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* Spelling mistake in comment in utility.cSimon Riggs2017-04-05
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* Fix two undocumented parameters to functions from ENR patch.Kevin Grittner2017-04-01
| | | | | | | | | | | | On ProcessUtility document the parameter, to match others. On CreateCachedPlan drop the queryEnv parameter. It was not referenced within the function, and had been added on the assumption that with some unknown future usage of QueryEnvironment it might be useful to do something there. We have avoided other "just in case" implementation of unused paramters, so drop it here. Per gripe from Tom Lane
* Add infrastructure to support EphemeralNamedRelation references.Kevin Grittner2017-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A QueryEnvironment concept is added, which allows new types of objects to be passed into queries from parsing on through execution. At this point, the only thing implemented is a collection of EphemeralNamedRelation objects -- relations which can be referenced by name in queries, but do not exist in the catalogs. The only type of ENR implemented is NamedTuplestore, but provision is made to add more types fairly easily. An ENR can carry its own TupleDesc or reference a relation in the catalogs by relid. Although these features can be used without SPI, convenience functions are added to SPI so that ENRs can easily be used by code run through SPI. The initial use of all this is going to be transition tables in AFTER triggers, but that will be added to each PL as a separate commit. An incidental effect of this patch is to produce a more informative error message if an attempt is made to modify the contents of a CTE from a referencing DML statement. No tests previously covered that possibility, so one is added. Kevin Grittner and Thomas Munro Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro with valuable comments and suggestions from many others
* Cast result of copyObject() to correct typePeter Eisentraut2017-03-28
| | | | | | | | | | | | | | copyObject() is declared to return void *, which allows easily assigning the result independent of the input, but it loses all type checking. If the compiler supports typeof or something similar, cast the result to the input type. This creates a greater amount of type safety. In some cases, where the result is assigned to a generic type such as Node * or Expr *, new casts are now necessary, but in general casts are now unnecessary in the normal case and indicate that something unusual is happening. Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
* Add missing breakAlvaro Herrera2017-03-26
| | | | Noticed by Coverity
* Add missing breakPeter Eisentraut2017-03-25
| | | | Reported-by: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
* Implement multivariate n-distinct coefficientsAlvaro Herrera2017-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for explicitly declared statistic objects (CREATE STATISTICS), allowing collection of statistics on more complex combinations that individual table columns. Companion commands DROP STATISTICS and ALTER STATISTICS ... OWNER TO / SET SCHEMA / RENAME are added too. All this DDL has been designed so that more statistic types can be added later on, such as multivariate most-common-values and multivariate histograms between columns of a single table, leaving room for permitting columns on multiple tables, too, as well as expressions. This commit only adds support for collection of n-distinct coefficient on user-specified sets of columns in a single table. This is useful to estimate number of distinct groups in GROUP BY and DISTINCT clauses; estimation errors there can cause over-allocation of memory in hashed aggregates, for instance, so it's a worthwhile problem to solve. A new special pseudo-type pg_ndistinct is used. (num-distinct estimation was deemed sufficiently useful by itself that this is worthwhile even if no further statistic types are added immediately; so much so that another version of essentially the same functionality was submitted by Kyotaro Horiguchi: https://postgr.es/m/20150828.173334.114731693.horiguchi.kyotaro@lab.ntt.co.jp though this commit does not use that code.) Author: Tomas Vondra. Some code rework by Álvaro. Reviewed-by: Dean Rasheed, David Rowley, Kyotaro Horiguchi, Jeff Janes, Ideriha Takeshi Discussion: https://postgr.es/m/543AFA15.4080608@fuzzy.cz https://postgr.es/m/20170320190220.ixlaueanxegqd5gr@alvherre.pgsql
* ICU supportPeter Eisentraut2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a column collprovider to pg_collation that determines which library provides the collation data. The existing choices are default and libc, and this adds an icu choice, which uses the ICU4C library. The pg_locale_t type is changed to a union that contains the provider-specific locale handles. Users of locale information are changed to look into that struct for the appropriate handle to use. Also add a collversion column that records the version of the collation when it is created, and check at run time whether it is still the same. This detects potentially incompatible library upgrades that can corrupt indexes and other structures. This is currently only supported by ICU-provided collations. initdb initializes the default collation set as before from the `locale -a` output but also adds all available ICU locales with a "-x-icu" appended. Currently, ICU-provided collations can only be explicitly named collations. The global database locales are still always libc-provided. ICU support is enabled by configure --with-icu. Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com> Reviewed-by: Andreas Karlsson <andreas@proxel.se>
* Allow for parallel execution whenever ExecutorRun() is done only once.Robert Haas2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, it was unsafe to execute a plan in parallel if ExecutorRun() might be called with a non-zero row count. However, it's quite easy to fix things up so that we can support that case, provided that it is known that we will never call ExecutorRun() a second time for the same QueryDesc. Add infrastructure to signal this, and cross-checks to make sure that a caller who claims this is true doesn't later reneg. While that pattern never happens with queries received directly from a client -- there's no way to know whether multiple Execute messages will be sent unless the first one requests all the rows -- it's pretty common for queries originating from procedural languages, which often limit the result to a single tuple or to a user-specified number of tuples. This commit doesn't actually enable parallelism in any additional cases, because currently none of the places that would be able to benefit from this infrastructure pass CURSOR_OPT_PARALLEL_OK in the first place, but it makes it much more palatable to pass CURSOR_OPT_PARALLEL_OK in places where we currently don't, because it eliminates some cases where we'd end up having to run the parallel plan serially. Patch by me, based on some ideas from Rafia Sabih and corrected by Rafia Sabih based on feedback from Dilip Kumar and myself. Discussion: http://postgr.es/m/CA+TgmobXEhvHbJtWDuPZM9bVSLiTj-kShxQJ2uM5GPDze9fRYA@mail.gmail.com
* Logical replication support for initial data copyPeter Eisentraut2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | Add functionality for a new subscription to copy the initial data in the tables and then sync with the ongoing apply process. For the copying, add a new internal COPY option to have the COPY source data provided by a callback function. The initial data copy works on the subscriber by receiving COPY data from the publisher and then providing it locally into a COPY that writes to the destination table. A WAL receiver can now execute full SQL commands. This is used here to obtain information about tables and publications. Several new options were added to CREATE and ALTER SUBSCRIPTION to control whether and when initial table syncing happens. Change pg_dump option --no-create-subscription-slots to --no-subscription-connect and use the new CREATE SUBSCRIPTION ... NOCONNECT option for that. Author: Petr Jelinek <petr.jelinek@2ndquadrant.com> Tested-by: Erik Rijkers <er@xs4all.nl>
* Disallow CREATE/DROP SUBSCRIPTION in transaction blockPeter Eisentraut2017-03-03
| | | | | | | | Disallow CREATE SUBSCRIPTION and DROP SUBSCRIPTION in a transaction block when the replication slot is to be created or dropped, since that cannot be rolled back. based on patch by Masahiko Sawada <sawada.mshk@gmail.com>
* Consistently declare timestamp variables as TimestampTz.Tom Lane2017-02-23
| | | | | | | | | | | | | | | | | | | Twiddle the replication-related code so that its timestamp variables are declared TimestampTz, rather than the uninformative "int64" that was previously used for meant-to-be-always-integer timestamps. This resolves the int64-vs-TimestampTz declaration inconsistencies introduced by commit 7c030783a, though in the opposite direction to what was originally suggested. This required including datatype/timestamp.h in a couple more places than before. I decided it would be a good idea to slim down that header by not having it pull in <float.h> etc, as those headers are no longer at all relevant to its purpose. Unsurprisingly, a small number of .c files turn out to have been depending on those inclusions, so add them back in the .c files as needed. Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us Discussion: https://postgr.es/m/27694.1487456324@sss.pgh.pa.us
* Add CREATE COLLATION IF NOT EXISTS clausePeter Eisentraut2017-02-15
| | | | | | The core of the functionality was already implemented when pg_import_system_collations was added. This just exposes it as an option in the SQL command.
* Improve comments about ProcessUtility's queryString parameter.Tom Lane2017-01-27
| | | | Per discussion with Craig Ringer.
* Use castNode() in a bunch of statement-list-related code.Tom Lane2017-01-26
| | | | | | | | | | | | | When I wrote commit ab1f0c822, I really missed the castNode() macro that Peter E. had proposed shortly before. This back-fills the uses I would have put it to. It's probably not all that significant, but there are more assertions here than there were before, and conceivably they will help catch any bugs associated with those representation changes. I left behind a number of usages like "(Query *) copyObject(query_var)". Those could have been converted as well, but Peter has proposed another notational improvement that would handle copyObject cases automatically, so I let that be for now.
* Add castNode(type, ptr) for safe casting between NodeTag based types.Andres Freund2017-01-26
| | | | | | | | | | | | | | | | | | | | | | | | The new function allows to cast from one NodeTag based type to another, while asserting that the conversion is valid. This replaces the common pattern of doing a cast and a Assert(IsA(ptr, type)) close-by. As this seems likely to be used pervasively, we decided to backpatch this change the addition of this macro. Otherwise backpatched fixes are more likely not to work on back-branches. On branches before 9.6, where we do not yet rely on inline functions being available, the type assertion is only performed if PG_USE_INLINE support is detected. The cast obviously is performed regardless. For the benefit of verifying the macro compiles in the back-branches, this commit contains a single use of the new macro. On master, a somewhat larger conversion will be committed separately. Author: Peter Eisentraut and Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com Backpatch: 9.2-
* Add a new DestReceiver for printing tuples without catalog access.Robert Haas2017-01-24
| | | | | | | | | | | | | | | If you create a DestReciver of type DestRemote and try to use it from a replication connection that is not bound to a specific daabase, or any other hypothetical type of backend that is not bound to a specific database, it will fail because it doesn't have a pg_proc catalog to look up properties of the types being printed. In general, that's an unavoidable problem, but we can hardwire the properties of a few builtin types in order to support utility commands. This new DestReceiver of type DestRemoteSimple does just that. Patch by me, reviewed by Michael Paquier. Discussion: http://postgr.es/m/CA+TgmobNo4qz06wHEmy9DszAre3dYx-WNhHSCbU9SAwf+9Ft6g@mail.gmail.com
* Logical replicationPeter Eisentraut2017-01-20
| | | | | | | | | | | | | - Add PUBLICATION catalogs and DDL - Add SUBSCRIPTION catalog and DDL - Define logical replication protocol and output plugin - Add logical replication workers From: Petr Jelinek <petr@2ndquadrant.com> Reviewed-by: Steve Singer <steve@ssinger.info> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Erik Rijkers <er@xs4all.nl> Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
* Avoid core dump for empty prepared statement in an aborted transaction.Tom Lane2017-01-19
| | | | | | | | | | | | Brown-paper-bag bug in commit ab1f0c822: the old code here coped with null CachedPlanSource.raw_parse_tree, the new code not so much. Per report from Dave Cramer. No regression test, because our core testing infrastructure doesn't provide any easy way to exercise this path. Fortunately, the JDBC crew test it regularly. Discussion: https://postgr.es/m/CADK3HH+Ug3xCysKqw_dZOnaNnytZ1Rh5yP05hjO-e4NoyRxVvA@mail.gmail.com
* Change representation of statement lists, and add statement location info.Tom Lane2017-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Use TSConfigRelationId in AlterTSConfiguration()Stephen Frost2016-12-22
| | | | | | | | | | | | | | | | | | | | When we are altering a text search configuration, we are getting the tuple from pg_ts_config and using its OID, so use TSConfigRelationId when invoking any post-alter hooks and setting the object address. Further, in the functions called from AlterTSConfiguration(), we're saving information about the command via EventTriggerCollectAlterTSConfig(), so we should be setting commandCollected to true. Also add a regression test to test_ddl_deparse for ALTER TEXT SEARCH CONFIGURATION. Author: Artur Zakirov, a few additional comments by me Discussion: https://www.postgresql.org/message-id/57a71eba-f2c7-e7fd-6fc0-2126ec0b39bd%40postgrespro.ru Back-patch the fix for the InvokeObjectPostAlterHook() call to 9.3 where it was introduced, and the fix for the ObjectAddressSet() call and setting commandCollected to true to 9.5 where those changes to ProcessUtilitySlow() were introduced.
* Add support for temporary replication slotsPeter Eisentraut2016-12-12
| | | | | | | This allows creating temporary replication slots that are removed automatically at the end of the session or on error. From: Petr Jelinek <petr.jelinek@2ndquadrant.com>
* Implement table partitioning.Robert Haas2016-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
* Remove or reduce verbosity of some debug messages.Robert Haas2016-11-17
| | | | | | | | | | | | | | | | | | | The debug messages that merely print StartTransactionCommand, CommitTransactionCommand, ProcessUtilty, or ProcessQuery with no additional details seem to be useless. Get rid of them. The transaction status messages produced by ShowTransactionState are occasionally useful, but they are extremely verbose, producing multiple lines of log output every time they fire, which can happens multiple times per transaction. So, reduce the level to DEBUG5; avoid emitting an extra line just to explain which debug point is at issue; and tighten up the rest of the message so it doesn't use quite so much horizontal space. With these changes, it's possible to run a somewhat busy system with a log level even as high as DEBUG4, whereas previously anything above DEBUG2 would flood the log with output that probably wasn't really all that useful.
* 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