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2018-12-19Doc: fix typo in "Generic File Access Functions" section.Tatsuo Ishii
Issue reported by me and fix by Tom Lane. Discussion: https://postgr.es/m/20181219.080458.1434575730369741406.t-ishii%40sraoss.co.jp
2018-12-18Update project link of pgBadger in documentationMichael Paquier
The project has moved to a new place. Reported-by: Peter Neave Discussion: https://postgr.es/m/154474118231.5066.16352227860913505754@wrigleys.postgresql.org
2018-12-17Fix tablespace handling for partitioned tablesAlvaro Herrera
When partitioned tables were introduced, we failed to realize that by copying the tablespace handling for other relation kinds with no physical storage we were causing the secondary effect that their partitions would not automatically inherit the tablespace setting. This is surprising and unhelpful, so change it to adopt the behavior introduced in pg11 (commit 33e6c34c3267) for partitioned indexes: the parent relation remembers the tablespace specification, which is then used for any new partitions that don't declare one. Because this commit changes behavior of the TABLESPACE clause for partitioned tables (it's no longer a no-op), it is not backpatched. Author: David Rowley, Álvaro Herrera Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/CAKJS1f9SxVzqDrGD1teosFd6jBMM0UEaa14_8mRvcWE19Tu0hA@mail.gmail.com
2018-12-17Clarify runtime pruning in EXPLAINAlvaro Herrera
Author: Amit Langote Reviewed-by: David Rowley Discussion: https://postgr.es/m/002dec69-9afb-b621-5630-235eceafe0bd@lab.ntt.co.jp
2018-12-14Make pg_statistic and related code account more honestly for collations.Tom Lane
When we first put in collations support, we basically punted on teaching pg_statistic, ANALYZE, and the planner selectivity functions about that. They've just used DEFAULT_COLLATION_OID independently of the actual collation of the data. It's time to improve that, so: * Add columns to pg_statistic that record the specific collation associated with each statistics slot. * Teach ANALYZE to use the column's actual collation when comparing values for statistical purposes, and record this in the appropriate slot. (Note that type-specific typanalyze functions are now expected to fill stats->stacoll with the appropriate collation, too.) * Teach assorted selectivity functions to use the actual collation of the stats they are looking at, instead of just assuming it's DEFAULT_COLLATION_OID. This should give noticeably better results in selectivity estimates for columns with nondefault collations, at least for query clauses that use that same collation (which would be the default behavior in most cases). It's still true that comparisons with explicit COLLATE clauses different from the stored data's collation won't be well-estimated, but that's no worse than before. Also, this patch does make the first step towards doing better with that, which is that it's now theoretically possible to collect stats for a collation other than the column's own collation. Patch by me; thanks to Peter Eisentraut for review. Discussion: https://postgr.es/m/14706.1544630227@sss.pgh.pa.us
2018-12-14Introduce new extended routines for FDW and foreign server lookupsMichael Paquier
The cache lookup routines for foreign-data wrappers and foreign servers are extended with an extra argument to handle a set of flags. The only value which can be used now is to indicate if a missing object should result in an error or not, and are designed to be extensible on need. Those new routines are added into the existing set of user-visible FDW APIs and documented in consequence. They will be used for future patches to improve the SQL interface for object addresses. Author: Michael Paquier Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/CAB7nPqSZxrSmdHK-rny7z8mi=EAFXJ5J-0RbzDw6aus=wB5azQ@mail.gmail.com
2018-12-11Doc: improve documentation about ALTER LARGE OBJECT requirements.Tom Lane
Unlike other ALTER ref pages, this one neglected to mention that ALTER OWNER requires being a member of the new owning role. Per bug #15546 from Stefan Kadow. Discussion: https://postgr.es/m/15546-0558c75fd2025e7c@postgresql.org
2018-12-10Doc: remove obsolete reference to recursive expression evaluation.Tom Lane
John Naylor Discussion: https://postgr.es/m/CAJVSVGUPH-0q5feP4v9b+Y8K3HGTn3bEd5KV7VbyUj-oFdSLzA@mail.gmail.com
2018-12-09Add timestamp of last received message from standby to pg_stat_replicationMichael Paquier
The timestamp generated by the standby at message transmission has been included in the protocol since its introduction for both the status update message and hot standby feedback message, but it has never appeared in pg_stat_replication. Seeing this timestamp does not matter much with a cluster which has a lot of activity, but on a mostly-idle cluster, this makes monitoring able to react faster than the configured timeouts. Author: MyungKyu LIM Reviewed-by: Michael Paquier, Masahiko Sawada Discussion: https://postgr.es/m/1657809367.407321.1533027417725.JavaMail.jboss@ep2ml404
2018-12-07Doc: document that we expect CHECK constraint conditions to be immutable.Tom Lane
This restriction is implicit in the check-only-once implementation we use for table and domain constraints, but it wasn't spelled out anywhere, nor was there any advice about how to alter a constraint's behavior safely. Improve that. I was also dissatisfied with the documentation of ALTER DOMAIN VALIDATE CONSTRAINT, which entirely failed to explain the use of that feature; and thence decided that ALTER TABLE VALIDATE CONSTRAINT could be documented better as well. Perhaps we should back-patch this, along with the related commit 36d442a25, but for now I refrained. Discussion: https://postgr.es/m/12539.1544107316@sss.pgh.pa.us
2018-12-07Doc: remove obsolete statements about system OID columns in ALTER TABLE.Tom Lane
Missed in commit 578b22971.
2018-12-07Doc: make cross-reference to format() function more specific.Tom Lane
Jeff Janes Discussion: https://postgr.es/m/CAMkU=1w7Tn2M9BhK+rt8Shtz1AkU+ty7By8gj5C==z65=U4vyQ@mail.gmail.com
2018-12-06Improve planner stats documentationStephen Frost
It was pointed out that in the planner stats documentation under Extended Statistics, one of the sentences was a bit awkward. Improve that by rewording it slightly. Discussion: https://postgr.es/m/154409976780.14137.2785644488950047100@wrigleys.postgresql.org
2018-12-06Change true/false to on/off.Tatsuo Ishii
We prefer to use on/off than true/false for boolean configuration parameters in the documentation, but there were a few places where true/false were still used. Dicussion: https://postgr.es/m/20181202.072508.618341295047874293.t-ishii%40sraoss.co.jp
2018-12-05Fix invalid value of synchronous_commit in description of flush_lagMichael Paquier
"remote_flush" has never been a valid user-facing value, but "on" is. Author: Maksim Milyutin Discussion: https://postgr.es/m/27b3b80c-3615-2d76-02c5-44566b53136c@gmail.com
2018-12-03Refactor documentation about privileges to centralize the info.Tom Lane
Expand section 5.6 "Privileges" to include the full definition of each privilege type, and an explanation of aclitem privilege displays, along with some helpful summary tables. Most of this material came out of the GRANT reference page, although some of it is new. Adjust a bunch of links that were pointing to GRANT to point to 5.6. Fabien Coelho and Tom Lane, reviewed by Bradley DeJong Discussion: https://postgr.es/m/alpine.DEB.2.21.1807311735200.20743@lancre
2018-12-03Add PGXS options to control TAP and isolation tests, take twoMichael Paquier
The following options are added for extensions: - TAP_TESTS, to allow an extention to run TAP tests which are the ones present in t/*.pl. A subset of tests can always be run with the existing PROVE_TESTS for developers. - ISOLATION, to define a list of isolation tests. - ISOLATION_OPTS, to pass custom options to isolation_tester. A couple of custom Makefile rules have been accumulated across the tree to cover the lack of facility in PGXS for a couple of releases when using those test suites, which are all now replaced with the new flags, without reducing the test coverage. Note that tests of contrib/bloom/ are not enabled yet, as those are proving unstable in the buildfarm. Author: Michael Paquier Reviewed-by: Adam Berlin, Álvaro Herrera, Tom Lane, Nikolay Shaplov, Arthur Zakirov Discussion: https://postgr.es/m/20180906014849.GG2726@paquier.xyz
2018-12-01Add a --socketdir option to pg_upgrade.Tom Lane
This allows control of the directory in which the postmaster sockets are created for the temporary postmasters started by pg_upgrade. The default location remains the current working directory, which is typically fine, but if it is deeply nested then its pathname might be too long to be a socket name. In passing, clean up some messiness in pg_upgrade's option handling, particularly the confusing and undocumented way that configuration-only datadirs were handled. And fix check_required_directory's substantially under-baked cleanup of directory pathnames. Daniel Gustafsson, reviewed by Hironobu Suzuki, some code cleanup by me Discussion: https://postgr.es/m/E72DD5C3-2268-48A5-A907-ED4B34BEC223@yesql.se
2018-11-29Document handling of invalid/ambiguous timestamp input near DST boundaries.Tom Lane
The source code comments documented this, but the user-facing docs, not so much. Add a section to Appendix B that discusses it. In passing, improve a couple other things in Appendix B --- notably, a long-obsolete claim that time zone abbreviations are looked up in a fixed table. Per bug #15527 from Michael Davidson. Discussion: https://postgr.es/m/15527-f1be0b4dc99ebbe7@postgresql.org
2018-11-29Add log_statement_sample_rate parameterAlvaro Herrera
This allows to set a lower log_min_duration_statement value without incurring excessive log traffic (which reduces performance). This can be useful to analyze workloads with lots of short queries. Author: Adrien Nayrat Reviewed-by: David Rowley, Vik Fearing Discussion: https://postgr.es/m/c30ee535-ee1e-db9f-fa97-146b9f62caed@anayrat.info
2018-11-29doc: Add appendix detailing some limits of PostgreSQLPeter Eisentraut
This used to be on the web site but was removed. The documentation is a better place for it anyway. Author: David Rowley <david.rowley@2ndquadrant.com> Reviewed-by: John Naylor <jcnaylor@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CAKJS1f_dKdejdKB94nKZC9S5NzB-UZRcAKkE84e=JEEecDuotg@mail.gmail.com/
2018-11-29Add pg_partition_tree to documentation indexMichael Paquier
This fixes an oversight from d5eec4ee. Author: Michael Paquier Reviewed-by: Amit Langote Discussion: https://postgr.es/m/20181129072719.GC9004@paquier.xyz
2018-11-28Only allow one recovery target settingPeter Eisentraut
The previous recovery.conf regime accepted multiple recovery_target* settings and used the last one. This does not translate well to the general GUC system. Specifically, under EXEC_BACKEND, the settings are written out not in any particular order, so the order in which they were originally set is not available to new processes. Rather than redesign the GUC system, it was decided to abandon the old behavior and only allow one recovery target setting. A second setting will cause an error. However, it is allowed to set the same parameter multiple times or unset a parameter and set a different one. Discussion: https://www.postgresql.org/message-id/flat/27802171543235530%40iva2-6ec8f0a6115e.qloud-c.yandex.net#701a59c837ad0bf8c244344aaf3ef5a4
2018-11-26doc: fix wording for plpgsql, add "and"Bruce Momjian
Reported-by: Anthony Greene Discussion: https://postgr.es/m/CAPRNmnsSZ4QL75FUjcS8ND_oV+WjgyPbZ4ch2RUwmW6PWzF38w@mail.gmail.com Backpatch-through: 9.4
2018-11-26Fix typo introduced in 578b229718.Andres Freund
Author: Andreas Karlsson Discussion: https://postgr.es/m/0917c86f-e906-27c0-740e-abc581480823@proxel.se
2018-11-26Fix sample output for hash_metapage_info queryAlvaro Herrera
One output column was duplicated. Couldn't resist fixing the version number while at it. Reported-by: Gianni Ciolli
2018-11-26Add CSV table output mode in psql.Tom Lane
"\pset format csv", or --csv, selects comma-separated values table format. This is compliant with RFC 4180, except that we aren't too picky about whether the record separator is LF or CRLF; also, the user may choose a field separator other than comma. This output format is directly compatible with the server's COPY CSV format, and will also be useful as input to other programs. It's considerably safer for that purpose than the old recommendation to use "unaligned" format, since the latter couldn't handle data containing the field separator character. Daniel Vérité, reviewed by Fabien Coelho and David Fetter, some tweaking by me Discussion: https://postgr.es/m/a8de371e-006f-4f92-ab72-2bbe3ee78f03@manitou-mail.org
2018-11-26Clarify that cross-row constraints are unsupportedAlvaro Herrera
Maybe we'll implement them later, or maybe not, but let's make the statu quo clear for now. Author: Lætitia Avrot, Patrick Francelle Reviewers: too many to list Discussion: https://postgr.es/m/CAB_COdhUuzNFOJfc7SNNso5rOuVA3ui93KMVunEM8Yih+K5A6A@mail.gmail.com
2018-11-26Revert "Fix typo in documentation of toast storage"Michael Paquier
This reverts commit 058ef3a, per complains from Magnus Hagander and Vik Fearing.
2018-11-26Fix typo in documentation of toast storageMichael Paquier
Author: Nawaz Ahmed Discussion: https://postgr.es/m/154319327168.1315.1846953598601966513@wrigleys.postgresql.org
2018-11-26Revert all new recent changes to add PGXS options for TAP and isolationMichael Paquier
A set of failures in buildfarm machines are proving that this is not quite ready yet because of another set of issues: - MSVC scripts assume that REGRESS_OPTS can only use top_builddir. Some test suites actually finish by using top_srcdir, like pg_stat_statements which cause the regression tests to never run. - Trying to enforce top_builddir does not work either when using VPATH as this is not recognized properly. - TAP tests of bloom are unstable on various platforms, causing various failures.
2018-11-26Add PGXS options to control TAP and isolation testsMichael Paquier
The following options are added for extensions: - TAP_TESTS, to allow an extention to run TAP tests which are the ones present in t/*.pl. A subset of tests can always be run with the existing PROVE_TESTS for developers. - ISOLATION, to define a list of isolation tests. - ISOLATION_OPTS, to pass custom options to isolation_tester. A couple of custom Makefile targets have been accumulated across the tree to cover the lack of facility in PGXS for a couple of releases when using those test suites, which are all now replaced with the new flags, without reducing the test coverage. This also fixes an issue with contrib/bloom/, which had a custom target to trigger its TAP tests of its own not part of the main check runs. Author: Michael Paquier Reviewed-by: Adam Berlin, Álvaro Herrera, Tom Lane, Nikolay Shaplov, Arthur Zakirov Discussion: https://postgr.es/m/20180906014849.GG2726@paquier.xyz
2018-11-25Integrate recovery.conf into postgresql.confPeter Eisentraut
recovery.conf settings are now set in postgresql.conf (or other GUC sources). Currently, all the affected settings are PGC_POSTMASTER; this could be refined in the future case by case. Recovery is now initiated by a file recovery.signal. Standby mode is initiated by a file standby.signal. The standby_mode setting is gone. If a recovery.conf file is found, an error is issued. The trigger_file setting has been renamed to promote_trigger_file as part of the move. The documentation chapter "Recovery Configuration" has been integrated into "Server Configuration". pg_basebackup -R now appends settings to postgresql.auto.conf and creates a standby.signal file. Author: Fujii Masao <masao.fujii@gmail.com> Author: Simon Riggs <simon@2ndquadrant.com> Author: Abhijit Menon-Sen <ams@2ndquadrant.com> Author: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
2018-11-23doc: Fix typoPeter Eisentraut
2018-11-23Clarify documentation about PASSWORD in CREATE/ALTER ROLEMichael Paquier
The documentation of CREATE/ALTER ROLE has been missing two things related to PASSWORD: - The password value provided needs to be quoted, some places of the documentation marked the field with quotes, but not others, which led to confusion. - PASSWORD NULL was not provided consistently, with ENCRYPTED being not compatible with it. Reported-by: Steven Winfield Author: Michael Paquier Reviewed-by: David G. Johnston Discussion: https://postgr.es/m/154282901979.1316.7418475422120496802@wrigleys.postgresql.org
2018-11-22Doc: rework introductory documentation about covering indexes.Tom Lane
Documenting INCLUDE in the section about unique indexes is confusing, as complained of by Emilio Platzer. Furthermore, it entirely failed to explain why you might want to use the feature. The section about index-only scans is really the right place; it already talked about making such things the hard way. Rewrite that text to describe INCLUDE as the normal way to make a covering index. Also, move that section up a couple of places, as it now seems more important than some of the stuff we had before it. It still has to be after expression and partial indexes, since otherwise some of it would involve forward references. Discussion: https://postgr.es/m/154031939560.30897.14677735588262722042@wrigleys.postgresql.org
2018-11-21doc: adjust time zone names text, v2Bruce Momjian
Removed one too many words. Fix for 7906de847f229f391b9e6b5892b4b4a89f29edb4. Reported-by: Thomas Munro Backpatch-through: 9.4
2018-11-21doc: adjust time zone names textBruce Momjian
Reported-by: Kevin <kcolagio@gmail.com> Discussion: https://postgr.es/m/154082462281.30897.14043119084654378035@wrigleys.postgresql.org Backpatch-through: 9.4
2018-11-20Remove WITH OIDS support, change oid catalog column visibility.Andres Freund
Previously tables declared WITH OIDS, including a significant fraction of the catalog tables, stored the oid column not as a normal column, but as part of the tuple header. This special column was not shown by default, which was somewhat odd, as it's often (consider e.g. pg_class.oid) one of the more important parts of a row. Neither pg_dump nor COPY included the contents of the oid column by default. The fact that the oid column was not an ordinary column necessitated a significant amount of special case code to support oid columns. That already was painful for the existing, but upcoming work aiming to make table storage pluggable, would have required expanding and duplicating that "specialness" significantly. WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0). Remove it. Removing includes: - CREATE TABLE and ALTER TABLE syntax for declaring the table to be WITH OIDS has been removed (WITH (oids[ = true]) will error out) - pg_dump does not support dumping tables declared WITH OIDS and will issue a warning when dumping one (and ignore the oid column). - restoring an pg_dump archive with pg_restore will warn when restoring a table with oid contents (and ignore the oid column) - COPY will refuse to load binary dump that includes oids. - pg_upgrade will error out when encountering tables declared WITH OIDS, they have to be altered to remove the oid column first. - Functionality to access the oid of the last inserted row (like plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed. The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false) for CREATE TABLE) is still supported. While that requires a bit of support code, it seems unnecessary to break applications / dumps that do not use oids, and are explicit about not using them. The biggest user of WITH OID columns was postgres' catalog. This commit changes all 'magic' oid columns to be columns that are normally declared and stored. To reduce unnecessary query breakage all the newly added columns are still named 'oid', even if a table's column naming scheme would indicate 'reloid' or such. This obviously requires adapting a lot code, mostly replacing oid access via HeapTupleGetOid() with access to the underlying Form_pg_*->oid column. The bootstrap process now assigns oids for all oid columns in genbki.pl that do not have an explicit value (starting at the largest oid previously used), only oids assigned later by oids will be above FirstBootstrapObjectId. As the oid column now is a normal column the special bootstrap syntax for oids has been removed. Oids are not automatically assigned during insertion anymore, all backend code explicitly assigns oids with GetNewOidWithIndex(). For the rare case that insertions into the catalog via SQL are called for the new pg_nextoid() function can be used (which only works on catalog tables). The fact that oid columns on system tables are now normal columns means that they will be included in the set of columns expanded by * (i.e. SELECT * FROM pg_class will now include the table's oid, previously it did not). It'd not technically be hard to hide oid column by default, but that'd mean confusing behavior would either have to be carried forward forever, or it'd cause breakage down the line. While it's not unlikely that further adjustments are needed, the scope/invasiveness of the patch makes it worthwhile to get merge this now. It's painful to maintain externally, too complicated to commit after the code code freeze, and a dependency of a number of other patches. Catversion bump, for obvious reasons. Author: Andres Freund, with contributions by John Naylor Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
2018-11-20Add settings to control SSL/TLS protocol versionPeter Eisentraut
For example: ssl_min_protocol_version = 'TLSv1.1' ssl_max_protocol_version = 'TLSv1.2' Reviewed-by: Steve Singer <steve@ssinger.info> Discussion: https://www.postgresql.org/message-id/flat/1822da87-b862-041a-9fc2-d0310c3da173@2ndquadrant.com
2018-11-20doc: Clarify CREATE TYPE ENUM documentationPeter Eisentraut
The documentation claimed that an enum type requires "one or more" labels, but since 1fd9883ff49, zero labels are also allowed. Reported-by: Lukas Eder <lukas.eder@gmail.com> Bug: #15356
2018-11-19psql: Show IP address in \conninfoAlvaro Herrera
When hostaddr is given, the actual IP address that psql is connected to can be totally unexpected for the given host. The more verbose output we now generate makes things clearer. Since the "host" and "hostaddr" parts of the conninfo could come from different sources (say, one of them is in the service specification or a URI-style conninfo and the other is not), this is not as silly as it may first appear. This is also definitely useful if the hostname resolves to multiple addresses. Author: Fabien Coelho Reviewed-by: Pavel Stehule, Arthur Zakirov Discussion: https://postgr.es/m/alpine.DEB.2.21.1810261532380.27686@lancre https://postgr.es/m/alpine.DEB.2.21.1808201323020.13832@lancre
2018-11-19Disallow COPY FREEZE on partitioned tablesAlvaro Herrera
This didn't actually work: COPY would fail to flush the right files, and instead would try to flush a non-existing file, causing the whole transaction to fail. Cope by raising an error as soon as the command is sent instead, to avoid a nasty later surprise. Of course, it would be much better to make it work, but we don't have a patch for that yet, and we don't know if we'll want to backpatch one when we do. Reported-by: Tomas Vondra Author: David Rowley Reviewed-by: Amit Langote, Steve Singer, Tomas Vondra
2018-11-19PANIC on fsync() failure.Thomas Munro
On some operating systems, it doesn't make sense to retry fsync(), because dirty data cached by the kernel may have been dropped on write-back failure. In that case the only remaining copy of the data is in the WAL. A subsequent fsync() could appear to succeed, but not have flushed the data. That means that a future checkpoint could apparently complete successfully but have lost data. Therefore, violently prevent any future checkpoint attempts by panicking on the first fsync() failure. Note that we already did the same for WAL data; this change extends that behavior to non-temporary data files. Provide a GUC data_sync_retry to control this new behavior, for users of operating systems that don't eject dirty data, and possibly forensic/testing uses. If it is set to on and the write-back error was transient, a later checkpoint might genuinely succeed (on a system that does not throw away buffers on failure); if the error is permanent, later checkpoints will continue to fail. The GUC defaults to off, meaning that we panic. Back-patch to all supported releases. There is still a narrow window for error-loss on some operating systems: if the file is closed and later reopened and a write-back error occurs in the intervening time, but the inode has the bad luck to be evicted due to memory pressure before we reopen, we could miss the error. A later patch will address that with a scheme for keeping files with dirty data open at all times, but we judge that to be too complicated to back-patch. Author: Craig Ringer, with some adjustments by Thomas Munro Reported-by: Craig Ringer Reviewed-by: Robert Haas, Thomas Munro, Andres Freund Discussion: https://postgr.es/m/20180427222842.in2e4mibx45zdth5%40alap3.anarazel.de
2018-11-19Rework documentation of pg_promoteMichael Paquier
This clarifies the behavior of how the "wait" flag works, which is something that the previous version of the documentation failed to do. Author: Ian Barwick Discussion: https://postgr.es/m/cbd38450-2295-10a1-1f73-591a692ae0b0@2ndquadrant.com
2018-11-15Fix the omission in docs.Amit Kapila
Commit 5373bc2a08 has added type for background workers but forgot to update at one place in the documentation. Reported-by: John Naylor Author: John Naylor Reviewed-by: Amit Kapila Backpatch-through: 11 Discussion: https://postgr.es/m/CAJVSVGVmvgJ8Lq4WBxC3zV5wf0txdCqRSgkWVP+jaBF=HgWscA@mail.gmail.com
2018-11-14Doc: remove claim that all \pset format options are unique in 1 letter.Tom Lane
This hasn't been correct since 9.3 added "latex-longtable". I left the phraseology "Unique abbreviations are allowed" alone. It's correct as far as it goes, and we are studiously refraining from specifying exactly what happens if you give a non-unique abbreviation. (The answer in the back branches is "you get a backwards-compatible choice", and the answer in HEAD will shortly be "you get an error", but there seems no need to mention such details here.) Daniel Vérité Discussion: https://postgr.es/m/cb7e1caf-3ea6-450d-af28-f524903a030c@manitou-mail.org
2018-11-14Add a timezone-specific variant of date_trunc().Tom Lane
date_trunc(field, timestamptz, zone_name) performs truncation using the named time zone as reference, rather than working in the session time zone as is the default behavior. It's equivalent to date_trunc(field, timestamptz at time zone zone_name) at time zone zone_name but it's faster, easier to type, and arguably easier to understand. Vik Fearing and Tom Lane Discussion: https://postgr.es/m/6249ffc4-2b22-4c1b-4e7d-7af84fedd7c6@2ndquadrant.com
2018-11-14Lower lock level for renaming indexesPeter Eisentraut
Change lock level for renaming index (either ALTER INDEX or implicitly via some other commands) from AccessExclusiveLock to ShareUpdateExclusiveLock. One reason we need a strong lock for relation renaming is that the name change causes a rebuild of the relcache entry. Concurrent sessions that have the relation open might not be able to handle the relcache entry changing underneath them. Therefore, we need to lock the relation in a way that no one can have the relation open concurrently. But for indexes, the relcache handles reloads specially in RelationReloadIndexInfo() in a way that keeps changes in the relcache entry to a minimum. As long as no one keeps pointers to rd_amcache and rd_options around across possible relcache flushes, which is the case, this ought to be safe. We also want to use a self-exclusive lock for correctness, so that concurrent DDL doesn't overwrite the rename if they start updating while still seeing the old version. Therefore, we use ShareUpdateExclusiveLock, which is already used by other DDL commands that want to operate in a concurrent manner. The reason this is interesting at all is that renaming an index is a typical part of a concurrent reindexing workflow (CREATE INDEX CONCURRENTLY new + DROP INDEX CONCURRENTLY old + rename back). And indeed a future built-in REINDEX CONCURRENTLY might rely on the ability to do concurrent renames as well. Reviewed-by: Andrey Klychkov <aaklychkov@mail.ru> Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/1531767486.432607658@f357.i.mail.ru
2018-11-13doc: Fix minor whitespace issuePeter Eisentraut
Reported-by: David G. Johnston <david.g.johnston@gmail.com>