25 Commits (9c58101117d25f174c8d8013befdc33c632922d0)

Author	SHA1	Message	Date
Tom Lane	9c58101117	Fix mishandling of system columns in FDW queries. ... postgres_fdw would send query conditions involving system columns to the remote server, even though it makes no effort to ensure that system columns other than CTID match what the remote side thinks. tableoid, in particular, probably won't match and might have some use in queries. Hence, prevent sending conditions that include non-CTID system columns. Also, create_foreignscan_plan neglected to check local restriction conditions while determining whether to set fsSystemCol for a foreign scan plan node. This again would bollix the results for queries that test a foreign table's tableoid. Back-patch the first fix to 9.3 where postgres_fdw was introduced. Back-patch the second to 9.2. The code is probably broken in 9.1 as well, but the patch doesn't apply cleanly there; given the weak state of support for FDWs in 9.1, it doesn't seem worth fixing. Etsuro Fujita, reviewed by Ashutosh Bapat, and somewhat modified by me	11 years ago
Andres Freund	57ca1d4f01	Specify the port in dblink and postgres_fdw tests. ... That allows to run those tests against a postmaster listening on a nonstandard port without requiring to export PGPORT in postmaster's environment. This still doesn't support connecting to a nondefault host without configuring it in postmaster's environment. That's harder and less frequently used though. So this is a useful step.	11 years ago
Andres Freund	ddc2504dbc	Don't hardcode contrib_regression dbname in postgres_fdw and dblink tests. ... That allows parallel installcheck to succeed inside contrib/. The output is not particularly pretty unless make's -O option to synchronize the output is used. There's other tests, outside contrib, that use a hardcoded, non-unique, database name. Those prohibit paralell installcheck to be used across more directories; but that's something for a separate patch.	11 years ago
Tom Lane	59efda3e50	Implement IMPORT FOREIGN SCHEMA. ... This command provides an automated way to create foreign table definitions that match remote tables, thereby reducing tedium and chances for error. In this patch, we provide the necessary core-server infrastructure and implement the feature fully in the postgres_fdw foreign-data wrapper. Other wrappers will throw a "feature not supported" error until/unless they are updated. Ronan Dunklau and Michael Paquier, additional work by me	11 years ago
Tom Lane	5b68d81697	Fix contrib/postgres_fdw's remote-estimate representation of array Params. ... We were emitting "(SELECT null::typename)", which is usually interpreted as a scalar subselect, but not so much in the context "x = ANY(...)". This led to remote-side parsing failures when remote_estimate is enabled. A quick and ugly fix is to stick in an extra cast step, "((SELECT null::typename)::typename)". The cast will be thrown away as redundant by parse analysis, but not before it's done its job of making sure the grammar sees the ANY argument as an a_expr rather than a select_with_parens. Per an example from Hannu Krosing.	11 years ago
Noah Misch	b2b2491b06	Don't test xmin/xmax columns of a postgres_fdw foreign table. ... Their values are unspecified and system-dependent. Per buildfarm member kouprey.	11 years ago
Noah Misch	7cbe57c34d	Offer triggers on foreign tables. ... This covers all the SQL-standard trigger types supported for regular tables; it does not cover constraint triggers. The approach for acquiring the old row mirrors that for view INSTEAD OF triggers. For AFTER ROW triggers, we spool the foreign tuples to a tuplestore. This changes the FDW API contract; when deciding which columns to populate in the slot returned from data modification callbacks, writable FDWs will need to check for AFTER ROW triggers in addition to checking for a RETURNING clause. In support of the feature addition, refactor the TriggerFlags bits and the assembly of old tuples in ModifyTable. Ronan Dunklau, reviewed by KaiGai Kohei; some additional hacking by me.	11 years ago
Tom Lane	83204e100c	Fix contrib/postgres_fdw to handle multiple join conditions properly. ... The previous coding supposed that it could consider just a single join condition in any one parameterized path for the foreign table. But in reality, the parameterized-path machinery forces all join clauses that are "movable to" the foreign table to be evaluated at that node; including clauses that we might not consider safe to send across. Such cases would result in an Assert failure in an assert-enabled build, and otherwise in sending an unsafe clause to the foreign server, which might result in errors or silently-wrong answers. A lesser problem was that the cost/rowcount estimates generated for the parameterized path failed to account for any additional join quals that get assigned to the scan. To fix, rewrite postgresGetForeignPaths so that it correctly collects all the movable quals for any one outer relation when generating parameterized paths; we'll now generate just one path per outer relation not one per join qual. Also fix bogus assumptions in postgresGetForeignPlan and estimate_path_cost_size that only safe-to-send join quals will be presented. Based on complaint from Etsuro Fujita that the path costs were being miscalculated, though this is significantly different from his proposed patch.	11 years ago
Tom Lane	dc3eb56383	Improve updatability checking for views and foreign tables. ... Extend the FDW API (which we already changed for 9.3) so that an FDW can report whether specific foreign tables are insertable/updatable/deletable. The default assumption continues to be that they're updatable if the relevant executor callback function is supplied by the FDW, but finer granularity is now possible. As a test case, add an "updatable" option to contrib/postgres_fdw. This patch also fixes the information_schema views, which previously did not think that foreign tables were ever updatable, and fixes view_is_auto_updatable() so that a view on a foreign table can be auto-updatable. initdb forced due to changes in information_schema views and the functions they rely on. This is a bit unfortunate to do post-beta1, but if we don't change this now then we'll have another API break for FDWs when we do change it. Dean Rasheed, somewhat editorialized on by Tom Lane	12 years ago
Tom Lane	e0b451e432	Tweak postgres_fdw regression test so autovacuum doesn't change results. ... Autovacuum occurring while the test runs could allow some of the inserts to go into recycled space, thus changing the output ordering of later queries. While we could complicate those queries to force sorting of their output rows, it doesn't seem like that would make the test better in any meaningful way, and conceivably it could hide unexpected diffs. Instead, tweak the affected queries so that the inserted rows aren't updated by the following UPDATE. Per buildfarm.	12 years ago
Tom Lane	b142068622	Allow CREATE FOREIGN TABLE to include SERIAL columns. ... The behavior is that the required sequence is created locally, which is appropriate because the default expression will be evaluated locally. Per gripe from Brad Nicholson that this case was refused with a confusing error message. We could have improved the error message but it seems better to just allow the case. Also, remove ALTER TABLE's arbitrary prohibition against being applied to foreign tables, which was pretty inconsistent considering we allow it for views, sequences, and other relation types that aren't even called tables. This is needed to avoid breaking pg_dump, which sometimes emits column defaults using separate ALTER TABLE commands. (I think this can happen even when the default is not associated with a sequence, so that was a pre-existing bug once we allowed column defaults for foreign tables.)	12 years ago
Tom Lane	e690b95150	Avoid retrieving dummy NULL columns in postgres_fdw. ... This should provide some marginal overall savings, since it surely takes many more cycles for the remote server to deal with the NULL columns than it takes for postgres_fdw not to emit them. But really the reason is to keep the emitted queries from looking quite so silly ...	12 years ago
Tom Lane	9cbc4b80dd	Redo postgres_fdw's planner code so it can handle parameterized paths. ... I wasn't going to ship this without having at least some example of how to do that. This version isn't terribly bright; in particular it won't consider any combinations of multiple join clauses. Given the cost of executing a remote EXPLAIN, I'm not sure we want to be very aggressive about doing that, anyway. In support of this, refactor generate_implied_equalities_for_indexcol so that it can be used to extract equivalence clauses that aren't necessarily tied to an index.	12 years ago
Tom Lane	ed3ddf918b	Introduce less-bogus handling of collations in contrib/postgres_fdw. ... Treat expressions as being remotely executable only if all collations used in them are determined by Vars of the foreign table. This means that, if the foreign server gets different answers than we do, it's the user's fault for not having marked the foreign table columns with collations equivalent to the remote table's. This rule allows most simple expressions such as "var < 'constant'" to be sent to the remote side, because the constant isn't determining the collation (the Var's collation would win). There's still room for improvement, but it's hard to see how to do it without a lot more knowledge and/or assumptions about what the remote side will do.	12 years ago
Tom Lane	50c19fc76f	Fix contrib/postgres_fdw's handling of column defaults. ... Adopt the position that only locally-defined defaults matter. Any defaults defined in the remote database do not affect insertions performed through a foreign table (unless they are for columns not known to the foreign table). While it'd arguably be more useful to permit remote defaults to be used, making that work in a consistent fashion requires far more work than seems possible for 9.3.	12 years ago
Tom Lane	0247d43dd9	Avoid row-processing-order dependency in postgres_fdw regression test. ... A test intended to provoke an error on the remote side was coded in such a way that multiple rows should be updated, so the output would vary depending on which one was processed first. Per buildfarm.	12 years ago
Tom Lane	cc3f281ffb	Fix postgres_fdw's issues with inconsistent interpretation of data values. ... For datatypes whose output formatting depends on one or more GUC settings, we have to worry about whether the other server will interpret the value the same way it was meant. pg_dump has been aware of this hazard for a long time, but postgres_fdw needs to deal with it too. To fix data retrieval from the remote server, set the necessary remote GUC settings at connection startup. (We were already assuming that settings made then would persist throughout the remote session.) To fix data transmission to the remote server, temporarily force the relevant GUCs to the right values when we're about to convert any data values to text for transmission. This is all pretty grotty, and not very cheap either. It's tempting to think of defining one uber-GUC that would override any settings that might render printed data values unportable. But of course, older remote servers wouldn't know any such thing and would still need this logic. While at it, revert commit f7951eef89, since this provides a real fix. (The timestamptz given in the error message returned from the "remote" server will now reliably be shown in UTC.)	12 years ago
Tom Lane	f7951eef89	Band-aid for regression test expected-results problem with timestamptz. ... We probably need to tell the remote server to use specific timezone and datestyle settings, and maybe other things. But for now let's just hack the postgres_fdw regression test to not provoke failures when run in non-EST5EDT environments. Per buildfarm.	12 years ago
Tom Lane	21734d2fb8	Support writable foreign tables. ... This patch adds the core-system infrastructure needed to support updates on foreign tables, and extends contrib/postgres_fdw to allow updates against remote Postgres servers. There's still a great deal of room for improvement in optimization of remote updates, but at least there's basic functionality there now. KaiGai Kohei, reviewed by Alexander Korotkov and Laurenz Albe, and rather heavily revised by Tom Lane.	12 years ago
Tom Lane	09a7cd409e	Rename postgres_fdw's use_remote_explain option to use_remote_estimate. ... The new name was originally my typo, but per discussion it seems like a better name anyway. So make the code match the docs, not vice versa.	13 years ago
Tom Lane	6da378dbc9	Fix whole-row references in postgres_fdw. ... The optimization to not retrieve unnecessary columns wasn't smart enough. Noted by Thom Brown.	13 years ago
Tom Lane	211e157a51	Change postgres_fdw to show casts as casts, not underlying function calls. ... On reflection this method seems to be exposing an unreasonable amount of implementation detail. It wouldn't matter when talking to a remote server of the identical Postgres version, but it seems likely to make things worse not better if the remote is a different version with different casting infrastructure. Instead adopt ruleutils.c's policy of regurgitating the cast as it was originally specified; including not showing it at all, if it was implicit to start with. (We must do that because for some datatypes explicit and implicit casts have different semantics.)	13 years ago
Tom Lane	5fd386bb31	Get rid of postgres_fdw's assumption that remote type OIDs match ours. ... The only place we depended on that was in sending numeric type OIDs in PQexecParams; but we can replace that usage with explicitly casting each Param symbol in the query string, so that the types are specified to the remote by name not OID. This makes no immediate difference but will be essential if we ever hope to support use of non-builtin types.	13 years ago
Tom Lane	6d06049493	Adjust postgres_fdw's search path handling. ... Set the remote session's search path to exactly "pg_catalog" at session start, then schema-qualify only names that aren't in that schema. This greatly reduces clutter in the generated SQL commands, as seen in the regression test changes. Per discussion. Also, rethink use of FirstNormalObjectId as the "built-in object" cutoff --- FirstBootstrapObjectId is safer, since the former will accept objects in information_schema for instance.	13 years ago
Tom Lane	d0d75c4022	Add postgres_fdw contrib module. ... There's still a lot of room for improvement, but it basically works, and we need this to be present before we can do anything much with the writable-foreign-tables patch. So let's commit it and get on with testing. Shigeru Hanada, reviewed by KaiGai Kohei and Tom Lane	13 years ago