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* Remove bogus restriction from BEFORE UPDATE triggersAlvaro Herrera2021-01-28
| | | | | | | | | | | | | | | | | | | | | | In trying to protect the user from inconsistent behavior, commit 487e9861d0cf "Enable BEFORE row-level triggers for partitioned tables" tried to prevent BEFORE UPDATE FOR EACH ROW triggers from moving the row from one partition to another. However, it turns out that the restriction is wrong in two ways: first, it fails spuriously, preventing valid situations from working, as in bug #16794; and second, they don't protect from any misbehavior, because tuple routing would cope anyway. Fix by removing that restriction. We keep the same restriction on BEFORE INSERT FOR EACH ROW triggers, though. It is valid and useful there. In the future we could remove it by having tuple reroute work for inserts as it does for updates. Backpatch to 13. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reported-by: Phillip Menke <pg@pmenke.de> Discussion: https://postgr.es/m/16794-350a655580fbb9ae@postgresql.org
* Remove gratuitous uses of deprecated SELECT INTOPeter Eisentraut2021-01-28
| | | | | | | | | | CREATE TABLE AS has been preferred over SELECT INTO (outside of ecpg and PL/pgSQL) for a long time. There were still a few uses of SELECT INTO in tests and documentation, some old, some more recent. This changes them to CREATE TABLE AS. Some occurrences in the tests remain where they are specifically testing SELECT INTO parsing or similar. Discussion: https://www.postgresql.org/message-id/flat/96dc0df3-e13a-a85d-d045-d6e2c85218da%40enterprisedb.com
* Reduce the default value of vacuum_cost_page_miss.Peter Geoghegan2021-01-27
| | | | | | | | | | | | | | | | | | | | | | | | | When commit f425b605 introduced cost based vacuum delays back in 2004, the defaults reflected then-current trends in hardware, as well as certain historical limitations in PostgreSQL. There have been enormous improvements in both areas since that time. The cost limit GUC defaults finally became much more representative of current trends following commit cbccac37, which decreased autovacuum_vacuum_cost_delay's default by 10x for PostgreSQL 12 (it went from 20ms to only 2ms). The relative costs have shifted too. This should also be accounted for by the defaults. More specifically, the relative importance of avoiding dirtying pages within VACUUM has greatly increased, primarily due to main memory capacity scaling and trends in flash storage. Within Postgres itself, improvements like sequential access during index vacuuming (at least in nbtree and GiST indexes) have also been contributing factors. To reflect all this, decrease the default of vacuum_cost_page_miss to 2. Since the default of vacuum_cost_page_dirty remains 20, dirtying a page is now considered 10x "costlier" than a page miss by default. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-WzmLPFnkWT8xMjmcsm7YS3+_Qi3iRWAb2+_Bc8UhVyHfuA@mail.gmail.com
* Doc: improve documentation for UNNEST().Tom Lane2021-01-27
| | | | | | | | | | | | | | Per a user question, spell out that UNNEST() returns array elements in storage order; also provide an example to clarify the behavior for multi-dimensional arrays. While here, also clarify the SELECT reference page's description of WITH ORDINALITY. These details were already given in 7.2.1.4, but a reference page should not omit details. Back-patch to v13; there's not room in the table in older versions. Discussion: https://postgr.es/m/FF1FB31F-0507-4F18-9559-2DE6E07E3B43@gmail.com
* doc: Remove reference to views for TRUNCATE privilegeMichael Paquier2021-01-27
| | | | | | | | | | | | | The page about privilege rights mentioned that TRUNCATE could be applied to views or even other relation types. This is confusing as this command can be used only on tables and on partitioned tables. Oversight in afc4a78. Reported-by: Harisai Hari Reviewed-by: Laurenz Albe Discussion: https://postgr.es/m/161157636877.14625.15340884663716426087@wrigleys.postgresql.org Backpatch-through: 12
* Rethink recently-added SPI interfaces.Tom Lane2021-01-26
| | | | | | | | | | | | | | SPI_execute_with_receiver and SPI_cursor_parse_open_with_paramlist are new in v14 (cf. commit 2f48ede08). Before they can get out the door, let's change their APIs to follow the practice recently established by SPI_prepare_extended etc: shove all optional arguments into a struct that callers are supposed to pre-zero. The hope is to allow future addition of more options without either API breakage or a continuing proliferation of new SPI entry points. With that in mind, choose slightly more generic names for them: SPI_execute_extended and SPI_cursor_parse_open respectively. Discussion: https://postgr.es/m/CAFj8pRCLPdDAETvR7Po7gC5y_ibkn_-bOzbeJb39WHms01194Q@mail.gmail.com
* postgres_fdw: Add functions to discard cached connections.Fujii Masao2021-01-26
| | | | | | | | | | | | | | | | | This commit introduces two new functions postgres_fdw_disconnect() and postgres_fdw_disconnect_all(). The former function discards the cached connections to the specified foreign server. The latter discards all the cached connections. If the connection is used in the current transaction, it's not closed and a warning message is emitted. For example, these functions are useful when users want to explicitly close the foreign server connections that are no longer necessary and then to prevent them from eating up the foreign servers connections capacity. Author: Bharath Rupireddy, tweaked a bit by Fujii Masao Reviewed-by: Alexey Kondratov, Zhijie Hou, Zhihong Yu, Fujii Masao Discussion: https://postgr.es/m/CALj2ACVvrp5=AVp2PupEm+nAC8S4buqR3fJMmaCoc7ftT0aD2A@mail.gmail.com
* Improve performance of repeated CALLs within plpgsql procedures.Tom Lane2021-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch essentially is cleaning up technical debt left behind by the original implementation of plpgsql procedures, particularly commit d92bc83c4. That patch (or more precisely, follow-on patches fixing its worst bugs) forced us to re-plan CALL and DO statements each time through, if we're in a non-atomic context. That wasn't for any fundamental reason, but just because use of a saved plan requires having a ResourceOwner to hold a reference count for the plan, and we had no suitable resowner at hand, nor would the available APIs support using one if we did. While it's not that expensive to create a "plan" for CALL/DO, the cycles do add up in repeated executions. This patch therefore makes the following API changes: * GetCachedPlan/ReleaseCachedPlan are modified to let the caller specify which resowner to use to pin the plan, rather than forcing use of CurrentResourceOwner. * spi.c gains a "SPI_execute_plan_extended" entry point that lets callers say which resowner to use to pin the plan. This borrows the idea of an options struct from the recently added SPI_prepare_extended, hopefully allowing future options to be added without more API breaks. This supersedes SPI_execute_plan_with_paramlist (which I've marked deprecated) as well as SPI_execute_plan_with_receiver (which is new in v14, so I just took it out altogether). * I also took the opportunity to remove the crude hack of letting plpgsql reach into SPI private data structures to mark SPI plans as "no_snapshot". It's better to treat that as an option of SPI_prepare_extended. Now, when running a non-atomic procedure or DO block that contains any CALL or DO commands, plpgsql creates a ResourceOwner that will be used to pin the plans of the CALL/DO commands. (In an atomic context, we just use CurrentResourceOwner, as before.) Having done this, we can just save CALL/DO plans normally, whether or not they are used across transaction boundaries. This seems to be good for something like 2X speedup of a CALL of a trivial procedure with a few simple argument expressions. By restricting the creation of an extra ResourceOwner like this, there's essentially zero penalty in cases that can't benefit. Pavel Stehule, with some further hacking by me Discussion: https://postgr.es/m/CAFj8pRCLPdDAETvR7Po7gC5y_ibkn_-bOzbeJb39WHms01194Q@mail.gmail.com
* Remove CheckpointLock.Robert Haas2021-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up until now, we've held this lock when performing a checkpoint or restartpoint, but commit 076a055acf3c55314de267c62b03191586d79cf6 back in 2004 and commit 7e48b77b1cebb9a43f9fdd6b17128a0ba36132f9 from 2009, taken together, have removed all need for this. In the present code, there's only ever one process entitled to attempt a checkpoint: either the checkpointer, during normal operation, or the postmaster, during single-user operation. So, we don't need the lock. One possible concern in making this change is that it means that a substantial amount of code where HOLD_INTERRUPTS() was previously in effect due to the preceding LWLockAcquire() will now be running without that. This could mean that ProcessInterrupts() gets called in places from which it didn't before. However, this seems unlikely to do very much, because the checkpointer doesn't have any signal mapped to die(), so it's not clear how, for example, ProcDiePending = true could happen in the first place. Similarly with ClientConnectionLost and recovery conflicts. Also, if there are any such problems, we might want to fix them rather than reverting this, since running lots of code with interrupt handling suspended is generally bad. Patch by me, per an inquiry by Amul Sul. Review by Tom Lane and Michael Paquier. Discussion: http://postgr.es/m/CAAJ_b97XnBBfYeSREDJorFsyoD1sHgqnNuCi=02mNQBUMnA=FA@mail.gmail.com
* Doc: improve documentation of pg_proc.protrftypes.Tom Lane2021-01-25
| | | | | | | | | Add a "references" link pointing to pg_type, as we have for other arrays of type OIDs. Wordsmith the explanation a bit. Joel Jacobson, additional editing by me Discussion: https://postgr.es/m/d1cc628c-3953-4209-957b-29427acc38c8@www.fastmail.com
* Doc: clean up contrib/pageinspect's GIST function documentation.Tom Lane2021-01-23
| | | | | I came to fix the overwidth-PDF-page warnings seen in the buildfarm, but stayed long enough to copy-edit some nearby text.
* Doc: update example connection-failure messages in the documentation.Tom Lane2021-01-23
| | | | | Now that the dust has more or less settled on 52a10224e and follow-ons, make sure the examples in the documentation are up-to-date.
* Doc: improve directions for building on macOS.Tom Lane2021-01-22
| | | | | | | | | | | | | | In light of recent discussions, we should instruct people to install Apple's command line tools; installing Xcode is secondary. Also, fix sample command for finding out the default sysroot, as we now know that the command originally recommended can give a result that doesn't match your OS version. Also document the workaround to use if you really don't want configure to select a sysroot at all. Discussion: https://postgr.es/m/20210119111625.20435-1-james.hilliard1@gmail.com
* Avoid redundantly prefixing PQerrorMessage for a connection failure.Tom Lane2021-01-22
| | | | | | | | | | | | | libpq's error messages for connection failures pretty well stand on their own, especially since commits 52a10224e/27a48e5a1. Prefixing them with 'could not connect to database "foo"' or the like is just redundant, and perhaps even misleading if the specific database name isn't relevant to the failure. (When it is, we trust that the backend's error message will include the DB name.) Indeed, psql hasn't used any such prefix in a long time. So, make all our other programs and documentation examples agree with psql's practice. Discussion: https://postgr.es/m/1094524.1611266589@sss.pgh.pa.us
* Re-allow DISTINCT in pl/pgsql expressions.Tom Lane2021-01-22
| | | | | | | | | | | | | | | I'd omitted this from the grammar in commit c9d529848, figuring that it wasn't worth supporting. However we already have one complaint, so it seems that judgment was wrong. It doesn't require a huge amount of code, so add it back. (I'm still drawing the line at UNION/INTERSECT/EXCEPT though: those'd require an unreasonable amount of grammar refactoring, and the single-result-row restriction makes them near useless anyway.) Also rethink the documentation: this behavior is a property of all pl/pgsql expressions, not just assignments. Discussion: https://postgr.es/m/20210122134106.e94c5cd7@mail.verfriemelt.org
* Doc: remove misleading claim in documentation of PQreset().Tom Lane2021-01-22
| | | | | | | | | | This text claimed that the reconnection would occur "to the same server", but there is no such guarantee in the code, nor would insisting on that be an improvement. Back-patch to v10 where multi-host connection strings were added. Discussion: https://postgr.es/m/1095901.1611268376@sss.pgh.pa.us
* Remove reference to ftp servers from documentationMagnus Hagander2021-01-22
| | | | | | | | It's been a long time since we used ftp, but there was a single reference left in the docs. Author: Daniel Gustafsson <daniel@yesql.se> Discussion: https://postgr.es/m/6880D602-7286-46EC-8A03-14E3248FEC7A@yesql.se
* doc: Copy-edit the "Overview of PostgreSQL Internals" chapterHeikki Linnakangas2021-01-22
| | | | | | | | | | | | | | Rephrase a few sentences to be more concise. Refer to the postmaster process as "postmaster", not "postgres". This originally said "postmaster process", but was changed to "postgres process" in commit 5266f221a2, when we merged the "postmaster" and "postgres" commands, and "postmaster" became just a symlink. That was a case of overzealous search & replace, because the process is still called "postmaster". Author: Erik Rijkers and Jürgen Purtz Discussion: https://www.postgresql.org/message-id/aa31f359-1168-ded5-53d0-0ed228bfe097%40iki.fi
* Implement support for bulk inserts in postgres_fdwTomas Vondra2021-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Extends the FDW API to allow batching inserts into foreign tables. That is usually much more efficient than inserting individual rows, due to high latency for each round-trip to the foreign server. It was possible to implement something similar in the regular FDW API, but it was inconvenient and there were issues with reporting the number of actually inserted rows etc. This extends the FDW API with two new functions: * GetForeignModifyBatchSize - allows the FDW picking optimal batch size * ExecForeignBatchInsert - inserts a batch of rows at once Currently, only INSERT queries support batching. Support for DELETE and UPDATE may be added in the future. This also implements batching for postgres_fdw. The batch size may be specified using "batch_size" option both at the server and table level. The initial patch version was written by me, but it was rewritten and improved in many ways by Takayuki Tsunakawa. Author: Takayuki Tsunakawa Reviewed-by: Tomas Vondra, Amit Langote Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* psql \dX: list extended statistics objectsTomas Vondra2021-01-20
| | | | | | | | | | | | | | The new command lists extended statistics objects. All past releases with extended statistics are supported. This is a simplified version of commit 891a1d0bca, which had to be reverted due to not considering pg_statistic_ext_data is not accessible by regular users. Fields requiring access to this catalog were removed. It's possible to add them, but it'll require changes to core. Author: Tatsuro Yamada Reviewed-by: Julien Rouhaud, Alvaro Herrera, Tomas Vondra, Noriyoshi Shinoda Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
* Fix sample output of EXPLAIN ANALYZE.Thomas Munro2021-01-20
| | | | | | | | | | Since commit f0f13a3a08b2757997410f3a1c38bdc22973c525, we estimate ModifyTable paths without a RETURNING clause differently. Update an example from the manual that showed the old behavior. Author: Takayuki Tsunakawa <tsunakawa.takay@fujitsu.com> Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at> Discussion: https://postgr.es/m/TYAPR01MB29905674F41693BBA9DA28CAFEA20%40TYAPR01MB2990.jpnprd01.prod.outlook.com
* pageinspect: Change block number arguments to bigintPeter Eisentraut2021-01-19
| | | | | | | | | | | | | | | | | | | | | | Block numbers are 32-bit unsigned integers. Therefore, the smallest SQL integer type that they can fit in is bigint. However, in the pageinspect module, most input and output parameters dealing with block numbers were declared as int. The behavior with block numbers larger than a signed 32-bit integer was therefore dubious. Change these arguments to type bigint and add some more explicit error checking on the block range. (Other contrib modules appear to do this correctly already.) Since we are changing argument types of existing functions, in order to not misbehave if the binary is updated before the extension is updated, we need to create new C symbols for the entry points, similar to how it's done in other extensions as well. Reported-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/d8f6bdd536df403b9b33816e9f7e0b9d@G08CNEXMBPEKD05.g08.fujitsu.local
* doc: Add note about the server name of postgres_fdw_get_connections() returns.Fujii Masao2021-01-19
| | | | | | | | | | | | | | Previously the document didn't mention the case where postgres_fdw_get_connections() returns NULL in server_name column. Users might be confused about why NULL was returned. This commit adds the note that, in postgres_fdw_get_connections(), the server name of an invalid connection will be NULL if the server is dropped. Suggested-by: Zhijie Hou Author: Bharath Rupireddy Reviewed-by: Zhijie Hou, Fujii Masao Discussion: https://postgr.es/m/e7ddd14e96444fce88e47a709c196537@G08CNEXMBPEKD05.g08.fujitsu.local
* doc: adjust alignment of doc file list for "pg_waldump.sgml"Bruce Momjian2021-01-18
| | | | Backpatch-through: 10
* Add bytea equivalents of ltrim() and rtrim().Tom Lane2021-01-18
| | | | | | | | We had bytea btrim() already, but for some reason not the other two. Joel Jacobson Discussion: https://postgr.es/m/d10cd5cd-a901-42f1-b832-763ac6f7ff3a@www.fastmail.com
* Pause recovery for insufficient parameter settingsPeter Eisentraut2021-01-18
| | | | | | | | | | | | | | | | | | When certain parameters are changed on a physical replication primary, this is communicated to standbys using the XLOG_PARAMETER_CHANGE WAL record. The standby then checks whether its own settings are at least as big as the ones on the primary. If not, the standby shuts down with a fatal error. This patch changes this behavior for hot standbys to pause recovery at that point instead. That allows read traffic on the standby to continue while database administrators figure out next steps. When recovery is unpaused, the server shuts down (as before). The idea is to fix the parameters while recovery is paused and then restart when there is a maintenance window. Reviewed-by: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/4ad69a4c-cc9b-0dfe-0352-8b1b0cd36c7b@2ndquadrant.com
* postgres_fdw: Add function to list cached connections to foreign servers.Fujii Masao2021-01-18
| | | | | | | | | | | | | | | | | | This commit adds function postgres_fdw_get_connections() to return the foreign server names of all the open connections that postgres_fdw established from the local session to the foreign servers. This function also returns whether each connection is valid or not. This function is useful when checking all the open foreign server connections. If we found some connection to drop, from the result of function, probably we can explicitly close them by the function that upcoming commit will add. This commit bumps the version of postgres_fdw to 1.1 since it adds new function. Author: Bharath Rupireddy, tweaked by Fujii Masao Reviewed-by: Zhijie Hou, Alexey Kondratov, Zhihong Yu, Fujii Masao Discussion: https://postgr.es/m/2d5cb0b3-a6e8-9bbb-953f-879f47128faa@oss.nttdata.com
* Add documentation chapter about checksumsMagnus Hagander2021-01-17
| | | | | | | | | | | | Data checksums did not have a longer discussion in the docs, this adds a short section with an overview. Extracted from the larger patch for on-line enabling of checksums, which has many more authors and reviewers. Author: Daniel Gustafsson Reviewed-By: Magnus Hagander, Michael Banck (and others through the big patch) Discussion: https://postgr.es/m/5ff49fa4.1c69fb81.658f3.04ac@mx.google.com
* Revert "psql \dX: list extended statistics objects"Tomas Vondra2021-01-17
| | | | | | | | | Reverts 891a1d0bca, because the new psql command \dX only worked for users users who can read pg_statistic_ext_data catalog, and most regular users lack that privilege (the catalog may contain sensitive user data). Reported-by: Noriyoshi Shinoda Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
* Add --no-instructions parameter to initdbMagnus Hagander2021-01-17
| | | | | | | | | | | | Specifying this parameter removes the informational messages about how to start the server. This is intended for use by wrappers in different packaging systems, where those instructions would most likely be wrong anyway, but the other output from initdb would still be useful (and thus just redirecting everything to /dev/null would be bad). Author: Magnus Hagander Reviewed-By: Peter Eisentraut Discusion: https://postgr.es/m/CABUevEzo4t5bmTXF0_B9WzmuWpVbMpkNZZiGvzV8NZa-=fPqeQ@mail.gmail.com
* Add pg_stat_database counters for sessions and session timeMagnus Hagander2021-01-17
| | | | | | | | | | | | | | | This add counters for number of sessions, the different kind of session termination types, and timers for how much time is spent in active vs idle in a database to pg_stat_database. Internally this also renames the parameter "force" to disconnect. This was the only use-case for the parameter before, so repurposing it to this mroe narrow usecase makes things cleaner than inventing something new. Author: Laurenz Albe Reviewed-By: Magnus Hagander, Soumyadeep Chakraborty, Masahiro Ikeda Discussion: https://postgr.es/m/b07e1f9953701b90c66ed368656f2aef40cac4fb.camel@cybertec.at
* psql \dX: list extended statistics objectsTomas Vondra2021-01-17
| | | | | | | | | The new command lists extended statistics objects, possibly with their sizes. All past releases with extended statistics are supported. Author: Tatsuro Yamada Reviewed-by: Julien Rouhaud, Alvaro Herrera, Tomas Vondra Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
* Documenation fixups for replication protocol.Jeff Davis2021-01-16
| | | | | | | | | | There is no CopyResponse message; it should be CopyOutResponse. Also, if there is no WAL to stream, the server does not immediately send a CommandComplete; it's a historical timeline, so it will send a response tuple first. Discussion: https://postgr.es/m/0a2c985ebcaa1acd385350aeba561b6509187394.camel@j-davis.com
* Prevent drop of tablespaces used by partitioned relationsAlvaro Herrera2021-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a tablespace is used in a partitioned relation (per commits ca4103025dfe in pg12 for tables and 33e6c34c3267 in pg11 for indexes), it is possible to drop the tablespace, potentially causing various problems. One such was reported in bug #16577, where a rewriting ALTER TABLE causes a server crash. Protect against this by using pg_shdepend to keep track of tablespaces when used for relations that don't keep physical files; we now abort a tablespace if we see that the tablespace is referenced from any partitioned relations. Backpatch this to 11, where this problem has been latent all along. We don't try to create pg_shdepend entries for existing partitioned indexes/tables, but any ones that are modified going forward will be protected. Note slight behavior change: when trying to drop a tablespace that contains both regular tables as well as partitioned ones, you'd previously get ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE and now you'll get ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST. Arguably, the latter is more correct. It is possible to add protecting pg_shdepend entries for existing tables/indexes, by doing ALTER TABLE ONLY some_partitioned_table SET TABLESPACE pg_default; ALTER TABLE ONLY some_partitioned_table SET TABLESPACE original_tablespace; for each partitioned table/index that is not in the database default tablespace. Because these partitioned objects do not have storage, no file needs to be actually moved, so it shouldn't take more time than what's required to acquire locks. This query can be used to search for such relations: SELECT ... FROM pg_class WHERE relkind IN ('p', 'I') AND reltablespace <> 0 Reported-by: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/16577-881633a9f9894fd5@postgresql.org Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Michael Paquier <michael@paquier.xyz>
* Call out vacuum considerations in create index docsAlvaro Herrera2021-01-13
| | | | | | | | Backpatch to pg12, which is as far as it goes without conflicts. Author: James Coleman <jtc331@gmail.com> Reviewed-by: "David G. Johnston" <david.g.johnston@gmail.com> Discussion: https://postgr.es/m/CAAaqYe9oEfbz7AxXq7OX+FFVi5w5p1e_Of8ON8ZnKO9QqBfmjg@mail.gmail.com
* Disallow a digit as the first character of a variable name in pgbench.Tom Lane2021-01-13
| | | | | | | | | | | | | | | | | | The point of this restriction is to avoid trying to substitute variables into timestamp literal values, which may contain strings like '12:34'. There is a good deal more that should be done to reduce pgbench's tendency to substitute where it shouldn't. But this is sufficient to solve the case complained of by Jaime Soler, and it's simple enough to back-patch. Back-patch to v11; before commit 9d36a3866, pgbench had a slightly different definition of what a variable name is, and anyway it seems unwise to change long-stable branches for this. Fabien Coelho Discussion: https://postgr.es/m/alpine.DEB.2.22.394.2006291740420.805678@pseudo
* Doc: clarify behavior of back-half options in pg_dump.Tom Lane2021-01-13
| | | | | | | | Options that change how the archive data is converted to SQL text are ignored when dumping to archive formats. The documentation previously said "not meaningful", which is not helpful. Discussion: https://postgr.es/m/161052021249.12228.9598689907884726185@wrigleys.postgresql.org
* Enhance nbtree index tuple deletion.Peter Geoghegan2021-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach nbtree and heapam to cooperate in order to eagerly remove duplicate tuples representing dead MVCC versions. This is "bottom-up deletion". Each bottom-up deletion pass is triggered lazily in response to a flood of versions on an nbtree leaf page. This usually involves a "logically unchanged index" hint (these are produced by the executor mechanism added by commit 9dc718bd). The immediate goal of bottom-up index deletion is to avoid "unnecessary" page splits caused entirely by version duplicates. It naturally has an even more useful effect, though: it acts as a backstop against accumulating an excessive number of index tuple versions for any given _logical row_. Bottom-up index deletion complements what we might now call "top-down index deletion": index vacuuming performed by VACUUM. Bottom-up index deletion responds to the immediate local needs of queries, while leaving it up to autovacuum to perform infrequent clean sweeps of the index. The overall effect is to avoid certain pathological performance issues related to "version churn" from UPDATEs. The previous tableam interface used by index AMs to perform tuple deletion (the table_compute_xid_horizon_for_tuples() function) has been replaced with a new interface that supports certain new requirements. Many (perhaps all) of the capabilities added to nbtree by this commit could also be extended to other index AMs. That is left as work for a later commit. Extend deletion of LP_DEAD-marked index tuples in nbtree by adding logic to consider extra index tuples (that are not LP_DEAD-marked) for deletion in passing. This increases the number of index tuples deleted significantly in many cases. The LP_DEAD deletion process (which is now called "simple deletion" to clearly distinguish it from bottom-up deletion) won't usually need to visit any extra table blocks to check these extra tuples. We have to visit the same table blocks anyway to generate a latestRemovedXid value (at least in the common case where the index deletion operation's WAL record needs such a value). Testing has shown that the "extra tuples" simple deletion enhancement increases the number of index tuples deleted with almost any workload that has LP_DEAD bits set in leaf pages. That is, it almost never fails to delete at least a few extra index tuples. It helps most of all in cases that happen to naturally have a lot of delete-safe tuples. It's not uncommon for an individual deletion operation to end up deleting an order of magnitude more index tuples compared to the old naive approach (e.g., custom instrumentation of the patch shows that this happens fairly often when the regression tests are run). Add a further enhancement that augments simple deletion and bottom-up deletion in indexes that make use of deduplication: Teach nbtree's _bt_delitems_delete() function to support granular TID deletion in posting list tuples. It is now possible to delete individual TIDs from posting list tuples provided the TIDs have a tableam block number of a table block that gets visited as part of the deletion process (visiting the table block can be triggered directly or indirectly). Setting the LP_DEAD bit of a posting list tuple is still an all-or-nothing thing, but that matters much less now that deletion only needs to start out with the right _general_ idea about which index tuples are deletable. Bump XLOG_PAGE_MAGIC because xl_btree_delete changed. No bump in BTREE_VERSION, since there are no changes to the on-disk representation of nbtree indexes. Indexes built on PostgreSQL 12 or PostgreSQL 13 will automatically benefit from bottom-up index deletion (i.e. no reindexing required) following a pg_upgrade. The enhancement to simple deletion is available with all B-Tree indexes following a pg_upgrade, no matter what PostgreSQL version the user upgrades from. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-By: Victor Yegorov <vyegorov@gmail.com> Discussion: https://postgr.es/m/CAH2-Wzm+maE3apHB8NOtmM=p-DO65j2V5GzAWCOEEuy3JZgb2g@mail.gmail.com
* Pass down "logically unchanged index" hint.Peter Geoghegan2021-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an executor aminsert() hint mechanism that informs index AMs that the incoming index tuple (the tuple that accompanies the hint) is not being inserted by execution of an SQL statement that logically modifies any of the index's key columns. The hint is received by indexes when an UPDATE takes place that does not apply an optimization like heapam's HOT (though only for indexes where all key columns are logically unchanged). Any index tuple that receives the hint on insert is expected to be a duplicate of at least one existing older version that is needed for the same logical row. Related versions will typically be stored on the same index page, at least within index AMs that apply the hint. Recognizing the difference between MVCC version churn duplicates and true logical row duplicates at the index AM level can help with cleanup of garbage index tuples. Cleanup can intelligently target tuples that are likely to be garbage, without wasting too many cycles on less promising tuples/pages (index pages with little or no version churn). This is infrastructure for an upcoming commit that will teach nbtree to perform bottom-up index deletion. No index AM actually applies the hint just yet. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Victor Yegorov <vyegorov@gmail.com> Discussion: https://postgr.es/m/CAH2-Wz=CEKFa74EScx_hFVshCOn6AA5T-ajFASTdzipdkLTNQQ@mail.gmail.com
* Log long wait time on recovery conflict when it's resolved.Fujii Masao2021-01-13
| | | | | | | | | | | | | This is a follow-up of the work done in commit 0650ff2303. This commit extends log_recovery_conflict_waits so that a log message is produced also when recovery conflict has already been resolved after deadlock_timeout passes, i.e., when the startup process finishes waiting for recovery conflict after deadlock_timeout. This is useful in investigating how long recovery conflicts prevented the recovery from applying WAL. Author: Fujii Masao Reviewed-by: Kyotaro Horiguchi, Bertrand Drouvot Discussion: https://postgr.es/m/9a60178c-a853-1440-2cdc-c3af916cff59@amazon.com
* Remove incorrect markupMagnus Hagander2021-01-13
| | | | | | | | | Seems 737d69ffc3c made a copy/paste or automation error resulting in two extra right-parenthesis. Reported-By: Michael Vastola Backpatch-through: 13 Discussion: https://postgr.es/m/161051035421.12224.1741822783166533529@wrigleys.postgresql.org
* Add functions to 'pageinspect' to inspect GiST indexes.Heikki Linnakangas2021-01-13
| | | | | Author: Andrey Borodin and me Discussion: https://www.postgresql.org/message-id/3E4F9093-A1B5-4DF8-A292-0B48692E3954%40yandex-team.ru
* Doc: fix description of privileges needed for ALTER PUBLICATION.Tom Lane2021-01-12
| | | | | | Adding a table to a publication requires ownership of the table (in addition to ownership of the publication). This was mentioned nowhere.
* doc: expand description of how non-SELECT queries are processedBruce Momjian2021-01-09
| | | | | | | | | | | | The previous description of how the executor processes non-SELECT queries was very dense, causing lack of clarity. This expanded text spells it out more simply. Reported-by: fotis.koutoupas@gmail.com Discussion: https://postgr.es/m/160912275508.676.17469511338925622905@wrigleys.postgresql.org Backpatch-through: 9.5
* Minor fixes in COPY progress docsTomas Vondra2021-01-07
| | | | | Author: Justin Pryzby Discussion: https://postgr.es/m/CAFp7Qwr6_FmRM6pCO0x_a0mymOfX_Gg+FEKet4XaTGSW=LitKQ@mail.gmail.com
* Add GUC to log long wait times on recovery conflicts.Fujii Masao2021-01-08
| | | | | | | | | | | | | | | | This commit adds GUC log_recovery_conflict_waits that controls whether a log message is produced when the startup process is waiting longer than deadlock_timeout for recovery conflicts. This is useful in determining if recovery conflicts prevent the recovery from applying WAL. Note that currently a log message is produced only when recovery conflict has not been resolved yet even after deadlock_timeout passes, i.e., only when the startup process is still waiting for recovery conflict even after deadlock_timeout. Author: Bertrand Drouvot, Masahiko Sawada Reviewed-by: Alvaro Herrera, Kyotaro Horiguchi, Fujii Masao Discussion: https://postgr.es/m/9a60178c-a853-1440-2cdc-c3af916cff59@amazon.com
* Add idle_session_timeout.Tom Lane2021-01-06
| | | | | | | | | | | | This GUC variable works much like idle_in_transaction_session_timeout, in that it kills sessions that have waited too long for a new client query. But it applies when we're not in a transaction, rather than when we are. Li Japin, reviewed by David Johnston and Hayato Kuroda, some fixes by me Discussion: https://postgr.es/m/763A0689-F189-459E-946F-F0EC4458980B@hotmail.com
* Report progress of COPY commandsTomas Vondra2021-01-06
| | | | | | | | | | | | This commit introduces a view pg_stat_progress_copy, reporting progress of COPY commands. This allows rough estimates how far a running COPY progressed, with the caveat that the total number of bytes may not be available in some cases (e.g. when the input comes from the client). Author: Josef Šimánek Reviewed-by: Fujii Masao, Bharath Rupireddy, Vignesh C, Matthias van de Meent Discussion: https://postgr.es/m/CAFp7QwqMGEi4OyyaLEK9DR0+E+oK3UtA4bEjDVCa4bNkwUY2PQ@mail.gmail.com Discussion: https://postgr.es/m/CAFp7Qwr6_FmRM6pCO0x_a0mymOfX_Gg+FEKet4XaTGSW=LitKQ@mail.gmail.com
* Replace CLOBBER_CACHE_ALWAYS with run-time GUCPeter Eisentraut2021-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Forced cache invalidation (CLOBBER_CACHE_ALWAYS) has been impractical to use for testing in PostgreSQL because it's so slow and because it's toggled on/off only at build time. It is helpful when hunting bugs in any code that uses the sycache/relcache because causes cache invalidations to be injected whenever it would be possible for an invalidation to occur, whether or not one was really pending. Address this by providing run-time control over cache clobber behaviour using the new debug_invalidate_system_caches_always GUC. Support is not compiled in at all unless assertions are enabled or CLOBBER_CACHE_ENABLED is explicitly defined at compile time. It defaults to 0 if compiled in, so it has negligible effect on assert build performance by default. When support is compiled in, test code can now set debug_invalidate_system_caches_always=1 locally to a backend to test specific queries, functions, extensions, etc. Or tests can toggle it globally for a specific test case while retaining normal performance during test setup and teardown. For backwards compatibility with existing test harnesses and scripts, debug_invalidate_system_caches_always defaults to 1 if CLOBBER_CACHE_ALWAYS is defined, and to 3 if CLOBBER_CACHE_RECURSIVE is defined. CLOBBER_CACHE_ENABLED is now visible in pg_config_manual.h, as is the related RECOVER_RELATION_BUILD_MEMORY setting for the relcache. Author: Craig Ringer <craig.ringer@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/CAMsr+YF=+ctXBZj3ywmvKNUjWpxmuTuUKuv-rgbHGX5i5pLstQ@mail.gmail.com
* doc: Fix description about default behavior of recovery_target_timeline.Fujii Masao2021-01-06
| | | | | | | | | | | | The default value of recovery_target_timeline was changed in v12, but the description about the default behavior of that was not updated. Back-patch to v12 where the default behavior of recovery_target_timeline was changed. Author: Benoit Lobréau Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/CAPE8EZ7c3aruEmM24GYkj8y8WmHKD1m9TtPtgCF0nQ3zw4LCkQ@mail.gmail.com