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* C comments: adjust execTuples.c for new structureBruce Momjian2014-10-13
| | | | Report by Peter Geoghegan
* Increase number of hash join buckets for underestimate.Kevin Grittner2014-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | If we expect batching at the very beginning, we size nbuckets for "full work_mem" (see how many tuples we can get into work_mem, while not breaking NTUP_PER_BUCKET threshold). If we expect to be fine without batching, we start with the 'right' nbuckets and track the optimal nbuckets as we go (without actually resizing the hash table). Once we hit work_mem (considering the optimal nbuckets value), we keep the value. At the end of the first batch, we check whether (nbuckets != nbuckets_optimal) and resize the hash table if needed. Also, we keep this value for all batches (it's OK because it assumes full work_mem, and it makes the batchno evaluation trivial). So the resize happens only once. There could be cases where it would improve performance to allow the NTUP_PER_BUCKET threshold to be exceeded to keep everything in one batch rather than spilling to a second batch, but attempts to generate such a case have so far been unsuccessful; that issue may be addressed with a follow-on patch after further investigation. Tomas Vondra with minor format and comment cleanup by me Reviewed by Robert Haas, Heikki Linnakangas, and Kevin Grittner
* Implement SKIP LOCKED for row-level locksAlvaro Herrera2014-10-07
| | | | | | | | | | | | | | | | | | This clause changes the behavior of SELECT locking clauses in the presence of locked rows: instead of causing a process to block waiting for the locks held by other processes (or raise an error, with NOWAIT), SKIP LOCKED makes the new reader skip over such rows. While this is not appropriate behavior for general purposes, there are some cases in which it is useful, such as queue-like tables. Catalog version bumped because this patch changes the representation of stored rules. Reviewed by Craig Ringer (based on a previous attempt at an implementation by Simon Riggs, who also provided input on the syntax used in the current patch), David Rowley, and Álvaro Herrera. Author: Thomas Munro
* Row-Level Security Policies (RLS)Stephen Frost2014-09-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building on the updatable security-barrier views work, add the ability to define policies on tables to limit the set of rows which are returned from a query and which are allowed to be added to a table. Expressions defined by the policy for filtering are added to the security barrier quals of the query, while expressions defined to check records being added to a table are added to the with-check options of the query. New top-level commands are CREATE/ALTER/DROP POLICY and are controlled by the table owner. Row Security is able to be enabled and disabled by the owner on a per-table basis using ALTER TABLE .. ENABLE/DISABLE ROW SECURITY. Per discussion, ROW SECURITY is disabled on tables by default and must be enabled for policies on the table to be used. If no policies exist on a table with ROW SECURITY enabled, a default-deny policy is used and no records will be visible. By default, row security is applied at all times except for the table owner and the superuser. A new GUC, row_security, is added which can be set to ON, OFF, or FORCE. When set to FORCE, row security will be applied even for the table owner and superusers. When set to OFF, row security will be disabled when allowed and an error will be thrown if the user does not have rights to bypass row security. Per discussion, pg_dump sets row_security = OFF by default to ensure that exports and backups will have all data in the table or will error if there are insufficient privileges to bypass row security. A new option has been added to pg_dump, --enable-row-security, to ask pg_dump to export with row security enabled. A new role capability, BYPASSRLS, which can only be set by the superuser, is added to allow other users to be able to bypass row security using row_security = OFF. Many thanks to the various individuals who have helped with the design, particularly Robert Haas for his feedback. Authors include Craig Ringer, KaiGai Kohei, Adam Brightwell, Dean Rasheed, with additional changes and rework by me. Reviewers have included all of the above, Greg Smith, Jeff McCormick, and Robert Haas.
* Fix pointer type in size passed to memset.Heikki Linnakangas2014-09-14
| | | | | | | Pointers are all the same size, so it makes no practical difference, but let's be tidy. Found by Coverity, noted off-list by Tom Lane.
* Change NTUP_PER_BUCKET to 1 to improve hash join lookup speed.Robert Haas2014-09-12
| | | | | | | | | | | | | | | | Since this makes the bucket headers use ~10x as much memory, properly account for that memory when we figure out whether everything fits in work_mem. This might result in some cases that previously used only a single batch getting split into multiple batches, but it's unclear as yet whether we need defenses against that case, and if so, what the shape of those defenses should be. It's worth noting that even in these edge cases, users should still be no worse off than they would have been last week, because commit 45f6240a8fa9d35548eb2ef23dba2c11540aa02a saved a big pile of memory on exactly the same workloads. Tomas Vondra, reviewed and somewhat revised by me.
* Pack tuples in a hash join batch densely, to save memory.Heikki Linnakangas2014-09-10
| | | | | | | | | | | | | Instead of palloc'ing each HashJoinTuple individually, allocate 32kB chunks and pack the tuples densely in the chunks. This avoids the AllocChunk header overhead, and the space wasted by standard allocator's habit of rounding sizes up to the nearest power of two. This doesn't contain any planner changes, because the planner's estimate of memory usage ignores the palloc overhead. Now that the overhead is smaller, the planner's estimates are in fact more accurate. Tomas Vondra, reviewed by Robert Haas.
* Assorted message fixes and improvementsPeter Eisentraut2014-09-05
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* Fix FOR UPDATE NOWAIT on updated tuple chainsAlvaro Herrera2014-08-27
| | | | | | | | | | | | | | | | | | | | | If SELECT FOR UPDATE NOWAIT tries to lock a tuple that is concurrently being updated, it might fail to honor its NOWAIT specification and block instead of raising an error. Fix by adding a no-wait flag to EvalPlanQualFetch which it can pass down to heap_lock_tuple; also use it in EvalPlanQualFetch itself to avoid blocking while waiting for a concurrent transaction. Authors: Craig Ringer and Thomas Munro, tweaked by Álvaro http://www.postgresql.org/message-id/51FB6703.9090801@2ndquadrant.com Per Thomas Munro in the course of his SKIP LOCKED feature submission, who also provided one of the isolation test specs. Backpatch to 9.4, because that's as far back as it applies without conflicts (although the bug goes all the way back). To that branch also backpatch Thomas Munro's new NOWAIT test cases, committed in master by Heikki as commit 9ee16b49f0aac819bd4823d9b94485ef608b34e8 .
* Don't require sort support functions to provide a comparator.Robert Haas2014-08-06
| | | | | | | | | This could be useful for datatypes like text, where we might want to optimize for some collations but not others. However, this patch doesn't introduce any new sortsupport functions that work this way; it merely revises the code so that future patches may do so. Patch by me. Review by Peter Geoghegan.
* Fix typo in C comment.Kevin Grittner2014-08-05
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* Fix bug with whole-row references to append subplans.Tom Lane2014-07-11
| | | | | | | | | | | | | | ExecEvalWholeRowVar incorrectly supposed that it could "bless" the source TupleTableSlot just once per query. But if the input is coming from an Append (or, perhaps, other cases?) more than one slot might be returned over the query run. This led to "record type has not been registered" errors when a composite datum was extracted from a non-blessed slot. This bug has been there a long time; I guess it escaped notice because when dealing with subqueries the planner tends to expand whole-row Vars into RowExprs, which don't have the same problem. It is possible to trigger the problem in all active branches, though, as illustrated by the added regression test.
* Redesign API presented by nodeAgg.c for ordered-set and similar aggregates.Tom Lane2014-07-03
| | | | | | | | | | | | | The previous design exposed the input and output ExprContexts of the Agg plan node, but work on grouping sets has suggested that we'll regret doing that. Instead provide more narrowly-defined APIs that can be implemented in multiple ways, namely a way to get a short-term memory context and a way to register an aggregate shutdown callback. Back-patch to 9.4 where the bad APIs were introduced, since we don't want third-party code using these APIs and then having to change in 9.5. Andrew Gierth
* Avoid leaking memory while evaluating arguments for a table function.Tom Lane2014-06-19
| | | | | | | | | | | | | ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM in the query-lifespan memory context. This is insignificant in simple cases where the function relation is scanned only once; but if the function is in a sub-SELECT or is on the inside of a nested loop, any memory consumed during argument evaluation can add up quickly. (The potential for trouble here had been foreseen long ago, per existing comments; but we'd not previously seen a complaint from the field about it.) To fix, create an additional temporary context just for this purpose. Per an example from MauMau. Back-patch to all active branches.
* Implement UPDATE tab SET (col1,col2,...) = (SELECT ...), ...Tom Lane2014-06-18
| | | | | | | | | | | | | | | | This SQL-standard feature allows a sub-SELECT yielding multiple columns (but only one row) to be used to compute the new values of several columns to be updated. While the same results can be had with an independent sub-SELECT per column, such a workaround can require a great deal of duplicated computation. The standard actually says that the source for a multi-column assignment could be any row-valued expression. The implementation used here is tightly tied to our existing sub-SELECT support and can't handle other cases; the Bison grammar would have some issues with them too. However, I don't feel too bad about this since other cases can be converted into sub-SELECTs. For instance, "SET (a,b,c) = row_valued_function(x)" could be written "SET (a,b,c) = (SELECT * FROM row_valued_function(x))".
* Improve comment for tricky aspect of index-only scans.Jeff Davis2014-05-06
| | | | | | | | | Index-only scans avoid taking a lock on the VM buffer, which would cause a lot of contention. To be correct, that requires some intricate assumptions that weren't completely documented in the previous comment. Reviewed by Robert Haas.
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Fix failure to detoast fields in composite elements of structured types.Tom Lane2014-05-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have an array of records stored on disk, the individual record fields cannot contain out-of-line TOAST pointers: the tuptoaster.c mechanisms are only prepared to deal with TOAST pointers appearing in top-level fields of a stored row. The same applies for ranges over composite types, nested composites, etc. However, the existing code only took care of expanding sub-field TOAST pointers for the case of nested composites, not for other structured types containing composites. For example, given a command such as UPDATE tab SET arraycol = ARRAY[(ROW(x,42)::mycompositetype] ... where x is a direct reference to a field of an on-disk tuple, if that field is long enough to be toasted out-of-line then the TOAST pointer would be inserted as-is into the array column. If the source record for x is later deleted, the array field value would become a dangling pointer, leading to errors along the line of "missing chunk number 0 for toast value ..." when the value is referenced. A reproducible test case for this was provided by Jan Pecek, but it seems likely that some of the "missing chunk number" reports we've heard in the past were caused by similar issues. Code-wise, the problem is that PG_DETOAST_DATUM() is not adequate to produce a self-contained Datum value if the Datum is of composite type. Seen in this light, the problem is not just confined to arrays and ranges, but could also affect some other places where detoasting is done in that way, for example form_index_tuple(). I tried teaching the array code to apply toast_flatten_tuple_attribute() along with PG_DETOAST_DATUM() when the array element type is composite, but this was messy and imposed extra cache lookup costs whether or not any TOAST pointers were present, indeed sometimes when the array element type isn't even composite (since sometimes it takes a typcache lookup to find that out). The idea of extending that approach to all the places that currently use PG_DETOAST_DATUM() wasn't attractive at all. This patch instead solves the problem by decreeing that composite Datum values must not contain any out-of-line TOAST pointers in the first place; that is, we expand out-of-line fields at the point of constructing a composite Datum, not at the point where we're about to insert it into a larger tuple. This rule is applied only to true composite Datums, not to tuples that are being passed around the system as tuples, so it's not as invasive as it might sound at first. With this approach, the amount of code that has to be touched for a full solution is greatly reduced, and added cache lookup costs are avoided except when there actually is a TOAST pointer that needs to be inlined. The main drawback of this approach is that we might sometimes dereference a TOAST pointer that will never actually be used by the query, imposing a rather large cost that wasn't there before. On the other side of the coin, if the field value is used multiple times then we'll come out ahead by avoiding repeat detoastings. Experimentation suggests that common SQL coding patterns are unaffected either way, though. Applications that are very negatively affected could be advised to modify their code to not fetch columns they won't be using. In future, we might consider reverting this solution in favor of detoasting only at the point where data is about to be stored to disk, using some method that can drill down into multiple levels of nested structured types. That will require defining new APIs for structured types, though, so it doesn't seem feasible as a back-patchable fix. Note that this patch changes HeapTupleGetDatum() from a macro to a function call; this means that any third-party code using that macro will not get protection against creating TOAST-pointer-containing Datums until it's recompiled. The same applies to any uses of PG_RETURN_HEAPTUPLEHEADER(). It seems likely that this is not a big problem in practice: most of the tuple-returning functions in core and contrib produce outputs that could not possibly be toasted anyway, and the same probably holds for third-party extensions. This bug has existed since TOAST was invented, so back-patch to all supported branches.
* Allow polymorphic aggregates to have non-polymorphic state data types.Tom Lane2014-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before 9.4, such an aggregate couldn't be declared, because its final function would have to have polymorphic result type but no polymorphic argument, which CREATE FUNCTION would quite properly reject. The ordered-set-aggregate patch found a workaround: allow the final function to be declared as accepting additional dummy arguments that have types matching the aggregate's regular input arguments. However, we failed to notice that this problem applies just as much to regular aggregates, despite the fact that we had a built-in regular aggregate array_agg() that was known to be undeclarable in SQL because its final function had an illegal signature. So what we should have done, and what this patch does, is to decouple the extra-dummy-arguments behavior from ordered-set aggregates and make it generally available for all aggregate declarations. We have to put this into 9.4 rather than waiting till later because it slightly alters the rules for declaring ordered-set aggregates. The patch turned out a bit bigger than I'd hoped because it proved necessary to record the extra-arguments option in a new pg_aggregate column. I'd thought we could just look at the final function's pronargs at runtime, but that didn't work well for variadic final functions. It's probably just as well though, because it simplifies life for pg_dump to record the option explicitly. While at it, fix array_agg() to have a valid final-function signature, and add an opr_sanity test to notice future deviations from polymorphic consistency. I also marked the percentile_cont() aggregates as not needing extra arguments, since they don't.
* Improve some O(N^2) behavior in window function evaluation.Tom Lane2014-04-13
| | | | | | | | | | | | | | | | | | | Repositioning the tuplestore seek pointer in window_gettupleslot() turns out to be a very significant expense when the window frame is sizable and the frame end can move. To fix, introduce a tuplestore function for skipping an arbitrary number of tuples in one call, parallel to the one we introduced for tuplesort objects in commit 8d65da1f. This reduces the cost of window_gettupleslot() to O(1) if the tuplestore has not spilled to disk. As in the previous commit, I didn't try to do any real optimization of tuplestore_skiptuples for the case where the tuplestore has spilled to disk. There is probably no practical way to get the cost to less than O(N) anyway, but perhaps someone can think of something later. Also fix PersistHoldablePortal() to make use of this API now that we have it. Based on a suggestion by Dean Rasheed, though this turns out not to look much like his patch.
* Create infrastructure for moving-aggregate optimization.Tom Lane2014-04-12
| | | | | | | | | | | | | | | | | | | Until now, when executing an aggregate function as a window function within a window with moving frame start (that is, any frame start mode except UNBOUNDED PRECEDING), we had to recalculate the aggregate from scratch each time the frame head moved. This patch allows an aggregate definition to include an alternate "moving aggregate" implementation that includes an inverse transition function for removing rows from the aggregate's running state. As long as this can be done successfully, runtime is proportional to the total number of input rows, rather than to the number of input rows times the average frame length. This commit includes the core infrastructure, documentation, and regression tests using user-defined aggregates. Follow-on commits will update some of the built-in aggregates to use this feature. David Rowley and Florian Pflug, reviewed by Dean Rasheed; additional hacking by me
* Offer triggers on foreign tables.Noah Misch2014-03-23
| | | | | | | | | | | | | | | | | 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.
* Setup error context callback for transaction lock waitsAlvaro Herrera2014-03-19
| | | | | | | | | | | | | | | | | | With this in place, a session blocking behind another one because of tuple locks will get a context line mentioning the relation name, tuple TID, and operation being done on tuple. For example: LOG: process 11367 still waiting for ShareLock on transaction 717 after 1000.108 ms DETAIL: Process holding the lock: 11366. Wait queue: 11367. CONTEXT: while updating tuple (0,2) in relation "foo" STATEMENT: UPDATE foo SET value = 3; Most usefully, the new line is displayed by log entries due to log_lock_waits, although of course it will be printed by any other log message as well. Author: Christian Kruse, some tweaks by Álvaro Herrera Reviewed-by: Amit Kapila, Andres Freund, Tom Lane, Robert Haas
* Don't reject ROW_MARK_REFERENCE rowmarks for materialized views.Tom Lane2014-03-06
| | | | | | | | | | We should allow this so that matviews can be referenced in UPDATE/DELETE statements in READ COMMITTED isolation level. The requirement for that is that a re-fetch by TID will see the same row version the query saw earlier, which is true of matviews, so there's no reason for the restriction. Per bug #9398. Michael Paquier, after a suggestion by me
* Introduce logical decoding.Robert Haas2014-03-03
| | | | | | | | | | | | | | | | | | | | | | This feature, building on previous commits, allows the write-ahead log stream to be decoded into a series of logical changes; that is, inserts, updates, and deletes and the transactions which contain them. It is capable of handling decoding even across changes to the schema of the effected tables. The output format is controlled by a so-called "output plugin"; an example is included. To make use of this in a real replication system, the output plugin will need to be modified to produce output in the format appropriate to that system, and to perform filtering. Currently, information can be extracted from the logical decoding system only via SQL; future commits will add the ability to stream changes via walsender. Andres Freund, with review and other contributions from many other people, including Álvaro Herrera, Abhijit Menon-Sen, Peter Gheogegan, Kevin Grittner, Robert Haas, Heikki Linnakangas, Fujii Masao, Abhijit Menon-Sen, Michael Paquier, Simon Riggs, Craig Ringer, and Steve Singer.
* Fix *-qualification of named parameters in SQL-language functions.Tom Lane2014-02-03
| | | | | | | Given a composite-type parameter named x, "$1.*" worked fine, but "x.*" not so much. This has been broken since named parameter references were added in commit 9bff0780cf5be2193a5bad0d3df2dbe143085264, so patch back to 9.2. Per bug #9085 from Hardy Falk.
* Make bitmap heap scans show exact/lossy block info in EXPLAIN ANALYZE.Robert Haas2014-01-13
| | | | Etsuro Fujita
* Fix "cannot accept a set" error when only some arms of a CASE return a set.Tom Lane2014-01-08
| | | | | | | | | | | | | | | In commit c1352052ef1d4eeb2eb1d822a207ddc2d106cb13, I implemented an optimization that assumed that a function's argument expressions would either always return a set (ie multiple rows), or always not. This is wrong however: we allow CASE expressions in which some arms return a set of some type and others just return a scalar of that type. There may be other examples as well. To fix, replace the run-time test of whether an argument returned a set with a static precheck (expression_returns_set). This adds a little bit of query startup overhead, but it seems barely measurable. Per bug #8228 from David Johnston. This has been broken since 8.0, so patch all supported branches.
* Save a few cycles in advance_transition_function().Tom Lane2014-01-08
| | | | | | | | | | | | | | Keep a pre-initialized FunctionCallInfoData in AggStatePerAggData, and re-use that at each row instead of doing InitFunctionCallInfoData each time. This saves only half a dozen assignments and maybe some stack manipulation, and yet that seems to be good for a percent or two of the overall query run time for simple aggregates such as count(*). The cost is that the FunctionCallInfoData (which is about a kilobyte, on 64-bit machines) stays allocated for the duration of the query instead of being short-lived stack data. But we're already paying an equivalent space cost for each regular FuncExpr or OpExpr node, so I don't feel bad about paying it for aggregate functions. The code seems a little cleaner this way too, since the number of things passed to advance_transition_function decreases.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Support ordered-set (WITHIN GROUP) aggregates.Tom Lane2013-12-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces generic support for ordered-set and hypothetical-set aggregate functions, as well as implementations of the instances defined in SQL:2008 (percentile_cont(), percentile_disc(), rank(), dense_rank(), percent_rank(), cume_dist()). We also added mode() though it is not in the spec, as well as versions of percentile_cont() and percentile_disc() that can compute multiple percentile values in one pass over the data. Unlike the original submission, this patch puts full control of the sorting process in the hands of the aggregate's support functions. To allow the support functions to find out how they're supposed to sort, a new API function AggGetAggref() is added to nodeAgg.c. This allows retrieval of the aggregate call's Aggref node, which may have other uses beyond the immediate need. There is also support for ordered-set aggregates to install cleanup callback functions, so that they can be sure that infrastructure such as tuplesort objects gets cleaned up. In passing, make some fixes in the recently-added support for variadic aggregates, and make some editorial adjustments in the recent FILTER additions for aggregates. Also, simplify use of IsBinaryCoercible() by allowing it to succeed whenever the target type is ANY or ANYELEMENT. It was inconsistent that it dealt with other polymorphic target types but not these. Atri Sharma and Andrew Gierth; reviewed by Pavel Stehule and Vik Fearing, and rather heavily editorialized upon by Tom Lane
* Support multi-argument UNNEST(), and TABLE() syntax for multiple functions.Tom Lane2013-11-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
* Prevent display of dropped columns in row constraint violation messages.Tom Lane2013-11-07
| | | | | | | | | | | | | | | ExecBuildSlotValueDescription() printed "null" for each dropped column in a row being complained of by ExecConstraints(). This has some sanity in terms of the underlying implementation, but is of course pretty surprising to users. To fix, we must pass the target relation's descriptor to ExecBuildSlotValueDescription(), because the slot descriptor it had been using doesn't get labeled with attisdropped markers. Per bug #8408 from Maxim Boguk. Back-patch to 9.2 where the feature of printing row values in NOT NULL and CHECK constraint violation messages was introduced. Michael Paquier and Tom Lane
* Prevent memory leaks from accumulating across printtup() calls.Tom Lane2013-11-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically, printtup() has assumed that it could prevent memory leakage by pfree'ing the string result of each output function and manually managing detoasting of toasted values. This amounts to assuming that datatype output functions never leak any memory internally; an assumption we've already decided to be bogus elsewhere, for example in COPY OUT. range_out in particular is known to leak multiple kilobytes per call, as noted in bug #8573 from Godfried Vanluffelen. While we could go in and fix that leak, it wouldn't be very notationally convenient, and in any case there have been and undoubtedly will again be other leaks in other output functions. So what seems like the best solution is to run the output functions in a temporary memory context that can be reset after each row, as we're doing in COPY OUT. Some quick experimentation suggests this is actually a tad faster than the retail pfree's anyway. This patch fixes all the variants of printtup, except for debugtup() which is used in standalone mode. It doesn't seem worth worrying about query-lifespan leaks in standalone mode, and fixing that case would be a bit tedious since debugtup() doesn't currently have any startup or shutdown functions. While at it, remove manual detoast management from several other output-function call sites that had copied it from printtup(). This doesn't make a lot of difference right now, but in view of recent discussions about supporting "non-flattened" Datums, we're going to want that code gone eventually anyway. Back-patch to 9.2 where range_out was introduced. We might eventually decide to back-patch this further, but in the absence of known major leaks in older output functions, I'll refrain for now.
* Fix subquery reference to non-populated MV in CMV.Kevin Grittner2013-11-02
| | | | | | | | | A subquery reference to a matview should be allowed by CREATE MATERIALIZED VIEW WITH NO DATA, just like a direct reference is. Per bug report from Laurent Sartran. Backpatch to 9.3.
* Don't allow system columns in CHECK constraints, except tableoid.Robert Haas2013-09-23
| | | | | | | | | | | | | | | | | | | | | Previously, arbitray system columns could be mentioned in table constraints, but they were not correctly checked at runtime, because the values weren't actually set correctly in the tuple. Since it seems easy enough to initialize the table OID properly, do that, and continue allowing that column, but disallow the rest unless and until someone figures out a way to make them work properly. No back-patch, because this doesn't seem important enough to take the risk of destabilizing the back branches. In fact, this will pose a dump-and-reload hazard for those upgrading from previous versions: constraints that were accepted before but were not correctly enforced will now either be enforced correctly or not accepted at all. Either could result in restore failures, but in practice I think very few users will notice the difference, since the use case is pretty marginal anyway and few users will be relying on features that have not historically worked. Amit Kapila, reviewed by Rushabh Lathia, with doc changes by me.
* Allow aggregate functions to be VARIADIC.Tom Lane2013-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | There's no inherent reason why an aggregate function can't be variadic (even VARIADIC ANY) if its transition function can handle the case. Indeed, this patch to add the feature touches none of the planner or executor, and little of the parser; the main missing stuff was DDL and pg_dump support. It is true that variadic aggregates can create the same sort of ambiguity about parameters versus ORDER BY keys that was complained of when we (briefly) had both one- and two-argument forms of string_agg(). However, the policy formed in response to that discussion only said that we'd not create any built-in aggregates with varying numbers of arguments, not that we shouldn't allow users to do it. So the logical extension of that is we can allow users to make variadic aggregates as long as we're wary about shipping any such in core. In passing, this patch allows aggregate function arguments to be named, to the extent of remembering the names in pg_proc and dumping them in pg_dump. You can't yet call an aggregate using named-parameter notation. That seems like a likely future extension, but it'll take some work, and it's not what this patch is really about. Likewise, there's still some work needed to make window functions handle VARIADIC fully, but I left that for another day. initdb forced because of new aggvariadic field in Aggref parse nodes.
* Reset the binary heap in MergeAppend rescans.Tom Lane2013-08-30
| | | | | | | | Failing to do so can cause queries to return wrong data, error out or crash. This requires adding a new binaryheap_reset() method to binaryheap.c, but that probably should have been there anyway. Per bug #8410 from Terje Elde. Diagnosis and patch by Andres Freund.
* Improve error message when view is not updatablePeter Eisentraut2013-08-14
| | | | | Avoid using the term "updatable" in confusing ways. Suggest a trigger first, before a rule.
* Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF)Greg Stark2013-07-29
| | | | | Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
* Prevent leakage of SPI tuple tables during subtransaction abort.Tom Lane2013-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | plpgsql often just remembers SPI-result tuple tables in local variables, and has no mechanism for freeing them if an ereport(ERROR) causes an escape out of the execution function whose local variable it is. In the original coding, that wasn't a problem because the tuple table would be cleaned up when the function's SPI context went away during transaction abort. However, once plpgsql grew the ability to trap exceptions, repeated trapping of errors within a function could result in significant intra-function-call memory leakage, as illustrated in bug #8279 from Chad Wagner. We could fix this locally in plpgsql with a bunch of PG_TRY/PG_CATCH coding, but that would be tedious, probably slow, and prone to bugs of omission; moreover it would do nothing for similar risks elsewhere. What seems like a better plan is to make SPI itself responsible for freeing tuple tables at subtransaction abort. This patch attacks the problem that way, keeping a list of live tuple tables within each SPI function context. Currently, such freeing is automatic for tuple tables made within the failed subtransaction. We might later add a SPI call to mark a tuple table as not to be freed this way, allowing callers to opt out; but until someone exhibits a clear use-case for such behavior, it doesn't seem worth bothering. A very useful side-effect of this change is that SPI_freetuptable() can now defend itself against bad calls, such as duplicate free requests; this should make things more robust in many places. (In particular, this reduces the risks involved if a third-party extension contains now-redundant SPI_freetuptable() calls in error cleanup code.) Even though the leakage problem is of long standing, it seems imprudent to back-patch this into stable branches, since it does represent an API semantics change for SPI users. We'll patch this in 9.3, but live with the leakage in older branches.
* Use InvalidSnapshot, now SnapshotNow, as the default snapshot.Robert Haas2013-07-23
| | | | | | | | | | | | As far as I can determine, there's no code in the core distribution that fails to explicitly set the snapshot of a scan or executor state. If there is any such code, this will probably cause it to seg fault; friendlier suggestions were discussed on pgsql-hackers, but there was no consensus that anything more than this was needed. This is another step towards the hoped-for complete removal of SnapshotNow.
* Adjust HeapTupleSatisfies* routines to take a HeapTuple.Robert Haas2013-07-22
| | | | | | | | | | | | | | | | | | Previously, these functions took a HeapTupleHeader, but upcoming patches for logical replication will introduce new a new snapshot type under which the tuple's TID will be used to lookup (CMIN, CMAX) for visibility determination purposes. This makes that information available. Code churn is minimal since HeapTupleSatisfiesVisibility took the HeapTuple anyway, and deferenced it before calling the satisfies function. Independently of logical replication, this allows t_tableOid and t_self to be cross-checked via assertions in tqual.c. This seems like a useful way to make sure that all callers are setting these values properly, which has been previously put forward as desirable. Andres Freund, reviewed by Álvaro Herrera
* WITH CHECK OPTION support for auto-updatable VIEWsStephen Frost2013-07-18
| | | | | | | | | | | | | For simple views which are automatically updatable, this patch allows the user to specify what level of checking should be done on records being inserted or updated. For 'LOCAL CHECK', new tuples are validated against the conditionals of the view they are being inserted into, while for 'CASCADED CHECK' the new tuples are validated against the conditionals for all views involved (from the top down). This option is part of the SQL specification. Dean Rasheed, reviewed by Pavel Stehule
* Implement the FILTER clause for aggregate function calls.Noah Misch2013-07-16
| | | | | | | | | This is SQL-standard with a few extensions, namely support for subqueries and outer references in clause expressions. catversion bump due to change in Aggref and WindowFunc. David Fetter, reviewed by Dean Rasheed.
* Add support for REFRESH MATERIALIZED VIEW CONCURRENTLY.Kevin Grittner2013-07-16
| | | | | | | | | | | | This allows reads to continue without any blocking while a REFRESH runs. The new data appears atomically as part of transaction commit. Review questioned the Assert that a matview was not a system relation. This will be addressed separately. Reviewed by Hitoshi Harada, Robert Haas, Andres Freund. Merged after review with security patch f3ab5d4.
* Make comments reflect that omission of SPI_gettypmod() is intentional.Noah Misch2013-07-12
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* Use an MVCC snapshot, rather than SnapshotNow, for catalog scans.Robert Haas2013-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | SnapshotNow scans have the undesirable property that, in the face of concurrent updates, the scan can fail to see either the old or the new versions of the row. In many cases, we work around this by requiring DDL operations to hold AccessExclusiveLock on the object being modified; in some cases, the existing locking is inadequate and random failures occur as a result. This commit doesn't change anything related to locking, but will hopefully pave the way to allowing lock strength reductions in the future. The major issue has held us back from making this change in the past is that taking an MVCC snapshot is significantly more expensive than using a static special snapshot such as SnapshotNow. However, testing of various worst-case scenarios reveals that this problem is not severe except under fairly extreme workloads. To mitigate those problems, we avoid retaking the MVCC snapshot for each new scan; instead, we take a new snapshot only when invalidation messages have been processed. The catcache machinery already requires that invalidation messages be sent before releasing the related heavyweight lock; else other backends might rely on locally-cached data rather than scanning the catalog at all. Thus, making snapshot reuse dependent on the same guarantees shouldn't break anything that wasn't already subtly broken. Patch by me. Review by Michael Paquier and Andres Freund.
* Improve updatability checking for views and foreign tables.Tom Lane2013-06-12
| | | | | | | | | | | | | | | | | | | | | 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
* pgindent run for release 9.3Bruce Momjian2013-05-29
| | | | | This is the first run of the Perl-based pgindent script. Also update pgindent instructions.