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* Disable WAL-skipping optimization for COPY on views and foreign tablesMichael Paquier2018-12-23
| | | | | | | | | | | | | | | | | | | | COPY can skip writing WAL when loading data on a table which has been created in the same transaction as the one loading the data, however this cannot work on views or foreign table as this would result in trying to flush relation files which do not exist. So disable the optimization so as commands are able to work the same way with any configuration of wal_level. Tests are added to cover the different cases, which need to have wal_level set to minimal to allow the problem to show up, and that is not the default configuration. Reported-by: Luis M. Carril, Etsuro Fujita Author: Amit Langote, Michael Paquier Reviewed-by: Etsuro Fujita Discussion: https://postgr.es/m/15552-c64aa14c5c22f63c@postgresql.org Backpatch-through: 10, where support for COPY on views has been added, while v11 has added support for COPY on foreign tables.
* postgres_fdw: Improve cost and size estimation for aggregate pushdown.Etsuro Fujita2018-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | In commit 7012b132d07c2b4ea15b0b3cb1ea9f3278801d98, which added aggregate pushdown to postgres_fdw, we didn't account for the evaluation cost and the selectivity of HAVING quals attached to ForeignPaths performing aggregate pushdown, as core had never accounted for that for AggPaths and GroupPaths. And we didn't set these values of the locally-checked quals (ie, fpinfo's local_conds_cost and local_conds_sel), which were initialized to zeros, but since estimate_path_cost_size factors in these to estimate the result size and the evaluation cost of such a ForeignPath when the use_remote_estimate option is enabled, this caused it to produce underestimated results in that case. By commit 7b6c07547190f056b0464098bb5a2247129d7aa2 core was changed so that it accounts for the evaluation cost and the selectivity of HAVING quals in aggregation paths, so change the postgres_fdw's aggregate pushdown code as well as such. This not only fixes the underestimation issue mentioned above, but improves the estimation using local statistics in that function when that option is disabled. This would be a bug fix rather than an improvement, but apply it to HEAD only to avoid destabilizing existing plan choices. Author: Etsuro Fujita Discussion: https://postgr.es/m/5BFD3EAD.2060301%40lab.ntt.co.jp
* Remove WITH OIDS support, change oid catalog column visibility.Andres Freund2018-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously tables declared WITH OIDS, including a significant fraction of the catalog tables, stored the oid column not as a normal column, but as part of the tuple header. This special column was not shown by default, which was somewhat odd, as it's often (consider e.g. pg_class.oid) one of the more important parts of a row. Neither pg_dump nor COPY included the contents of the oid column by default. The fact that the oid column was not an ordinary column necessitated a significant amount of special case code to support oid columns. That already was painful for the existing, but upcoming work aiming to make table storage pluggable, would have required expanding and duplicating that "specialness" significantly. WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0). Remove it. Removing includes: - CREATE TABLE and ALTER TABLE syntax for declaring the table to be WITH OIDS has been removed (WITH (oids[ = true]) will error out) - pg_dump does not support dumping tables declared WITH OIDS and will issue a warning when dumping one (and ignore the oid column). - restoring an pg_dump archive with pg_restore will warn when restoring a table with oid contents (and ignore the oid column) - COPY will refuse to load binary dump that includes oids. - pg_upgrade will error out when encountering tables declared WITH OIDS, they have to be altered to remove the oid column first. - Functionality to access the oid of the last inserted row (like plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed. The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false) for CREATE TABLE) is still supported. While that requires a bit of support code, it seems unnecessary to break applications / dumps that do not use oids, and are explicit about not using them. The biggest user of WITH OID columns was postgres' catalog. This commit changes all 'magic' oid columns to be columns that are normally declared and stored. To reduce unnecessary query breakage all the newly added columns are still named 'oid', even if a table's column naming scheme would indicate 'reloid' or such. This obviously requires adapting a lot code, mostly replacing oid access via HeapTupleGetOid() with access to the underlying Form_pg_*->oid column. The bootstrap process now assigns oids for all oid columns in genbki.pl that do not have an explicit value (starting at the largest oid previously used), only oids assigned later by oids will be above FirstBootstrapObjectId. As the oid column now is a normal column the special bootstrap syntax for oids has been removed. Oids are not automatically assigned during insertion anymore, all backend code explicitly assigns oids with GetNewOidWithIndex(). For the rare case that insertions into the catalog via SQL are called for the new pg_nextoid() function can be used (which only works on catalog tables). The fact that oid columns on system tables are now normal columns means that they will be included in the set of columns expanded by * (i.e. SELECT * FROM pg_class will now include the table's oid, previously it did not). It'd not technically be hard to hide oid column by default, but that'd mean confusing behavior would either have to be carried forward forever, or it'd cause breakage down the line. While it's not unlikely that further adjustments are needed, the scope/invasiveness of the patch makes it worthwhile to get merge this now. It's painful to maintain externally, too complicated to commit after the code code freeze, and a dependency of a number of other patches. Catversion bump, for obvious reasons. Author: Andres Freund, with contributions by John Naylor Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
* Disable support for partitionwise joins in problematic cases.Etsuro Fujita2018-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f49842d, which added support for partitionwise joins, built the child's tlist by applying adjust_appendrel_attrs() to the parent's. So in the case where the parent's included a whole-row Var for the parent, the child's contained a ConvertRowtypeExpr. To cope with that, that commit added code to the planner, such as setrefs.c, but some code paths still assumed that the tlist for a scan (or join) rel would only include Vars and PlaceHolderVars, which was true before that commit, causing errors: * When creating an explicit sort node for an input path for a mergejoin path for a child join, prepare_sort_from_pathkeys() threw the 'could not find pathkey item to sort' error. * When deparsing a relation participating in a pushed down child join as a subquery in contrib/postgres_fdw, get_relation_column_alias_ids() threw the 'unexpected expression in subquery output' error. * When performing set_plan_references() on a local join plan generated by contrib/postgres_fdw for EvalPlanQual support for a pushed down child join, fix_join_expr() threw the 'variable not found in subplan target lists' error. To fix these, two approaches have been proposed: one by Ashutosh Bapat and one by me. While the former keeps building the child's tlist with a ConvertRowtypeExpr, the latter builds it with a whole-row Var for the child not to violate the planner assumption, and tries to fix it up later, But both approaches need more work, so refuse to generate partitionwise join paths when whole-row Vars are involved, instead. We don't need to handle ConvertRowtypeExprs in the child's tlists for now, so this commit also removes the changes to the planner. Previously, partitionwise join computed attr_needed data for each child separately, and built the child join's tlist using that data, which also required an extra step for adding PlaceHolderVars to that tlist, but it would be more efficient to build it from the parent join's tlist through the adjust_appendrel_attrs() transformation. So this commit builds that list that way, and simplifies build_joinrel_tlist() and placeholder.c as well as part of set_append_rel_size() to basically what they were before partitionwise join went in. Back-patch to PG11 where partitionwise join was introduced. Report by Rajkumar Raghuwanshi. Analysis by Ashutosh Bapat, who also provided some of regression tests. Patch by me, reviewed by Robert Haas. Discussion: https://postgr.es/m/CAKcux6ktu-8tefLWtQuuZBYFaZA83vUzuRd7c1YHC-yEWyYFpg@mail.gmail.com
* Spell "partitionwise" consistently.Heikki Linnakangas2018-08-09
| | | | | | | | | I'm not sure which spelling is better, "partitionwise" or "partition-wise", but everywhere else we spell it "partitionwise", so be consistent. Tatsuro Yamada reported the one in README, I found the other one with grep. Discussion: https://www.postgresql.org/message-id/d25ebf36-5a6d-8b2c-1ff3-d6f022a56000@lab.ntt.co.jp
* Fix WITH CHECK OPTION on views referencing postgres_fdw tables.Jeff Davis2018-07-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a view references a foreign table, and the foreign table has a BEFORE INSERT trigger, then it's possible for a tuple inserted or updated through the view to be changed such that it violates the view's WITH CHECK OPTION constraint. Before this commit, postgres_fdw handled this case inconsistently. A RETURNING clause on the INSERT or UPDATE statement targeting the view would cause the finally-inserted tuple to be read back, and the WITH CHECK OPTION violation would throw an error. But without a RETURNING clause, postgres_fdw would not read the final tuple back, and WITH CHECK OPTION would not throw an error for the violation (or may throw an error when there is no real violation). AFTER ROW triggers on the foreign table had a similar effect as a RETURNING clause on the INSERT or UPDATE statement. To fix, this commit retrieves the attributes needed to enforce the WITH CHECK OPTION constraint along with the attributes needed for the RETURNING clause (if any) from the remote side. Thus, the WITH CHECK OPTION constraint is always evaluated against the final tuple after any triggers on the remote side. This fix may be considered inconsistent with CHECK constraints declared on foreign tables, which are not enforced locally at all (because the constraint is on a remote object). The discussion concluded that this difference is reasonable, because the WITH CHECK OPTION is a constraint on the local view (not any remote object); therefore it only makes sense to enforce its WITH CHECK OPTION constraint locally. Author: Etsuro Fujita Reviewed-by: Arthur Zakirov, Stephen Frost Discussion: https://www.postgresql.org/message-id/7eb58fab-fd3b-781b-ac33-f7cfec96021f%40lab.ntt.co.jp
* Pass the correct PlannerInfo to PlanForeignModify/PlanDirectModify.Robert Haas2018-05-16
| | | | | | | | | | | | | | | | | | Previously, we passed the toplevel PlannerInfo, but we actually want to pass the relevant subroot. One problem with passing the toplevel PlannerInfo is that the FDW which wants to push down an UPDATE or DELETE against a join won't find the relevant joinrel there. As of commit 1bc0100d270e5bcc980a0629b8726a32a497e788, postgres_fdw tries to do exactly this and can be made to fail an assertion as a result. It's possible that this should be regarded as a bug fix and back-patched to earlier releases, but for lack of a test case that fails in earlier releases, no back-patch for now. Etsuro Fujita, reviewed by Amit Langote. Discussion: http://postgr.es/m/5AF43E02.30000@lab.ntt.co.jp
* Fix interaction of foreign tuple routing with remote triggers.Robert Haas2018-05-01
| | | | | | | | | | | | | | | | | | | | | | | | Without these fixes, changes to the inserted tuple made by remote triggers are ignored when building local RETURNING tuples. In the core code, call ExecInitRoutingInfo at a later point from within ExecInitPartitionInfo so that the FDW callback gets invoked after the returning list has been built. But move CheckValidResultRel out of ExecInitRoutingInfo so that it can happen at an earlier stage. In postgres_fdw, refactor assorted deparsing functions to work with the RTE rather than the PlannerInfo, which saves us having to construct a fake PlannerInfo in cases where we don't have a real one. Then, we can pass down a constructed RTE that yields the correct deparse result when no real one exists. Unfortunately, this necessitates a hack that understands how the core code manages RT indexes for update tuple routing, which is ugly, but we don't have a better idea right now. Original report, analysis, and patch by Etsuro Fujita. Heavily refactored by me. Then worked over some more by Amit Langote. Discussion: http://postgr.es/m/5AD4882B.10002@lab.ntt.co.jp
* YA attempt to stabilize the results of the postgres_fdw regression test.Tom Lane2018-04-12
| | | | | | | | | | | | | | | | | | | We've made multiple attempts to stabilize the plans shown by commit 1bc0100d2, with little success so far. The reason for the remaining instability seems to be that if a transaction (such as auto-analyze) is running concurrently with the test, then get_actual_variable_range may return a maximum value for "T 1"."C 1" that's far away from the actual max, as a result of our having transiently inserted such a value earlier in the test. Because we use a non-MVCC snapshot to fetch the value (for performance reasons), the presence of other transactions can cause that function to return entries that are actually dead. To fix, use a less extreme value in the earlier transient insertion, so that whether it is visible or not won't affect the selectivity estimate. The use of 9999 there seems to have been picked with the aid of a dartboard anyway, rather than having a specific reason. Discussion: https://postgr.es/m/16962.1523551784@sss.pgh.pa.us
* Allow insert and update tuple routing and COPY for foreign tables.Robert Haas2018-04-06
| | | | | | | | | | | Also enable this for postgres_fdw. Etsuro Fujita, based on an earlier patch by Amit Langote. The larger patch series of which this is a part has been reviewed by Amit Langote, David Fetter, Maksim Milyutin, Álvaro Herrera, Stephen Frost, and me. Minor documentation changes to the final version by me. Discussion: http://postgr.es/m/29906a26-da12-8c86-4fb9-d8f88442f2b9@lab.ntt.co.jp
* postgres_fdw: Push down partition-wise aggregation.Robert Haas2018-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 7012b132d07c2b4ea15b0b3cb1ea9f3278801d98, postgres_fdw has been able to push down the toplevel aggregation operation to the remote server. Commit e2f1eb0ee30d144628ab523432320f174a2c8966 made it possible to break down the toplevel aggregation into one aggregate per partition. This commit lets postgres_fdw push down aggregation in that case just as it does at the top level. In order to make this work, this commit adds an additional argument to the GetForeignUpperPaths FDW API. A matching argument is added to the signature for create_upper_paths_hook. Third-party code using either of these will need to be updated. Also adjust create_foreignscan_plan() so that it picks up the correct set of relids in this case. Jeevan Chalke, reviewed by Ashutosh Bapat and by me and with some adjustments by me. The larger patch series of which this patch is a part was also reviewed and tested by Antonin Houska, Rajkumar Raghuwanshi, David Rowley, Dilip Kumar, Konstantin Knizhnik, Pascal Legrand, and Rafia Sabih. Discussion: http://postgr.es/m/CAM2+6=V64_xhstVHie0Rz=KPEQnLJMZt_e314P0jaT_oJ9MR8A@mail.gmail.com Discussion: http://postgr.es/m/CAM2+6=XPWujjmj5zUaBTGDoB38CemwcPmjkRy0qOcsQj_V+2sQ@mail.gmail.com
* Revert "Temporarily instrument postgres_fdw test to look for statistics ↵Tom Lane2018-03-08
| | | | | | | | | changes." This reverts commit c2c537c56dc30ec3cdc12051f4ea5363aa66d73c. It's now clear that whatever is going on there, it can't be blamed on unexpected ANALYZE runs, because the statistics are the same just before the failing query as they were at the start of the test.
* Temporarily instrument postgres_fdw test to look for statistics changes.Tom Lane2018-03-05
| | | | | | | | | | | | | It seems fairly hard to explain recent buildfarm failures without the theory that something is doing an ANALYZE behind our backs. Probe for this directly to see if it's true. In principle the outputs of these queries should be stable, since the table in question is small enough that ANALYZE's sample will include all rows. But even if that turns out to be wrong, we can put up with some failures for a bit. I don't intend to leave this here indefinitely. Discussion: https://postgr.es/m/25502.1520277552@sss.pgh.pa.us
* postgres_fdw: Fourth attempt to stabilize regression tests.Robert Haas2018-03-02
| | | | | | | | | | | | | | | | Commit 1bc0100d270e5bcc980a0629b8726a32a497e788 added this test, and commits 882ea509fe7a4711fe25463427a33262b873dfa1, 958e20e42d6c346ab89f6c72e4262230161d1663, 4fa396464e5fe238b7994535182f28318c61c78e tried to stabilize it. It's still not stable, so keep trying. The latest comment from Tom Lane is that disabling autovacuum seems like a good strategy, but we might need to do it on more tables, hence this patch. Etsuro Fujita Discussion: http://postgr.es/m/5A9928F1.2010206@lab.ntt.co.jp
* postgres_fdw: Third attempt to stabilize regression tests.Robert Haas2018-02-28
| | | | | | | | | | | | | | | Commit 1bc0100d270e5bcc980a0629b8726a32a497e788 added this test, and commit 882ea509fe7a4711fe25463427a33262b873dfa1 tried to stabilize it. There were still failures, so commit 958e20e42d6c346ab89f6c72e4262230161d1663 tried again to stabilize it. That approach is still failing on jaguarundi, though, so back it out and try something else. Specifically, instead of disabling remote estimates for the table in question, let's tell autovacuum to leave it alone. Etsuro Fujita Discussion: http://postgr.es/m/5A82DCCE.3060107@lab.ntt.co.jp
* postgres_fdw: Fix interaction of PHVs with child joins.Robert Haas2018-02-22
| | | | | | | | | Commit f49842d1ee31b976c681322f76025d7732e860f3 introduced the concept of a child join, but did not update this code accordingly. Ashutosh Bapat, with cosmetic changes by me Discussion: http://postgr.es/m/CAFjFpRf=J_KPOtw+bhZeURYkbizr8ufSaXg6gPEF6DKpgH-t6g@mail.gmail.com
* Rename enable_partition_wise_join to enable_partitionwise_joinPeter Eisentraut2018-02-16
| | | | Discussion: https://www.postgresql.org/message-id/flat/ad24e4f4-6481-066e-e3fb-6ef4a3121882%402ndquadrant.com
* postgres_fdw: Attmempt to stabilize regression tests.Robert Haas2018-02-09
| | | | | | | | | | | Even after commit 882ea509fe7a4711fe25463427a33262b873dfa1, some buildfarm members are still failing in the postgres_fdw tests. Try to fix that by disabling use of remote statistics for some test cases. Etsuro Fujita Discussion: http://postgr.es/m/5A7D76CF.8080601@lab.ntt.co.jp
* postgres_fdw: Remove CTID output from some tests.Robert Haas2018-02-07
| | | | | | Commit 1bc0100d270e5bcc980a0629b8726a32a497e788 added these tests, but they're not stable enough to survive in the buildfarm. Remove CTIDs from the output in the hopes of fixing that.
* postgres_fdw: Push down UPDATE/DELETE joins to remote servers.Robert Haas2018-02-07
| | | | | | | | | | | | | | | | | | | | | | Commit 0bf3ae88af330496517722e391e7c975e6bad219 allowed direct foreign table modification; instead of fetching each row, updating it locally, and then pushing the modification back to the remote side, we would instead do all the work on the remote server via a single remote UPDATE or DELETE command. However, that commit only enabled this optimization when join tree consisted only of the target table. This change allows the same optimization when an UPDATE statement has a FROM clause or a DELETE statement has a USING clause. This works much like ordinary foreign join pushdown, in that the tables must be on the same remote server, relevant parts of the query must be pushdown-safe, and so forth. Etsuro Fujita, reviewed by Ashutosh Bapat, Rushabh Lathia, and me. Some formatting corrections by me. Discussion: http://postgr.es/m/5A57193A.2080003@lab.ntt.co.jp Discussion: http://postgr.es/m/b9cee735-62f8-6c07-7528-6364ce9347d0@lab.ntt.co.jp
* Fix test case for 'outer pathkeys do not match mergeclauses' fix.Robert Haas2018-01-30
| | | | | | | | | | | | Commit 4bbf6edfbd5d03743ff82dda2f00c738fb3208f5 added a test case, but it turns out that the test case doesn't reliably test for the bug, and in the context of the regression test suite did not because ANALYZE had not been run. Report and patch by Etsuro Fujita. I added a comment along lines previously suggested by Tom Lane. Discussion: http://postgr.es/m/5A6195D8.8060206@lab.ntt.co.jp
* postgres_fdw: Avoid 'outer pathkeys do not match mergeclauses' error.Robert Haas2018-01-17
| | | | | | | | | | | | | | | | | | | | | | When pushing down a join to a foreign server, postgres_fdw constructs an alternative plan to be used for any EvalPlanQual rechecks that prove to be necessary. This plan is stored as the outer subplan of the Foreign Scan implementing the pushed-down join. Previously, this alternative plan could have a different nominal sort ordering than its parent, which seemed OK since there will only be one tuple per base table anyway in the case of an EvalPlanQual recheck. Actually, though, it caused a problem if that path was used as a building block for the EvalPlanQual recheck plan of a higher-level foreign join, because we could end up with a merge join one of whose inputs was not labelled with the correct sort order. Repair by injecting an extra Sort node into the EvalPlanQual recheck plan whenever it would otherwise fail to be sorted at least as well as its parent Foreign Scan. Report by Jeff Janes. Patch by me, reviewed by Tom Lane, who also provided the test case and comment text. Discussion: http://postgr.es/m/CAMkU=1y2G8VOVBHv3iXU2TMAj7-RyBFFW1uhkr5sm9LQ2=X35g@mail.gmail.com
* Fix postgres_fdw to cope with duplicate GROUP BY entries.Tom Lane2018-01-12
| | | | | | | | | | | | | | | | | | | | | Commit 7012b132d, which added the ability to push down aggregates and grouping to the remote server, wasn't careful to ensure that the remote server would have the same idea we do about which columns are the grouping columns, in cases where there are textually identical GROUP BY expressions. Such cases typically led to "targetlist item has multiple sortgroupref labels" errors. To fix this reliably, switch over to using "GROUP BY column-number" syntax rather than "GROUP BY expression" in transmitted queries, and adjust foreign_grouping_ok() to be more careful about duplicating the sortgroupref labeling of the local pathtarget. Per bug #14890 from Sean Johnston. Back-patch to v10 where the buggy code was introduced. Jeevan Chalke, reviewed by Ashutosh Bapat Discussion: https://postgr.es/m/20171107134948.1508.94783@wrigleys.postgresql.org
* postgres_fdw: Fix failing regression test.Robert Haas2017-12-05
| | | | | | | | Commit ab3f008a2dc364cf7fb75de0a691fb0c61586c8e broke this. Report by Stephen Frost. Discussion: http://postgr.es/m/20171205180342.GO4628@tamriel.snowman.net
* postgres_fdw: Fix test that didn't test what it claimed.Robert Haas2017-12-01
| | | | | | | | | | | | Antonin Houska reported that the planner does consider pushing postgres_fdw_abs() to the remote side, which happens because we make it shippable earlier in the test case file. Jeevan Chalke provided this patch, which changes the join condition to use random(), which is not shippable, instead. Antonin reviewed the patch. Discussion: http://postgr.es/m/15265.1511985971@localhost
* Fix creation of resjunk tlist entries for inherited mixed UPDATE/DELETE.Tom Lane2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rewriteTargetListUD's processing is dependent on the relkind of the query's target table. That was fine at the time it was made to act that way, even for queries on inheritance trees, because all tables in an inheritance tree would necessarily be plain tables. However, the 9.5 feature addition allowing some members of an inheritance tree to be foreign tables broke the assumption that rewriteTargetListUD's output tlist could be applied to all child tables with nothing more than column-number mapping. This led to visible failures if foreign child tables had row-level triggers, and would also break in cases where child tables belonged to FDWs that used methods other than CTID for row identification. To fix, delay running rewriteTargetListUD until after the planner has expanded inheritance, so that it is applied separately to the (already mapped) tlist for each child table. We can conveniently call it from preprocess_targetlist. Refactor associated code slightly to avoid the need to heap_open the target relation multiple times during preprocess_targetlist. (The APIs remain a bit ugly, particularly around the point of which steps scribble on parse->targetList and which don't. But avoiding such scribbling would require a change in FDW callback APIs, which is more pain than it's worth.) Also fix ExecModifyTable to ensure that "tupleid" is reset to NULL when we transition from rows providing a CTID to rows that don't. (That's really an independent bug, but it manifests in much the same cases.) Add a regression test checking one manifestation of this problem, which was that row-level triggers on a foreign child table did not work right. Back-patch to 9.5 where the problem was introduced. Etsuro Fujita, reviewed by Ildus Kurbangaliev and Ashutosh Bapat Discussion: https://postgr.es/m/20170514150525.0346ba72@postgrespro.ru
* Basic partition-wise join functionality.Robert Haas2017-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of joining two partitioned tables in their entirety we can, if it is an equi-join on the partition keys, join the matching partitions individually. This involves teaching the planner about "other join" rels, which are related to regular join rels in the same way that other member rels are related to baserels. This can use significantly more CPU time and memory than regular join planning, because there may now be a set of "other" rels not only for every base relation but also for every join relation. In most practical cases, this probably shouldn't be a problem, because (1) it's probably unusual to join many tables each with many partitions using the partition keys for all joins and (2) if you do that scenario then you probably have a big enough machine to handle the increased memory cost of planning and (3) the resulting plan is highly likely to be better, so what you spend in planning you'll make up on the execution side. All the same, for now, turn this feature off by default. Currently, we can only perform joins between two tables whose partitioning schemes are absolutely identical. It would be nice to cope with other scenarios, such as extra partitions on one side or the other with no match on the other side, but that will have to wait for a future patch. Ashutosh Bapat, reviewed and tested by Rajkumar Raghuwanshi, Amit Langote, Rafia Sabih, Thomas Munro, Dilip Kumar, Antonin Houska, Amit Khandekar, and by me. A few final adjustments by me. Discussion: http://postgr.es/m/CAFjFpRfQ8GrQvzp3jA2wnLqrHmaXna-urjm_UY9BqXj=EaDTSA@mail.gmail.com Discussion: http://postgr.es/m/CAFjFpRcitjfrULr5jfuKWRPsGUX0LQ0k8-yG0Qw2+1LBGNpMdw@mail.gmail.com
* When WCOs are present, disable direct foreign table modification.Robert Haas2017-07-24
| | | | | | | | | | | | | | | If the user modifies a view that has CHECK OPTIONs and this gets translated into a modification to an underlying relation which happens to be a foreign table, the check options should be enforced. In the normal code path, that was happening properly, but it was not working properly for "direct" modification because the whole operation gets pushed to the remote side in that case and we never have an option to enforce the constraint against individual tuples. Fix by disabling direct modification when there is a need to enforce CHECK OPTIONs. Etsuro Fujita, reviewed by Kyotaro Horiguchi and by me. Discussion: http://postgr.es/m/f8a48f54-6f02-9c8a-5250-9791603171ee@lab.ntt.co.jp
* Stabilize postgres_fdw regression tests.Tom Lane2017-07-21
| | | | | | | | | | | | | The new test cases added in commit 8bf58c0d9 turn out to have output that can vary depending on the lc_messages setting prevailing on the test server. Hide the remote end's error messages to ensure stable output. This isn't a terribly desirable solution; we'd rather know that the connection failed for the expected reason and not some other one. But there seems little choice for the moment. Per buildfarm. Discussion: https://postgr.es/m/18419.1500658570@sss.pgh.pa.us
* Re-establish postgres_fdw connections after server or user mapping changes.Tom Lane2017-07-21
| | | | | | | | | | | | | | | | | Previously, postgres_fdw would keep on using an existing connection even if the user did ALTER SERVER or ALTER USER MAPPING commands that should affect connection parameters. Teach it to watch for catcache invals on these catalogs and re-establish connections when the relevant catalog entries change. Per bug #14738 from Michal Lis. In passing, clean up some rather crufty decisions in commit ae9bfc5d6 about where fields of ConnCacheEntry should be reset. We now reset all the fields whenever we open a new connection. Kyotaro Horiguchi, reviewed by Ashutosh Bapat and myself. Back-patch to 9.3 where postgres_fdw appeared. Discussion: https://postgr.es/m/20170710113917.7727.10247@wrigleys.postgresql.org
* postgres_fdw: Fix join push down with extensionsPeter Eisentraut2017-04-24
| | | | | | | | | | | | | | | | | | | | Objects in an extension are shippable to a foreign server if the extension is part of the foreign server definition's shippable extensions list. But this was not properly considered in some cases when checking whether a join condition can be pushed to a foreign server and the join condition uses an object from a shippable extension. So the join would never be pushed down in those cases. So, the list of extensions needs to be made available in fpinfo of the relation being considered to be pushed down before any expressions are assessed for being shippable. Fix foreign_join_ok() to do that for a join relation. The code to save FDW options in fpinfo is scattered at multiple places. Bring all of that together into functions apply_server_options(), apply_table_options(), and merge_fdw_options(). David Rowley and Ashutosh Bapat, per report from David Rowley
* Capitalize names of PLs consistentlyPeter Eisentraut2017-04-05
| | | | Author: Daniel Gustafsson <daniel@yesql.se>
* postgres_fdw: Teach IMPORT FOREIGN SCHEMA about partitioning.Robert Haas2017-03-31
| | | | | | | | | | Don't import partitions. Do import partitioned tables which are not themselves partitions. Report by Stephen Frost. Design and patch by Michael Paquier, reviewed by Amit Langote. Documentation revised by me. Discussion: http://postgr.es/m/20170309141531.GD9812@tamriel.snowman.net
* postgres_fdw: Push down FULL JOINs with restriction clauses.Robert Haas2017-03-16
| | | | | | | | | | | The previous deparsing logic wasn't smart enough to produce subqueries when deparsing; make it smart enough to do that. However, we only do it that way when necessary, because it generates more complicated SQL which will be harder for any humans reading the queries to understand. Etsuro Fujita, reviewed by Ashutosh Bapat Discussion: http://postgr.es/m/c449261a-b033-dc02-9254-2fe5b7044795@lab.ntt.co.jp
* Fix typos in comments.Heikki Linnakangas2017-02-06
| | | | | | | | | Backpatch to all supported versions, where applicable, to make backpatching of future fixes go more smoothly. Josh Soref Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com
* Improve speed of contrib/postgres_fdw regression tests.Tom Lane2017-01-25
| | | | | | | | | | | Commit 7012b132d added some tests that consumed an excessive amount of time, more than tripling the time needed for "make installcheck" for this module. Add filter conditions to reduce the number of rows scanned, bringing the runtime down to within hailing distance of what it was before. Jeevan Chalke and Ashutosh Bapat, per a gripe from me Discussion: https://postgr.es/m/16565.1478104765@sss.pgh.pa.us
* Invalidate cached plans on FDW option changes.Tom Lane2017-01-06
| | | | | | | | | | | | | | | | | | | | | | | | This fixes problems where a plan must change but fails to do so, as seen in a bug report from Rajkumar Raghuwanshi. For ALTER FOREIGN TABLE OPTIONS, do this through the standard method of forcing a relcache flush on the table. For ALTER FOREIGN DATA WRAPPER and ALTER SERVER, just flush the whole plan cache on any change in pg_foreign_data_wrapper or pg_foreign_server. That matches the way we handle some other low-probability cases such as opclass changes, and it's unclear that the case arises often enough to be worth working harder. Besides, that gives a patch that is simple enough to back-patch with confidence. Back-patch to 9.3. In principle we could apply the code change to 9.2 as well, but (a) we lack postgres_fdw to test it with, (b) it's doubtful that anyone is doing anything exciting enough with FDWs that far back to need this desperately, and (c) the patch doesn't apply cleanly. Patch originally by Amit Langote, reviewed by Etsuro Fujita and Ashutosh Bapat, who each contributed substantial changes as well. Discussion: https://postgr.es/m/CAKcux6m5cA6rRPTKkqVdJ-R=KKDfe35Q_ZuUqxDSV_4hwga=og@mail.gmail.com
* postgres_fdw: Try again to stabilize aggregate pushdown regression tests.Robert Haas2016-10-24
| | | | | | | | A query that only aggregates one row isn't a great argument for pushdown, and buildfarm member brolga decides against it. Adjust the query a bit in the hopes of getting remote aggregation to win consistently. Jeevan Chalke, per suggestion from Tom Lane
* postgres_fdw: Attempt to stabilize regression results.Robert Haas2016-10-21
| | | | | | | | | | | Set enable_hashagg to false for tests involving least_agg(), so that we get the same plan regardless of local costing variances. Also, remove a test involving sqrt(); it's there to test deparsing of HAVING clauses containing expressions, but that's tested elsewhere anyway, and sqrt(2) deparses with different amounts of precision on different machines. Per buildfarm.
* postgres_fdw: Push down aggregates to remote servers.Robert Haas2016-10-21
| | | | | | | | | | | | | Now that the upper planner uses paths, and now that we have proper hooks to inject paths into the upper planning process, it's possible for foreign data wrappers to arrange to push aggregates to the remote side instead of fetching all of the rows and aggregating them locally. This figures to be a massive win for performance, so teach postgres_fdw to do it. Jeevan Chalke and Ashutosh Bapat. Reviewed by Ashutosh Bapat with additional testing by Prabhat Sahu. Various mostly cosmetic changes by me.
* Support OID system column in postgres_fdw.Heikki Linnakangas2016-08-26
| | | | | | | | | | You can use ALTER FOREIGN TABLE SET WITH OIDS on a foreign table, but the oid column read out as zeros, because the postgres_fdw didn't know about it. Teach postgres_fdw how to fetch it. Etsuro Fujita, with an additional test case by me. Discussion: <56E90A76.5000503@lab.ntt.co.jp>
* Avoid invalidating all foreign-join cached plans when user mappings change.Tom Lane2016-07-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We must not push down a foreign join when the foreign tables involved should be accessed under different user mappings. Previously we tried to enforce that rule literally during planning, but that meant that the resulting plans were dependent on the current contents of the pg_user_mapping catalog, and we had to blow away all cached plans containing any remote join when anything at all changed in pg_user_mapping. This could have been improved somewhat, but the fact that a syscache inval callback has very limited info about what changed made it hard to do better within that design. Instead, let's change the planner to not consider user mappings per se, but to allow a foreign join if both RTEs have the same checkAsUser value. If they do, then they necessarily will use the same user mapping at runtime, and we don't need to know specifically which one that is. Post-plan-time changes in pg_user_mapping no longer require any plan invalidation. This rule does give up some optimization ability, to wit where two foreign table references come from views with different owners or one's from a view and one's directly in the query, but nonetheless the same user mapping would have applied. We'll sacrifice the first case, but to not regress more than we have to in the second case, allow a foreign join involving both zero and nonzero checkAsUser values if the nonzero one is the same as the prevailing effective userID. In that case, mark the plan as only runnable by that userID. The plancache code already had a notion of plans being userID-specific, in order to support RLS. It was a little confused though, in particular lacking clarity of thought as to whether it was the rewritten query or just the finished plan that's dependent on the userID. Rearrange that code so that it's clearer what depends on which, and so that the same logic applies to both RLS-injected role dependency and foreign-join-injected role dependency. Note that this patch doesn't remove the other issue mentioned in the original complaint, which is that while we'll reliably stop using a foreign join if it's disallowed in a new context, we might fail to start using a foreign join if it's now allowed, but we previously created a generic cached plan that didn't use one. It was agreed that the chance of winning that way was not high enough to justify the much larger number of plan invalidations that would have to occur if we tried to cause it to happen. In passing, clean up randomly-varying spelling of EXPLAIN commands in postgres_fdw.sql, and fix a COSTS ON example that had been allowed to leak into the committed tests. This reverts most of commits fbe5a3fb7 and 5d4171d1c, which were the previous attempt at ensuring we wouldn't push down foreign joins that span permissions contexts. Etsuro Fujita and Tom Lane Discussion: <d49c1e5b-f059-20f4-c132-e9752ee0113e@lab.ntt.co.jp>
* postgres_fdw: Fix cache lookup failure while creating error context.Robert Haas2016-07-01
| | | | | | | | This is fallout from join pushdown; get_relid_attribute_name can't handle an attribute number of 0, indicating a whole-row reference, and shouldn't be called in that case. Etsuro Fujita, reviewed by Ashutosh Bapat
* postgres_fdw: Fix incorrect NULL handling in join pushdown.Robert Haas2016-06-24
| | | | | | | | | | something.* IS NOT NULL means that every attribute of the row is not NULL, not that the row itself is non-NULL (e.g. because it's coming from below an outer join. Use (somevar.*)::pg_catalog.text IS NOT NULL instead. Ashutosh Bapat, per a report by Rushabh Lathia. Reviewed by Amit Langote and Etsuro Fujita. Schema-qualification added by me.
* postgres_fdw: Check PlaceHolderVars before pushing down a join.Robert Haas2016-06-14
| | | | | | | | | | | | | | | | | | | As discovered by Andreas Seltenreich via sqlsmith, it's possible for a remote join to need to generate a target list which contains a PlaceHolderVar which would need to be evaluated on the remote server. This happens when we try to push down a join tree which contains outer joins and the nullable side of the join contains a subquery which evauates some expression which can go to NULL above the level of the join. Since the deparsing logic can't build a remote query that involves subqueries, it fails while trying to produce an SQL query that can be sent to the remote side. Detect such cases and don't try to push down the join at all. It's actually fine to push down the join if the PlaceHolderVar needs to be evaluated at the current join level. This patch makes a small change to build_tlist_to_deparse so that this case will work. Amit Langote, Ashutosh Bapat, and me.
* postgres_fdw: Fix the fix for crash when pushing down multiple joins.Robert Haas2016-05-16
| | | | | | | | | | | | | | Commit 3151f16e1874db82ed85a005dac15368903ca9fb was intended to be a commit of a patch from Ashutosh Bapat, but instead I mistakenly committed an earlier version from Michael Paquier (because both patches were submitted with the same filename, and I confused them). Michael's patch fixes the crash but doesn't actually implement the correct test. Repair the incorrect logic, and also expand the comments considerably so that this is all more clear. Ashutosh Bapat and Robert Haas
* postgres_fdw: Don't push down certain full joins.Robert Haas2016-04-20
| | | | | | | | | | | | | | | | If there's a filter condition on either side of a full outer join, it is neither correct to attach it to the join's ON clause nor to throw it into the toplevel WHERE clause. Just don't push down the join in that case. To maximize the number of cases where we can still push down full joins, push inner join conditions into the ON clause at the first opportunity rather than postponing them to the top-level WHERE clause. This produces nicer SQL, anyway. This bug was introduced in e4106b2528727c4b48639c0e12bf2f70a766b910. Ashutosh Bapat, per report from Rajkumar Raghuwanshi.
* Don't require a user mapping for FDWs to work.Robert Haas2016-03-28
| | | | | | | | | Commit fbe5a3fb73102c2cfec11aaaa4a67943f4474383 accidentally changed this behavior; put things back the way they were, and add some regression tests. Report by Andres Freund; patch by Ashutosh Bapat, with a bit of kibitzing by me.
* postgres_fdw: Fix crash when pushing down multiple joins.Robert Haas2016-03-23
| | | | | | | | | A join clause might mention multiple relations on either side, so it need not be the case that a given joinrel's constituent relations are all on one side of the join clause or all on the other. Report by Rajkumar Raghuwanshi. Analysis and fix by Michael Paquier and Ashutosh Bapat.
* 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.