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* Revert changes for SSL compression in libpqMichael Paquier2021-03-10
| | | | | | | | | | | | | | | This partially reverts 096bbf7 and 9d2d457, undoing the libpq changes as it could cause breakages in distributions that share one single libpq version across multiple major versions of Postgres for extensions and applications linking to that. Note that the backend is unchanged here, and it still disables SSL compression while simplifying the underlying catalogs that tracked if compression was enabled or not for a SSL connection. Per discussion with Tom Lane and Daniel Gustafsson. Discussion: https://postgr.es/m/YEbq15JKJwIX+S6m@paquier.xyz
* Switch back sslcompression to be a normal input field in libpqMichael Paquier2021-03-09
| | | | | | | | | | | | Per buildfarm member crake, any servers including a postgres_fdw server with this option set would fail to do a pg_upgrade properly as the option got hidden in f9264d1 by becoming a debug option, making the restore of the FDW server fail. This changes back the option in libpq to be visible, but still inactive to fix this upgrade issue. Discussion: https://postgr.es/m/YEbq15JKJwIX+S6m@paquier.xyz
* Remove support for SSL compressionMichael Paquier2021-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | PostgreSQL disabled compression as of e3bdb2d and the documentation recommends against using it since. Additionally, SSL compression has been disabled in OpenSSL since version 1.1.0, and was disabled in many distributions long before that. The most recent TLS version, TLSv1.3, disallows compression at the protocol level. This commit removes the feature itself, removing support for the libpq parameter sslcompression (parameter still listed for compatibility reasons with existing connection strings, just ignored), and removes the equivalent field in pg_stat_ssl and de facto PgBackendSSLStatus. Note that, on top of removing the ability to activate compression by configuration, compression is actively disabled in both frontend and backend to avoid overrides from local configurations. A TAP test is added for deprecated SSL parameters to check after backwards compatibility. Bump catalog version. Author: Daniel Gustafsson Reviewed-by: Peter Eisentraut, Magnus Hagander, Michael Paquier Discussion: https://postgr.es/m/7E384D48-11C5-441B-9EC3-F7DB1F8518F6@yesql.se
* Fix tuple routing to initialize batching only for insertsTomas Vondra2021-02-18
| | | | | | | | | | | | | | | | | | A cross-partition update on a partitioned table is implemented as a delete followed by an insert. With foreign partitions, this was however causing issues, because the FDW and core may disagree on when to enable batching. postgres_fdw was only allowing batching for plain inserts (CMD_INSERT) while core was trying to batch the insert component of the cross-partition update. Fix by restricting core to apply batching only to plain CMD_INSERT queries. It's possible to allow batching for cross-partition updates, but that will require more extensive changes, so better to leave that for a separate patch. Author: Amit Langote Reviewed-by: Tomas Vondra, Takayuki Tsunakawa Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* postgres_fdw: Fix assertion in estimate_path_cost_size().Etsuro Fujita2021-02-05
| | | | | | | | | | | | | | | | Commit 08d2d58a2 added an assertion assuming that the retrieved_rows estimate for a foreign relation, which is re-used to cost pre-sorted foreign paths with local stats, is set to at least one row in estimate_path_cost_size(), which isn't correct because if the relation is a foreign table with tuples=0, the estimate would be set to 0 there when not using remote estimates. Per bug #16807 from Alexander Lakhin. Back-patch to v13 where the aforementioned commit went in. Author: Etsuro Fujita Reviewed-by: Kyotaro Horiguchi Discussion: https://postgr.es/m/16807-9fe4e08fbaa5c7ce%40postgresql.org
* postgres_fdw: Fix tests for CLOBBER_CACHE_ALWAYS.Fujii Masao2021-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The regression tests added in commits 708d165ddb and 411ae64997 caused buildfarm failures when CLOBBER_CACHE_ALWAYS was enabled. This commit stabilizes those tests. The foreign server connections established by postgres_fdw behaves differently depending on whether CLOBBER_CACHE_ALWAYS is enabled or not. If it's not enabled, those connections are cached. On the other hand, if it's enabled, when the connections are established outside transaction block, they are not cached (i.e., they are immediately closed at the end of query that established them). So the subsequent postgres_fdw_get_connections() cannot list those connections and postgres_fdw_disconnect() cannot close them (because they are already closed). When the connections are established inside transaction block, they are cached whether CLOBBER_CACHE_ALWAYS was enabled or not. But if it's enabled, they are immediately marked as invalid, otherwise not. This causes the subsequent postgres_fdw_get_connections() to return different result in "valid" column depending on whether CLOBBER_CACHE_ALWAYS was enabled or not. This commit prevents the above differences of behavior from affecting the regression tests. Per buildfarm failure on trilobite. Original patch by Bharath Rupireddy. I (Fujii Masao) extracted the regression test fix from that and revised it a bit. Reported-by: Tom Lane Author: Bharath Rupireddy Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/2688508.1611865371@sss.pgh.pa.us
* postgres_fdw: Fix test failure with -DENFORCE_REGRESSION_TEST_NAME_RESTRICTIONSFujii Masao2021-01-26
| | | | | | | | | The roles created by regression test should have names starting with "regress_", and the test introduced in commit 411ae64997 did not do that. Per buildfarm member longfin. Discussion: https://postgr.es/m/73fc5ae4-3c54-1262-4533-f8c547de2e60@oss.nttdata.com
* postgres_fdw: Stabilize regression test for postgres_fdw_disconnect_all().Fujii Masao2021-01-26
| | | | | | | | | | | The regression test added in commit 411ae64997 caused buildfarm failures. The cause of them was that the order of warning messages output in the test was not stable. To fix this, this commit sets client_min_messages to ERROR temporarily when performing the test generating those warnings. Per buildfarm failures. Discussion: https://postgr.es/m/2147113.1611644754@sss.pgh.pa.us
* postgres_fdw: Add functions to discard cached connections.Fujii Masao2021-01-26
| | | | | | | | | | | | | | | | | This commit introduces two new functions postgres_fdw_disconnect() and postgres_fdw_disconnect_all(). The former function discards the cached connections to the specified foreign server. The latter discards all the cached connections. If the connection is used in the current transaction, it's not closed and a warning message is emitted. For example, these functions are useful when users want to explicitly close the foreign server connections that are no longer necessary and then to prevent them from eating up the foreign servers connections capacity. Author: Bharath Rupireddy, tweaked a bit by Fujii Masao Reviewed-by: Alexey Kondratov, Zhijie Hou, Zhihong Yu, Fujii Masao Discussion: https://postgr.es/m/CALj2ACVvrp5=AVp2PupEm+nAC8S4buqR3fJMmaCoc7ftT0aD2A@mail.gmail.com
* Implement support for bulk inserts in postgres_fdwTomas Vondra2021-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Extends the FDW API to allow batching inserts into foreign tables. That is usually much more efficient than inserting individual rows, due to high latency for each round-trip to the foreign server. It was possible to implement something similar in the regular FDW API, but it was inconvenient and there were issues with reporting the number of actually inserted rows etc. This extends the FDW API with two new functions: * GetForeignModifyBatchSize - allows the FDW picking optimal batch size * ExecForeignBatchInsert - inserts a batch of rows at once Currently, only INSERT queries support batching. Support for DELETE and UPDATE may be added in the future. This also implements batching for postgres_fdw. The batch size may be specified using "batch_size" option both at the server and table level. The initial patch version was written by me, but it was rewritten and improved in many ways by Takayuki Tsunakawa. Author: Takayuki Tsunakawa Reviewed-by: Tomas Vondra, Amit Langote Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* postgres_fdw: Add function to list cached connections to foreign servers.Fujii Masao2021-01-18
| | | | | | | | | | | | | | | | | | This commit adds function postgres_fdw_get_connections() to return the foreign server names of all the open connections that postgres_fdw established from the local session to the foreign servers. This function also returns whether each connection is valid or not. This function is useful when checking all the open foreign server connections. If we found some connection to drop, from the result of function, probably we can explicitly close them by the function that upcoming commit will add. This commit bumps the version of postgres_fdw to 1.1 since it adds new function. Author: Bharath Rupireddy, tweaked by Fujii Masao Reviewed-by: Zhijie Hou, Alexey Kondratov, Zhihong Yu, Fujii Masao Discussion: https://postgr.es/m/2d5cb0b3-a6e8-9bbb-953f-879f47128faa@oss.nttdata.com
* postgres_fdw: Fix connection leak.Fujii Masao2020-12-28
| | | | | | | | | | | | | | | | | | | | | In postgres_fdw, the cached connections to foreign servers will not be closed until the local session exits if the user mappings or foreign servers that those connections depend on are dropped. Those connections can be leaked. To fix that connection leak issue, after a change to a pg_foreign_server or pg_user_mapping catalog entry, this commit makes postgres_fdw close the connections depending on that entry immediately if current transaction has not used those connections yet. Otherwise, mark those connections as invalid and then close them at the end of current transaction, since they cannot be closed in the midst of the transaction using them. Closed connections will be remade at the next opportunity if necessary. Back-patch to all supported branches. Author: Bharath Rupireddy Reviewed-by: Zhihong Yu, Zhijie Hou, Fujii Masao Discussion: https://postgr.es/m/CALj2ACVNcGH_6qLY-4_tXz8JLvA+4yeBThRfxMz7Oxbk1aHcpQ@mail.gmail.com
* Band-aid new postgres_fdw test case to remove error text dependency.Tom Lane2020-10-10
| | | | | | | | | | | | | | | Buildfarm member lorikeet is still failing the test from commit 32a9c0bdf, but now it's down to the should-have-foreseen-it problem that the error message isn't what the expected-output file expects. Let's see if we can get stable results by printing just the SQLSTATE. I believe we'll reliably see ERRCODE_CONNECTION_FAILURE, since pgfdw_report_error() will report that for any libpq-originated error. There may be a better way to do this, but I'd like to get the buildfarm back to green before we discuss further improvements. Discussion: https://postgr.es/m/E1kPc9v-0005L4-2l@gemulon.postgresql.org Discussion: https://postgr.es/m/2621622.1602184554@sss.pgh.pa.us
* postgres_fdw: reestablish new connection if cached one is detected as broken.Fujii Masao2020-10-06
| | | | | | | | | | | | | | | | | | In postgres_fdw, once remote connections are established, they are cached and re-used for subsequent queries and transactions. There can be some cases where those cached connections are unavaiable, for example, by the restart of remote server. In these cases, previously an error was reported and the query accessing to remote server failed if new remote transaction failed to start because the cached connection was broken. This commit improves postgres_fdw so that new connection is remade if broken connection is detected when starting new remote transaction. This is useful to avoid unnecessary failure of queries when connection is broken but can be reestablished. Author: Bharath Rupireddy, tweaked a bit by Fujii Masao Reviewed-by: Ashutosh Bapat, Tatsuhito Kasahara, Fujii Masao Discussion: https://postgr.es/m/CALj2ACUAi23vf1WiHNar_LksM9EDOWXcbHCo-fD4Mbr1d=78YQ@mail.gmail.com
* Remove factorial operators, leaving only the factorial() function.Tom Lane2020-09-17
| | | | | | | | | | | | | | | | The "!" operator is our only built-in postfix operator. Remove it, on the way to removal of grammar support for postfix operators. There is also a "!!" prefix operator, but since it's been marked deprecated for most of its existence, we might as well remove it too. Also zap the SQL alias function numeric_fac(), which seems to have equally little reason to live. Mark Dilger, based on work by myself and Robert Haas; review by John Naylor Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
* Add support for partitioned tables and indexes in REINDEXMichael Paquier2020-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, REINDEX was not able to work with partitioned tables and indexes, forcing users to reindex partitions one by one. This extends REINDEX INDEX and REINDEX TABLE so as they can accept a partitioned index and table in input, respectively, to reindex all the partitions assigned to them with physical storage (foreign tables, partitioned tables and indexes are then discarded). This shares some logic with schema and database REINDEX as each partition gets processed in its own transaction after building a list of relations to work on. This choice has the advantage to minimize the number of invalid indexes to one partition with REINDEX CONCURRENTLY in the event a cancellation or failure in-flight, as the only indexes handled at once in a single REINDEX CONCURRENTLY loop are the ones from the partition being working on. Isolation tests are added to emulate some cases I bumped into while developing this feature, particularly with the concurrent drop of a leaf partition reindexed. However, this is rather limited as LOCK would cause REINDEX to block in the first transaction building the list of partitions. Per its multi-transaction nature, this new flavor cannot run in a transaction block, similarly to REINDEX SCHEMA, SYSTEM and DATABASE. Author: Justin Pryzby, Michael Paquier Reviewed-by: Anastasia Lubennikova Discussion: https://postgr.es/m/db12e897-73ff-467e-94cb-4af03705435f.adger.lj@alibaba-inc.com
* In postgres_fdw, don't try to ship MULTIEXPR updates to remote server.Tom Lane2020-01-26
| | | | | | | | | | | | | | | | | | | | | | | | In a statement like "UPDATE remote_tab SET (x,y) = (SELECT ...)", we'd conclude that the statement could be directly executed remotely, because the sub-SELECT is in a resjunk tlist item that's not examined for shippability. Currently that ends up crashing if the sub-SELECT contains any remote Vars. Prevent the crash by deeming MULTIEXEC Params to be unshippable. This is a bit of a brute-force solution, since if the sub-SELECT *doesn't* contain any remote Vars, the current execution technology would work; but that's not a terribly common use-case for this syntax, I think. In any case, we generally don't try to ship sub-SELECTs, so it won't surprise anybody that this doesn't end up as a remote direct update. I'd be inclined to see if that general limitation can be fixed before worrying about this case further. Per report from Lukáš Sobotka. Back-patch to 9.6. 9.5 had MULTIEXPR, but we didn't try to perform remote direct updates then, so the case didn't arise anyway. Discussion: https://postgr.es/m/CAJif3k+iA_ekBB5Zw2hDBaE1wtiQa4LH4_JUXrrMGwTrH0J01Q@mail.gmail.com
* Only superuser can set sslcert/sslkey in postgres_fdw user mappingsAndrew Dunstan2020-01-13
| | | | | | Othrwise there is a security risk. Discussion: https://postgr.es/m/20200109103014.GA4192@msg.df7cb.de
* Allow 'sslkey' and 'sslcert' in postgres_fdw user mappingsAndrew Dunstan2020-01-09
| | | | | | This allows different users to authenticate with different certificates. Author: Craig Ringer
* Adjust test case added by commit 6136e94dc.Tom Lane2019-12-20
| | | | | | | | | Per project policy, transient roles created by regression test cases should be named "regress_something", to reduce the risks of running such cases against installed servers. And no such role should ever be left behind after running a test. Discussion: https://postgr.es/m/11297.1576868677@sss.pgh.pa.us
* libpq should expose GSS-related parameters even when not implemented.Tom Lane2019-12-20
| | | | | | | | | | | | | | | | | | | | | | We realized years ago that it's better for libpq to accept all connection parameters syntactically, even if some are ignored or restricted due to lack of the feature in a particular build. However, that lesson from the SSL support was for some reason never applied to the GSSAPI support. This is causing various buildfarm members to have problems with a test case added by commit 6136e94dc, and it's just a bad idea from a user-experience standpoint anyway, so fix it. While at it, fix some places where parameter-related infrastructure was added with the aid of a dartboard, or perhaps with the aid of the anti-pattern "add new stuff at the end". It should be safe to rearrange the contents of struct pg_conn even in released branches, since that's private to libpq (and we'd have to move some fields in some builds to fix this, anyway). Back-patch to all supported branches. Discussion: https://postgr.es/m/11297.1576868677@sss.pgh.pa.us
* Superuser can permit passwordless connections on postgres_fdwAndrew Dunstan2019-12-20
| | | | | | | | | | | | | | | | | | | | Currently postgres_fdw doesn't permit a non-superuser to connect to a foreign server without specifying a password, or to use an authentication mechanism that doesn't use the password. This is to avoid using the settings and identity of the user running Postgres. However, this doesn't make sense for all authentication methods. We therefore allow a superuser to set "password_required 'false'" for user mappings for the postgres_fdw. The superuser must ensure that the foreign server won't try to rely solely on the server identity (e.g. trust, peer, ident) or use an authentication mechanism that relies on the password settings (e.g. md5, scram-sha-256). This feature is a prelude to better support for sslcert and sslkey settings in user mappings. Author: Craig Ringer. Discussion: https://postgr.es/m/075135da-545c-f958-fed0-5dcb462d6dae@2ndQuadrant.com
* Fix handling of multiple AFTER ROW triggers on a foreign table.Etsuro Fujita2019-12-10
| | | | | | | | | | | | | | | | | | | | | | AfterTriggerExecute() retrieves a fresh tuple or pair of tuples from a tuplestore and then stores the tuple(s) in the passed-in slot(s) if AFTER_TRIGGER_FDW_FETCH, while it uses the most-recently-retrieved tuple(s) stored in the slot(s) if AFTER_TRIGGER_FDW_REUSE. This was done correctly before 12, but commit ff11e7f4b broke it by mistakenly clearing the tuple(s) stored in the slot(s) in that function, leading to an assertion failure as reported in bug #16139 from Alexander Lakhin. Also, fix some other issues with the aforementioned commit in passing: * For tg_newslot, which is a slot added to the TriggerData struct by the commit to store new updated tuples, it didn't ensure the slot was NULL if there was no such tuple. * The commit failed to update the documentation about the trigger interface. Author: Etsuro Fujita Backpatch-through: 12 Discussion: https://postgr.es/m/16139-94f9ccf0db6119ec%40postgresql.org
* Add regression test for two-phase transaction in postgres_fdwMichael Paquier2019-11-13
| | | | | | | | | | | | postgres_fdw does not support two-phase transactions, so let's add a small negative test case to check after it. Note that this is checked using an end-of-xact callback to ensure a proper connection cleanup with the foreign server, which is called before checking if a server is able to handle 2PC with max_prepared_xacts, so this test does not need an alternate output file. Author: Gilles Darold Discussion: https://postgr.es/m/20191108090507.GC1768@paquier.xyz
* Fix many typos and inconsistenciesMichael Paquier2019-07-01
| | | | | Author: Alexander Lakhin Discussion: https://postgr.es/m/af27d1b3-a128-9d62-46e0-88f424397f44@gmail.com
* postgres_fdw: Account for triggers in non-direct remote UPDATE planning.Etsuro Fujita2019-06-13
| | | | | | | | | | | | | | | | | | Previously, in postgresPlanForeignModify, we planned an UPDATE operation on a foreign table so that we transmit only columns that were explicitly targets of the UPDATE, so as to avoid unnecessary data transmission, but if there were BEFORE ROW UPDATE triggers on the foreign table, those triggers might change values for non-target columns, in which case we would miss sending changed values for those columns. Prevent optimizing away transmitting all columns if there are BEFORE ROW UPDATE triggers on the foreign table. This is an oversight in commit 7cbe57c34 which added triggers on foreign tables, so apply the patch all the way back to 9.4 where that came in. Author: Shohei Mochizuki Reviewed-by: Amit Langote Discussion: https://postgr.es/m/201905270152.x4R1q3qi014550@toshiba.co.jp
* Avoid postgres_fdw crash for a targetlist entry that's just a Param.Tom Lane2019-04-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | foreign_grouping_ok() is willing to put fairly arbitrary expressions into the targetlist of a remote SELECT that's doing grouping or aggregation on the remote side, including expressions that have no foreign component to them at all. This is possibly a bit dubious from an efficiency standpoint; but it rises to the level of a crash-causing bug if the expression is just a Param or non-foreign Var. In that case, the expression will necessarily also appear in the fdw_exprs list of values we need to send to the remote server, and then setrefs.c's set_foreignscan_references will mistakenly replace the fdw_exprs entry with a Var referencing the targetlist result. The root cause of this problem is bad design in commit e7cb7ee14: it put logic into set_foreignscan_references that IMV is postgres_fdw-specific, and yet this bug shows that it isn't postgres_fdw-specific enough. The transformation being done on fdw_exprs assumes that fdw_exprs is to be evaluated with the fdw_scan_tlist as input, which is not how postgres_fdw uses it; yet it could be the right thing for some other FDW. (In the bigger picture, setrefs.c has no business assuming this for the other expression fields of a ForeignScan either.) The right fix therefore would be to expand the FDW API so that the FDW could inform setrefs.c how it intends to evaluate these various expressions. We can't change that in the back branches though, and we also can't just summarily change setrefs.c's behavior there, or we're likely to break external FDWs. As a stopgap, therefore, hack up postgres_fdw so that it won't attempt to send targetlist entries that look exactly like the fdw_exprs entries they'd produce. In most cases this actually produces a superior plan, IMO, with less data needing to be transmitted and returned; so we probably ought to think harder about whether we should ship tlist expressions at all when they don't contain any foreign Vars or Aggs. But that's an optimization not a bug fix so I left it for later. One case where this produces an inferior plan is where the expression in question is actually a GROUP BY expression: then the restriction prevents us from using remote grouping. It might be possible to work around that (since that would reduce to group-by-a-constant on the remote side); but it seems like a pretty unlikely corner case, so I'm not sure it's worth expending effort solely to improve that. In any case the right long-term answer is to fix the API as sketched above, and then revert this hack. Per bug #15781 from Sean Johnston. Back-patch to v10 where the problem was introduced. Discussion: https://postgr.es/m/15781-2601b1002bad087c@postgresql.org
* postgres_fdw: Fix incorrect handling of row movement for remote partitions.Etsuro Fujita2019-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 3d956d9562 added support for update row movement in postgres_fdw. This patch fixes the following issues introduced by that commit: * When a remote partition chosen to insert routed rows into was also an UPDATE subplan target rel that would be updated later, the UPDATE that used a direct modification plan modified those routed rows incorrectly because those routed rows were visible to the later UPDATE command. The right fix for this would be to have some way in postgres_fdw in which the later UPDATE command ignores those routed rows, but it seems hard to do so with the current infrastructure. For now throw an error in that case. * When a remote partition chosen to insert routed rows into was also an UPDATE subplan target rel, fmstate created for the UPDATE that used a non-direct modification plan was mistakenly overridden by another fmstate created for inserting those routed rows into the partition. This caused 1) server crash when the partition would be updated later, and 2) resource leak when the partition had been already updated. To avoid that, adjust the treatment of the fmstate for the inserting. As for #1, since we would also have the incorrectness issue as mentioned above, error out in that case as well. Update the docs to mention that postgres_fdw currently does not handle the case where a remote partition chosen to insert a routed row into is also an UPDATE subplan target rel that will be updated later. Author: Amit Langote and Etsuro Fujita Reviewed-by: Amit Langote Backpatch-through: 11 where row movement in postgres_fdw was added Discussion: https://postgr.es/m/21e7eaa4-0d4d-20c2-a1f7-c7e96f4ce440@lab.ntt.co.jp
* Add support TCP user timeout in libpq and the backend serverMichael Paquier2019-04-06
| | | | | | | | | | | | | | | | | Similarly to the set of parameters for keepalive, a connection parameter for libpq is added as well as a backend GUC, called tcp_user_timeout. Increasing the TCP user timeout is useful to allow a connection to survive extended periods without end-to-end connection, and decreasing it allows application to fail faster. By default, the parameter is 0, which makes the connection use the system default, and follows a logic close to the keepalive parameters in its handling. When connecting through a Unix-socket domain, the parameters have no effect. Author: Ryohei Nagaura Reviewed-by: Fabien Coelho, Robert Haas, Kyotaro Horiguchi, Kirk Jamison, Mikalai Keida, Takayuki Tsunakawa, Andrei Yahorau Discussion: https://postgr.es/m/EDA4195584F5064680D8130B1CA91C45367328@G01JPEXMBYT04
* postgres_fdw: Perform the (FINAL, NULL) upperrel operations remotely.Etsuro Fujita2019-04-02
| | | | | | | | | | | | | | | | The upper-planner pathification allows FDWs to arrange to push down different types of upper-stage operations to the remote side. This commit teaches postgres_fdw to do it for the (FINAL, NULL) upperrel, which is responsible for doing LockRows, LIMIT, and/or ModifyTable. This provides the ability for postgres_fdw to handle SELECT commands so that it 1) skips the LockRows step (if any) (note that this is safe since it performs early locking) and 2) pushes down the LIMIT and/or OFFSET restrictions (if any) to the remote side. This doesn't handle the INSERT/UPDATE/DELETE cases. Author: Etsuro Fujita Reviewed-By: Antonin Houska and Jeff Janes Discussion: https://postgr.es/m/87pnz1aby9.fsf@news-spur.riddles.org.uk
* postgres_fdw: Modify regression tests for EPQ-related planning problems.Etsuro Fujita2019-04-02
| | | | | | | | | This prevents the tests added by commit 4bbf6edfbd and adjusted by commit 99f6a17dd6 from being useless by plan changes created by an upcoming commit. Author: Etsuro Fujita Discussion: https://postgr.es/m/87pnz1aby9.fsf@news-spur.riddles.org.uk
* Generated columnsPeter Eisentraut2019-03-30
| | | | | | | | | | | | | | This is an SQL-standard feature that allows creating columns that are computed from expressions rather than assigned, similar to a view or materialized view but on a column basis. This implements one kind of generated column: stored (computed on write). Another kind, virtual (computed on read), is planned for the future, and some room is left for it. Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/b151f851-4019-bdb1-699e-ebab07d2f40a@2ndquadrant.com
* Suppress Append and MergeAppend plan nodes that have a single child.Tom Lane2019-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | If there's only one child relation, the Append or MergeAppend isn't doing anything useful, and can be elided. It does have a purpose during planning though, which is to serve as a buffer between parent and child Var numbering. Therefore we keep it all the way through to setrefs.c, and get rid of it only after fixing references in the plan level(s) above it. This works largely the same as setrefs.c's ancient hack to get rid of no-op SubqueryScan nodes, and can even share some code with that. Note the change to make setrefs.c use apply_tlist_labeling rather than ad-hoc code. This has the effect of propagating the child's resjunk and ressortgroupref labels, which formerly weren't propagated when removing a SubqueryScan. Doing that is demonstrably necessary for the [Merge]Append cases, and seems harmless for SubqueryScan, if only because trivial_subqueryscan is afraid to collapse cases where the resjunk marking differs. (I suspect that restriction could now be removed, though it's unclear that it'd make any new matches possible, since the outer query can't have references to a child resjunk column.) David Rowley, reviewed by Alvaro Herrera and Tomas Vondra Discussion: https://postgr.es/m/CAKJS1f_7u8ATyJ1JGTMHFoKDvZdeF-iEBhs+sM_SXowOr9cArg@mail.gmail.com
* Allow user control of CTE materialization, and change the default behavior.Tom Lane2019-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically we've always materialized the full output of a CTE query, treating WITH as an optimization fence (so that, for example, restrictions from the outer query cannot be pushed into it). This is appropriate when the CTE query is INSERT/UPDATE/DELETE, or is recursive; but when the CTE query is non-recursive and side-effect-free, there's no hazard of changing the query results by pushing restrictions down. Another argument for materialization is that it can avoid duplicate computation of an expensive WITH query --- but that only applies if the WITH query is called more than once in the outer query. Even then it could still be a net loss, if each call has restrictions that would allow just a small part of the WITH query to be computed. Hence, let's change the behavior for WITH queries that are non-recursive and side-effect-free. By default, we will inline them into the outer query (removing the optimization fence) if they are called just once. If they are called more than once, we will keep the old behavior by default, but the user can override this and force inlining by specifying NOT MATERIALIZED. Lastly, the user can force the old behavior by specifying MATERIALIZED; this would mainly be useful when the query had deliberately been employing WITH as an optimization fence to prevent a poor choice of plan. Andreas Karlsson, Andrew Gierth, David Fetter Discussion: https://postgr.es/m/87sh48ffhb.fsf@news-spur.riddles.org.uk
* Split create_foreignscan_path() into three functions.Tom Lane2019-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now postgres_fdw has been using create_foreignscan_path() to generate not only base-relation paths, but also paths for foreign joins and foreign upperrels. This is wrong, because create_foreignscan_path() calls get_baserel_parampathinfo() which will only do the right thing for baserels. It accidentally fails to fail for unparameterized paths, which are the only ones postgres_fdw (thought it) was handling, but we really need different APIs for the baserel and join cases. In HEAD, the best thing to do seems to be to split up the baserel, joinrel, and upperrel cases into three functions so that they can have different APIs. I haven't actually given create_foreign_join_path a different API in this commit: we should spend a bit of time thinking about just what we want to do there, since perhaps FDWs would want to do something different from the build-up-a-join-pairwise approach that get_joinrel_parampathinfo expects. In the meantime, since postgres_fdw isn't prepared to generate parameterized joins anyway, just give it a defense against trying to plan joins with lateral refs. In addition (and this is what triggered this whole mess) fix bug #15613 from Srinivasan S A, by teaching file_fdw and postgres_fdw that plain baserel foreign paths still have outer refs if the relation has lateral_relids. Add some assertions in relnode.c to catch future occurrences of the same error --- in particular, to catch other FDWs doing that, but also as backstop against core-code mistakes like the one fixed by commit bdd9a99aa. Bug #15613 also needs to be fixed in the back branches, but the appropriate fix will look quite a bit different there, since we don't want to assume that existing FDWs get the word right away. Discussion: https://postgr.es/m/15613-092be1be9576c728@postgresql.org
* 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