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* Prevent BEFORE triggers from violating partitioning constraints.Robert Haas2017-06-07
| | | | | | | | | | | | | | | | | | | | | Since tuple-routing implicitly checks the partitioning constraints at least for the levels of the partitioning hierarchy it traverses, there's normally no need to revalidate the partitioning constraint after performing tuple routing. However, if there's a BEFORE trigger on the target partition, it could modify the tuple, causing the partitioning constraint to be violated. Catch that case. Also, instead of checking the root table's partition constraint after tuple-routing, check it beforehand. Otherwise, the rules for when the partitioning constraint gets checked get too complicated, because you sometimes have to check part of the constraint but not all of it. This effectively reverts commit 39162b2030fb0a35a6bb28dc636b5a71b8df8d1c in favor of a different approach altogether. Report by me. Initial debugging by Jeevan Ladhe. Patch by Amit Langote, reviewed by me. Discussion: http://postgr.es/m/CA+Tgmoa9DTgeVOqopieV8d1QRpddmP65aCdxyjdYDoEO5pS5KA@mail.gmail.com
* Post-PG 10 beta1 pgindent runBruce Momjian2017-05-17
| | | | perltidy run not included.
* Fire per-statement triggers on partitioned tables.Robert Haas2017-05-01
| | | | | | | | | | | Even though no actual tuples are ever inserted into a partitioned table (the actual tuples are in the partitions, not the partitioned table itself), we still need to have a ResultRelInfo for the partitioned table, or per-statement triggers won't get fired. Amit Langote, per a report from Rajkumar Raghuwanshi. Reviewed by me. Discussion: http://postgr.es/m/CAKcux6%3DwYospCRY2J4XEFuVy0L41S%3Dfic7rmkbsU-GXhhSbmBg%40mail.gmail.com
* Improve castNode notation by introducing list-extraction-specific variants.Tom Lane2017-04-10
| | | | | | | | | | | | | | | | | This extends the castNode() notation introduced by commit 5bcab1114 to provide, in one step, extraction of a list cell's pointer and coercion to a concrete node type. For example, "lfirst_node(Foo, lc)" is the same as "castNode(Foo, lfirst(lc))". Almost half of the uses of castNode that have appeared so far include a list extraction call, so this is pretty widely useful, and it saves a few more keystrokes compared to the old way. As with the previous patch, back-patch the addition of these macros to pg_list.h, so that the notation will be available when back-patching. Patch by me, after an idea of Andrew Gierth's. Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
* Fix reporting of violations in ExecConstraints, again.Robert Haas2017-04-10
| | | | | | | | | | | | We decided in f1b4c771ea74f42447dccaed42ffcdcccf3aa694 to pass the original slot to ExecConstraints(), but that breaks when there are BEFORE ROW triggers involved. So we need to do reverse-map the tuples back to the original descriptor instead, as Amit originally proposed. Amit Langote, reviewed by Ashutosh Bapat. One overlooked comment fixed by me. Discussion: http://postgr.es/m/b3a17254-6849-e542-2353-bde4e880b6a4@lab.ntt.co.jp
* Faster expression evaluation and targetlist projection.Andres Freund2017-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This replaces the old, recursive tree-walk based evaluation, with non-recursive, opcode dispatch based, expression evaluation. Projection is now implemented as part of expression evaluation. This both leads to significant performance improvements, and makes future just-in-time compilation of expressions easier. The speed gains primarily come from: - non-recursive implementation reduces stack usage / overhead - simple sub-expressions are implemented with a single jump, without function calls - sharing some state between different sub-expressions - reduced amount of indirect/hard to predict memory accesses by laying out operation metadata sequentially; including the avoidance of nearly all of the previously used linked lists - more code has been moved to expression initialization, avoiding constant re-checks at evaluation time Future just-in-time compilation (JIT) has become easier, as demonstrated by released patches intended to be merged in a later release, for primarily two reasons: Firstly, due to a stricter split between expression initialization and evaluation, less code has to be handled by the JIT. Secondly, due to the non-recursive nature of the generated "instructions", less performance-critical code-paths can easily be shared between interpreted and compiled evaluation. The new framework allows for significant future optimizations. E.g.: - basic infrastructure for to later reduce the per executor-startup overhead of expression evaluation, by caching state in prepared statements. That'd be helpful in OLTPish scenarios where initialization overhead is measurable. - optimizing the generated "code". A number of proposals for potential work has already been made. - optimizing the interpreter. Similarly a number of proposals have been made here too. The move of logic into the expression initialization step leads to some backward-incompatible changes: - Function permission checks are now done during expression initialization, whereas previously they were done during execution. In edge cases this can lead to errors being raised that previously wouldn't have been, e.g. a NULL array being coerced to a different array type previously didn't perform checks. - The set of domain constraints to be checked, is now evaluated once during expression initialization, previously it was re-built every time a domain check was evaluated. For normal queries this doesn't change much, but e.g. for plpgsql functions, which caches ExprStates, the old set could stick around longer. The behavior around might still change. Author: Andres Freund, with significant changes by Tom Lane, changes by Heikki Linnakangas Reviewed-By: Tom Lane, Heikki Linnakangas Discussion: https://postgr.es/m/20161206034955.bh33paeralxbtluv@alap3.anarazel.de
* Don't scan partitioned tables.Robert Haas2017-03-21
| | | | | | | | | | | | | | | | | | | Partitioned tables do not contain any data; only their unpartitioned descendents need to be scanned. However, the partitioned tables still need to be locked, even though they're not scanned. To make that work, Append and MergeAppend relations now need to carry a list of (unscanned) partitioned relations that must be locked, and InitPlan must lock all partitioned result relations. Aside from the obvious advantage of avoiding some work at execution time, this has two other advantages. First, it may improve the planner's decision-making in some cases since the empty relation might throw things off. Second, it paves the way to getting rid of the storage for partitioned tables altogether. Amit Langote, reviewed by me. Discussion: http://postgr.es/m/6837c359-45c4-8044-34d1-736756335a15@lab.ntt.co.jp
* Use the new castNode() macro in a number of places.Andres Freund2017-01-26
| | | | | | | | | This is far from a pervasive conversion, but it's a good starting point. Author: Peter Eisentraut, with some minor changes by me Reviewed-By: Tom Lane Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com
* Fix things so that updatable views work with partitioned tables.Robert Haas2017-01-24
| | | | | | | | Previously, ExecInitModifyTable was missing handling for WITH CHECK OPTION, and view_query_is_auto_updatable was missing handling for RELKIND_PARTITIONED_TABLE. Amit Langote, reviewed by me.
* Reindent table partitioning code.Robert Haas2017-01-24
| | | | | | We've accumulated quite a bit of stuff with which pgindent is not quite happy in this code; clean it up to provide a less-annoying base for future pgindent runs.
* Remove obsoleted code relating to targetlist SRF evaluation.Andres Freund2017-01-19
| | | | | | | | | | | | | Since 69f4b9c plain expression evaluation (and thus normal projection) can't return sets of tuples anymore. Thus remove code dealing with that possibility. This will require adjustments in external code using ExecEvalExpr()/ExecProject() - that should neither be hard nor very common. Author: Andres Freund and Tom Lane Discussion: https://postgr.es/m/20160822214023.aaxz5l4igypowyri@alap3.anarazel.de
* Fix RETURNING to work correctly with partition tuple routing.Robert Haas2017-01-19
| | | | | | | | | | In ExecInsert(), do not switch back to the root partitioned table ResultRelInfo until after we finish ExecProcessReturning(), so that RETURNING projection is done using the partition's descriptor. For the projection to work correctly, we must initialize the same for each leaf partition during ModifyTableState initialization. Amit Langote
* Fix reporting of constraint violations for table partitioning.Robert Haas2017-01-04
| | | | | | | | | After a tuple is routed to a partition, it has been converted from the root table's row type to the partition's row type. ExecConstraints needs to report the failure using the original tuple and the parent's tuple descriptor rather than the ones for the selected partition. Amit Langote
* Move partition_tuple_slot out of EState.Robert Haas2017-01-04
| | | | | | | | | | | Commit 2ac3ef7a01df859c62d0a02333b646d65eaec5ff added a TupleTapleSlot for partition tuple slot to EState (es_partition_tuple_slot) but it's more logical to have it as part of ModifyTableState (mt_partition_tuple_slot) and CopyState (partition_tuple_slot). Discussion: http://postgr.es/m/1bd459d9-4c0c-197a-346e-e5e59e217d97@lab.ntt.co.jp Amit Langote, per a gripe from me
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Fix tuple routing in cases where tuple descriptors don't match.Robert Haas2016-12-22
| | | | | | | | | | | | | | | The previous coding failed to work correctly when we have a multi-level partitioned hierarchy where tables at successive levels have different attribute numbers for the partition key attributes. To fix, have each PartitionDispatch object store a standalone TupleTableSlot initialized with the TupleDesc of the corresponding partitioned table, along with a TupleConversionMap to map tuples from the its parent's rowtype to own rowtype. After tuple routing chooses a leaf partition, we must use the leaf partition's tuple descriptor, not the root table's. To that end, a dedicated TupleTableSlot for tuple routing is now allocated in EState. Amit Langote
* Refactor partition tuple routing code to reduce duplication.Robert Haas2016-12-21
| | | | Amit Langote
* Clean up code, comments, and formatting for table partitioning.Robert Haas2016-12-13
| | | | | Amit Langote, plus pgindent-ing by me. Inspired in part by review comments from Tomas Vondra.
* Implement table partitioning.Robert Haas2016-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
* Avoid testing tuple visibility without buffer lock.Tom Lane2016-10-23
| | | | | | | | | | | | | | | | | | | | INSERT ... ON CONFLICT (specifically ExecCheckHeapTupleVisible) contains another example of this unsafe coding practice. It is much harder to get a failure out of it than the case fixed in commit 6292c2339, because in most scenarios any hint bits that could be set would have already been set earlier in the command. However, Konstantin Knizhnik reported a failure with a custom transaction manager, and it's clearly possible to get a failure via a race condition in async-commit mode. For lack of a reproducible example, no regression test case in this commit. I did some testing with Asserts added to tqual.c's functions, and can say that running "make check-world" exposed these two bugs and no others. The Asserts are messy enough that I've not added them to the code for now. Report: <57EE93C8.8080504@postgrespro.ru> Related-Discussion: <CAO3NbwOycQjt2Oqy2VW-eLTq2M5uGMyHnGm=RNga4mjqcYD7gQ@mail.gmail.com>
* Don't throw serialization errors for self-conflicts in INSERT ON CONFLICT.Tom Lane2016-10-23
| | | | | | | | | | | | | | | | | A transaction that conflicts against itself, for example INSERT INTO t(pk) VALUES (1),(1) ON CONFLICT DO NOTHING; should behave the same regardless of isolation level. It certainly shouldn't throw a serialization error, as retrying will not help. We got this wrong due to the ON CONFLICT logic not considering the case, as reported by Jason Dusek. Core of this patch is by Peter Geoghegan (based on an earlier patch by Thomas Munro), though I didn't take his proposed code refactoring for fear that it might have unexpected side-effects. Test cases by Thomas Munro and myself. Report: <CAO3NbwOycQjt2Oqy2VW-eLTq2M5uGMyHnGm=RNga4mjqcYD7gQ@mail.gmail.com> Related-Discussion: <57EE93C8.8080504@postgrespro.ru>
* pgindent run for 9.6Robert Haas2016-06-09
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* Directly modify foreign tables.Robert Haas2016-03-18
| | | | | | | | | postgres_fdw can now sent an UPDATE or DELETE statement directly to the foreign server in simple cases, rather than sending a SELECT FOR UPDATE statement and then updating or deleting rows one-by-one. Etsuro Fujita, reviewed by Rushabh Lathia, Shigeru Hanada, Kyotaro Horiguchi, Albe Laurenz, Thom Brown, and me.
* When modifying a foreign table, initialize tableoid field properly.Robert Haas2016-02-04
| | | | | | | Failure to do this can cause AFTER ROW triggers or RETURNING expressions that reference this field to misbehave. Etsuro Fujita, reviewed by Thom Brown
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Fix ON CONFLICT UPDATE bug breaking AFTER UPDATE triggers.Andres Freund2015-12-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ExecOnConflictUpdate() passed t_ctid of the to-be-updated tuple to ExecUpdate(). That's problematic primarily because of two reason: First and foremost t_ctid could point to a different tuple. Secondly, and that's what triggered the complaint by Stanislav, t_ctid is changed by heap_update() to point to the new tuple version. The behavior of AFTER UPDATE triggers was therefore broken, with NEW.* and OLD.* tuples spuriously identical within AFTER UPDATE triggers. To fix both issues, pass a pointer to t_self of a on-stack HeapTuple instead. Fixing this bug lead to one change in regression tests, which previously failed due to the first issue mentioned above. There's a reasonable expectation that test fails, as it updates one row repeatedly within one INSERT ... ON CONFLICT statement. That is only possible if the second update is triggered via ON CONFLICT ... SET, ON CONFLICT ... WHERE, or by a WITH CHECK expression, as those are executed after ExecOnConflictUpdate() does a visibility check. That could easily be prohibited, but given it's allowed for plain UPDATEs and a rare corner case, it doesn't seem worthwhile. Reported-By: Stanislav Grozev Author: Andres Freund and Peter Geoghegan Discussion: CAA78GVqy1+LisN-8DygekD_Ldfy=BJLarSpjGhytOsgkpMavfQ@mail.gmail.com Backpatch: 9.5, where ON CONFLICT was introduced
* Fix ON CONFLICT DO UPDATE for tables with oids.Andres Freund2015-09-28
| | | | | | | | | | When taking the UPDATE path in an INSERT .. ON CONFLICT .. UPDATE tables with oids were not supported. The tuple generated by the update target list was projected without space for an oid - a simple oversight. Reported-By: Peter Geoghegan Author: Andres Freund Backpatch: 9.5, where ON CONFLICT was introduced
* Remove false comment about speculative insertion.Heikki Linnakangas2015-07-27
| | | | | | | | There is no full discussion of speculative insertions in the executor README. There is a high-level explanation in execIndexing.c, but it doesn't seem necessary to refer it from here. Peter Geoghegan
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Attach ON CONFLICT SET ... WHERE to the correct planstate.Andres Freund2015-05-19
| | | | | | | | | | The previous coding was a leftover from attempting to hang all the on conflict logic onto modify table's child nodes. It appears to not have actually caused problems except for explain. Add test exercising the broken and some other code paths. Author: Peter Geoghegan and Andres Freund
* Fix ON CONFLICT bugs that manifest when used in rules.Andres Freund2015-05-13
| | | | | | | | | | | | | | Specifically the tlist and rti of the pseudo "excluded" relation weren't properly treated by expression_tree_walker, which lead to errors when excluded was referenced inside a rule because the varnos where not properly adjusted. Similar omissions in OffsetVarNodes and expression_tree_mutator had less impact, but should obviously be fixed nonetheless. A couple tests of for ON CONFLICT UPDATE into INSERT rule bearing relations have been added. In passing I updated a couple comments.
* Add support for doing late row locking in FDWs.Tom Lane2015-05-12
| | | | | | | | | | | | | | | | | | | | | Previously, FDWs could only do "early row locking", that is lock a row as soon as it's fetched, even though local restriction/join conditions might discard the row later. This patch adds callbacks that allow FDWs to do late locking in the same way that it's done for regular tables. To make use of this feature, an FDW must support the "ctid" column as a unique row identifier. Currently, since ctid has to be of type TID, the feature is of limited use, though in principle it could be used by postgres_fdw. We may eventually allow FDWs to specify another data type for ctid, which would make it possible for more FDWs to use this feature. This commit does not modify postgres_fdw to use late locking. We've tested some prototype code for that, but it's not in committable shape, and besides it's quite unclear whether it actually makes sense to do late locking against a remote server. The extra round trips required are likely to outweigh any benefit from improved concurrency. Etsuro Fujita, reviewed by Ashutosh Bapat, and hacked up a lot by me
* Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.Andres Freund2015-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
* Fix various typos and grammar errors in comments.Andres Freund2015-04-26
| | | | | Author: Dmitriy Olshevskiy Discussion: 553D00A6.4090205@bk.ru
* Perform RLS WITH CHECK before constraints, etcStephen Frost2015-04-24
| | | | | | | | | | | | | | | | | | | | | | | The RLS capability is built on top of the WITH CHECK OPTION system which was added for auto-updatable views, however, unlike WCOs on views (which are mandated by the SQL spec to not fire until after all other constraints and checks are done), it makes much more sense for RLS checks to happen earlier than constraint and uniqueness checks. This patch reworks the structure which holds the WCOs a bit to be explicitly either VIEW or RLS checks and the RLS-related checks are done prior to the constraint and uniqueness checks. This also allows better error reporting as we are now reporting when a violation is due to a WITH CHECK OPTION and when it's due to an RLS policy violation, which was independently noted by Craig Ringer as being confusing. The documentation is also updated to include a paragraph about when RLS WITH CHECK handling is performed, as there have been a number of questions regarding that and the documentation was previously silent on the matter. Author: Dean Rasheed, with some kabitzing and comment changes by me.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Offer triggers on foreign tables.Noah Misch2014-03-23
| | | | | | | | | | | | | | | | | This covers all the SQL-standard trigger types supported for regular tables; it does not cover constraint triggers. The approach for acquiring the old row mirrors that for view INSTEAD OF triggers. For AFTER ROW triggers, we spool the foreign tuples to a tuplestore. This changes the FDW API contract; when deciding which columns to populate in the slot returned from data modification callbacks, writable FDWs will need to check for AFTER ROW triggers in addition to checking for a RETURNING clause. In support of the feature addition, refactor the TriggerFlags bits and the assembly of old tuples in ModifyTable. Ronan Dunklau, reviewed by KaiGai Kohei; some additional hacking by me.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Don't allow system columns in CHECK constraints, except tableoid.Robert Haas2013-09-23
| | | | | | | | | | | | | | | | | | | | | Previously, arbitray system columns could be mentioned in table constraints, but they were not correctly checked at runtime, because the values weren't actually set correctly in the tuple. Since it seems easy enough to initialize the table OID properly, do that, and continue allowing that column, but disallow the rest unless and until someone figures out a way to make them work properly. No back-patch, because this doesn't seem important enough to take the risk of destabilizing the back branches. In fact, this will pose a dump-and-reload hazard for those upgrading from previous versions: constraints that were accepted before but were not correctly enforced will now either be enforced correctly or not accepted at all. Either could result in restore failures, but in practice I think very few users will notice the difference, since the use case is pretty marginal anyway and few users will be relying on features that have not historically worked. Amit Kapila, reviewed by Rushabh Lathia, with doc changes by me.
* WITH CHECK OPTION support for auto-updatable VIEWsStephen Frost2013-07-18
| | | | | | | | | | | | | For simple views which are automatically updatable, this patch allows the user to specify what level of checking should be done on records being inserted or updated. For 'LOCAL CHECK', new tuples are validated against the conditionals of the view they are being inserted into, while for 'CASCADED CHECK' the new tuples are validated against the conditionals for all views involved (from the top down). This option is part of the SQL specification. Dean Rasheed, reviewed by Pavel Stehule
* Add support for REFRESH MATERIALIZED VIEW CONCURRENTLY.Kevin Grittner2013-07-16
| | | | | | | | | | | | This allows reads to continue without any blocking while a REFRESH runs. The new data appears atomically as part of transaction commit. Review questioned the Assert that a matview was not a system relation. This will be addressed separately. Reviewed by Hitoshi Harada, Robert Haas, Andres Freund. Merged after review with security patch f3ab5d4.
* pgindent run for release 9.3Bruce Momjian2013-05-29
| | | | | This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
* Support writable foreign tables.Tom Lane2013-03-10
| | | | | | | | | | | This patch adds the core-system infrastructure needed to support updates on foreign tables, and extends contrib/postgres_fdw to allow updates against remote Postgres servers. There's still a great deal of room for improvement in optimization of remote updates, but at least there's basic functionality there now. KaiGai Kohei, reviewed by Alexander Korotkov and Laurenz Albe, and rather heavily revised by Tom Lane.
* Improve concurrency of foreign key lockingAlvaro Herrera2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces two additional lock modes for tuples: "SELECT FOR KEY SHARE" and "SELECT FOR NO KEY UPDATE". These don't block each other, in contrast with already existing "SELECT FOR SHARE" and "SELECT FOR UPDATE". UPDATE commands that do not modify the values stored in the columns that are part of the key of the tuple now grab a SELECT FOR NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently with tuple locks of the FOR KEY SHARE variety. Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this means the concurrency improvement applies to them, which is the whole point of this patch. The added tuple lock semantics require some rejiggering of the multixact module, so that the locking level that each transaction is holding can be stored alongside its Xid. Also, multixacts now need to persist across server restarts and crashes, because they can now represent not only tuple locks, but also tuple updates. This means we need more careful tracking of lifetime of pg_multixact SLRU files; since they now persist longer, we require more infrastructure to figure out when they can be removed. pg_upgrade also needs to be careful to copy pg_multixact files over from the old server to the new, or at least part of multixact.c state, depending on the versions of the old and new servers. Tuple time qualification rules (HeapTupleSatisfies routines) need to be careful not to consider tuples with the "is multi" infomask bit set as being only locked; they might need to look up MultiXact values (i.e. possibly do pg_multixact I/O) to find out the Xid that updated a tuple, whereas they previously were assured to only use information readily available from the tuple header. This is considered acceptable, because the extra I/O would involve cases that would previously cause some commands to block waiting for concurrent transactions to finish. Another important change is the fact that locking tuples that have previously been updated causes the future versions to be marked as locked, too; this is essential for correctness of foreign key checks. This causes additional WAL-logging, also (there was previously a single WAL record for a locked tuple; now there are as many as updated copies of the tuple there exist.) With all this in place, contention related to tuples being checked by foreign key rules should be much reduced. As a bonus, the old behavior that a subtransaction grabbing a stronger tuple lock than the parent (sub)transaction held on a given tuple and later aborting caused the weaker lock to be lost, has been fixed. Many new spec files were added for isolation tester framework, to ensure overall behavior is sane. There's probably room for several more tests. There were several reviewers of this patch; in particular, Noah Misch and Andres Freund spent considerable time in it. Original idea for the patch came from Simon Riggs, after a problem report by Joel Jacobson. Most code is from me, with contributions from Marti Raudsepp, Alexander Shulgin, Noah Misch and Andres Freund. This patch was discussed in several pgsql-hackers threads; the most important start at the following message-ids: AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com 1290721684-sup-3951@alvh.no-ip.org 1294953201-sup-2099@alvh.no-ip.org 1320343602-sup-2290@alvh.no-ip.org 1339690386-sup-8927@alvh.no-ip.org 4FE5FF020200002500048A3D@gw.wicourts.gov 4FEAB90A0200002500048B7D@gw.wicourts.gov
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Throw error if expiring tuple is again updated or deleted.Kevin Grittner2012-10-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This prevents surprising behavior when a FOR EACH ROW trigger BEFORE UPDATE or BEFORE DELETE directly or indirectly updates or deletes the the old row. Prior to this patch the requested action on the row could be silently ignored while all triggered actions based on the occurence of the requested action could be committed. One example of how this could happen is if the BEFORE DELETE trigger for a "parent" row deleted "children" which had trigger functions to update summary or status data on the parent. This also prevents similar surprising problems if the query has a volatile function which updates a target row while it is already being updated. There are related issues present in FOR UPDATE cursors and READ COMMITTED queries which are not handled by this patch. These issues need further evalution to determine what change, if any, is needed. Where the new error messages are generated, in most cases the best fix will be to move code from the BEFORE trigger to an AFTER trigger. Where this is not feasible, the trigger can avoid the error by re-issuing the triggering statement and returning NULL. Documentation changes will be submitted in a separate patch. Kevin Grittner and Tom Lane with input from Florian Pflug and Robert Haas, based on problems encountered during conversion of Wisconsin Circuit Court trigger logic to plpgsql triggers.
* Split tuple struct defs from htup.h to htup_details.hAlvaro Herrera2012-08-30
| | | | | | | | | | | | This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
* Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian2012-06-10
| | | | commit-fest.
* Fix handling of data-modifying CTE subplans in EvalPlanQual.Tom Lane2012-01-28
| | | | | | | | | | | | | | | We can't just skip initializing such subplans, because the referencing CTE node will expect to find the subplan available when it initializes. That in turn means that ExecInitModifyTable must allow the case (which actually it needed to do anyway, since there's no guarantee that ModifyTable is exactly at the top of the CTE plan tree). So move the complaint about not being allowed in EvalPlanQual mode to execution instead of initialization. Testing turned up yet another problem, which is that we'd try to re-initialize the result relation's index list, leading to leaks and dangling pointers. Per report from Phil Sorber. Back-patch to 9.1 where data-modifying CTEs were introduced.