user_mappings limits to information_schema.user_mapping_options.
Both views replace the umoptions field with NULL when the user does not
meet qualifications to see it.  They used different qualifications, and
pg_user_mappings documented qualifications did not match its implemented
qualifications.  Make its documentation and implementation match those
of user_mapping_options.  One might argue for stronger qualifications,
but these have long, documented tenure.  pg_user_mappings has always
exhibited this problem, so back-patch to 9.2 (all supported versions).

Michael Paquier and Feike Steenbergen.  Reviewed by Jeff Janes.
Reported by Andrew Wheelwright.

Security: CVE-2017-7486
2017-05-08 07:24:24 -07:00
Robert Haas
0d1e1f0ea4 Fix typos in comments.
Etsuro Fujita

Discussion: http://postgr.es/m/00e88999-684d-d79a-70e4-908c937a0126@lab.ntt.co.jp
2017-05-02 14:47:46 -04:00
Robert Haas
c1e0e7e1d7 Speed up dropping tables with many partitions.
We need to lock the parent, but we don't need a relcache entry
for it.

Gao Zeng Qi, reviewed by Amit Langote

Discussion: http://postgr.es/m/CAFmBtr0ukqJjRJEhPWL5wt4rNMrJUUxggVAGXPR3SyYh3E+HDQ@mail.gmail.com
2017-04-28 14:02:24 -04:00
Peter Eisentraut
e495c1683f Spelling fixes in code comments
Author: Euler Taveira <euler@timbira.com.br>
2017-04-26 12:07:11 -04:00
Peter Eisentraut
594b526bcf Modify message when partitioned table is added to publication
Give a more specific error message than "xyz is not a table".

Also document in CREATE PUBLICATION which kinds of relations are not
supported.

based on patch by Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
2017-04-20 14:18:33 -04:00
Simon Riggs
123aaffb5b Fix minor typo in comment
Reported-by: Amit Langote
2017-04-18 11:57:11 +01:00
Alvaro Herrera
ee6922112e Rename columns in new pg_statistic_ext catalog
The new catalog reused a column prefix "sta" from pg_statistic, but this
is undesirable, so change the catalog to use prefix "stx" instead.
Also, rename the column that lists enabled statistic kinds as "stxkind"
rather than "enabled".

Discussion: https://postgr.es/m/CAKJS1f_2t5jhSN7huYRFH3w3rrHfG2QU7hiUHsu-Vdjd1rYT3w@mail.gmail.com
2017-04-17 18:34:29 -03:00
Fujii Masao
9e0e5550c5 Fix typos in comment and log message. 2017-04-18 03:19:39 +09:00
Peter Eisentraut
887227a1cc Add option to modify sync commit per subscription
This also changes default behaviour of subscription workers to
synchronous_commit = off.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-04-14 13:58:46 -04:00
Peter Eisentraut
25371a72b9 Remove pstrdup of TextDatumGetCString
The result of TextDatumGetCString is already palloc'ed.
2017-04-14 12:54:09 -04:00
Tom Lane
5e39f06cfe Move bootstrap-time lookup of regproc OIDs into genbki.pl.
Formerly, the bootstrap backend looked up the OIDs corresponding to
names in regproc catalog entries using brute-force searches of pg_proc.
It was somewhat remarkable that that worked at all, since it was used
while populating other pretty-fundamental catalogs like pg_operator.
And it was also quite slow, and getting slower as pg_proc gets bigger.

This patch moves the lookup work into genbki.pl, so that the values in
postgres.bki for regproc columns are always numeric OIDs, an option
that regprocin() already supported.  Perl isn't the world's speediest
language, so this about doubles the time needed to run genbki.pl (from
0.3 to 0.6 sec on my machine).  But we only do that at most once per
build.  The time needed to run initdb drops significantly --- on my
machine, initdb --no-sync goes from 1.8 to 1.3 seconds.  So this is
a small net win even for just one initdb per build, and it becomes
quite a nice win for test sequences requiring many initdb runs.

Strip out the now-dead code for brute-force catalog searching in
regprocin.  We'd also cargo-culted similar logic into regoperin
and some (not all) of the other reg*in functions.  That is all
dead code too since we currently have no need to load such values
during bootstrap.  I removed it all, reasoning that if we ever
need such functionality it'd be much better to do it in a similar
way to this patch.

There might be some simplifications possible in the backend now that
regprocin doesn't require doing catalog reads so early in bootstrap.
I've not looked into that, though.

Andreas Karlsson, with some small adjustments by me

Discussion: https://postgr.es/m/30896.1492006367@sss.pgh.pa.us
2017-04-13 12:07:57 -04:00
Alvaro Herrera
3d5facfd9a Remove pg_stats_ext view
It was created as equivalent of pg_stats, but since the code underlying
pg_statistic_ext is more convenient than the one for pg_statistic,
pg_stats_ext is no longer useful.

Author: David Rowley
Reviewed-by: Tomas Vondra
Discussion: https://postgr.es/m/CAKJS1f9zAkPUf9nQrqpFBAsrOHvb5eYa2FVNsmCJy1wegcO_TQ@mail.gmail.com
2017-04-13 11:35:22 -03:00
Robert Haas
258cef1254 Fix possibile deadlock when dropping partitions.
heap_drop_with_catalog and RangeVarCallbackForDropRelation should
lock the parent before locking the target relation.

Amit Langote

Discussion: http://postgr.es/m/29588799-a8ce-b0a2-3dae-f39ff6d35922@lab.ntt.co.jp
2017-04-11 09:08:36 -04:00
Peter Eisentraut
521fd4795e Use weaker locks when updating pg_subscription_rel
The previously used ShareRowExclusiveLock, while technically probably
more correct, led to deadlocks during seemingly unrelated operations and
thus a poor experience.  Use RowExclusiveLock, like for most similar
catalog operations.  In some care cases, the user might see an error
from DDL commands.

Discussion: https://www.postgresql.org/message-id/flat/13592.1490851519%40sss.pgh.pa.us

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-04-10 15:08:14 -04:00
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
Peter Eisentraut
28afad5c85 Fix compiler warning
on MSVC 2010

Author: Michael Paquier <michael.paquier@gmail.com>
2017-04-07 17:37:12 -04:00
Peter Eisentraut
5f21f5292c Mark immutable functions in information schema as parallel safe
Also add opr_sanity check that all preloaded immutable functions are
parallel safe.  (Per discussion, this does not necessarily have to be
true for all possible such functions, but deviations would be unlikely
enough that maintaining such a test is reasonable.)

Reported-by: David Rowley <david.rowley@2ndquadrant.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2017-04-06 14:30:13 -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
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
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
Robert Haas
c94e6942ce Don't allocate storage for partitioned tables.
Also, don't allow setting reloptions on them, since that would have no
effect given the lack of storage.  The patch does this by introducing
a new reloption kind for which there are currently no reloptions -- we
might have some in the future -- so it adjusts parseRelOptions to
handle that case correctly.

Bumped catversion.  System catalogs that contained reloptions for
partitioned tables are no longer valid; plus, there are now fewer
physical files on disk, which is not technically a catalog change but
still a good reason to re-initdb.

Amit Langote, reviewed by Maksim Milyutin and Kyotaro Horiguchi and
revised a bit by me.

Discussion: http://postgr.es/m/20170331.173326.212311140.horiguchi.kyotaro@lab.ntt.co.jp
2017-03-31 16:28:51 -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
e0eb5e0aea Improve Node vs Expr use a bit
Author: Mark Dilger <hornschnorter@gmail.com>
2017-03-28 21:59:23 -04:00
Teodor Sigaev
ab89e465cb Altering default privileges on schemas
Extend ALTER DEFAULT PRIVILEGES command to schemas.

Author: Matheus Oliveira
Reviewed-by: Petr Jelínek, Ashutosh Sharma

https://commitfest.postgresql.org/13/887/
2017-03-28 18:58:55 +03:00
Teodor Sigaev
827d6f9779 Improve performance of find_all_inheritors()
Previous coding uses three nested loops which obviously were a pain for
large number of table's children. Patch replaces inner loop with
a hashmap.

Author: Aleksander Alekseev
Reviewed-by: me

https://commitfest.postgresql.org/13/1058/
2017-03-27 19:07:48 +03:00
Robert Haas
7ecb714358 Fix improper NULL handling in list partitioning code.
The previous logic was wrong when the value was NULL but there was
no partition for NULL.

Amit Langote, reviewed by Jeevan Ladhe

Discussion: http://postgr.es/m/d64f8498-70eb-3c88-b56d-c54fd3b0500f@lab.ntt.co.jp
2017-03-27 10:51:46 -04:00
Peter Eisentraut
facde2a98f Clean up Perl code according to perlcritic
Fix all perlcritic warnings of severity level 5, except in
src/backend/utils/Gen_dummy_probes.pl, which is automatically generated.

Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
2017-03-27 08:18:22 -04:00
Robert Haas
fc70a4b0df Show more processes in pg_stat_activity.
Previously, auxiliary processes and background workers not connected
to a database (such as the logical replication launcher) weren't
shown.  Include them, so that we can see the associated wait state
information.  Add a new column to identify the processes type, so that
people can filter them out easily using SQL if they wish.

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

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

Discussion: http://postgr.es/m/CA+TgmoYES5nhkEGw9nZXU8_FhA8XEm8NTm3-SO+3ML1B81Hkww@mail.gmail.com
2017-03-26 22:02:22 -04:00
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
87dee41f3e Add COMMENT and SECURITY LABEL support for publications and subscriptions 2017-03-24 23:44:23 -04:00
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
Simon Riggs
6912acc04f Replication lag tracking for walsenders
Adds write_lag, flush_lag and replay_lag cols to pg_stat_replication.

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

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

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

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

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

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

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

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

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Tested-by: Erik Rijkers <er@xs4all.nl>
2017-03-23 08:55:37 -04:00
Stephen Frost
017e4f2588 Expose waitforarchive option through pg_stop_backup()
Internally, we have supported the option to either wait for all of the
WAL associated with a backup to be archived, or to return immediately.
This option is useful to users of pg_stop_backup() as well, when they
are reading the stop backup record position and checking that the WAL
they need has been archived independently.

This patch adds an additional, optional, argument to pg_stop_backup()
which allows the user to indicate if they wish to wait for the WAL to be
archived or not.  The default matches current behavior, which is to
wait.

Author: David Steele, with some minor changes, doc updates by me.
Reviewed by: Takayuki Tsunakawa, Fujii Masao
Discussion: https://postgr.es/m/758e3fd1-45b4-5e28-75cd-e9e7f93a4c02@pgmasters.net
2017-03-22 23:44:58 -04:00