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* Support INCLUDE'd columns in SP-GiST.Tom Lane2021-04-05
| | | | | | | | | | | | | Not much to say here: does what it says on the tin. We steal a previously-always-zero bit from the nextOffset field of leaf index tuples in order to track whether there is a nulls bitmap. Otherwise it works about like included columns in other index types. Pavel Borisov, reviewed by Andrey Borodin and Anastasia Lubennikova, and rather heavily editorialized on by me Discussion: https://postgr.es/m/CALT9ZEFi-vMp4faht9f9Junb1nO3NOSjhpxTmbm1UGLMsLqiEQ@mail.gmail.com
* Add pg_read_all_data and pg_write_all_data rolesStephen Frost2021-04-05
| | | | | | | | | | | | | | | | | | | | | | | A commonly requested use-case is to have a role who can run an unfettered pg_dump without having to explicitly GRANT that user access to all tables, schemas, et al, without that role being a superuser. This address that by adding a "pg_read_all_data" role which implicitly gives any member of this role SELECT rights on all tables, views and sequences, and USAGE rights on all schemas. As there may be cases where it's also useful to have a role who has write access to all objects, pg_write_all_data is also introduced and gives users implicit INSERT, UPDATE and DELETE rights on all tables, views and sequences. These roles can not be logged into directly but instead should be GRANT'd to a role which is able to log in. As noted in the documentation, if RLS is being used then an administrator may (or may not) wish to set BYPASSRLS on the login role which these predefined roles are GRANT'd to. Reviewed-by: Georgios Kokolatos Discussion: https://postgr.es/m/20200828003023.GU29590@tamriel.snowman.net
* Align some terms in arch-dev.sgml to glossaryAlvaro Herrera2021-04-05
| | | | | | | | | This mostly adds links to the glossary to the existing text, instead of using <firstterm>. Heikki left this out of 29ad6595ef7f out of stylistic concerns; these have since been addressed. Author: Jürgen Purtz <juergen@purtz.de> Discussion: https://postgr.es/m/67d7240f-8596-83fc-5e15-af06c128a0f5@purtz.de
* Fix confusion in SP-GiST between attribute type and leaf storage type.Tom Lane2021-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to the documentation, the attType passed to the opclass config function (and also relied on by the core code) is the type of the heap column or expression being indexed. But what was actually being passed was the type stored for the index column. This made no difference for user-defined SP-GiST opclasses, because we weren't allowing the STORAGE clause of CREATE OPCLASS to be used, so the two types would be the same. But it's silly not to allow that, seeing that the built-in poly_ops opclass has a different value for opckeytype than opcintype, and that if you want to do lossy storage then the types must really be different. (Thus, user-defined opclasses doing lossy storage had to lie about what type is in the index.) Hence, remove the restriction, and make sure that we use the input column type not opckeytype where relevant. For reasons of backwards compatibility with existing user-defined opclasses, we can't quite insist that the specified leafType match the STORAGE clause; instead just add an amvalidate() warning if they don't match. Also fix some bugs that would only manifest when trying to return index entries when attType is different from attLeafType. It's not too surprising that these have not been reported, because the only usual reason for such a difference is to store the leaf value lossily, rendering index-only scans impossible. Add a src/test/modules module to exercise cases where attType is different from attLeafType and yet index-only scan is supported. Discussion: https://postgr.es/m/3728741.1617381471@sss.pgh.pa.us
* Improve psql's behavior when the editor is exited without saving.Tom Lane2021-04-03
| | | | | | | | | | | | | | | | | | | | When editing the previous query buffer, if the editor is exited without modifying the temp file then clear the query buffer, rather than re-loading (and probably re-executing) the previous query buffer. This reduces the probability of accidentally re-executing something you didn't intend to. Similarly, in "\e file", if the file isn't actually modified then don't load it into the query buffer. And in "\ef" and "\ev", if no changes are made then clear the query buffer instead of loading the function or view definition into it. Cases where we fail to invoke the editor at all, or it returns a nonzero status, are treated like the no-file-modification case. Laurenz Albe, reviewed by Jacob Champion Discussion: https://postgr.es/m/0ba3f2a658bac6546d9934ab6ba63a805d46a49b.camel@cybertec.at
* Detect POLLHUP/POLLRDHUP while running queries.Thomas Munro2021-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | Provide a new GUC check_client_connection_interval that can be used to check whether the client connection has gone away, while running very long queries. It is disabled by default. For now this uses a non-standard Linux extension (also adopted by at least one other OS). POLLRDHUP is not defined by POSIX, and other OSes don't have a reliable way to know if a connection was closed without actually trying to read or write. In future we might consider trying to send a no-op/heartbeat message instead, but that could require protocol changes. Author: Sergey Cherkashin <s.cherkashin@postgrespro.ru> Author: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Tatsuo Ishii <ishii@sraoss.co.jp> Reviewed-by: Konstantin Knizhnik <k.knizhnik@postgrespro.ru> Reviewed-by: Zhihong Yu <zyu@yugabyte.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Maksim Milyutin <milyutinma@gmail.com> Reviewed-by: Tsunakawa, Takayuki/綱川 貴之 <tsunakawa.takay@fujitsu.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (much earlier version) Discussion: https://postgr.es/m/77def86b27e41f0efcba411460e929ae%40postgrespro.ru
* Clarify documentation of RESET ROLEJoe Conway2021-04-02
| | | | | | | | | | | | | | | Command-line options, or previous "ALTER (ROLE|DATABASE) ... SET ROLE ..." commands, can change the value of the default role for a session. In the presence of one of these, RESET ROLE will change the current user identifier to the default role rather than the session user identifier. Fix the documentation to reflect this reality. Backpatch to all supported versions. Author: Nathan Bossart Reviewed-By: Laurenz Albe, David G. Johnston, Joe Conway Reported by: Nathan Bossart Discussion: https://postgr.es/m/flat/925134DB-8212-4F60-8AB1-B1231D750CB4%40amazon.com Backpatch-through: 9.6
* postgres_fdw: Add option to control whether to keep connections open.Fujii Masao2021-04-02
| | | | | | | | | | | | | | | | | | This commit adds a new option keep_connections that controls whether postgres_fdw keeps the connections to the foreign server open so that the subsequent queries can re-use them. This option can only be specified for a foreign server. The default is on. If set to off, all connections to the foreign server will be discarded at the end of transaction. Closed connections will be re-established when they are necessary by future queries using a foreign table. This option is useful, for example, when users want to prevent the connections from eating up the foreign servers connections capacity. Author: Bharath Rupireddy Reviewed-by: Alexey Kondratov, Vignesh C, Fujii Masao Discussion: https://postgr.es/m/CALj2ACVvrp5=AVp2PupEm+nAC8S4buqR3fJMmaCoc7ftT0aD2A@mail.gmail.com
* doc: Clarify how to generate backup files with non-exclusive backupsMichael Paquier2021-04-02
| | | | | | | | | | | | | | | | | | The current instructions describing how to write the backup_label and tablespace_map files are confusing. For example, opening a file in text mode on Windows and copy-pasting the file's contents would result in a failure at recovery because of the extra CRLF characters generated. The documentation was not stating that clearly, and per discussion this is not considered as a supported scenario. This commit extends a bit the documentation to mention that it may be required to open the file in binary mode before writing its data. Reported-by: Wang Shenhao Author: David Steele Reviewed-by: Andrew Dunstan, Magnus Hagander Discussion: https://postgr.es/m/8373f61426074f2cb6be92e02f838389@G08CNEXMBPEKD06.g08.fujitsu.local Backpatch-through: 9.6
* doc: mention that intervening major releases can be skippedBruce Momjian2021-04-01
| | | | | | | | | Also mention that you should read the intervening major releases notes. This change was also applied to the website. Discussion: https://postgr.es/m/20210330144949.GA8259@momjian.us Backpatch-through: 9.6
* Add Result Cache executor node (take 2)David Rowley2021-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here we add a new executor node type named "Result Cache". The planner can include this node type in the plan to have the executor cache the results from the inner side of parameterized nested loop joins. This allows caching of tuples for sets of parameters so that in the event that the node sees the same parameter values again, it can just return the cached tuples instead of rescanning the inner side of the join all over again. Internally, result cache uses a hash table in order to quickly find tuples that have been previously cached. For certain data sets, this can significantly improve the performance of joins. The best cases for using this new node type are for join problems where a large portion of the tuples from the inner side of the join have no join partner on the outer side of the join. In such cases, hash join would have to hash values that are never looked up, thus bloating the hash table and possibly causing it to multi-batch. Merge joins would have to skip over all of the unmatched rows. If we use a nested loop join with a result cache, then we only cache tuples that have at least one join partner on the outer side of the join. The benefits of using a parameterized nested loop with a result cache increase when there are fewer distinct values being looked up and the number of lookups of each value is large. Also, hash probes to lookup the cache can be much faster than the hash probe in a hash join as it's common that the result cache's hash table is much smaller than the hash join's due to result cache only caching useful tuples rather than all tuples from the inner side of the join. This variation in hash probe performance is more significant when the hash join's hash table no longer fits into the CPU's L3 cache, but the result cache's hash table does. The apparent "random" access of hash buckets with each hash probe can cause a poor L3 cache hit ratio for large hash tables. Smaller hash tables generally perform better. The hash table used for the cache limits itself to not exceeding work_mem * hash_mem_multiplier in size. We maintain a dlist of keys for this cache and when we're adding new tuples and realize we've exceeded the memory budget, we evict cache entries starting with the least recently used ones until we have enough memory to add the new tuples to the cache. For parameterized nested loop joins, we now consider using one of these result cache nodes in between the nested loop node and its inner node. We determine when this might be useful based on cost, which is primarily driven off of what the expected cache hit ratio will be. Estimating the cache hit ratio relies on having good distinct estimates on the nested loop's parameters. For now, the planner will only consider using a result cache for parameterized nested loop joins. This works for both normal joins and also for LATERAL type joins to subqueries. It is possible to use this new node for other uses in the future. For example, to cache results from correlated subqueries. However, that's not done here due to some difficulties obtaining a distinct estimation on the outer plan to calculate the estimated cache hit ratio. Currently we plan the inner plan before planning the outer plan so there is no good way to know if a result cache would be useful or not since we can't estimate the number of times the subplan will be called until the outer plan is generated. The functionality being added here is newly introducing a dependency on the return value of estimate_num_groups() during the join search. Previously, during the join search, we only ever needed to perform selectivity estimations. With this commit, we need to use estimate_num_groups() in order to estimate what the hit ratio on the result cache will be. In simple terms, if we expect 10 distinct values and we expect 1000 outer rows, then we'll estimate the hit ratio to be 99%. Since cache hits are very cheap compared to scanning the underlying nodes on the inner side of the nested loop join, then this will significantly reduce the planner's cost for the join. However, it's fairly easy to see here that things will go bad when estimate_num_groups() incorrectly returns a value that's significantly lower than the actual number of distinct values. If this happens then that may cause us to make use of a nested loop join with a result cache instead of some other join type, such as a merge or hash join. Our distinct estimations have been known to be a source of trouble in the past, so the extra reliance on them here could cause the planner to choose slower plans than it did previous to having this feature. Distinct estimations are also fairly hard to estimate accurately when several tables have been joined already or when a WHERE clause filters out a set of values that are correlated to the expressions we're estimating the number of distinct value for. For now, the costing we perform during query planning for result caches does put quite a bit of faith in the distinct estimations being accurate. When these are accurate then we should generally see faster execution times for plans containing a result cache. However, in the real world, we may find that we need to either change the costings to put less trust in the distinct estimations being accurate or perhaps even disable this feature by default. There's always an element of risk when we teach the query planner to do new tricks that it decides to use that new trick at the wrong time and causes a regression. Users may opt to get the old behavior by turning the feature off using the enable_resultcache GUC. Currently, this is enabled by default. It remains to be seen if we'll maintain that setting for the release. Additionally, the name "Result Cache" is the best name I could think of for this new node at the time I started writing the patch. Nobody seems to strongly dislike the name. A few people did suggest other names but no other name seemed to dominate in the brief discussion that there was about names. Let's allow the beta period to see if the current name pleases enough people. If there's some consensus on a better name, then we can change it before the release. Please see the 2nd discussion link below for the discussion on the "Result Cache" name. Author: David Rowley Reviewed-by: Andy Fan, Justin Pryzby, Zhihong Yu, Hou Zhijie Tested-By: Konstantin Knizhnik Discussion: https://postgr.es/m/CAApHDvrPcQyQdWERGYWx8J%2B2DLUNgXu%2BfOSbQ1UscxrunyXyrQ%40mail.gmail.com Discussion: https://postgr.es/m/CAApHDvq=yQXr5kqhRviT2RhNKwToaWr9JAN5t+5_PzhuRJ3wvg@mail.gmail.com
* Rename Default Roles to Predefined RolesStephen Frost2021-04-01
| | | | | | | | | | | | | The term 'default roles' wasn't quite apt as these roles aren't able to be modified or removed after installation, so rename them to be 'Predefined Roles' instead, adding an entry into the newly added Obsolete Appendix to help users of current releases find the new documentation. Bruce Momjian and Stephen Frost Discussion: https://postgr.es/m/157742545062.1149.11052653770497832538%40wrigleys.postgresql.org and https://www.postgresql.org/message-id/20201120211304.GG16415@tamriel.snowman.net
* Add 'noError' argument to encoding conversion functions.Heikki Linnakangas2021-04-01
| | | | | | | | | | | | | | | | | | | | | | With the 'noError' argument, you can try to convert a buffer without knowing the character boundaries beforehand. The functions now need to return the number of input bytes successfully converted. This is is a backwards-incompatible change, if you have created a custom encoding conversion with CREATE CONVERSION. This adds a check to pg_upgrade for that, refusing the upgrade if there are any user-defined encoding conversions. Custom conversions are very rare, there are no commonly used extensions that I know of that uses that feature. No other objects can depend on conversions, so if you do have one, you can fairly easily drop it before upgrading, and recreate it after the upgrade with an updated version. Add regression tests for built-in encoding conversions. This doesn't cover every conversion, but it covers all the internal functions in conv.c that are used to implement the conversions. Reviewed-by: John Naylor Discussion: https://www.postgresql.org/message-id/e7861509-3960-538a-9025-b75a61188e01%40iki.fi
* doc: Clarify use of ACCESS EXCLUSIVE lock in various sectionsMichael Paquier2021-04-01
| | | | | | | | | | | | Some sections of the documentation used "exclusive lock" to describe that an ACCESS EXCLUSIVE lock is taken during a given operation. This can be confusing to the reader as ACCESS SHARE is allowed with an EXCLUSIVE lock is used, but that would not be the case with what is described on those parts of the documentation. Author: Greg Rychlewski Discussion: https://postgr.es/m/CAKemG7VptD=7fNWckFMsMVZL_zzvgDO6v2yVmQ+ZiBfc_06kCQ@mail.gmail.com Backpatch-through: 9.6
* Ensure to send a prepare after we detect concurrent abort during decoding.Amit Kapila2021-04-01
| | | | | | | | | | | | | It is possible that while decoding a prepared transaction, it gets aborted concurrently via a ROLLBACK PREPARED command. In that case, we were skipping all the changes and directly sending Rollback Prepared when we find the same in WAL. However, the downstream has no idea of the GID of such a transaction. So, ensure to send prepare even when a concurrent abort is detected. Author: Ajin Cherian Reviewed-by: Markus Wanner, Amit Kapila Discussion: https://postgr.es/m/f82133c6-6055-b400-7922-97dae9f2b50b@enterprisedb.com
* Revert b6002a796David Rowley2021-04-01
| | | | | | | | | | | | | This removes "Add Result Cache executor node". It seems that something weird is going on with the tracking of cache hits and misses as highlighted by many buildfarm animals. It's not yet clear what the problem is as other parts of the plan indicate that the cache did work correctly, it's just the hits and misses that were being reported as 0. This is especially a bad time to have the buildfarm so broken, so reverting before too many more animals go red. Discussion: https://postgr.es/m/CAApHDvq_hydhfovm4=izgWs+C5HqEeRScjMbOgbpC-jRAeK3Yw@mail.gmail.com
* Add Result Cache executor nodeDavid Rowley2021-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here we add a new executor node type named "Result Cache". The planner can include this node type in the plan to have the executor cache the results from the inner side of parameterized nested loop joins. This allows caching of tuples for sets of parameters so that in the event that the node sees the same parameter values again, it can just return the cached tuples instead of rescanning the inner side of the join all over again. Internally, result cache uses a hash table in order to quickly find tuples that have been previously cached. For certain data sets, this can significantly improve the performance of joins. The best cases for using this new node type are for join problems where a large portion of the tuples from the inner side of the join have no join partner on the outer side of the join. In such cases, hash join would have to hash values that are never looked up, thus bloating the hash table and possibly causing it to multi-batch. Merge joins would have to skip over all of the unmatched rows. If we use a nested loop join with a result cache, then we only cache tuples that have at least one join partner on the outer side of the join. The benefits of using a parameterized nested loop with a result cache increase when there are fewer distinct values being looked up and the number of lookups of each value is large. Also, hash probes to lookup the cache can be much faster than the hash probe in a hash join as it's common that the result cache's hash table is much smaller than the hash join's due to result cache only caching useful tuples rather than all tuples from the inner side of the join. This variation in hash probe performance is more significant when the hash join's hash table no longer fits into the CPU's L3 cache, but the result cache's hash table does. The apparent "random" access of hash buckets with each hash probe can cause a poor L3 cache hit ratio for large hash tables. Smaller hash tables generally perform better. The hash table used for the cache limits itself to not exceeding work_mem * hash_mem_multiplier in size. We maintain a dlist of keys for this cache and when we're adding new tuples and realize we've exceeded the memory budget, we evict cache entries starting with the least recently used ones until we have enough memory to add the new tuples to the cache. For parameterized nested loop joins, we now consider using one of these result cache nodes in between the nested loop node and its inner node. We determine when this might be useful based on cost, which is primarily driven off of what the expected cache hit ratio will be. Estimating the cache hit ratio relies on having good distinct estimates on the nested loop's parameters. For now, the planner will only consider using a result cache for parameterized nested loop joins. This works for both normal joins and also for LATERAL type joins to subqueries. It is possible to use this new node for other uses in the future. For example, to cache results from correlated subqueries. However, that's not done here due to some difficulties obtaining a distinct estimation on the outer plan to calculate the estimated cache hit ratio. Currently we plan the inner plan before planning the outer plan so there is no good way to know if a result cache would be useful or not since we can't estimate the number of times the subplan will be called until the outer plan is generated. The functionality being added here is newly introducing a dependency on the return value of estimate_num_groups() during the join search. Previously, during the join search, we only ever needed to perform selectivity estimations. With this commit, we need to use estimate_num_groups() in order to estimate what the hit ratio on the result cache will be. In simple terms, if we expect 10 distinct values and we expect 1000 outer rows, then we'll estimate the hit ratio to be 99%. Since cache hits are very cheap compared to scanning the underlying nodes on the inner side of the nested loop join, then this will significantly reduce the planner's cost for the join. However, it's fairly easy to see here that things will go bad when estimate_num_groups() incorrectly returns a value that's significantly lower than the actual number of distinct values. If this happens then that may cause us to make use of a nested loop join with a result cache instead of some other join type, such as a merge or hash join. Our distinct estimations have been known to be a source of trouble in the past, so the extra reliance on them here could cause the planner to choose slower plans than it did previous to having this feature. Distinct estimations are also fairly hard to estimate accurately when several tables have been joined already or when a WHERE clause filters out a set of values that are correlated to the expressions we're estimating the number of distinct value for. For now, the costing we perform during query planning for result caches does put quite a bit of faith in the distinct estimations being accurate. When these are accurate then we should generally see faster execution times for plans containing a result cache. However, in the real world, we may find that we need to either change the costings to put less trust in the distinct estimations being accurate or perhaps even disable this feature by default. There's always an element of risk when we teach the query planner to do new tricks that it decides to use that new trick at the wrong time and causes a regression. Users may opt to get the old behavior by turning the feature off using the enable_resultcache GUC. Currently, this is enabled by default. It remains to be seen if we'll maintain that setting for the release. Additionally, the name "Result Cache" is the best name I could think of for this new node at the time I started writing the patch. Nobody seems to strongly dislike the name. A few people did suggest other names but no other name seemed to dominate in the brief discussion that there was about names. Let's allow the beta period to see if the current name pleases enough people. If there's some consensus on a better name, then we can change it before the release. Please see the 2nd discussion link below for the discussion on the "Result Cache" name. Author: David Rowley Reviewed-by: Andy Fan, Justin Pryzby, Zhihong Yu Tested-By: Konstantin Knizhnik Discussion: https://postgr.es/m/CAApHDvrPcQyQdWERGYWx8J%2B2DLUNgXu%2BfOSbQ1UscxrunyXyrQ%40mail.gmail.com Discussion: https://postgr.es/m/CAApHDvq=yQXr5kqhRviT2RhNKwToaWr9JAN5t+5_PzhuRJ3wvg@mail.gmail.com
* Add a docs section for obsoleted and renamed functions and settingsStephen Frost2021-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | The new appendix groups information on renamed or removed settings, commands, etc into an out-of-the-way part of the docs. The original id elements are retained in each subsection to ensure that the same filenames are produced for HTML docs. This prevents /current/ links on the web from breaking, and allows users of the web docs to follow links from old version pages to info on the changes in the new version. Prior to this change, a link to /current/ for renamed sections like the recovery.conf docs would just 404. Similarly if someone searched for recovery.conf they would find the pg11 docs, but there would be no /12/ or /current/ link, so they couldn't easily find out that it was removed in pg12 or how to adapt. Index entries are also added so that there's a breadcrumb trail for users to follow when they know the old name, but not what we changed it to. So a user who is trying to find out how to set standby_mode in PostgreSQL 12+, or where pg_resetxlog went, now has more chance of finding that information. Craig Ringer and Stephen Frost Reviewed-by: Euler Taveira Discussion: https://postgr.es/m/CAGRY4nzPNOyYQ_1-pWYToUVqQ0ThqP5jdURnJMZPm539fdizOg%40mail.gmail.com Backpatch-through: 10
* Rework planning and execution of UPDATE and DELETE.Tom Lane2021-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes two closely related sets of changes: 1. For UPDATE, the subplan of the ModifyTable node now only delivers the new values of the changed columns (i.e., the expressions computed in the query's SET clause) plus row identity information such as CTID. ModifyTable must re-fetch the original tuple to merge in the old values of any unchanged columns. The core advantage of this is that the changed columns are uniform across all tables of an inherited or partitioned target relation, whereas the other columns might not be. A secondary advantage, when the UPDATE involves joins, is that less data needs to pass through the plan tree. The disadvantage of course is an extra fetch of each tuple to be updated. However, that seems to be very nearly free in context; even worst-case tests don't show it to add more than a couple percent to the total query cost. At some point it might be interesting to combine the re-fetch with the tuple access that ModifyTable must do anyway to mark the old tuple dead; but that would require a good deal of refactoring and it seems it wouldn't buy all that much, so this patch doesn't attempt it. 2. For inherited UPDATE/DELETE, instead of generating a separate subplan for each target relation, we now generate a single subplan that is just exactly like a SELECT's plan, then stick ModifyTable on top of that. To let ModifyTable know which target relation a given incoming row refers to, a tableoid junk column is added to the row identity information. This gets rid of the horrid hack that was inheritance_planner(), eliminating O(N^2) planning cost and memory consumption in cases where there were many unprunable target relations. Point 2 of course requires point 1, so that there is a uniform definition of the non-junk columns to be returned by the subplan. We can't insist on uniform definition of the row identity junk columns however, if we want to keep the ability to have both plain and foreign tables in a partitioning hierarchy. Since it wouldn't scale very far to have every child table have its own row identity column, this patch includes provisions to merge similar row identity columns into one column of the subplan result. In particular, we can merge the whole-row Vars typically used as row identity by FDWs into one column by pretending they are type RECORD. (It's still okay for the actual composite Datums to be labeled with the table's rowtype OID, though.) There is more that can be done to file down residual inefficiencies in this patch, but it seems to be committable now. FDW authors should note several API changes: * The argument list for AddForeignUpdateTargets() has changed, and so has the method it must use for adding junk columns to the query. Call add_row_identity_var() instead of manipulating the parse tree directly. You might want to reconsider exactly what you're adding, too. * PlanDirectModify() must now work a little harder to find the ForeignScan plan node; if the foreign table is part of a partitioning hierarchy then the ForeignScan might not be the direct child of ModifyTable. See postgres_fdw for sample code. * To check whether a relation is a target relation, it's no longer sufficient to compare its relid to root->parse->resultRelation. Instead, check it against all_result_relids or leaf_result_relids, as appropriate. Amit Langote and Tom Lane Discussion: https://postgr.es/m/CA+HiwqHpHdqdDn48yCEhynnniahH78rwcrv1rEX65-fsZGBOLQ@mail.gmail.com
* Allow an alias to be attached to a JOIN ... USINGPeter Eisentraut2021-03-31
| | | | | | | | | | | | | | | This allows something like SELECT ... FROM t1 JOIN t2 USING (a, b, c) AS x where x has the columns a, b, c and unlike a regular alias it does not hide the range variables of the tables being joined t1 and t2. Per SQL:2016 feature F404 "Range variable for common column names". Reviewed-by: Vik Fearing <vik.fearing@2ndquadrant.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/454638cf-d563-ab76-a585-2564428062af@2ndquadrant.com
* Add support for asynchronous execution.Etsuro Fujita2021-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements asynchronous execution, which runs multiple parts of a non-parallel-aware Append concurrently rather than serially to improve performance when possible. Currently, the only node type that can be run concurrently is a ForeignScan that is an immediate child of such an Append. In the case where such ForeignScans access data on different remote servers, this would run those ForeignScans concurrently, and overlap the remote operations to be performed simultaneously, so it'll improve the performance especially when the operations involve time-consuming ones such as remote join and remote aggregation. We may extend this to other node types such as joins or aggregates over ForeignScans in the future. This also adds the support for postgres_fdw, which is enabled by the table-level/server-level option "async_capable". The default is false. Robert Haas, Kyotaro Horiguchi, Thomas Munro, and myself. This commit is mostly based on the patch proposed by Robert Haas, but also uses stuff from the patch proposed by Kyotaro Horiguchi and from the patch proposed by Thomas Munro. Reviewed by Kyotaro Horiguchi, Konstantin Knizhnik, Andrey Lepikhov, Movead Li, Thomas Munro, Justin Pryzby, and others. Discussion: https://postgr.es/m/CA%2BTgmoaXQEt4tZ03FtQhnzeDEMzBck%2BLrni0UWHVVgOTnA6C1w%40mail.gmail.com Discussion: https://postgr.es/m/CA%2BhUKGLBRyu0rHrDCMC4%3DRn3252gogyp1SjOgG8SEKKZv%3DFwfQ%40mail.gmail.com Discussion: https://postgr.es/m/20200228.170650.667613673625155850.horikyota.ntt%40gmail.com
* Add errhint_plural() function and make use of itPeter Eisentraut2021-03-31
| | | | | Similar to existing errmsg_plural() and errdetail_plural(). Some errhint() calls hadn't received the proper plural treatment yet.
* doc: Remove Cyrillic from unistr examplePeter Eisentraut2021-03-31
| | | | Not supported by PDF build right now, so let's do without it.
* Doc: Use consistent terminology for tablesync slots.Amit Kapila2021-03-31
| | | | | | | | | | At some places in the docs, we refer to them as tablesync slots and at other places as table synchronization slots. For consistency, we refer to them as table synchronization slots at all places. Author: Peter Smith Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/CAHut+PvzYNKCeZ=kKBDkh3dw-r=2D3fk=nNc9SXSW=CZGk69xg@mail.gmail.com
* Add support for --extension in pg_dumpMichael Paquier2021-03-31
| | | | | | | | | | | | | | | | | When specified, only extensions matching the given pattern are included in dumps. Similarly to --table and --schema, when --strict-names is used, a perfect match is required. Also, like the two other options, this new option offers no guarantee that dependent objects have been dumped, so a restore may fail on a clean database. Tests are added in test_pg_dump/, checking after a set of positive and negative cases, with or without an extension's contents added to the dump generated. Author: Guillaume Lelarge Reviewed-by: David Fetter, Tom Lane, Michael Paquier, Asif Rehman, Julien Rouhaud Discussion: https://postgr.es/m/CAECtzeXOt4cnMU5+XMZzxBPJ_wu76pNy6HZKPRBL-j7yj1E4+g@mail.gmail.com
* Improve PQtrace() output formatAlvaro Herrera2021-03-30
| | | | | | | | | | | | | | | | | | | | | | Transform the PQtrace output format from its ancient (and mostly useless) byte-level output format to a logical-message-level output, making it much more usable. This implementation allows the printing code to be written (as it indeed was) by looking at the protocol documentation, which gives more confidence that the three (docs, trace code and actual code) actually match. Author: 岩田 彩 (Aya Iwata) <iwata.aya@fujitsu.com> Reviewed-by: 綱川 貴之 (Takayuki Tsunakawa) <tsunakawa.takay@fujitsu.com> Reviewed-by: Kirk Jamison <k.jamison@fujitsu.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: 黒田 隼人 (Hayato Kuroda) <kuroda.hayato@fujitsu.com> Reviewed-by: "Nagaura, Ryohei" <nagaura.ryohei@jp.fujitsu.com> Reviewed-by: Ryo Matsumura <matsumura.ryo@fujitsu.com> Reviewed-by: Greg Nancarrow <gregn4422@gmail.com> Reviewed-by: Jim Doty <jdoty@pivotal.io> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/71E660EB361DF14299875B198D4CE5423DE3FBA4@g01jpexmbkw25
* Add a xid argument to the filter_prepare callback for output plugins.Amit Kapila2021-03-30
| | | | | | | | | | | | Along with gid, this provides a different way to identify the transaction. The users that use xid in some way to prepare the transactions can use it to filter prepare transactions. The later commands COMMIT PREPARED or ROLLBACK PREPARED carries both identifiers, providing an output plugin the choice of what to use. Author: Markus Wanner Reviewed-by: Vignesh C, Amit Kapila Discussion: https://postgr.es/m/ee280000-7355-c4dc-e47b-2436e7be959c@enterprisedb.com
* Allow matching the DN of a client certificate for authenticationAndrew Dunstan2021-03-29
| | | | | | | | | | | | | | | | | | | Currently we only recognize the Common Name (CN) of a certificate's subject to be matched against the user name. Thus certificates with subjects '/OU=eng/CN=fred' and '/OU=sales/CN=fred' will have the same connection rights. This patch provides an option to match the whole Distinguished Name (DN) instead of just the CN. On any hba line using client certificate identity, there is an option 'clientname' which can have values of 'DN' or 'CN'. The default is 'CN', the current procedure. The DN is matched against the RFC2253 formatted DN, which looks like 'CN=fred,OU=eng'. This facility of probably best used in conjunction with an ident map. Discussion: https://postgr.es/m/92e70110-9273-d93c-5913-0bccb6562740@dunslane.net Reviewed-By: Michael Paquier, Daniel Gustafsson, Jacob Champion
* Add unistr functionPeter Eisentraut2021-03-29
| | | | | | | | | This allows decoding a string with Unicode escape sequences. It is similar to Unicode escape strings, but offers some more flexibility. Author: Pavel Stehule <pavel.stehule@gmail.com> Reviewed-by: Asif Rehman <asifr.rehman@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CAFj8pRA5GnKT+gDVwbVRH2ep451H_myBt+NTz8RkYUARE9+qOQ@mail.gmail.com
* doc: Define TLS as an acronymStephen Frost2021-03-28
| | | | | | | | | | Commit c6763156589 added an acronym reference for "TLS" but the definition was never added. Author: Daniel Gustafsson Reviewed-by: Michael Paquier Backpatch-through: 9.6 Discussion: https://postgr.es/m/27109504-82DB-41A8-8E63-C0498314F5B0@yesql.se
* Extended statistics on expressionsTomas Vondra2021-03-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow defining extended statistics on expressions, not just just on simple column references. With this commit, expressions are supported by all existing extended statistics kinds, improving the same types of estimates. A simple example may look like this: CREATE TABLE t (a int); CREATE STATISTICS s ON mod(a,10), mod(a,20) FROM t; ANALYZE t; The collected statistics are useful e.g. to estimate queries with those expressions in WHERE or GROUP BY clauses: SELECT * FROM t WHERE mod(a,10) = 0 AND mod(a,20) = 0; SELECT 1 FROM t GROUP BY mod(a,10), mod(a,20); This introduces new internal statistics kind 'e' (expressions) which is built automatically when the statistics object definition includes any expressions. This represents single-expression statistics, as if there was an expression index (but without the index maintenance overhead). The statistics is stored in pg_statistics_ext_data as an array of composite types, which is possible thanks to 79f6a942bd. CREATE STATISTICS allows building statistics on a single expression, in which case in which case it's not possible to specify statistics kinds. A new system view pg_stats_ext_exprs can be used to display expression statistics, similarly to pg_stats and pg_stats_ext views. ALTER TABLE ... ALTER COLUMN ... TYPE now treats indexes the same way it treats indexes, i.e. it drops and recreates the statistics. This means all statistics are reset, and we no longer try to preserve at least the functional dependencies. This should not be a major issue in practice, as the functional dependencies actually rely on per-column statistics, which were always reset anyway. Author: Tomas Vondra Reviewed-by: Justin Pryzby, Dean Rasheed, Zhihong Yu Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com
* Add "pg_database_owner" default role.Noah Misch2021-03-26
| | | | | | | | | | | Membership consists, implicitly, of the current database owner. Expect use in template databases. Once pg_database_owner has rights within a template, each owner of a database instantiated from that template will exercise those rights. Reviewed by John Naylor. Discussion: https://postgr.es/m/20201228043148.GA1053024@rfd.leadboat.com
* BRIN minmax-multi indexesTomas Vondra2021-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds BRIN opclasses similar to the existing minmax, except that instead of summarizing the page range into a single [min,max] range, the summary consists of multiple ranges and/or points, allowing gaps. This allows more efficient handling of data with poor correlation to physical location within the table and/or outlier values, for which the regular minmax opclassed tend to work poorly. It's possible to specify the number of values kept for each page range, either as a single point or an interval boundary. CREATE TABLE t (a int); CREATE INDEX ON t USING brin (a int4_minmax_multi_ops(values_per_range=16)); When building the summary, the values are combined into intervals with the goal to minimize the "covering" (sum of interval lengths), using a support procedure computing distance between two values. Bump catversion, due to various catalog changes. Author: Tomas Vondra <tomas.vondra@postgresql.org> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: Sokolov Yura <y.sokolov@postgrespro.ru> Reviewed-by: John Naylor <john.naylor@enterprisedb.com> Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com Discussion: https://postgr.es/m/5d78b774-7e9c-c94e-12cf-fef51cc89b1a%402ndquadrant.com
* BRIN bloom indexesTomas Vondra2021-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds a BRIN opclass using a Bloom filter to summarize the range. Indexes using the new opclasses allow only equality queries (similar to hash indexes), but that works fine for data like UUID, MAC addresses etc. for which range queries are not very common. This also means the indexes work for data that is not well correlated to physical location within the table, or perhaps even entirely random (which is a common issue with existing BRIN minmax opclasses). It's possible to specify opclass parameters with the usual Bloom filter parameters, i.e. the desired false-positive rate and the expected number of distinct values per page range. CREATE TABLE t (a int); CREATE INDEX ON t USING brin (a int4_bloom_ops(false_positive_rate = 0.05, n_distinct_per_range = 100)); The opclasses do not operate on the indexed values directly, but compute a 32-bit hash first, and the Bloom filter is built on the hash value. Collisions should not be a huge issue though, as the number of distinct values in a page ranges is usually fairly small. Bump catversion, due to various catalog changes. Author: Tomas Vondra <tomas.vondra@postgresql.org> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: Sokolov Yura <y.sokolov@postgrespro.ru> Reviewed-by: Nico Williams <nico@cryptonector.com> Reviewed-by: John Naylor <john.naylor@enterprisedb.com> Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com Discussion: https://postgr.es/m/5d78b774-7e9c-c94e-12cf-fef51cc89b1a%402ndquadrant.com
* Support the old signature of BRIN consistent functionTomas Vondra2021-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a1c649d889 changed the signature of the BRIN consistent function by adding a new required parameter. Treating the parameter as optional, which would make the change backwards incompatibile, was rejected with the justification that there are few out-of-core extensions, so it's not worth adding making the code more complex, and it's better to deal with that in the extension. But after further thought, that would be rather problematic, because pg_upgrade simply dumps catalog contents and the same version of an extension needs to work on both PostgreSQL versions. Supporting both variants of the consistent function (with 3 or 4 arguments) makes that possible. The signature is not the only thing that changed, as commit 72ccf55cb9 moved handling of IS [NOT] NULL keys from the support procedures. But this change is backward compatible - handling the keys in exension is unnecessary, but harmless. The consistent function will do a bit of unnecessary work, but it should be very cheap. This also undoes most of the changes to the existing opclasses (minmax and inclusion), making them use the old signature again. This should make backpatching simpler. Catversion bump, because of changes in pg_amproc. Author: Tomas Vondra <tomas.vondra@postgresql.org> Author: Nikita Glukhov <n.gluhov@postgrespro.ru> Reviewed-by: Mark Dilger <hornschnorter@gmail.com> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: Masahiko Sawada <masahiko.sawada@enterprisedb.com> Reviewed-by: John Naylor <john.naylor@enterprisedb.com> Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
* ALTER TABLE ... DETACH PARTITION ... CONCURRENTLYAlvaro Herrera2021-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow a partition be detached from its partitioned table without blocking concurrent queries, by running in two transactions and only requiring ShareUpdateExclusive in the partitioned table. Because it runs in two transactions, it cannot be used in a transaction block. This is the main reason to use dedicated syntax: so that users can choose to use the original mode if they need it. But also, it doesn't work when a default partition exists (because an exclusive lock would still need to be obtained on it, in order to change its partition constraint.) In case the second transaction is cancelled or a crash occurs, there's ALTER TABLE .. DETACH PARTITION .. FINALIZE, which executes the final steps. The main trick to make this work is the addition of column pg_inherits.inhdetachpending, initially false; can only be set true in the first part of this command. Once that is committed, concurrent transactions that use a PartitionDirectory will include or ignore partitions so marked: in optimizer they are ignored if the row is marked committed for the snapshot; in executor they are always included. As a result, and because of the way PartitionDirectory caches partition descriptors, queries that were planned before the detach will see the rows in the detached partition and queries that are planned after the detach, won't. A CHECK constraint is created that duplicates the partition constraint. This is probably not strictly necessary, and some users will prefer to remove it afterwards, but if the partition is re-attached to a partitioned table, the constraint needn't be rechecked. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20200803234854.GA24158@alvherre.pgsql
* Document lock obtained during partition detachAlvaro Herrera2021-03-25
| | | | | | | | | | On partition detach, we acquire a SHARE lock on all tables that reference the partitioned table that we're detaching a partition from, but failed to document this fact. My oversight in commit f56f8f8da6af. Repair. Backpatch to 12. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20210325180244.GA12738@alvherre.pgsql
* Add DECLARE STATEMENT command to ECPGMichael Meskes2021-03-24
| | | | | | | | | This command declares a SQL identifier for a SQL statement to be used in other embedded SQL statements. The identifier is linked to a connection. Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Shawn Wang <shawn.wang.pg@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/TY2PR01MB24438A52DB04E71D0E501452F5630@TY2PR01MB2443.jpnprd01.prod.outlook.com
* doc: Fix typoPeter Eisentraut2021-03-24
| | | | Reported-by: Erik Rijkers <er@xs4all.nl>
* Change checkpoint_completion_target default to 0.9Stephen Frost2021-03-24
| | | | | | | | | | | | | | | | | | | Common recommendations are that the checkpoint should be spread out as much as possible, provided we avoid having it take too long. This change updates the default to 0.9 (from 0.5) to match that recommendation. There was some debate about possibly removing the option entirely but it seems there may be some corner-cases where having it set much lower to try to force the checkpoint to be as fast as possible could result in fewer periods of time of reduced performance due to kernel flushing. General agreement is that the "spread more" is the preferred approach though and those who need to tune away from that value are much less common. Reviewed-By: Michael Paquier, Peter Eisentraut, Tom Lane, David Steele, Nathan Bossart Discussion: https://postgr.es/m/20201207175329.GM16415%40tamriel.snowman.net
* Tidy up more loose ends related to configurable TOAST compression.Robert Haas2021-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | Change the default_toast_compression GUC to be an enum rather than a string. Earlier, uncommitted versions of the patch supported using CREATE ACCESS METHOD to add new compression methods to a running system, but that idea was dropped before commit. So, we can simplify the GUC handling as well, which has the nice side effect of improving the error messages. While updating the documentation to reflect the new GUC type, also move it back to the right place in the list. I moved this while revising what became commit 24f0e395ac5892cd12e8914646fe921fac5ba23d, but apparently the intended ordering is "alphabetical" rather than "whatever Robert thinks looks nice." Rejigger things to avoid having access/toast_compression.h depend on utils/guc.h, so that we don't end up with every file that includes it also depending on something largely unrelated. Move a few inline functions back into the C source file partly to help reduce dependencies and partly just to avoid clutter. A few very minor cosmetic fixes. Original patch by Justin Pryzby, but very heavily edited by me, and reverse reviewed by him and also reviewed by by Tom Lane. Discussion: http://postgr.es/m/CA+TgmoYp=GT_ztUCeZg2i4hkHAQv8o=-nVJ1-TKWTG1zQOmOpg@mail.gmail.com
* Add date_bin functionPeter Eisentraut2021-03-24
| | | | | | | | | | | | Similar to date_trunc, but allows binning by an arbitrary interval rather than just full units. Author: John Naylor <john.naylor@enterprisedb.com> Reviewed-by: David Fetter <david@fetter.org> Reviewed-by: Isaac Morland <isaac.morland@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Artur Zakirov <zaartur@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CACPNZCt4buQFRgy6DyjuZS-2aPDpccRkrJBmgUfwYc1KiaXYxg@mail.gmail.com
* Revert "Enable parallel SELECT for "INSERT INTO ... SELECT ..."."Amit Kapila2021-03-24
| | | | | | | | | | | | | | | | | | | To allow inserts in parallel-mode this feature has to ensure that all the constraints, triggers, etc. are parallel-safe for the partition hierarchy which is costly and we need to find a better way to do that. Additionally, we could have used existing cached information in some cases like indexes, domains, etc. to determine the parallel-safety. List of commits reverted, in reverse chronological order: ed62d3737c Doc: Update description for parallel insert reloption. c8f78b6161 Add a new GUC and a reloption to enable inserts in parallel-mode. c5be48f092 Improve FK trigger parallel-safety check added by 05c8482f7f. e2cda3c20a Fix use of relcache TriggerDesc field introduced by commit 05c8482f7f. e4e87a32cc Fix valgrind issue in commit 05c8482f7f. 05c8482f7f Enable parallel SELECT for "INSERT INTO ... SELECT ...". Discussion: https://postgr.es/m/E1lMiB9-0001c3-SY@gemulon.postgresql.org
* Rename wait event WalrcvExit to WalReceiverExit.Fujii Masao2021-03-24
| | | | | | | | | | | Commit de829ddf23 added wait event WalrcvExit. But its name is not consistent with other wait events like WalReceiverMain or WalReceiverWaitStart, etc. So this commit renames WalrcvExit to WalReceiverExit. Author: Fujii Masao Reviewed-by: Thomas Munro Discussion: https://postgr.es/m/cced9995-8fa2-7b22-9d91-3f22a2b8c23c@oss.nttdata.com
* Add bit_count SQL functionPeter Eisentraut2021-03-23
| | | | | | | | | | | This function for bit and bytea counts the set bits in the bit or byte string. Internally, we use the existing popcount functionality. For the name, after some discussion, we settled on bit_count, which also exists with this meaning in MySQL, Java, and Python. Author: David Fetter <david@fetter.org> Discussion: https://www.postgresql.org/message-id/flat/20201230105535.GJ13234@fetter.org
* Use correct spelling of statistics kindTomas Vondra2021-03-23
| | | | | | | | A couple error messages and comments used 'statistic kind', not the correct 'statistics kind'. Fix and backpatch all the way back to 10, where extended statistics were introduced. Backpatch-through: 10
* Change the type of WalReceiverWaitStart wait event from Client to IPC.Fujii Masao2021-03-23
| | | | | | | | | | | | | Previously the type of this wait event was Client. But while this wait event is being reported, walreceiver process is waiting for the startup process to set initial data for streaming replication. It's not waiting for any activity on a socket connected to a user application or walsender. So this commit changes the type for WalReceiverWaitStart wait event to IPC. Author: Fujii Masao Reviewed-by: Kyotaro Horiguchi Discussion: https://postgr.es/m/cdacc27c-37ff-f1a4-20e2-ce19933abfcc@oss.nttdata.com
* Pass all scan keys to BRIN consistent function at onceTomas Vondra2021-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit changes how we pass scan keys to BRIN consistent function. Instead of passing them one by one, we now pass all scan keys for a given attribute at once. That makes the consistent function a bit more complex, as it has to loop through the keys, but it does allow more elaborate opclasses that can use multiple keys to eliminate ranges much more effectively. The existing BRIN opclasses (minmax, inclusion) don't really benefit from this change. The primary purpose is to allow future opclases to benefit from seeing all keys at once. This does change the BRIN API, because the signature of the consistent function changes (a new parameter with number of scan keys). So this breaks existing opclasses, and will require supporting two variants of the code for different PostgreSQL versions. We've considered supporting two variants of the consistent, but we've decided not to do that. Firstly, there's another patch that moves handling of NULL values from the opclass, which means the opclasses need to be updated anyway. Secondly, we're not aware of any out-of-core BRIN opclasses, so it does not seem worth the extra complexity. Bump catversion, because of pg_proc changes. Author: Tomas Vondra <tomas.vondra@postgresql.org> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Mark Dilger <hornschnorter@gmail.com> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: John Naylor <john.naylor@enterprisedb.com> Reviewed-by: Nikita Glukhov <n.gluhov@postgrespro.ru> Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
* docs: Fix omissions related to configurable TOAST compression.Robert Haas2021-03-22
| | | | | | | | | Previously, the default_toast_compression GUC was not documented, and neither was pg_dump's new --no-toast-compression option. Justin Pryzby and Robert Haas Discussion: http://postgr.es/m/20210321235544.GD4203@telsasoft.com
* Provide recovery_init_sync_method=syncfs.Thomas Munro2021-03-20
| | | | | | | | | | | | | | | | | | | | | | | | | Since commit 2ce439f3 we have opened every file in the data directory and called fsync() at the start of crash recovery. This can be very slow if there are many files, leading to field complaints of systems taking minutes or even hours to begin crash recovery. Provide an alternative method, for Linux only, where we call syncfs() on every possibly different filesystem under the data directory. This is equivalent, but avoids faulting in potentially many inodes from potentially slow storage. The new mode comes with some caveats, described in the documentation, so the default value for the new setting is "fsync", preserving the older behavior. Reported-by: Michael Brown <michael.brown@discourse.org> Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com> Reviewed-by: Paul Guo <guopa@vmware.com> Reviewed-by: Bruce Momjian <bruce@momjian.us> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: David Steele <david@pgmasters.net> Discussion: https://postgr.es/m/11bc2bb7-ecb5-3ad0-b39f-df632734cd81%40discourse.org Discussion: https://postgr.es/m/CAEET0ZHGnbXmi8yF3ywsDZvb3m9CbdsGZgfTXscQ6agcbzcZAw%40mail.gmail.com