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* Fix collection of typos and grammar mistakes in the tree, volume 2Michael Paquier2020-04-14
| | | | | | | | This fixes some comments and documentation new as of Postgres 13, and is a follow-up of the work done in dd0f37e. Author: Justin Pryzby Discussion: https://postgr.es/m/20200408165653.GF2228@telsasoft.com
* Use perl warnings pragma consistentlyAndrew Dunstan2020-04-13
| | | | | | | | | | We've had a mixture of the warnings pragma, the -w switch on the shebang line, and no warnings at all. This patch removes the -w swicth and add the warnings pragma to all perl sources missing it. It raises the severity of the TestingAndDebugging::RequireUseWarnings perlcritic policy to level 5, so that we catch any future violations. Discussion: https://postgr.es/m/20200412074245.GB623763@rfd.leadboat.com
* Allow publishing partition changes via ancestorsPeter Eisentraut2020-04-08
| | | | | | | | | | | | | | | To control whether partition changes are replicated using their own identity and schema or an ancestor's, add a new parameter that can be set per publication named 'publish_via_partition_root'. This allows replicating a partitioned table into a different partition structure on the subscriber. Author: Amit Langote <amitlangote09@gmail.com> Reviewed-by: Rafia Sabih <rafia.pghackers@gmail.com> Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> Reviewed-by: Petr Jelinek <petr@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/CA+HiwqH=Y85vRK3mOdjEkqFK+E=ST=eQiHdpj43L=_eJMOOznQ@mail.gmail.com
* Revert 0f5ca02f53Alexander Korotkov2020-04-08
| | | | | | | | 0f5ca02f53 introduces 3 new keywords. It appears to be too much for relatively small feature. Given now we past feature freeze, it's already late for discussion of the new syntax. So, revert. Discussion: https://postgr.es/m/28209.1586294824%40sss.pgh.pa.us
* Modify additional power 2 calculations to use new helper functionsDavid Rowley2020-04-08
| | | | | | | | | | | | 2nd pass of modifying various places which obtain the next power of 2 of a number and make them use the new functions added in f0705bb62. In passing, also modify num_combinations(). This can be implemented using simple bitshifting rather than looping. Reviewed-by: John Naylor Discussion: https://postgr.es/m/20200114173553.GE32763%40fetter.org
* Modify various power 2 calculations to use new helper functionsDavid Rowley2020-04-08
| | | | | | | | | | | | | | First pass of modifying various places that obtain the next power of 2 of a number and make them use the new functions added in pg_bitutils.h instead. This also removes the _hash_log2() function. There are no longer any callers in core. Other users can swap their _hash_log2(n) call to make use of pg_ceil_log2_32(n). Author: David Fetter, with some minor adjustments by me Reviewed-by: John Naylor, Jesse Zhang Discussion: https://postgr.es/m/20200114173553.GE32763%40fetter.org
* Fix circle_in to accept "(x,y),r" as it's advertised to do.Tom Lane2020-04-07
| | | | | | | | | | | Our documentation describes four allowed input syntaxes for circles, but the regression tests tried only three ... with predictable consequences. Remarkably, this has been wrong since the circle datatype was added in 1997, but nobody noticed till now. David Zhang, with some help from me Discussion: https://postgr.es/m/332c47fa-d951-7574-b5cc-a8f7f7201202@highgo.ca
* Allow users to limit storage reserved by replication slotsAlvaro Herrera2020-04-07
| | | | | | | | | | | | | | | | Replication slots are useful to retain data that may be needed by a replication system. But experience has shown that allowing them to retain excessive data can lead to the primary failing because of running out of space. This new feature allows the user to configure a maximum amount of space to be reserved using the new option max_slot_wal_keep_size. Slots that overrun that space are invalidated at checkpoint time, enabling the storage to be released. Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20170228.122736.123383594.horiguchi.kyotaro@lab.ntt.co.jp
* Implement waiting for given lsn at transaction startAlexander Korotkov2020-04-07
| | | | | | | | | | | | | | | | | | | | This commit adds following optional clause to BEGIN and START TRANSACTION commands. WAIT FOR LSN lsn [ TIMEOUT timeout ] New clause pospones transaction start till given lsn is applied on standby. This clause allows user be sure, that changes previously made on primary would be visible on standby. New shared memory struct is used to track awaited lsn per backend. Recovery process wakes up backend once required lsn is applied. Author: Ivan Kartyshov, Anna Akenteva Reviewed-by: Craig Ringer, Thomas Munro, Robert Haas, Kyotaro Horiguchi Reviewed-by: Masahiko Sawada, Ants Aasma, Dmitry Ivanov, Simon Riggs Reviewed-by: Amit Kapila, Alexander Korotkov Discussion: https://postgr.es/m/0240c26c-9f84-30ea-fca9-93ab2df5f305%40postgrespro.ru
* Support FETCH FIRST WITH TIESAlvaro Herrera2020-04-07
| | | | | | | | | | | | | | | | | | WITH TIES is an option to the FETCH FIRST N ROWS clause (the SQL standard's spelling of LIMIT), where you additionally get rows that compare equal to the last of those N rows by the columns in the mandatory ORDER BY clause. There was a proposal by Andrew Gierth to implement this functionality in a more powerful way that would yield more features, but the other patch had not been finished at this time, so we decided to use this one for now in the spirit of incremental development. Author: Surafel Temesgen <surafel3000@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> Discussion: https://postgr.es/m/CALAY4q9ky7rD_A4vf=FVQvCGngm3LOes-ky0J6euMrg=_Se+ag@mail.gmail.com Discussion: https://postgr.es/m/87o8wvz253.fsf@news-spur.riddles.org.uk
* Adjust bytea get_bit/set_bit to use int8 not int4 for bit numbering.Tom Lane2020-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | Since the existing bit number argument can't exceed INT32_MAX, it's not possible for these functions to manipulate bits beyond the first 256MB of a bytea value. Lift that restriction by redeclaring the bit number arguments as int8 (which requires a catversion bump, hence is not back-patchable). The similarly-named functions for bit/varbit don't really have a problem because we restrict those types to at most VARBITMAXLEN bits; hence leave them alone. While here, extend the encode/decode functions in utils/adt/encode.c to allow dealing with values wider than 1GB. This is not a live bug or restriction in current usage, because no input could be more than 1GB, and since none of the encoders can expand a string more than 4X, the result size couldn't overflow uint32. But it might be desirable to support more in future, so make the input length values size_t and the potential-output-length values uint64. Also add some test cases to improve the miserable code coverage of these functions. Movead Li, editorialized some by me; also reviewed by Ashutosh Bapat Discussion: https://postgr.es/m/20200312115135445367128@highgo.ca
* Introduce xid8-based functions to replace txid_XXX.Thomas Munro2020-04-07
| | | | | | | | | | | | | | | | | | | | | The txid_XXX family of fmgr functions exposes 64 bit transaction IDs to users as int8. Now that we have an SQL type xid8 for FullTransactionId, define a new set of functions including pg_current_xact_id() and pg_current_snapshot() based on that. Keep the old functions around too, for now. It's a bit sneaky to use the same C functions for both, but since the binary representation is identical except for the signedness of the type, and since older functions are the ones using the wrong signedness, and since we'll presumably drop the older ones after a reasonable period of time, it seems reasonable to switch to FullTransactionId internally and share the code for both. Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com> Reviewed-by: Takao Fujii <btfujiitkp@oss.nttdata.com> Reviewed-by: Yoshikazu Imai <imai.yoshikazu@fujitsu.com> Reviewed-by: Mark Dilger <mark.dilger@enterprisedb.com> Discussion: https://postgr.es/m/20190725000636.666m5mad25wfbrri%40alap3.anarazel.de
* Add SQL type xid8 to expose FullTransactionId to users.Thomas Munro2020-04-07
| | | | | | | | | | | Similar to xid, but 64 bits wide. This new type is suitable for use in various system views and administration functions. Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com> Reviewed-by: Takao Fujii <btfujiitkp@oss.nttdata.com> Reviewed-by: Yoshikazu Imai <imai.yoshikazu@fujitsu.com> Reviewed-by: Mark Dilger <mark.dilger@enterprisedb.com> Discussion: https://postgr.es/m/20190725000636.666m5mad25wfbrri%40alap3.anarazel.de
* Implement Incremental SortTomas Vondra2020-04-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Incremental Sort is an optimized variant of multikey sort for cases when the input is already sorted by a prefix of the requested sort keys. For example when the relation is already sorted by (key1, key2) and we need to sort it by (key1, key2, key3) we can simply split the input rows into groups having equal values in (key1, key2), and only sort/compare the remaining column key3. This has a number of benefits: - Reduced memory consumption, because only a single group (determined by values in the sorted prefix) needs to be kept in memory. This may also eliminate the need to spill to disk. - Lower startup cost, because Incremental Sort produce results after each prefix group, which is beneficial for plans where startup cost matters (like for example queries with LIMIT clause). We consider both Sort and Incremental Sort, and decide based on costing. The implemented algorithm operates in two different modes: - Fetching a minimum number of tuples without check of equality on the prefix keys, and sorting on all columns when safe. - Fetching all tuples for a single prefix group and then sorting by comparing only the remaining (non-prefix) keys. We always start in the first mode, and employ a heuristic to switch into the second mode if we believe it's beneficial - the goal is to minimize the number of unnecessary comparions while keeping memory consumption below work_mem. This is a very old patch series. The idea was originally proposed by Alexander Korotkov back in 2013, and then revived in 2017. In 2018 the patch was taken over by James Coleman, who wrote and rewrote most of the current code. There were many reviewers/contributors since 2013 - I've done my best to pick the most active ones, and listed them in this commit message. Author: James Coleman, Alexander Korotkov Reviewed-by: Tomas Vondra, Andreas Karlsson, Marti Raudsepp, Peter Geoghegan, Robert Haas, Thomas Munro, Antonin Houska, Andres Freund, Alexander Kuzmenkov Discussion: https://postgr.es/m/CAPpHfdscOX5an71nHd8WSUH6GNOCf=V7wgDaTXdDd9=goN-gfA@mail.gmail.com Discussion: https://postgr.es/m/CAPpHfds1waRZ=NOmueYq0sx1ZSCnt+5QJvizT8ndT2=etZEeAQ@mail.gmail.com
* Preserve clustered index after rewrites with ALTER TABLEMichael Paquier2020-04-06
| | | | | | | | | | | | | A table rewritten by ALTER TABLE would lose tracking of an index usable for CLUSTER. This setting is tracked by pg_index.indisclustered and is controlled by ALTER TABLE, so some extra work was needed to restore it properly. Note that ALTER TABLE only marks the index that can be used for clustering, and does not do the actual operation. Author: Amit Langote, Justin Pryzby Reviewed-by: Ibrar Ahmed, Michael Paquier Discussion: https://postgr.es/m/20200202161718.GI13621@telsasoft.com Backpatch-through: 9.5
* Recompute stack base in forked postmaster children.Andres Freund2020-04-05
| | | | | | | | | | | This is for the benefit of running postgres under the rr debugger. When using rr signal handlers running while a syscall is active use an alternative stack. As e.g. bgworkers are started from within signal handlers, the forked backend then has a different stack base than postmaster. Previously that subsequently lead to those processes triggering spurious "stack depth limit exceeded" errors. Discussion: https://postgr.es/m/20200327182217.ubrrl32lyfhxfwk5@alap3.anarazel.de
* Fix recently introduced typo.Andres Freund2020-04-05
| | | | Reported-By: David Rowley
* Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch2020-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Bump XLOG_PAGE_MAGIC, since this introduces XLOG_GIST_ASSIGN_LSN. Future servers accept older WAL, so this bump is discretionary. Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
* Improve user control over truncation of logged bind-parameter values.Tom Lane2020-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces the boolean GUC log_parameters_on_error introduced by commit ba79cb5dc with an integer log_parameter_max_length_on_error, adding the ability to specify how many bytes to trim each logged parameter value to. (The previous coding hard-wired that choice at 64 bytes.) In addition, add a new parameter log_parameter_max_length that provides similar control over truncation of query parameters that are logged in response to statement-logging options, as opposed to errors. Previous releases always logged such parameters in full, possibly causing log bloat. For backwards compatibility with prior releases, log_parameter_max_length defaults to -1 (log in full), while log_parameter_max_length_on_error defaults to 0 (no logging). Per discussion, log_parameter_max_length is SUSET since the DBA should control routine logging behavior, but log_parameter_max_length_on_error is USERSET because it also affects errcontext data sent back to the client. Alexey Bashtanov, editorialized a little by me Discussion: https://postgr.es/m/b10493cc-a399-a03a-67c7-068f2791ee50@imap.cc
* Add SQL functions for Unicode normalizationPeter Eisentraut2020-04-02
| | | | | | | | | | | | | | | | | This adds SQL expressions NORMALIZE() and IS NORMALIZED to convert and check Unicode normal forms, per SQL standard. To support fast IS NORMALIZED tests, we pull in a new data file DerivedNormalizationProps.txt from Unicode and build a lookup table from that, using techniques similar to ones already used for other Unicode data. make update-unicode will keep it up to date. We only build and use these tables for the NFC and NFKC forms, because they are too big for NFD and NFKD and the improvement is not significant enough there. Reviewed-by: Daniel Verite <daniel@manitou-mail.org> Reviewed-by: Andreas Karlsson <andreas@proxel.se> Discussion: https://www.postgresql.org/message-id/flat/c1909f27-c269-2ed9-12f8-3ab72c8caf7a@2ndquadrant.com
* Add maintenance_io_concurrency to postgresql.conf.sample.Thomas Munro2020-04-02
| | | | New GUC from commit fc34b0d9.
* Collect statistics about SLRU cachesTomas Vondra2020-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a number of SLRU caches used to access important data like clog, commit timestamps, multixact, asynchronous notifications, etc. Until now we had no easy way to monitor these shared caches, compute hit ratios, number of reads/writes etc. This commit extends the statistics collector to track this information for a predefined list of SLRUs, and also introduces a new system view pg_stat_slru displaying the data. The list of built-in SLRUs is fixed, but additional SLRUs may be defined in extensions. Unfortunately, there's no suitable registry of SLRUs, so this patch simply defines a fixed list of SLRUs with entries for the built-in ones and one entry for all additional SLRUs. Extensions adding their own SLRU are fairly rare, so this seems acceptable. This patch only allows monitoring of SLRUs, not tuning. The SLRU sizes are still fixed (hard-coded in the code) and it's not entirely clear which of the SLRUs might need a GUC to tune size. In a way, allowing us to determine that is one of the goals of this patch. Bump catversion as the patch introduces new functions and system view. Author: Tomas Vondra Reviewed-by: Alvaro Herrera Discussion: https://www.postgresql.org/message-id/flat/20200119143707.gyinppnigokesjok@development
* Improve selectivity estimation for assorted match-style operators.Tom Lane2020-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Quite a few matching operators such as JSONB's @> used "contsel" and "contjoinsel" as their selectivity estimators. That was a bad idea, because (a) contsel is only a stub, yielding a fixed default estimate, and (b) that default is 0.001, meaning we estimate these operators as five times more selective than equality, which is surely pretty silly. There's a good model for improving this in ltree's ltreeparentsel(): for any "var OP constant" query, we can try applying the operator to all of the column's MCV and histogram values, taking the latter as being a random sample of the non-MCV values. That code is actually 100% generic, except for the question of exactly what default selectivity ought to be plugged in when we don't have stats. Hence, migrate the guts of ltreeparentsel() into the core code, provide wrappers "matchingsel" and "matchingjoinsel" with a more-appropriate default estimate, and use those for the non-geometric operators that formerly used contsel (mostly JSONB containment operators and tsquery matching). Also apply this code to some match-like operators in hstore, ltree, and pg_trgm, including the former users of ltreeparentsel as well as ones that improperly used contsel. Since commit 911e70207 just created new versions of those extensions that we haven't released yet, we can sneak this change into those new versions instead of having to create an additional generation of update scripts. Patch by me, reviewed by Alexey Bashtanov Discussion: https://postgr.es/m/12237.1582833074@sss.pgh.pa.us
* Teach pg_ls_dir_files() to ignore ENOENT failures from stat().Tom Lane2020-03-31
| | | | | | | | | | | | | | | | Buildfarm experience shows that this function can fail with ENOENT if some other process unlinks a file between when we read the directory entry and when we try to stat() it. The problem is old but we had not noticed it until 085b6b667 added regression test coverage. To fix, just ignore ENOENT failures. There is one other case that this might hide: a symlink that points to nowhere. That seems okay though, at least better than erroring. Back-patch to v10 where this function was added, since the regression test cases were too. Discussion: https://postgr.es/m/20200308173103.GC1357@telsasoft.com
* Fix assorted typosMagnus Hagander2020-03-31
| | | | Author: Daniel Gustafsson <daniel@yesql.se>
* Remove rudiments of supporting procnum == 0 from 911e702077Alexander Korotkov2020-03-30
| | | | | | Early versions of opclass options patch uses zero support procedure as opclass options procedure. This commit removes rudiments of it, which were committed in 911e702077. Also, it implements correct handling of amoptsprocnum == 0.
* Implement operator class parametersAlexander Korotkov2020-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PostgreSQL provides set of template index access methods, where opclasses have much freedom in the semantics of indexing. These index AMs are GiST, GIN, SP-GiST and BRIN. There opclasses define representation of keys, operations on them and supported search strategies. So, it's natural that opclasses may be faced some tradeoffs, which require user-side decision. This commit implements opclass parameters allowing users to set some values, which tell opclass how to index the particular dataset. This commit doesn't introduce new storage in system catalog. Instead it uses pg_attribute.attoptions, which is used for table column storage options but unused for index attributes. In order to evade changing signature of each opclass support function, we implement unified way to pass options to opclass support functions. Options are set to fn_expr as the constant bytea expression. It's possible due to the fact that opclass support functions are executed outside of expressions, so fn_expr is unused for them. This commit comes with some examples of opclass options usage. We parametrize signature length in GiST. That applies to multiple opclasses: tsvector_ops, gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and gist_hstore_ops. Also we parametrize maximum number of integer ranges for gist__int_ops. However, the main future usage of this feature is expected to be json, where users would be able to specify which way to index particular json parts. Catversion is bumped. Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru Author: Nikita Glukhov, revised by me Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera
* Allow the planner-related functions and hook to accept the query string.Fujii Masao2020-03-30
| | | | | | | | | | | | | | | | | | This commit adds query_string argument into the planner-related functions and hook and allows us to pass the query string to them. Currently there is no user of the query string passed. But the upcoming patch for the planning counters will add the planning hook function into pg_stat_statements and the function will need the query string. So this change will be necessary for that patch. Also this change is useful for some extensions that want to use the query string in their planner hook function. Author: Pascal Legrand, Julien Rouhaud Reviewed-by: Yoshikazu Imai, Tom Lane, Fujii Masao Discussion: https://postgr.es/m/CAOBaU_bU1m3_XF5qKYtSj1ua4dxd=FWDyh2SH4rSJAUUfsGmAQ@mail.gmail.com Discussion: https://postgr.es/m/1583789487074-0.post@n3.nabble.com
* Ensure snapshot is registered within ScanPgRelation().Andres Freund2020-03-28
| | | | | | | | | | | | | | | | | | | | | In 9.4 I added support to use a historical snapshot in ScanPgRelation(), while adding logical decoding. Unfortunately a conflict with the concurrent removal of SnapshotNow was incorrectly resolved, leading to an unregistered snapshot being used. It is not correct to use an unregistered (or non-active) snapshot for anything non-trivial, because catalog invalidations can cause the snapshot to be invalidated. Luckily it seems unlikely to actively cause problems in practice, as ScanPgRelation() requires that we already have a lock on the relation, we only look for a single row, and we don't appear to rely on the result's tid to be correct. It however is clearly wrong and potential negative consequences would likely be hard to find. So it seems worth backpatching the fix, even without a concrete hazard. Discussion: https://postgr.es/m/20200229052459.wzhqnbhrriezg4v2@alap3.anarazel.de Backpatch: 9.5-
* Improve the performance and accuracy of numeric sqrt() and ln().Dean Rasheed2020-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using Newton's method to compute numeric square roots, use the Karatsuba square root algorithm, which performs better for numbers of all sizes. In practice, this is 3-5 times faster for inputs with just a few digits and up to around 10 times faster for larger inputs. Also, the new algorithm guarantees that the final digit of the result is correctly rounded, since it computes an integer square root with truncation, containing at least 1 extra decimal digit before rounding. The former algorithm would occasionally round the wrong way because it rounded both the intermediate and final results. In addition, arrange for sqrt_var() to explicitly support negative rscale values (rounding before the decimal point). This allows the argument reduction phase of ln_var() to be optimised for large inputs, since it only needs to compute square roots with a few more digits than the final ln() result, rather than computing all the digits before the decimal point. For very large inputs, this can be many thousands of times faster. In passing, optimise div_var_fast() in a couple of places where it was doing unnecessary work. Patch be me, reviewed by Tom Lane and Tels. Discussion: https://postgr.es/m/CAEZATCV1A7+jD3P30Zu31KjaxeSEyOn3v9d6tYegpxcq3cQu-g@mail.gmail.com
* Trigger autovacuum based on number of INSERTsDavid Rowley2020-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Traditionally autovacuum has only ever invoked a worker based on the estimated number of dead tuples in a table and for anti-wraparound purposes. For the latter, with certain classes of tables such as insert-only tables, anti-wraparound vacuums could be the first vacuum that the table ever receives. This could often lead to autovacuum workers being busy for extended periods of time due to having to potentially freeze every page in the table. This could be particularly bad for very large tables. New clusters, or recently pg_restored clusters could suffer even more as many large tables may have the same relfrozenxid, which could result in large numbers of tables requiring an anti-wraparound vacuum all at once. Here we aim to reduce the work required by anti-wraparound and aggressive vacuums in general, by triggering autovacuum when the table has received enough INSERTs. This is controlled by adding two new GUCs and reloptions; autovacuum_vacuum_insert_threshold and autovacuum_vacuum_insert_scale_factor. These work exactly the same as the existing scale factor and threshold controls, only base themselves off the number of inserts since the last vacuum, rather than the number of dead tuples. New controls were added rather than reusing the existing controls, to allow these new vacuums to be tuned independently and perhaps even completely disabled altogether, which can be done by setting autovacuum_vacuum_insert_threshold to -1. We make no attempt to skip index cleanup operations on these vacuums as they may trigger for an insert-mostly table which continually doesn't have enough dead tuples to trigger an autovacuum for the purpose of removing those dead tuples. If we were to skip cleaning the indexes in this case, then it is possible for the index(es) to become bloated over time. There are additional benefits to triggering autovacuums based on inserts, as tables which never contain enough dead tuples to trigger an autovacuum are now more likely to receive a vacuum, which can mark more of the table as "allvisible" and encourage the query planner to make use of Index Only Scans. Currently, we still obey vacuum_freeze_min_age when triggering these new autovacuums based on INSERTs. For large insert-only tables, it may be beneficial to lower the table's autovacuum_freeze_min_age so that tuples are eligible to be frozen sooner. Here we've opted not to zero that for these types of vacuums, since the table may just be insert-mostly and we may otherwise freeze tuples that are still destined to be updated or removed in the near future. There was some debate to what exactly the new scale factor and threshold should default to. For now, these are set to 0.2 and 1000, respectively. There may be some motivation to adjust these before the release. Author: Laurenz Albe, Darafei Praliaskouski Reviewed-by: Alvaro Herrera, Masahiko Sawada, Chris Travers, Andres Freund, Justin Pryzby Discussion: https://postgr.es/m/CAC8Q8t%2Bj36G_bLF%3D%2B0iMo6jGNWnLnWb1tujXuJr-%2Bx8ZCCTqoQ%40mail.gmail.com
* Allow walreceiver configuration to change on reloadAlvaro Herrera2020-03-27
| | | | | | | | | | | | | | | The parameters primary_conninfo, primary_slot_name and wal_receiver_create_temp_slot can now be changed with a simple "reload" signal, no longer requiring a server restart. This is achieved by signalling the walreceiver process to terminate and having it start again with the new values. Thanks to Andres Freund, Kyotaro Horiguchi, Fujii Masao for discussion. Author: Sergei Kornilov <sk@zsrv.org> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/19513901543181143@sas1-19a94364928d.qloud-c.yandex.net
* Set wal_receiver_create_temp_slot PGC_POSTMASTERAlvaro Herrera2020-03-27
| | | | | | | | | | | | | | | | | | | | | | | | | Commit 329730827848 gave walreceiver the ability to create and use a temporary replication slot, and made it controllable by a GUC (enabled by default) that can be changed with SIGHUP. That's useful but has two problems: one, it's possible to cause the origin server to fill its disk if the slot doesn't advance in time; and also there's a disconnect between state passed down via the startup process and GUCs that walreceiver reads directly. We handle the first problem by setting the option to disabled by default. If the user enables it, its on their head to make sure that disk doesn't fill up. We handle the second problem by passing the flag via startup rather than having walreceiver acquire it directly, and making it PGC_POSTMASTER (which ensures a walreceiver always has the fresh value). A future commit can relax this (to PGC_SIGHUP again) by having the startup process signal walreceiver to shutdown whenever the value changes. Author: Sergei Kornilov <sk@zsrv.org> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20200122055510.GH174860@paquier.xyz
* Rearrange validity checks for plpgsql "simple" expressions.Tom Lane2020-03-27
| | | | | | | | | | | | | | | | | | | | | Buildfarm experience shows what probably should've occurred to me before: if a cache flush occurs partway through building a generic plan, then the plansource may have is_valid = false even though the plan is valid. We need to accept this case, use the generated plan, and then try to replan the next time. We can't try to replan immediately, because that would produce an infinite loop in CLOBBER_CACHE_ALWAYS builds; moreover it's really overkill. (We can assume that the plan is valid, it's just possibly a bit stale. Note that the pre-existing code behaved this way, and the non-simple-expression code paths do too.) Conversely, not using the generated plan would drop us into the not-a-simple-expression code path, which is bad for performance and would also cause regression-test failures due to visibly different error-reporting behavior. Hence, refactor the validity-check functions so that the initial check and recheck cases can react differently to plansource->is_valid. This makes their usage a bit simpler, too. Discussion: https://postgr.es/m/7072.1585332104@sss.pgh.pa.us
* Improve performance of "simple expressions" in PL/pgSQL.Tom Lane2020-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For relatively simple expressions (say, "x + 1" or "x > 0"), plpgsql's management overhead exceeds the cost of evaluating the expression. This patch substantially improves that situation, providing roughly 2X speedup for such trivial expressions. First, add infrastructure in the plancache to allow fast re-validation of cached plans that contain no table access, and hence need no locks. Teach plpgsql to use this infrastructure for expressions that it's already deemed "simple" (which in particular will never contain table references). The fast path still requires checking that search_path hasn't changed, so provide a fast path for OverrideSearchPathMatchesCurrent by counting changes that have occurred to the active search path in the current session. This is simplistic but seems enough for now, seeing that PushOverrideSearchPath is not used in any performance-critical cases. Second, manage the refcounts on simple expressions' cached plans using a transaction-lifespan resource owner, so that we only need to take and release an expression's refcount once per transaction not once per expression evaluation. The management of this resource owner exactly parallels the existing management of plpgsql's simple-expression EState. Add some regression tests covering this area, in particular verifying that expression caching doesn't break semantics for search_path changes. Patch by me, but it owes something to previous work by Amit Langote, who recognized that getting rid of plancache-related overhead would be a useful thing to do here. Also thanks to Andres Freund for review. Discussion: https://postgr.es/m/CAFj8pRDRVfLdAxsWeVLzCAbkLFZhW549K+67tpOc-faC8uH8zw@mail.gmail.com
* Go back to returning int from ereport auxiliary functions.Tom Lane2020-03-25
| | | | | | | | | | | | | | | | | | | This reverts the parts of commit 17a28b03645e27d73bf69a95d7569b61e58f06eb that changed ereport's auxiliary functions from returning dummy integer values to returning void. It turns out that a minority of compilers complain (not entirely unreasonably) about constructs such as (condition) ? errdetail(...) : 0 if errdetail() returns void rather than int. We could update those call sites to say "(void) 0" perhaps, but the expectation for this patch set was that ereport callers would not have to change anything. And this aspect of the patch set was already the most invasive and least compelling part of it, so let's just drop it. Per buildfarm. Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com
* Add collation versions for Windows.Thomas Munro2020-03-25
| | | | | | | | On Vista and later, use GetNLSVersionEx() to request collation version information. Reviewed-by: Juan José Santamaría Flecha <juanjo.santamaria@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKGJvqup3s%2BJowVTcacZADO6dOhfdBmvOPHLS3KXUJu41Jw%40mail.gmail.com
* Allow NULL version for individual collations.Thomas Munro2020-03-25
| | | | | | | | | | | Remove the documented restriction that collation providers must either return NULL for all collations or non-NULL for all collations. Use NULL for glibc collations like "C.UTF-8", which might otherwise lead future proposed commits to force unnecessary index rebuilds. Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> Discussion: https://postgr.es/m/CA%2BhUKGJvqup3s%2BJowVTcacZADO6dOhfdBmvOPHLS3KXUJu41Jw%40mail.gmail.com
* Fix compiler warning on CygwinPeter Eisentraut2020-03-24
| | | | | bf68b79e50e3359accc85c94fa23cc03abb9350a introduced an unused variable compiler warning on Cygwin.
* Improve the internal implementation of ereport().Tom Lane2020-03-24
| | | | | | | | | | | | | | | | | | | | | | Change all the auxiliary error-reporting routines to return void, now that we no longer need to pretend they are passing something useful to errfinish(). While this probably doesn't save anything significant at the machine-code level, it allows detection of some additional types of mistakes. Pass the error location details (__FILE__, __LINE__, PG_FUNCNAME_MACRO) to errfinish not errstart. This shaves a few cycles off the case where errstart decides we're not going to emit anything. Re-implement elog() as a trivial wrapper around ereport(), removing the separate support infrastructure it used to have. Aside from getting rid of some now-surplus code, this means that elog() now really does have exactly the same semantics as ereport(), in particular that it can skip evaluation work if the message is not to be emitted. Andres Freund and Tom Lane Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com
* Re-implement the ereport() macro using __VA_ARGS__.Tom Lane2020-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we require C99, we can depend on __VA_ARGS__ to work, and revising ereport() to use it has several significant benefits: * The extra parentheses around the auxiliary function calls are now optional. Aside from being a bit less ugly, this removes a common gotcha for new contributors, because in some cases the compiler errors you got from forgetting them were unintelligible. * The auxiliary function calls are now evaluated as a comma expression list rather than as extra arguments to errfinish(). This means that compilers can be expected to warn about no-op expressions in the list, allowing detection of several other common mistakes such as forgetting to add errmsg(...) when converting an elog() call to ereport(). * Unlike the situation with extra function arguments, comma expressions are guaranteed to be evaluated left-to-right, so this removes platform dependency in the order of the auxiliary function calls. While that dependency hasn't caused us big problems in the past, this change does allow dropping some rather shaky assumptions around errcontext() domain handling. There's no intention to make wholesale changes of existing ereport calls, but as proof-of-concept this patch removes the extra parens from a couple of calls in postgres.c. While new code can be written either way, code intended to be back-patched will need to use extra parens for awhile yet. It seems worth back-patching this change into v12, so as to reduce the window where we have to be careful about that by one year. Hence, this patch is careful to preserve ABI compatibility; a followup HEAD-only patch will make some additional simplifications. Andres Freund and Tom Lane Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com
* Add object names to partition integrity violations.Amit Kapila2020-03-23
| | | | | | | | | | | | All errors of SQLSTATE class 23 should include the name of an object associated with the error in separate fields of the error report message. We do this so that applications need not try to extract them from the possibly-localized human-readable text of the message. Reported-by: Chris Bandy Author: Chris Bandy Reviewed-by: Amit Kapila and Amit Langote Discussion: https://postgr.es/m/0aa113a3-3c7f-db48-bcd8-f9290b2269ae@gmail.com
* Revert "Skip WAL for new relfilenodes, under wal_level=minimal."Noah Misch2020-03-22
| | | | | | | | This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f. Per numerous buildfarm members, it was incompatible with parallel query, and a test case assumed LP64. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
* Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch2020-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Back-patch to 9.5 (all supported versions). This introduces a new WAL record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As always, update standby systems before master systems. This changes sizeof(RelationData) and sizeof(IndexStmt), breaking binary compatibility for affected extensions. (The most recent commit to affect the same class of extensions was 089e4d405d0f3b94c74a2c6a54357a84a681754b.) Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
* Fix cosmetic blemishes involving rd_createSubid.Noah Misch2020-03-21
| | | | | | | Remove an obsolete comment from AtEOXact_cleanup(). Restore formatting of a comment in struct RelationData, mangled by the pgindent run in commit 9af4159fce6654aa0e081b00d02bca40b978745c. Back-patch to 9.5 (all supported versions), because another fix stacks on this.
* Revert "Specialize MemoryContextMemAllocated()."Jeff Davis2020-03-19
| | | | This reverts commit e00912e11a9ec2d29274ed8a6465e81385906dc2.
* Introduce "anycompatible" family of polymorphic types.Tom Lane2020-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the pseudo-types anycompatible, anycompatiblearray, anycompatiblenonarray, and anycompatiblerange. They work much like anyelement, anyarray, anynonarray, and anyrange respectively, except that the actual input values need not match precisely in type. Instead, if we can find a common supertype (using the same rules as for UNION/CASE type resolution), then the parser automatically promotes the input values to that type. For example, "myfunc(anycompatible, anycompatible)" can match a call with one integer and one bigint argument, with the integer automatically promoted to bigint. With anyelement in the definition, the user would have had to cast the integer explicitly. The new types also provide a second, independent set of type variables for function matching; thus with "myfunc(anyelement, anyelement, anycompatible) returns anycompatible" the first two arguments are constrained to be the same type, but the third can be some other type, and the result has the type of the third argument. The need for more than one set of type variables was foreseen back when we first invented the polymorphic types, but we never did anything about it. Pavel Stehule, revised a bit by me Discussion: https://postgr.es/m/CAFj8pRDna7VqNi8gR+Tt2Ktmz0cq5G93guc3Sbn_NVPLdXAkqA@mail.gmail.com
* Disk-based Hash Aggregation.Jeff Davis2020-03-18
| | | | | | | | | | | | | | | | | | | | | | While performing hash aggregation, track memory usage when adding new groups to a hash table. If the memory usage exceeds work_mem, enter "spill mode". In spill mode, new groups are not created in the hash table(s), but existing groups continue to be advanced if input tuples match. Tuples that would cause a new group to be created are instead spilled to a logical tape to be processed later. The tuples are spilled in a partitioned fashion. When all tuples from the outer plan are processed (either by advancing the group or spilling the tuple), finalize and emit the groups from the hash table. Then, create new batches of work from the spilled partitions, and select one of the saved batches and process it (possibly spilling recursively). Author: Jeff Davis Reviewed-by: Tomas Vondra, Adam Lee, Justin Pryzby, Taylor Vesely, Melanie Plageman Discussion: https://postgr.es/m/507ac540ec7c20136364b5272acbcd4574aa76ef.camel@j-davis.com
* Specialize MemoryContextMemAllocated().Jeff Davis2020-03-18
| | | | | | | | | | | An AllocSet doubles the size of allocated blocks (up to maxBlockSize), which means that the current block can represent half of the total allocated space for the memory context. But the free space in the current block may never have been touched, so don't count the untouched memory as allocated for the purposes of MemoryContextMemAllocated(). Discussion: https://postgr.es/m/ec63d70b668818255486a83ffadc3aec492c1f57.camel@j-davis.com
* Implement type regcollationPeter Eisentraut2020-03-18
| | | | | | | | | This will be helpful for a following commit and it's also just generally useful, like the other reg* types. Author: Julien Rouhaud Reviewed-by: Thomas Munro and Michael Paquier Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com