aboutsummaryrefslogtreecommitdiff
path: root/src/backend/tcop
Commit message (Collapse)AuthorAge
...
* Account for catalog snapshot in PGXACT->xmin updates.Tom Lane2016-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CatalogSnapshot was not plugged into SnapshotResetXmin()'s accounting for whether MyPgXact->xmin could be cleared or advanced. In normal transactions this was masked by the fact that the transaction snapshot would be older, but during backend startup and certain utility commands it was possible to re-use the CatalogSnapshot after MyPgXact->xmin had been cleared, meaning that recently-deleted rows could be pruned even though this snapshot could still see them, causing unexpected catalog lookup failures. This effect appears to be the explanation for a recent failure on buildfarm member piculet. To fix, add the CatalogSnapshot to the RegisteredSnapshots heap whenever it is valid. In the previous logic, it was possible for the CatalogSnapshot to remain valid across waits for client input, but with this change that would mean it delays advance of global xmin in cases where it did not before. To avoid possibly causing new table-bloat problems with clients that sit idle for long intervals, add code to invalidate the CatalogSnapshot before waiting for client input. (When the backend is busy, it's unlikely that the CatalogSnapshot would be the oldest snap for very long, so we don't worry about forcing early invalidation of it otherwise.) In passing, remove the CatalogSnapshotStale flag in favor of using "CatalogSnapshot != NULL" to represent validity, as we do for the other special snapshots in snapmgr.c. And improve some obsolete comments. No regression test because I don't know a deterministic way to cause this failure. But the stress test shown in the original discussion provokes "cache lookup failed for relation 1255" within a few dozen seconds for me. Back-patch to 9.4 where MVCC catalog scans were introduced. (Note: it's quite easy to produce similar failures with the same test case in branches before 9.4. But MVCC catalog scans were supposed to fix that.) Discussion: <16447.1478818294@sss.pgh.pa.us>
* Make getrusage() output a little more readablePeter Eisentraut2016-10-19
| | | | | Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Peter Geoghegan <pg@heroku.com>
* Drop server support for FE/BE protocol version 1.0.Tom Lane2016-10-11
| | | | | | | | | While this isn't a lot of code, it's been essentially untestable for a very long time, because libpq doesn't support anything older than protocol 2.0, and has not since release 6.3. There's no reason to believe any other client-side code still uses that protocol, either. Discussion: <2661.1475849167@sss.pgh.pa.us>
* Add location field to DefElemPeter Eisentraut2016-09-06
| | | | | | | | | | | | | | Add a location field to the DefElem struct, used to parse many utility commands. Update various error messages to supply error position information. To propogate the error position information in a more systematic way, create a ParseState in standard_ProcessUtility() and pass that to interested functions implementing the utility commands. This seems better than passing the query string and then reassembling a parse state ad hoc, which violates the encapsulation of the ParseState type. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
* Relax transactional restrictions on ALTER TYPE ... ADD VALUE.Tom Lane2016-09-05
| | | | | | | | | | | | | | | | | | | | To prevent possibly breaking indexes on enum columns, we must keep uncommitted enum values from getting stored in tables, unless we can be sure that any such column is new in the current transaction. Formerly, we enforced this by disallowing ALTER TYPE ... ADD VALUE from being executed at all in a transaction block, unless the target enum type had been created in the current transaction. This patch removes that restriction, and instead insists that an uncommitted enum value can't be referenced unless it belongs to an enum type created in the same transaction as the value. Per discussion, this should be a bit less onerous. It does require each function that could possibly return a new enum value to SQL operations to check this restriction, but there aren't so many of those that this seems unmaintainable. Andrew Dunstan and Tom Lane Discussion: <4075.1459088427@sss.pgh.pa.us>
* Add macros to make AllocSetContextCreate() calls simpler and safer.Tom Lane2016-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>
* Fix TOAST access failure in RETURNING queries.Tom Lane2016-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Discussion of commit 3e2f3c2e4 exposed a problem that is of longer standing: since we don't detoast data while sticking it into a portal's holdStore for PORTAL_ONE_RETURNING and PORTAL_UTIL_SELECT queries, and we release the query's snapshot as soon as we're done loading the holdStore, later readout of the holdStore can do TOAST fetches against data that can no longer be seen by any of the session's live snapshots. This means that a concurrent VACUUM could remove the TOAST data before we can fetch it. Commit 3e2f3c2e4 exposed the problem by showing that sometimes we had *no* live snapshots while fetching TOAST data, but we'd be at risk anyway. I believe this code was all right when written, because our management of a session's exposed xmin was such that the TOAST references were safe until end of transaction. But that's no longer true now that we can advance or clear our PGXACT.xmin intra-transaction. To fix, copy the query's snapshot during FillPortalStore() and save it in the Portal; release it only when the portal is dropped. This essentially implements a policy that we must hold a relevant snapshot whenever we access potentially-toasted data. We had already come to that conclusion in other places, cf commits 08e261cbc94ce9a7 and ec543db77b6b72f2. I'd have liked to add a regression test case for this, but I didn't see a way to make one that's not unreasonably bloated; it seems to require returning a toasted value to the client, and those will be big. In passing, improve PortalRunUtility() so that it positively verifies that its ending PopActiveSnapshot() call will pop the expected snapshot, removing a rather shaky assumption about which utility commands might do their own PopActiveSnapshot(). There's no known bug here, but now that we're actively referencing the snapshot it's almost free to make this code a bit more bulletproof. We might want to consider back-patching something like this into older branches, but it would be prudent to let it prove itself more in HEAD beforehand. Discussion: <87vazemeda.fsf@credativ.de>
* Revert "Add some temporary code to record stack usage at server process exit."Tom Lane2016-07-10
| | | | | | | This reverts commit 88cf37d2a86d5b66380003d7c3384530e3f91e40 as well as follow-on commits ea9c4a16d5ad88a1d28d43ef458e3209b53eb106 and c57562725d219c4249b82f4a4fb5aaeee3ae0d53. We've learned about as much as we can from the buildfarm.
* Add more temporary code to record stack usage at server process exit.Tom Lane2016-07-08
| | | | | | | | After a look at preliminary results from commit 88cf37d2a86d5b66, I realized it'd be a good idea to spew out the maximum depth measurement seen by check_stack_depth. So add some quick-n-dirty code to do that. Like the previous commit, this will be reverted once we've gathered a set of buildfarm runs with it.
* Stop the executor if no more tuples can be sent from worker to leader.Robert Haas2016-06-06
| | | | | | | | | | | | | | | | | | | | | If a Gather node has read as many tuples as it needs (for example, due to Limit) it may detach the queue connecting it to the worker before reading all of the worker's tuples. Rather than let the worker continue to generate and send all of the results, have it stop after sending the next tuple. More could be done here to stop the worker even quicker, but this is about as well as we can hope to do for 9.6. This is in response to a problem report from Andreas Seltenreich. Commit 44339b892a04e94bbb472235882dc6f7023bdc65 should be actually be sufficient to fix that example even without this change, but it seems better to do this, too, since we might otherwise waste quite a large amount of effort in one or more workers. Discussion: CAA4eK1KOKGqmz9bGu+Z42qhRwMbm4R5rfnqsLCNqFs9j14jzEA@mail.gmail.com Amit Kapila
* Be more predictable about reporting "lock timeout" vs "statement timeout".Tom Lane2016-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If both timeout indicators are set when we arrive at ProcessInterrupts, we've historically just reported "lock timeout". However, some buildfarm members have been observed to fail isolationtester's timeouts test by reporting "lock timeout" when the statement timeout was expected to fire first. The cause seems to be that the process is allowed to sleep longer than expected (probably due to heavy machine load) so that the lock timeout happens before we reach the point of reporting the error, and then this arbitrary tiebreak rule does the wrong thing. We can improve matters by comparing the scheduled timeout times to decide which error to report. I had originally proposed greatly reducing the 1-second window between the two timeouts in the test cases. On reflection that is a bad idea, at least for the case where the lock timeout is expected to fire first, because that would assume that it takes negligible time to get from statement start to the beginning of the lock wait. Thus, this patch doesn't completely remove the risk of test failures on slow machines. Empirically, however, the case this handles is the one we are seeing in the buildfarm. The explanation may be that the other case requires the scheduler to take the CPU away from a busy process, whereas the case fixed here only requires the scheduler to not give the CPU back right away to a process that has been woken from a multi-second sleep (and, perhaps, has been swapped out meanwhile). Back-patch to 9.3 where the isolationtester timeouts test was added. Discussion: <8693.1464314819@sss.pgh.pa.us>
* Support ALTER THING .. DEPENDS ON EXTENSIONAlvaro Herrera2016-04-05
| | | | | | | | | | | | | | This introduces a new dependency type which marks an object as depending on an extension, such that if the extension is dropped, the object automatically goes away; and also, if the database is dumped, the object is included in the dump output. Currently the grammar supports this for indexes, triggers, materialized views and functions only, although the utility code is generic so adding support for more object types is a matter of touching the parser rules only. Author: Abhijit Menon-Sen Reviewed-by: Alexander Korotkov, Álvaro Herrera Discussion: http://www.postgresql.org/message-id/20160115062649.GA5068@toroid.org
* Support CREATE ACCESS METHODAlvaro Herrera2016-03-23
| | | | | | | | | | | | | | | This enables external code to create access methods. This is useful so that extensions can add their own access methods which can be formally tracked for dependencies, so that DROP operates correctly. Also, having explicit support makes pg_dump work correctly. Currently only index AMs are supported, but we expect different types to be added in the future. Authors: Alexander Korotkov, Petr Jelínek Reviewed-By: Teodor Sigaev, Petr Jelínek, Jim Nasby Commitfest-URL: https://commitfest.postgresql.org/9/353/ Discussion: https://www.postgresql.org/message-id/CAPpHfdsXwZmojm6Dx+TJnpYk27kT4o7Ri6X_4OSWcByu1Rm+VA@mail.gmail.com
* Add idle_in_transaction_session_timeout.Robert Haas2016-03-16
| | | | | Vik Fearing, reviewed by Stéphane Schildknecht and me, and revised slightly by me.
* Widen query numbers-of-tuples-processed counters to uint64.Tom Lane2016-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch widens SPI_processed, EState's es_processed field, PortalData's portalPos field, FuncCallContext's call_cntr and max_calls fields, ExecutorRun's count argument, PortalRunFetch's result, and the max number of rows in a SPITupleTable to uint64, and deals with (I hope) all the ensuing fallout. Some of these values were declared uint32 before, and others "long". I also removed PortalData's posOverflow field, since that logic seems pretty useless given that portalPos is now always 64 bits. The user-visible results are that command tags for SELECT etc will correctly report tuple counts larger than 4G, as will plpgsql's GET GET DIAGNOSTICS ... ROW_COUNT command. Queries processing more tuples than that are still not exactly the norm, but they're becoming more common. Most values associated with FETCH/MOVE distances, such as PortalRun's count argument and the count argument of most SPI functions that have one, remain declared as "long". It's not clear whether it would be worth promoting those to int64; but it would definitely be a large dollop of additional API churn on top of this, and it would only help 32-bit platforms which seem relatively less likely to see any benefit. Andreas Scherbaum, reviewed by Christian Ullrich, additional hacking by me
* Enable parallelism for prepared statements and extended query protocol.Robert Haas2016-02-25
| | | | | | | | | | | | | | | | | | Parallel query can't handle running a query only partially rather than to completion. However, there seems to be no way to run a statement prepared via SQL PREPARE other than to completion, so we can enable it there without a problem. The situation is more complicated for the extend query protocol. libpq seems to provide no way to send an Execute message with a non-zero rowcount, but some other client might. If that happens, and a parallel plan was chosen, we'll execute the parallel plan without using any workers, which may be somewhat inefficient but should still work. Hopefully this won't be a problem; users can always set max_parallel_degree=0 to avoid choosing parallel plans in the first place. Amit Kapila, reviewed by me.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Adjust behavior of single-user -j mode for better initdb error reporting.Tom Lane2015-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | Previously, -j caused the entire input file to be read in and executed as a single command string. That's undesirable, not least because any error causes the entire file to be regurgitated as the "failing query". Some experimentation suggests a better rule: end the command string when we see a semicolon immediately followed by two newlines, ie, an empty line after a query. This serves nicely to break up the existing examples such as information_schema.sql and system_views.sql. A limitation is that it's no longer possible to write such a sequence within a string literal or multiline comment in a file meant to be read with -j; but there are no instances of such a problem within the data currently used by initdb. (If someone does make such a mistake in future, it'll be obvious because they'll get an unterminated-literal or unterminated-comment syntax error.) Other than that, there shouldn't be any negative consequences; you're not forced to end statements that way, it's just a better idea in most cases. In passing, remove src/include/tcop/tcopdebug.h, which is dead code because it's not included anywhere, and hasn't been for more than ten years. One of the debug-support symbols it purported to describe has been unreferenced for at least the same amount of time, and the other is removed by this commit on the grounds that it was useless: forcing -j mode all the time would have broken initdb. The lack of complaints about that, or about the missing inclusion, shows that no one has tried to use TCOP_DONTUSENEWLINE in many years.
* Fix problems with ParamListInfo serialization mechanism.Robert Haas2015-11-02
| | | | | | | | | | | | | | | | | | | | | | Commit d1b7c1ffe72e86932b5395f29e006c3f503bc53d introduced a mechanism for serializing a ParamListInfo structure to be passed to a parallel worker. However, this mechanism failed to handle external expanded values, as pointed out by Noah Misch. Repair. Moreover, plpgsql_param_fetch requires adjustment because the serialization mechanism needs it to skip evaluating unused parameters just as we would do when it is called from copyParamList, but params == estate->paramLI in that case. To fix, make the bms_is_member test in that function unconditional. Finally, have setup_param_list set a new ParamListInfo field, paramMask, to the parameters actually used in the expression, so that we don't try to fetch those that are not needed when serializing a parameter list. This isn't necessary for correctness, but it makes the performance of the parallel executor code comparable to what we do for cases involving cursors. Design suggestions and extensive review by Noah Misch. Patch by me.
* Message style improvementsPeter Eisentraut2015-10-28
| | | | | Message style, plurals, quoting, spelling, consistency with similar messages
* Remove set_latch_on_sigusr1 flag.Robert Haas2015-10-09
| | | | | | | | | This flag has proven to be a recipe for bugs, and it doesn't seem like it can really buy anything in terms of performance. So let's just *always* set the process latch when we receive SIGUSR1 instead of trying to do it only when needed. Per my recent proposal on pgsql-hackers.
* Add recursion depth protections to regular expression matching.Tom Lane2015-10-02
| | | | | | | | | | | | | | | Some of the functions in regex compilation and execution recurse, and therefore could in principle be driven to stack overflow. The Tcl crew has seen this happen in practice in duptraverse(), though their fix was to put in a hard-wired limit on the number of recursive levels, which is not too appetizing --- fortunately, we have enough infrastructure to check the actually available stack. Greg Stark has also seen it in other places while fuzz testing on a machine with limited stack space. Let's put guards in to prevent crashes in all these places. Since the regex code would leak memory if we simply threw elog(ERROR), we have to introduce an API that checks for stack depth without throwing such an error. Fortunately that's not difficult.
* Glue layer to connect the executor to the shm_mq mechanism.Robert Haas2015-09-18
| | | | | | | | | | | | | | | | | | | | | | | | | | The shm_mq mechanism was built to send error (and notice) messages and tuples between backends. However, shm_mq itself only deals in raw bytes. Since commit 2bd9e412f92bc6a68f3e8bcb18e04955cc35001d, we have had infrastructure for one message to redirect protocol messages to a queue and for another backend to parse them and do useful things with them. This commit introduces a somewhat analogous facility for tuples by adding a new type of DestReceiver, DestTupleQueue, which writes each tuple generated by a query into a shm_mq, and a new TupleQueueFunnel facility which reads raw tuples out of the queue and reconstructs the HeapTuple format expected by the executor. The TupleQueueFunnel abstraction supports reading from multiple tuple streams at the same time, but only in round-robin fashion. Someone could imaginably want other policies, but this should be good enough to meet our short-term needs related to parallel query, and we can always extend it later. This also makes one minor addition to the shm_mq API that didn' seem worth breaking out as a separate patch. Extracted from Amit Kapila's parallel sequential scan patch. This code was originally written by me, and then it was revised by Amit, and then it was revised some more by me.
* Determine whether it's safe to attempt a parallel plan for a query.Robert Haas2015-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 924bcf4f16d54c55310b28f77686608684734f42 introduced a framework for parallel computation in PostgreSQL that makes most but not all built-in functions safe to execute in parallel mode. In order to have parallel query, we'll need to be able to determine whether that query contains functions (either built-in or user-defined) that cannot be safely executed in parallel mode. This requires those functions to be labeled, so this patch introduces an infrastructure for that. Some functions currently labeled as safe may need to be revised depending on how pending issues related to heavyweight locking under paralllelism are resolved. Parallel plans can't be used except for the case where the query will run to completion. If portal execution were suspended, the parallel mode restrictions would need to remain in effect during that time, but that might make other queries fail. Therefore, this patch introduces a framework that enables consideration of parallel plans only when it is known that the plan will be run to completion. This probably needs some refinement; for example, at bind time, we do not know whether a query run via the extended protocol will be execution to completion or run with a limited fetch count. Having the client indicate its intentions at bind time would constitute a wire protocol break. Some contexts in which parallel mode would be safe are not adjusted by this patch; the default is not to try parallel plans except from call sites that have been updated to say that such plans are OK. This commit doesn't introduce any parallel paths or plans; it just provides a way to determine whether they could potentially be used. I'm committing it on the theory that the remaining parallel sequential scan patches will also get committed to this release, hopefully in the not-too-distant future. Robert Haas and Amit Kapila. Reviewed (in earlier versions) by Noah Misch.
* Fix subtransaction cleanup after an outer-subtransaction portal fails.Tom Lane2015-09-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Formerly, we treated only portals created in the current subtransaction as having failed during subtransaction abort. However, if the error occurred while running a portal created in an outer subtransaction (ie, a cursor declared before the last savepoint), that has to be considered broken too. To allow reliable detection of which ones those are, add a bookkeeping field to struct Portal that tracks the innermost subtransaction in which each portal has actually been executed. (Without this, we'd end up failing portals containing functions that had called the subtransaction, thereby breaking plpgsql exception blocks completely.) In addition, when we fail an outer-subtransaction Portal, transfer its resources into the subtransaction's resource owner, so that they're released early in cleanup of the subxact. This fixes a problem reported by Jim Nasby in which a function executed in an outer-subtransaction cursor could cause an Assert failure or crash by referencing a relation created within the inner subtransaction. The proximate cause of the Assert failure is that AtEOSubXact_RelationCache assumed it could blow away a relcache entry without first checking that the entry had zero refcount. That was a bad idea on its own terms, so add such a check there, and to the similar coding in AtEOXact_RelationCache. This provides an independent safety measure in case there are still ways to provoke the situation despite the Portal-level changes. This has been broken since subtransactions were invented, so back-patch to all supported branches. Tom Lane and Michael Paquier
* Clean up icc + ia64 situation.Tom Lane2015-08-31
| | | | | | | | | | | | | | Some googling turned up multiple sources saying that older versions of icc do not accept gcc-compatible asm blocks on IA64, though asm does work on x86[_64]. This is apparently fixed as of icc version 12.0 or so, but that doesn't help us much; if we have to carry the extra implementation anyway, we may as well just use it for icc rather than add a compiler version test. Hence, revert commit 2c713d6ea29c91cd2cbd92fa801a61e55ea2a3c4 (though I separated the icc code from the gcc code completely, producing what seems cleaner code). Document the state of affairs more explicitly, both in s_lock.h and postgres.c, and make some cosmetic adjustments around the IA64 code in s_lock.h.
* Remove theoretically-unnecessary special case for icc.Tom Lane2015-08-31
| | | | | | | | Intel's icc is generally able to swallow asm blocks written for gcc. We have a few places that don't seem to know that, though. Experiment with removing the special case for icc in ia64_get_bsp(); if the buildfarm likes this, I'll try more cleanup. This is a good test case because it involves a "stop" notation that seems like it might not be very portable.
* Add ALTER OPERATOR command, for changing selectivity estimator functions.Heikki Linnakangas2015-07-14
| | | | | | | | | Other options cannot be changed, as it's not totally clear if cached plans would need to be invalidated if one of the other options change. Selectivity estimator functions only change plan costs, not correctness of plans, so those should be safe. Original patch by Uriy Zhuravlev, heavily edited by me.
* Fix DDL command collection for TRANSFORMAlvaro Herrera2015-06-26
| | | | | | | | Commit b488c580ae, which added the DDL command collection feature, neglected to update the code that commit cac76582053e had previously added two weeks earlier for the TRANSFORM feature. Reported by Michael Paquier.
* pgindent run for 9.5Bruce Momjian2015-05-23
|
* Remove the new UPSERT command tag and use INSERT instead.Andres Freund2015-05-23
| | | | | | | | | | | | | | | | | Previously, INSERT with ON CONFLICT DO UPDATE specified used a new command tag -- UPSERT. It was introduced out of concern that INSERT as a command tag would be a misrepresentation for ON CONFLICT DO UPDATE, as some affected rows may actually have been updated. Alvaro Herrera noticed that the implementation of that new command tag was incomplete; in subsequent discussion we concluded that having it doesn't provide benefits that are in line with the compatibility breaks it requires. Catversion bump due to the removal of PlannedStmt->isUpsert. Author: Peter Geoghegan Discussion: 20150520215816.GI5885@postgresql.org
* Support VERBOSE option in REINDEX command.Fujii Masao2015-05-15
| | | | | | | | | | | | | | | | When this option is specified, a progress report is printed as each index is reindexed. Per discussion, we agreed on the following syntax for the extensibility of the options. REINDEX (flexible options) { INDEX | ... } name Sawada Masahiko. Reviewed by Robert Haas, Fabrízio Mello, Alvaro Herrera, Kyotaro Horiguchi, Jim Nasby and me. Discussion: CAD21AoA0pK3YcOZAFzMae+2fcc3oGp5zoRggDyMNg5zoaWDhdQ@mail.gmail.com
* Allow on-the-fly capture of DDL event detailsAlvaro Herrera2015-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This feature lets user code inspect and take action on DDL events. Whenever a ddl_command_end event trigger is installed, DDL actions executed are saved to a list which can be inspected during execution of a function attached to ddl_command_end. The set-returning function pg_event_trigger_ddl_commands can be used to list actions so captured; it returns data about the type of command executed, as well as the affected object. This is sufficient for many uses of this feature. For the cases where it is not, we also provide a "command" column of a new pseudo-type pg_ddl_command, which is a pointer to a C structure that can be accessed by C code. The struct contains all the info necessary to completely inspect and even reconstruct the executed command. There is no actual deparse code here; that's expected to come later. What we have is enough infrastructure that the deparsing can be done in an external extension. The intention is that we will add some deparsing code in a later release, as an in-core extension. A new test module is included. It's probably insufficient as is, but it should be sufficient as a starting point for a more complete and future-proof approach. Authors: Álvaro Herrera, with some help from Andres Freund, Ian Barwick, Abhijit Menon-Sen. Reviews by Andres Freund, Robert Haas, Amit Kapila, Michael Paquier, Craig Ringer, David Steele. Additional input from Chris Browne, Dimitri Fontaine, Stephen Frost, Petr Jelínek, Tom Lane, Jim Nasby, Steven Singer, Pavel Stěhule. Based on original work by Dimitri Fontaine, though I didn't use his code. Discussion: https://www.postgresql.org/message-id/m2txrsdzxa.fsf@2ndQuadrant.fr https://www.postgresql.org/message-id/20131108153322.GU5809@eldon.alvh.no-ip.org https://www.postgresql.org/message-id/20150215044814.GL3391@alvh.no-ip.org
* Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.Andres Freund2015-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
* Create an infrastructure for parallel computation in PostgreSQL.Robert Haas2015-04-30
| | | | | | | | | | | | | | | | | This does four basic things. First, it provides convenience routines to coordinate the startup and shutdown of parallel workers. Second, it synchronizes various pieces of state (e.g. GUCs, combo CID mappings, transaction snapshot) from the parallel group leader to the worker processes. Third, it prohibits various operations that would result in unsafe changes to that state while parallelism is active. Finally, it propagates events that would result in an ErrorResponse, NoticeResponse, or NotifyResponse message being sent to the client from the parallel workers back to the master, from which they can then be sent on to the client. Robert Haas, Amit Kapila, Noah Misch, Rushabh Lathia, Jeevan Chalke. Suggestions and review from Andres Freund, Heikki Linnakangas, Noah Misch, Simon Riggs, Euler Taveira, and Jim Nasby.
* Add transforms featurePeter Eisentraut2015-04-26
| | | | | | | | This provides a mechanism for specifying conversions between SQL data types and procedural languages. As examples, there are transforms for hstore and ltree for PL/Perl and PL/Python. reviews by Pavel Stěhule and Andres Freund
* Add OID output argument to DefineTSConfigurationAlvaro Herrera2015-03-25
| | | | | | | ... which is set to the OID of a copied text search config, whenever the COPY clause is used. This is in the spirit of commit a2e35b53c39.
* Rationalize vacuuming options and parametersAlvaro Herrera2015-03-18
| | | | | | | | | | | | | | | | | | | We were involving the parser too much in setting up initial vacuuming parameters. This patch moves that responsibility elsewhere to simplify code, and also to make future additions easier. To do this, create a new struct VacuumParams which is filled just prior to vacuum execution, instead of at parse time; for user-invoked vacuuming this is set up in a new function ExecVacuum, while autovacuum sets it up by itself. While at it, add a new member VACOPT_SKIPTOAST to enum VacuumOption, only set by autovacuum, which is used to disable vacuuming of the toast table instead of the old do_toast parameter; this relieves the argument list of vacuum() and some callees a bit. This partially makes up for having added more arguments in an effort to avoid having autovacuum from constructing a VacuumStmt parse node. Author: Michael Paquier. Some tweaks by Álvaro Reviewed by: Robert Haas, Stephen Frost, Álvaro Herrera
* Improve representation of PlanRowMark.Tom Lane2015-03-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes two inadequacies of the PlanRowMark representation. First, that the original LockingClauseStrength isn't stored (and cannot be inferred for foreign tables, which always get ROW_MARK_COPY). Since some PlanRowMarks are created out of whole cloth and don't actually have an ancestral RowMarkClause, this requires adding a dummy LCS_NONE value to enum LockingClauseStrength, which is fairly annoying but the alternatives seem worse. This fix allows getting rid of the use of get_parse_rowmark() in FDWs (as per the discussion around commits 462bd95705a0c23b and 8ec8760fc87ecde0), and it simplifies some things elsewhere. Second, that the representation assumed that all child tables in an inheritance hierarchy would use the same RowMarkType. That's true today but will soon not be true. We add an "allMarkTypes" field that identifies the union of mark types used in all a parent table's children, and use that where appropriate (currently, only in preprocess_targetlist()). In passing fix a couple of minor infelicities left over from the SKIP LOCKED patch, notably that _outPlanRowMark still thought waitPolicy is a bool. Catversion bump is required because the numeric values of enum LockingClauseStrength can appear in on-disk rules. Extracted from a much larger patch to support foreign table inheritance; it seemed worth breaking this out, since it's a separable concern. Shigeru Hanada and Etsuro Fujita, somewhat modified by me
* Code cleanup for REINDEX DATABASE/SCHEMA/SYSTEM.Tom Lane2015-03-08
| | | | | Fix some minor infelicities. Some of these things were introduced in commit fe263d115a7dd16095b8b8f1e943aff2bb4574d2, and some are older.
* Fix erroneous error message for REINDEX SYSTEM.Tom Lane2015-03-08
| | | | | | Missed case in commit fe263d115a7dd16095b8b8f1e943aff2bb4574d2. Sawada Masahiko
* Change many routines to return ObjectAddress rather than OIDAlvaro Herrera2015-03-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The changed routines are mostly those that can be directly called by ProcessUtilitySlow; the intention is to make the affected object information more precise, in support for future event trigger changes. Originally it was envisioned that the OID of the affected object would be enough, and in most cases that is correct, but upon actually implementing the event trigger changes it turned out that ObjectAddress is more widely useful. Additionally, some command execution routines grew an output argument that's an object address which provides further info about the executed command. To wit: * for ALTER DOMAIN / ADD CONSTRAINT, it corresponds to the address of the new constraint * for ALTER OBJECT / SET SCHEMA, it corresponds to the address of the schema that originally contained the object. * for ALTER EXTENSION {ADD, DROP} OBJECT, it corresponds to the address of the object added to or dropped from the extension. There's no user-visible change in this commit, and no functional change either. Discussion: 20150218213255.GC6717@tamriel.snowman.net Reviewed-By: Stephen Frost, Andres Freund
* Fix stupid merge errors in previous commitAlvaro Herrera2015-02-23
| | | | Brown paper bag installed permanently.
* Support more commands in event triggersAlvaro Herrera2015-02-23
| | | | | | | | COMMENT, SECURITY LABEL, and GRANT/REVOKE now also fire ddl_command_start and ddl_command_end event triggers, when they operate on database-local objects. Reviewed-By: Michael Paquier, Andres Freund, Stephen Frost
* Use FLEXIBLE_ARRAY_MEMBER in a bunch more places.Tom Lane2015-02-20
| | | | | | | | | | | | | | | | Replace some bogus "x[1]" declarations with "x[FLEXIBLE_ARRAY_MEMBER]". Aside from being more self-documenting, this should help prevent bogus warnings from static code analyzers and perhaps compiler misoptimizations. This patch is just a down payment on eliminating the whole problem, but it gets rid of a lot of easy-to-fix cases. Note that the main problem with doing this is that one must no longer rely on computing sizeof(the containing struct), since the result would be compiler-dependent. Instead use offsetof(struct, lastfield). Autoconf also warns against spelling that offsetof(struct, lastfield[0]). Michael Paquier, review and additional fixes by me.
* Remove ill-conceived Assertion in ProcessClientWriteInterrupt().Andres Freund2015-02-03
| | | | | | | | | | | | It's perfectly fine to have blocked interrupts when ProcessClientWriteInterrupt() is called. In fact it's commonly the case when emitting error reports. And we deal with that correctly. Even if that'd not be the case, it'd be a bad location for such a assertion. Because ProcessClientWriteInterrupt() is only called when the socket is blocked it's hard to hit. Per Heikki and buildfarm animals nightjar and dunlin.
* Remove remnants of ImmediateInterruptOK handling.Andres Freund2015-02-03
| | | | | | | Now that nothing sets ImmediateInterruptOK to true anymore, we can remove all the supporting code. Reviewed-By: Heikki Linnakangas
* Don't allow immediate interrupts during authentication anymore.Andres Freund2015-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | We used to handle authentication_timeout by setting ImmediateInterruptOK to true during large parts of the authentication phase of a new connection. While that happens to work acceptably in practice, it's not particularly nice and has ugly corner cases. Previous commits converted the FE/BE communication to use latches and implemented support for interrupt handling during both send/recv. Building on top of that work we can get rid of ImmediateInterruptOK during authentication, by immediately treating timeouts during authentication as a reason to die. As die interrupts are handled immediately during client communication that provides a sensibly quick reaction time to authentication timeout. Additionally add a few CHECK_FOR_INTERRUPTS() to some more complex authentication methods. More could be added, but this already should provides a reasonable coverage. While it this overall increases the maximum time till a timeout is reacted to, it greatly reduces complexity and increases reliability. That seems like a overall win. If the increase proves to be noticeable we can deal with those cases by moving to nonblocking network code and add interrupt checking there. Reviewed-By: Heikki Linnakangas
* Process 'die' interrupts while reading/writing from the client socket.Andres Freund2015-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now it was impossible to terminate a backend that was trying to send/recv data to/from the client when the socket's buffer was already full/empty. While the send/recv calls itself might have gotten interrupted by signals on some platforms, we just immediately retried. That could lead to situations where a backend couldn't be terminated , after a client died without the connection being closed, because it was blocked in send/recv. The problem was far more likely to be hit when sending data than when reading. That's because while reading a command from the client, and during authentication, we processed interrupts immediately . That primarily left COPY FROM STDIN as being problematic for recv. Change things so that that we process 'die' events immediately when the appropriate signal arrives. We can't sensibly react to query cancels at that point, because we might loose sync with the client as we could be in the middle of writing a message. We don't interrupt writes if the write buffer isn't full, as indicated by write() returning EWOULDBLOCK, as that would lead to fewer error messages reaching clients. Per discussion with Kyotaro HORIGUCHI and Heikki Linnakangas Discussion: 20140927191243.GD5423@alap3.anarazel.de
* Introduce and use infrastructure for interrupt processing during client reads.Andres Freund2015-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now large swathes of backend code ran inside signal handlers while reading commands from the client, to allow for speedy reaction to asynchronous events. Most prominently shared invalidation and NOTIFY handling. That means that complex code like the starting/stopping of transactions is run in signal handlers... The required code was fragile and verbose, and is likely to contain bugs. That approach also severely limited what could be done while communicating with the client. As the read might be from within openssl it wasn't safely possible to trigger an error, e.g. to cancel a backend in idle-in-transaction state. We did that in some cases, namely fatal errors, nonetheless. Now that FE/BE communication in the backend employs non-blocking sockets and latches to block, we can quite simply interrupt reads from signal handlers by setting the latch. That allows us to signal an interrupted read, which is supposed to be retried after returning from within the ssl library. As signal handlers now only need to set the latch to guarantee timely interrupt processing, remove a fair amount of complicated & fragile code from async.c and sinval.c. We could now actually start to process some kinds of interrupts, like sinval ones, more often that before, but that seems better done separately. This work will hopefully allow to handle cases like being blocked by sending data, interrupting idle transactions and similar to be implemented without too much effort. In addition to allowing getting rid of ImmediateInterruptOK, that is. Author: Andres Freund Reviewed-By: Heikki Linnakangas