Commit Graph

13186 Commits

Author SHA1 Message Date
Tom Lane f833c847b8 Allow psql variable substitution to occur in backtick command strings.
Previously, text between backquotes in a psql metacommand's arguments
was always passed to the shell literally.  That considerably hobbles
the usefulness of the feature for scripting, so we'd foreseen for a long
time that we'd someday want to allow substitution of psql variables into
the shell command.  IMO the addition of \if metacommands has brought us to
that point, since \if can greatly benefit from some sort of client-side
expression evaluation capability, and psql itself is not going to grow any
such thing in time for v10.  Hence, this patch.  It allows :VARIABLE to be
replaced by the exact contents of the named variable, while :'VARIABLE'
is replaced by the variable's contents suitably quoted to become a single
shell-command argument.  (The quoting rules for that are different from
those for SQL literals, so this is a bit of an abuse of the :'VARIABLE'
notation, but I doubt anyone will be confused.)

As with other situations in psql, no substitution occurs if the word
following a colon is not a known variable name.  That limits the risk of
compatibility problems for existing psql scripts; but the risk isn't zero,
so this needs to be called out in the v10 release notes.

Discussion: https://postgr.es/m/9561.1490895211@sss.pgh.pa.us
2017-04-01 21:44:54 -04:00
Alvaro Herrera c655899ba9 BRIN de-summarization
When the BRIN summary tuple for a page range becomes too "wide" for the
values actually stored in the table (because the tuples that were
present originally are no longer present due to updates or deletes), it
can be useful to remove the outdated summary tuple, so that a future
summarization can install a tighter summary.

This commit introduces a SQL-callable interface to do so.

Author: Álvaro Herrera
Reviewed-by: Eiji Seki
Discussion: https://postgr.es/m/20170228045643.n2ri74ara4fhhfxf@alvherre.pgsql
2017-04-01 16:10:04 -03:00
Alvaro Herrera 7526e10224 BRIN auto-summarization
Previously, only VACUUM would cause a page range to get initially
summarized by BRIN indexes, which for some use cases takes too much time
since the inserts occur.  To avoid the delay, have brininsert request a
summarization run for the previous range as soon as the first tuple is
inserted into the first page of the next range.  Autovacuum is in charge
of processing these requests, after doing all the regular vacuuming/
analyzing work on tables.

This doesn't impose any new tasks on autovacuum, because autovacuum was
already in charge of doing summarizations.  The only actual effect is to
change the timing, i.e. that it occurs earlier.  For this reason, we
don't go any great lengths to record these requests very robustly; if
they are lost because of a server crash or restart, they will happen at
a later time anyway.

Most of the new code here is in autovacuum, which can now be told about
"work items" to process.  This can be used for other things such as GIN
pending list cleaning, perhaps visibility map bit setting, both of which
are currently invoked during vacuum, but do not really depend on vacuum
taking place.

The requests are at the page range level, a granularity for which we did
not have SQL-level access; we only had index-level summarization
requests via brin_summarize_new_values().  It seems reasonable to add
SQL-level access to range-level summarization too, so add a function
brin_summarize_range() to do that.

Authors: Álvaro Herrera, based on sketch from Simon Riggs.
Reviewed-by: Thomas Munro.
Discussion: https://postgr.es/m/20170301045823.vneqdqkmsd4as4ds@alvherre.pgsql
2017-04-01 14:00:53 -03:00
Kevin Grittner 5970271632 Add transition table support to plpgsql.
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 23:30:08 -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
Robert Haas 2113ac4cbb Don't use bgw_main even to specify in-core bgworker entrypoints.
On EXEC_BACKEND builds, this can fail if ASLR is in use.

Backpatch to 9.5.  On master, completely remove the bgw_main field
completely, since there is no situation in which it is safe for an
EXEC_BACKEND build.  On 9.6 and 9.5, leave the field intact to avoid
breaking things for third-party code that doesn't care about working
under EXEC_BACKEND.  Prior to 9.5, there are no in-core bgworker
entrypoints.

Petr Jelinek, reviewed by me.

Discussion: http://postgr.es/m/09d8ad33-4287-a09b-a77f-77f8761adb5e@2ndquadrant.com
2017-03-31 20:43:32 -04:00
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
Robert Haas 8f18a880a5 Improve documentation for table partitioning.
Emphasize the new declarative partitioning more, and compare and
contrast it more clearly with inheritance-based partitioning.

Amit Langote, reviewed and somewhat revised by me

Discussion: http://postgr.es/m/a6f99cdb-21e7-1d65-1381-91f2cfa156e2@lab.ntt.co.jp
2017-03-31 17:33:34 -04:00
Robert Haas f05230752d Revert "Allow ON CONFLICT .. DO NOTHING on a partitioned table."
This reverts commit 8355a011a0, which
turns out to have been a misguided effort.  We can't really support
this in a partitioning hierarchy after all for exactly the reasons
stated in the documentation removed by that commit.  It's still
possible to use ON CONFLICT .. DO NOTHING (or for that matter ON
CONFLICT .. DO UPDATE) on individual partitions if desired, but
but to allow this on a partitioned table implies that we have some
way of evaluating uniqueness across the whole partitioning
hierarchy, which is false.

Shinoda Noriyoshi noticed that the old code was crashing (which we
could fix, though not in a nice way) and Amit Langote realized
that this was indicative of a fundamental problem with the commit
being reverted here.

Discussion: http://postgr.es/m/ff3dc21d-7204-c09c-50ac-cf11a8c45c81@lab.ntt.co.jp
2017-03-31 16:48:21 -04:00
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
Robert Haas f49bcd4ef3 postgres_fdw: Teach IMPORT FOREIGN SCHEMA about partitioning.
Don't import partitions.  Do import partitioned tables which are
not themselves partitions.

Report by Stephen Frost.  Design and patch by Michael Paquier,
reviewed by Amit Langote.  Documentation revised by me.

Discussion: http://postgr.es/m/20170309141531.GD9812@tamriel.snowman.net
2017-03-31 15:06:34 -04:00
Andrew Dunstan e306df7f9c Full Text Search support for json and jsonb
The new functions are ts_headline() and to_tsvector.

Dmitry Dolgov, edited and documented by me.
2017-03-31 14:26:03 -04:00
Tom Lane ab1e644005 Fix broken markup.
Per buildfarm.
2017-03-30 17:13:44 -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
Tom Lane e984ef5861 Support \if ... \elif ... \else ... \endif in psql scripting.
This patch adds nestable conditional blocks to psql.  The control
structure feature per se is complete, but the boolean expressions
understood by \if and \elif are pretty primitive; basically, after
variable substitution and backtick expansion, the result has to be
"true" or "false" or one of the other standard spellings of a boolean
value.  But that's enough for many purposes, since you can always
do the heavy lifting on the server side; and we can extend it later.

Along the way, pay down some of the technical debt that had built up
around psql/command.c:
* Refactor exec_command() into a function per command, instead of
being a 1500-line monstrosity.  This makes the file noticeably longer
because of repetitive function header/trailer overhead, but it seems
much more readable.
* Teach psql_get_variable() and psqlscanslash.l to suppress variable
substitution and backtick expansion on the basis of the conditional
stack state, thereby allowing removal of the OT_NO_EVAL kluge.
* Fix the no-doubt-once-expedient hack of sometimes silently substituting
mainloop.c's previous_buf for query_buf when calling HandleSlashCmds.
(It's a bit remarkable that commands like \r worked at all with that.)
Recall of a previous query is now done explicitly in the slash commands
where that should happen.

Corey Huinker, reviewed by Fabien Coelho, further hacking by me

Discussion: https://postgr.es/m/CADkLM=c94OSRTnat=LX0ivNq4pxDNeoomFfYvBKM5N_xfmLtAA@mail.gmail.com
2017-03-30 12:59:24 -04:00
Andres Freund ffae6733db Try to fix xml docs build broken in 5ded4bd.
Apparently the sgml to xml conversion treats non-closed <para>s
differently than jade does.
2017-03-30 09:42:07 -07:00
Fujii Masao ec19693014 Simplify the example of VACUUM in documentation.
Previously a detailed activity report by VACUUM VERBOSE ANALYZE was
described as an example of VACUUM in docs. But it had been obsolete
for a long time. For example, commit feb4f44d29
updated the content of that activity report in 2003, but we had
forgotten to update the example.

So basically we need to update the example. But since no one cared
about the details of VACUUM output and complained about that mistake
for such long time, per discussion on hackers, we decided to get rid
of the detailed activity report from the example and simplify it.

Back-patch to all supported versions.

Reported by Masahiko Sawada, patch by me.
Discussion: https://postgr.es/m/CAD21AoAGA2pB3p-CWmTkxBsbkZS1bcDGBLcYVcvcDxspG_XAfA@mail.gmail.com
2017-03-31 01:31:15 +09:00
Andres Freund 5ded4bd214 Remove support for version-0 calling conventions.
The V0 convention is failure prone because we've so far assumed that a
function is V0 if PG_FUNCTION_INFO_V1 is missing, leading to crashes
if a function was coded against the V1 interface.  V0 doesn't allow
proper NULL, SRF and toast handling.  V0 doesn't offer features that
V1 doesn't.

Thus remove V0 support and obsolete fmgr README contents relating to
it.

Author: Andres Freund, with contributions by Peter Eisentraut & Craig Ringer
Reviewed-By: Peter Eisentraut, Craig Ringer
Discussion: https://postgr.es/m/20161208213441.k3mbno4twhg2qf7g@alap3.anarazel.de
2017-03-30 06:25:46 -07:00
Peter Eisentraut 66b764341b doc: Mention --enable-tap-tests in regression test chapter
Reported-by: Jeff Janes <jeff.janes@gmail.com>
2017-03-28 21:12:30 -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
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
Tom Lane a6f22e8356 Show ignored constants as "$N" rather than "?" in pg_stat_statements.
The trouble with the original choice here is that "?" is a valid (and
indeed used) operator name, so that you could end up with ambiguous
statement texts like "SELECT ? ? ?".  With this patch, you instead
see "SELECT $1 ? $2", which seems significantly more readable.
The numbers used for this purpose begin after the last actual $N parameter
in the particular query.  The conflict with external parameters has its own
potential for confusion of course, but it was agreed to be an improvement
over the previous behavior.

Lukas Fittl

Discussion: https://postgr.es/m/CAP53PkxeaCuwYmF-A4J5z2-qk5fYFo5_NH3gpXGJJBxv1DMwEw@mail.gmail.com
2017-03-27 20:14:36 -04:00
Peter Eisentraut 6e31c3e135 doc: Improve rendering of notes/cautions using XSL-FO
Center title and put a border around it, like the output that the DSSSL
version gave.
2017-03-27 13:33:36 -04:00
Peter Eisentraut 5196f13b27 doc: Fix oldhtml/old PDF build again
Commit e259e1f748 was faulty and created
some broken output.  This one fixes it better.
2017-03-27 11:58:52 -04:00
Peter Eisentraut 70ec3f1f8f PL/Python: Add cursor and execute methods to plan object
Instead of

    plan = plpy.prepare(...)
    res = plpy.execute(plan, ...)

you can now write

    plan = plpy.prepare(...)
    res = plan.execute(...)

or even

    res = plpy.prepare(...).execute(...)

and similarly for the cursor() method.

This is more in object oriented style, and makes the hybrid nature of
the existing execute() function less confusing.

Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
2017-03-27 11:37:22 -04:00
Robert Haas d65561464f Improve documentation of how NOT NULL works with partitioning.
Amit Langote

Discussion: http://postgr.es/m/a6f99cdb-21e7-1d65-1381-91f2cfa156e2@lab.ntt.co.jp
2017-03-27 11:01:33 -04:00
Robert Haas 4785e377f9 Tidy up the CREATE TABLE documentation for partitioning.
Remove some <note> tags that make this too "loud".  Fix some typos.

Amit Langote, with a few minor corrections by me

Discussion: http://postgr.es/m/a6f99cdb-21e7-1d65-1381-91f2cfa156e2@lab.ntt.co.jp
2017-03-27 11:00:09 -04:00
Robert Haas 8355a011a0 Allow ON CONFLICT .. DO NOTHING on a partitioned table.
ON CONFLICT .. DO UPDATE still doesn't work, for lack of a way of
enforcing uniqueness across partitions, but we can still allow this
case.

Amit Langote, per discussion with Peter Geoghegan.  Additional
wordsmithing by me.

Discussion: http://postgr.es/m/CAA-aLv7Z4uygtq-Q5CvDi9Y=VZxUyEnuWjL=EwCfOof=L04hgg@mail.gmail.com
2017-03-27 10:37:41 -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 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
Peter Eisentraut e259e1f748 doc: Fix oldhtml/old PDF build
"xref to REFSECT1 unsupported" with the DSSSL stylesheets.

Reported-by: Devrim Gündüz <devrim@gunduz.org>
2017-03-26 15:03:27 -04:00
Peter Eisentraut d637624524 doc: Clean up bibliography rendering for XSLT
In the DSSSL stylesheets, we had an extensive customization of the
bibliography rendering.  Since the bibliography isn't that used much, it
doesn't seem worth doing an elaborate porting of that to XSLT.  So this
just moves some things around, removes some unused things, and does some
minimal XSLT stylesheet customizations to make things look clean.
2017-03-26 14:54:56 -04:00
Simon Riggs 5737c12df0 Report catalog_xmin separately in hot_standby_feedback
If the upstream walsender is using a physical replication slot, store the
catalog_xmin in the slot's catalog_xmin field. If the upstream doesn't use a
slot and has only a PGPROC entry behaviour doesn't change, as we store the
combined xmin and catalog_xmin in the PGPROC entry.

Author: Craig Ringer
2017-03-25 14:07:27 +00:00
Peter Eisentraut e148009740 Remove ICU tests from default run
These tests require the test database to be in UTF8 encoding.  Until
there is a better solution, take them out of the default test set and
treat them like the existing collate.linux.utf8 test, meaning it has to
be selected manually.
2017-03-25 00:30:26 -04:00
Peter Eisentraut 87dee41f3e Add COMMENT and SECURITY LABEL support for publications and subscriptions 2017-03-24 23:44:23 -04:00
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
Robert Haas 857ee8e391 Add a txid_status function.
If your connection to the database server is lost while a COMMIT is
in progress, it may be difficult to figure out whether the COMMIT was
successful or not.  This function will tell you, provided that you
don't wait too long to ask.  It may be useful in other situations,
too.

Craig Ringer, reviewed by Simon Riggs and by me

Discussion: http://postgr.es/m/CAMsr+YHQiWNEi0daCTboS40T+V5s_+dst3PYv_8v2wNVH+Xx4g@mail.gmail.com
2017-03-24 12:00:53 -04:00
Heikki Linnakangas 7ac955b347 Allow SCRAM authentication, when pg_hba.conf says 'md5'.
If a user has a SCRAM verifier in pg_authid.rolpassword, there's no reason
we cannot attempt to perform SCRAM authentication instead of MD5. The worst
that can happen is that the client doesn't support SCRAM, and the
authentication will fail. But previously, it would fail for sure, because
we would not even try. SCRAM is strictly more secure than MD5, so there's
no harm in trying it. This allows for a more graceful transition from MD5
passwords to SCRAM, as user passwords can be changed to SCRAM verifiers
incrementally, without changing pg_hba.conf.

Refactor the code in auth.c to support that better. Notably, we now have to
look up the user's pg_authid entry before sending the password challenge,
also when performing MD5 authentication. Also simplify the concept of a
"doomed" authentication. Previously, if a user had a password, but it had
expired, we still performed SCRAM authentication (but always returned error
at the end) using the salt and iteration count from the expired password.
Now we construct a fake salt, like we do when the user doesn't have a
password or doesn't exist at all. That simplifies get_role_password(), and
we can don't need to distinguish the  "user has expired password", and
"user does not exist" cases in auth.c.

On second thoughts, also rename uaSASL to uaSCRAM. It refers to the
mechanism specified in pg_hba.conf, and while we use SASL for SCRAM
authentication at the protocol level, the mechanism should be called SCRAM,
not SASL. As a comparison, we have uaLDAP, even though it looks like the
plain 'password' authentication at the protocol level.

Discussion: https://www.postgresql.org/message-id/6425.1489506016@sss.pgh.pa.us
Reviewed-by: Michael Paquier
2017-03-24 13:32:21 +02:00
Bruce Momjian 218747d2cf doc: add missing closing 'sect3' tag for ICU patch 2017-03-23 16:59:24 -04:00
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
Peter Eisentraut 50c956add8 Remove createlang and droplang
They have been deprecated since PostgreSQL 9.1.

Reviewed-by: Magnus Hagander <magnus@hagander.net>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
2017-03-23 14:16:45 -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
Peter Eisentraut cbf7ed51b8 doc: Improve CREATE PUBLICATION examples 2017-03-22 15:27:40 -04:00
Peter Eisentraut b941891190 doc: Fix logical replication setup instructions
The pg_hba.conf rules were changed in
8df9bd0b44.
2017-03-22 15:27:40 -04:00
Peter Eisentraut a2760915b3 doc: Markup and formatting improvements 2017-03-22 15:27:40 -04:00
Magnus Hagander 6b76f1bb58 Support multiple RADIUS servers
This changes all the RADIUS related parameters (radiusserver,
radiussecret, radiusport, radiusidentifier) to be plural and to accept a
comma separated list of servers, which will be tried in order.

Reviewed by Adam Brightwell
2017-03-22 18:11:08 +01:00
Peter Eisentraut 8df9bd0b44 Change logical replication pg_hba.conf use
Logical replication no longer uses the "replication" keyword.  It just
matches database entries in the normal way.  The "replication" keyword
now only applies to physical replication.

Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-03-22 11:19:30 -04:00
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
Andrew Dunstan 96a7128b7b Sync pg_dump and pg_dumpall output
Before exiting any files are fsync'ed. A --no-sync option is also
provided for a faster exit if desired.

Michael Paquier.

Reviewed by Albe Laurenz

Discussion: https://postgr.es/m/CAB7nPqS1uZ=Ov+UruW6jr3vB-S_DLVMPc0dQpV-fTDjmm0ZQMg@mail.gmail.com
2017-03-22 10:20:13 -04:00
Peter Eisentraut 9212810c4f doc: Update tool sets documentation for modern FreeBSD
For several operating systems, we give handy package manager one-liners
to install all the requirements for building our documentation.  All
current production FreeBSD releases have a friendly new package manager
a bit like apt/yum, so give a one line command here.  Also, add a brief
note about gmake vs make in the doc subdirectory.

Author: Thomas Munro <thomas.munro@enterprisedb.com>
2017-03-21 22:11:49 -04:00
Andrew Dunstan 80275561ff Document btree_gin support for enums 2017-03-21 11:11:42 -04:00
Andrew Dunstan f7946a92b6 Add btree_gist support for enum types.
This will allow enums to be used in exclusion constraints.

The code uses the new CallerFInfoFunctionCall infrastructure in fmgr,
and the support for it added to btree_gist in commit 393bb504d7.

Reviewed by Tom Lane and Anastasia Lubennikova

Discussion:  http://postgr.es/m/56EA8A71.8060107@dunslane.net
2017-03-21 10:43:27 -04:00
Peter Eisentraut 010505546a doc: Improve markup 2017-03-21 08:33:46 -04:00
Bruce Momjian 17fa3e834f doc: clarify that function "ownership" that controls permission
It used to say the creation user.

Reported-by: Nathan Wagner
2017-03-20 22:33:26 -04:00
Bruce Momjian 692ed0567d doc: adjust 'Infinity' example to include minus
This clarifies that quoted infinity values must have the negative signs
inside single quotes.

Reported-by: Don Morrison
2017-03-20 22:22:18 -04:00
Bruce Momjian c709b113e8 doc: improve createdb example
The previous example could error out due to encoding mismatches;  use
-T/template instead.

Reported-by: Jason O'Donnell
2017-03-20 21:23:56 -04:00
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
Peter Eisentraut 767ce36ff3 doc: Fix a few typos and awkward links 2017-03-18 23:43:47 -04:00
Peter Eisentraut 27f1f585fd doc: Improve wording
Link to CREATE and ALTER ROLE consistently, instead of mixing CREATE
USER and ALTER ROLE.
2017-03-18 17:40:47 -04:00
Peter Eisentraut a72188a35b doc: Add markup 2017-03-18 14:41:47 -04:00
Peter Eisentraut 5e86bb51ea doc: Update compatibility claim
Update outdated claim that TRUNCATE is a PostgreSQL extension.

Add cross-links between DELETE and TRUNCATE references pages.
2017-03-18 14:25:41 -04:00
Peter Eisentraut cb5fa4130e doc: Tweak reference page header style
Change the header style of references pages in HTML and PDF output to be
more like the old style under DSSSL.  In particular, the page should
start with a header containing the command name, instead of just "Name".
2017-03-18 14:17:28 -04:00
Peter Eisentraut 164bdbe9c2 doc: Correct row count in table
The incorrect count causes FOP to error out.
2017-03-18 09:42:26 -04:00
Robert Haas 249cf070e3 Create and use wait events for read, write, and fsync operations.
Previous commits, notably 53be0b1add and
6f3bd98ebf, made it possible to see from
pg_stat_activity when a backend was stuck waiting for another backend,
but it's also fairly common for a backend to be stuck waiting for an
I/O.  Add wait events for those operations, too.

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

Discussion: http://postgr.es/m/CAGPqQf0LsYHXREPAZqYGVkDqHSyjf=KsD=k0GTVPAuzyThh-VQ@mail.gmail.com
2017-03-18 07:43:01 -04:00
Peter Eisentraut fef2bcdcba pageinspect: Add page_checksum function
Author: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Reviewed-by: Ashutosh Sharma <ashu.coek88@gmail.com>
2017-03-17 10:55:17 -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
Robert Haas bd9028b824 Remove dead link.
David Christensen

Discussion: http://postgr.es/m/82299377-1480-4439-9ABA-5828D71AA22E@endpoint.com
2017-03-17 09:32:34 -04:00
Robert Haas b4ff8609db Fix grammar.
This would have ben grammatical if the closing tag name were actually
part of the output, but of course it's not.
2017-03-16 20:29:42 -04:00
Robert Haas befd73c50f Add pg_ls_logdir() and pg_ls_waldir() functions.
These functions are intended to be used by monitoring tools, and,
unlike pg_ls_dir(), access to them can be granted to non-superusers,
so that those monitoring tools can observe the principle of least
privilege.

Dave Page, revised by me, and also reviewed a bit by Thomas Munro.

Discussion: http://postgr.es/m/CA+OCxow-X=D2fWdKy+HP+vQ1LtrgbsYQ=CshzZBqyFT5jOYrFw@mail.gmail.com
2017-03-16 15:05:02 -04:00
Peter Eisentraut e76db009f0 Add more documentation and tests for publications
Add/correct documentation and add some tests related to how access
control around adding tables to publications works.
2017-03-15 13:52:07 -04:00
Stephen Frost c7a9fa399d Add support for EUI-64 MAC addresses as macaddr8
This adds in support for EUI-64 MAC addresses by adding a new data type
called 'macaddr8' (using our usual convention of indicating the number
of bytes stored).

This was largely a copy-and-paste from the macaddr data type, with
appropriate adjustments for having 8 bytes instead of 6 and adding
support for converting a provided EUI-48 (6 byte format) to the EUI-64
format.  Conversion from EUI-48 to EUI-64 inserts FFFE as the 4th and
5th bytes but does not perform the IPv6 modified EUI-64 action of
flipping the 7th bit, but we add a function to perform that specific
action for the user as it may be commonly done by users who wish to
calculate their IPv6 address based on their network prefix and 48-bit
MAC address.

Author: Haribabu Kommi, with a good bit of rework of macaddr8_in by me.
Reviewed by: Vitaly Burovoy, Kuntal Ghosh

Discussion: https://postgr.es/m/CAJrrPGcUi8ZH+KkK+=TctNQ+EfkeCEHtMU_yo1mvX8hsk_ghNQ@mail.gmail.com
2017-03-15 11:16:25 -04:00
Peter Eisentraut aefeb68741 Allow referring to functions without arguments when unique
In DDL commands referring to an existing function, allow omitting the
argument list if the function name is unique in its schema, per SQL
standard.

This uses the same logic that the regproc type uses for finding
functions by name only.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-03-14 23:55:19 -04:00
Peter Eisentraut 3f6ea5fc8d doc: Remove useless elements in bibliography
Under DSSSL, bibliodiv/para elements didn't show up, but under XSLT they
do, but they are kind of useless here, so remove them.
2017-03-14 23:30:01 -04:00
Peter Eisentraut 0c068205df doc: Fix TOC generation for refentries
The XSLT stylesheets by default don't show refentries inside sections in
table of contents, which for our documentation leads to some regressions
compared to the DSSSL output.  For example, in the SPI chapter, which is
mostly refentries, you don't get any usable table of contents.  Tweak
things so it's mostly back to what it was before.
2017-03-14 23:12:18 -04:00
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 bb4a39637a hash: Support WAL consistency checking.
Kuntal Ghosh, reviewed by Amit Kapila and Ashutosh Sharma, with
a few tweaks by me.

Discussion: http://postgr.es/m/CAGz5QCJLERUn_zoO0eDv6_Y_d0o4tNTMPeR7ivTLBg4rUrJdwg@mail.gmail.com
2017-03-14 14:58:56 -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 a47b38c9ee Spelling fixes
From: Josh Soref <jsoref@gmail.com>
2017-03-14 12:58:39 -04:00
Peter Eisentraut 37289ffdbf doc: Fix synopsis 2017-03-14 11:19:12 -04:00
Tom Lane 0c87cd003d Fix busted markup.
Oversight in commit 9ca5c8721.  Per buildfarm.
2017-03-13 19:06:28 -04:00
Michael Meskes 9ca5c8721d Document two phase commit commands in ecpg docu.
Patch by Masahiko Sawada
2017-03-13 21:03:55 +01:00
Noah Misch 9d7726c2ba Recommend wrappers of PG_DETOAST_DATUM_PACKED().
When commit 3e23b68dac introduced
single-byte varlena headers, its fmgr.h changes presented
PG_GETARG_TEXT_PP() and PG_GETARG_TEXT_P() as equals.  Its postgres.h
changes presented PG_DETOAST_DATUM_PACKED() and VARDATA_ANY() as the
exceptional case.  Now, instead, firmly recommend PG_GETARG_TEXT_PP()
over PG_GETARG_TEXT_P(); likewise for other ...PP() macros.  This shaves
cycles and invites consistency of style.
2017-03-12 19:35:33 -04:00
Tom Lane b58fd4a9ca Add a "subtransaction" command to PL/Tcl.
This allows rolling back the effects of some SPI commands without
having to fail the entire PL/Tcl function.

Victor Wagner, reviewed by Pavel Stehule

Discussion: https://postgr.es/m/20170108205750.2dab04a1@wagner.wagner.home
2017-03-11 14:37:05 -05:00
Tom Lane f9dfa5c977 Improve postmaster's logging of listen socket creation.
When one of the kernel calls in the socket()/bind()/listen() sequence
fails, include the specific address we're trying to bind to in the log
message.  This greatly eases debugging of network misconfigurations.

Also, after successfully setting up a listen socket, report its address
in the log, to ease verification that the expected addresses were bound.
There was some debate about whether to print this message at LOG level or
only DEBUG1, but the majority of votes were for the former.

Discussion: https://postgr.es/m/9564.1489091245@sss.pgh.pa.us
2017-03-10 16:32:25 -05:00
Tom Lane 8b358b42f8 Change the relkind for partitioned tables from 'P' to 'p'.
Seven of the eight other relkind codes are lower-case, so it wasn't
consistent for this one to be upper-case.  Fix it while we still can.

Historical notes: the reason for the lone exception, i.e. sequences being
'S', is that 's' was once used for "special" relations.  Also, at one time
the partitioned-tables patch used both 'P' and 'p', but that got changed,
leaving only a surprising choice behind.

This also fixes a couple little bits of technical debt, such as
type_sanity.sql not knowing that 'm' is a legal value for relkind.

Discussion: https://postgr.es/m/27899.1488909319@sss.pgh.pa.us
2017-03-10 13:15:47 -05:00
Peter Eisentraut 07a61e1670 Improve gitignore file
One file was listed under a wrong comment.
2017-03-10 10:16:04 -05:00
Andres Freund 3717dc149e Add amcheck extension to contrib.
This is the beginning of a collection of SQL-callable functions to
verify the integrity of data files.  For now it only contains code to
verify B-Tree indexes.

This adds two SQL-callable functions, validating B-Tree consistency to
a varying degree.  Check the, extensive, docs for details.

The goal is to later extend the coverage of the module to further
access methods, possibly including the heap.  Once checks for
additional access methods exist, we'll likely add some "dispatch"
functions that cover multiple access methods.

Author: Peter Geoghegan, editorialized by Andres Freund
Reviewed-By: Andres Freund, Tomas Vondra, Thomas Munro,
   Anastasia Lubennikova, Robert Haas, Amit Langote
Discussion: CAM3SWZQzLMhMwmBqjzK+pRKXrNUZ4w90wYMUWfkeV8mZ3Debvw@mail.gmail.com
2017-03-09 16:33:02 -08:00
Robert Haas b54aad8e34 Document lack of validation when attaching foreign partitions.
Ashutosh Bapat, revised a bit by me.

Discussion: http://postgr.es/m/CAFjFpRdLaCa-1wJase0=YWG5o3cJnbuUt_vrqm2TDBKM_vQ_oA@mail.gmail.com
2017-03-09 13:13:15 -05:00
Robert Haas 054637d2e0 Document some new parallel query capabilities.
This updates the text for parallel index scan, parallel index-only
scan, parallel bitmap heap scan, and parallel merge join.  It also
expands the discussion of parallel joins slightly.

Discussion: http://postgr.es/m/CA+TgmoZnCUoM31w3w7JSakVQJQOtcuTyX=HLUr-X1rto2=2bjw@mail.gmail.com
2017-03-09 13:06:18 -05:00
Peter Eisentraut be37c2120a Enable replication connections by default in pg_hba.conf
initdb now initializes a pg_hba.conf that allows replication connections
from the local host, same as it does for regular connections.  The
connecting user still needs to have the REPLICATION attribute or be a
superuser.

The intent is to allow pg_basebackup from the local host to succeed
without requiring additional configuration.

Michael Paquier <michael.paquier@gmail.com> and me
2017-03-09 08:39:44 -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
Robert Haas f35742ccb7 Support parallel bitmap heap scans.
The index is scanned by a single process, but then all cooperating
processes can iterate jointly over the resulting set of heap blocks.
In the future, we might also want to support using a parallel bitmap
index scan to set up for a parallel bitmap heap scan, but that's a
job for another day.

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

Discussion: http://postgr.es/m/CAFiTN-uc4=0WxRGfCzs-xfkMYcSEWUC-Fon6thkJGjkh9i=13A@mail.gmail.com
2017-03-08 12:05:43 -05:00
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
Peter Eisentraut 044d9efb6c Create INSTALL file via XSLT
As before, create an INSTALL.html file for processing with lynx, but use
xsltproc and a new XSLT stylesheet instead of jade and DSSSL.

Replacing jade with xsltproc removes jade from the requirements for
distribution building.

Reviewed-by: Magnus Hagander <magnus@hagander.net>
2017-03-08 08:41:23 -05:00