summaryrefslogtreecommitdiff
path: root/src/include/executor
AgeCommit message (Collapse)Author
2010-07-22Centralize DML permissions-checking logic.Robert Haas
Remove bespoke code in DoCopy and RI_Initial_Check, which now instead fabricate call ExecCheckRTPerms with a manufactured RangeTblEntry. This is intended to make it feasible for an enhanced security provider to actually make use of ExecutorCheckPerms_hook, but also has the advantage that RI_Initial_Check can allow use of the fast-path when column-level but not table-level permissions are present. KaiGai Kohei. Reviewed (in an earlier version) by Stephen Frost, and by me. Some further changes to the comments by me.
2010-07-12Make NestLoop plan nodes pass outer-relation variables into their innerTom Lane
relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
2010-07-09Add a hook in ExecCheckRTPerms().Robert Haas
This hook allows a loadable module to gain control when table permissions are checked. It is expected to be used by an eventual SE-PostgreSQL implementation, but there are other possible applications as well. A sample contrib module can be found in the archives at: http://archives.postgresql.org/pgsql-hackers/2010-05/msg01095.php Robert Haas and Stephen Frost
2010-02-26pgindent run for 9.0Bruce Momjian
2010-02-08Remove old-style VACUUM FULL (which was known for a little while asTom Lane
VACUUM FULL INPLACE), along with a boatload of subsidiary code and complexity. Per discussion, the use case for this method of vacuuming is no longer large enough to justify maintaining it; not to mention that we don't wish to invest the work that would be needed to make it play nicely with Hot Standby. Aside from the code directly related to old-style VACUUM FULL, this commit removes support for certain WAL record types that could only be generated within VACUUM FULL, redirect-pointer removal in heap_page_prune, and nontransactional generation of cache invalidation sinval messages (the last being the sticking point for Hot Standby). We still have to retain all code that copes with finding HEAP_MOVED_OFF and HEAP_MOVED_IN flag bits on existing tuples. This can't be removed as long as we want to support in-place update from pre-9.0 databases.
2010-02-01Augment EXPLAIN output with more details on Hash nodes.Robert Haas
We show the number of buckets, the number of batches (and also the original number if it has changed), and the peak space used by the hash table. Minor executor changes to track peak space used.
2010-01-08pgBufferUsage needs PGDLLIMPORT for pg_stat_statements on Windows.Itagaki Takahiro
2010-01-02Update copyright for the year 2010.Bruce Momjian
2009-12-15Add an EXPLAIN (BUFFERS) option to show buffer-usage statistics.Robert Haas
This patch also removes buffer-usage statistics from the track_counts output, since this (or the global server statistics) is deemed to be a better interface to this information. Itagaki Takahiro, reviewed by Euler Taveira de Oliveira.
2009-12-14Fix a bug introduced when set-returning SQL functions were made inline-able:Tom Lane
we have to cope with the possibility that the declared result rowtype contains dropped columns. This fails in 8.4, as per bug #5240. While at it, be more paranoid about inserting binary coercions when inlining. The pre-8.4 code did not really need to worry about that because it could not inline at all in any case where an added coercion could change the behavior of the function's statement. However, when inlining a SRF we allow sorting, grouping, and set-ops such as UNION. In these cases, modifying one of the targetlist entries that the sort/group/setop depends on could conceivably change the behavior of the function's statement --- so don't inline when such a case applies.
2009-12-07Add exclusion constraints, which generalize the concept of uniqueness toTom Lane
support any indexable commutative operator, not just equality. Two rows violate the exclusion constraint if "row1.col OP row2.col" is TRUE for each of the columns in the constraint. Jeff Davis, reviewed by Robert Haas
2009-11-04Add support for invoking parser callback hooks via SPI and in cached plans.Tom Lane
As proof of concept, modify plpgsql to use the hooks. plpgsql is still inserting $n symbols textually, but the "back end" of the parsing process now goes through the ParamRef hook instead of using a fixed parameter-type array, and then execution only fetches actually-referenced parameters, using a hook added to ParamListInfo. Although there's a lot left to be done in plpgsql, this already cures the "if (TG_OP = 'INSERT' and NEW.foo ...)" problem, as illustrated by the changed regression test.
2009-10-26Re-implement EvalPlanQual processing to improve its performance and eliminateTom Lane
a lot of strange behaviors that occurred in join cases. We now identify the "current" row for every joined relation in UPDATE, DELETE, and SELECT FOR UPDATE/SHARE queries. If an EvalPlanQual recheck is necessary, we jam the appropriate row into each scan node in the rechecking plan, forcing it to emit only that one row. The former behavior could rescan the whole of each joined relation for each recheck, which was terrible for performance, and what's much worse could result in duplicated output tuples. Also, the original implementation of EvalPlanQual could not re-use the recheck execution tree --- it had to go through a full executor init and shutdown for every row to be tested. To avoid this overhead, I've associated a special runtime Param with each LockRows or ModifyTable plan node, and arranged to make every scan node below such a node depend on that Param. Thus, by signaling a change in that Param, the EPQ machinery can just rescan the already-built test plan. This patch also adds a prohibition on set-returning functions in the targetlist of SELECT FOR UPDATE/SHARE. This is needed to avoid the duplicate-output-tuple problem. It seems fairly reasonable since the other restrictions on SELECT FOR UPDATE are meant to ensure that there is a unique correspondence between source tuples and result tuples, which an output SRF destroys as much as anything else does.
2009-10-12Move the handling of SELECT FOR UPDATE locking and rechecking out ofTom Lane
execMain.c and into a new plan node type LockRows. Like the recent change to put table updating into a ModifyTable plan node, this increases planning flexibility by allowing the operations to occur below the top level of the plan tree. It's necessary in any case to restore the previous behavior of having FOR UPDATE locking occur before ModifyTable does. This partially refactors EvalPlanQual to allow multiple rows-under-test to be inserted into the EPQ machinery before starting an EPQ test query. That isn't sufficient to fix EPQ's general bogosity in the face of plans that return multiple rows per test row, though. Since this patch is mostly about getting some plan node infrastructure in place and not about fixing ten-year-old bugs, I will leave EPQ improvements for another day. Another behavioral change that we could now think about is doing FOR UPDATE before LIMIT, but that too seems like it should be treated as a followon patch.
2009-10-10Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c.Tom Lane
They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
2009-10-08Remove very ancient tuple-counting infrastructure (IncrRetrieved() andTom Lane
friends). This code has all been ifdef'd out for many years, and doesn't seem to have any prospect of becoming any more useful in the future. EXPLAIN ANALYZE is what people use in practice, and I think if we did want process-wide counters we'd be more likely to put in dtrace events for that than try to resurrect this code. Get rid of it so as to have one less detail to worry about while refactoring execMain.c.
2009-09-27Remove no-longer-needed ExecCountSlots infrastructure.Tom Lane
2009-09-27Replace the array-style TupleTable data structure with a simple List ofTom Lane
TupleTableSlot nodes. This eliminates the need to count in advance how many Slots will be needed, which seems more than worth the small increase in the amount of palloc traffic during executor startup. The ExecCountSlots infrastructure is now all dead code, but I'll remove it in a separate commit for clarity. Per a comment from Robert Haas.
2009-09-12Rewrite the planner's handling of materialized plan types so that there isTom Lane
an explicit model of rescan costs being different from first-time costs. The costing of Material nodes in particular now has some visible relationship to the actual runtime behavior, where before it was essentially fantasy. This also fixes up a couple of places where different materialized plan types were treated differently for no very good reason (probably just oversights). A couple of the regression tests are affected, because the planner now chooses to put the other relation on the inside of a nestloop-with-materialize. So far as I can see both changes are sane, and the planner is now more consistently following the expectation that it should prefer to materialize the smaller of two relations. Per a recent discussion with Robert Haas.
2009-07-29Support deferrable uniqueness constraints.Tom Lane
The current implementation fires an AFTER ROW trigger for each tuple that looks like it might be non-unique according to the index contents at the time of insertion. This works well as long as there aren't many conflicts, but won't scale to massive unique-key reassignments. Improving that case is a TODO item. Dean Rasheed
2009-07-22Change do_tup_output() to take Datum/isnull arrays instead of a char * array,Tom Lane
so it doesn't go through BuildTupleFromCStrings. This is more or less a wash for current uses, but will avoid inefficiency for planned changes to EXPLAIN. Robert Haas
2009-07-18Fix error cleanup failure caused by 8.4 changes in plpgsql to try to avoidTom Lane
memory leakage in error recovery. We were calling FreeExprContext, and therefore invoking ExprContextCallback callbacks, in both normal and error exits from subtransactions. However this isn't very safe, as shown in recent trouble report from Frank van Vugt, in which releasing a tupledesc refcount failed. It's also unnecessary, since the resources that callbacks might wish to release should be cleaned up by other error recovery mechanisms (ie the resource owners). We only really want FreeExprContext to release memory attached to the exprcontext in the error-exit case. So, add a bool parameter to FreeExprContext to tell it not to call the callbacks. A more general solution would be to pass the isCommit bool parameter on to the callbacks, so they could do only safe things during error exit. But that would make the patch significantly more invasive and possibly break third-party code that registers ExprContextCallback callbacks. We might want to do that later in HEAD, but for now I'll just do what seems reasonable to back-patch.
2009-06-118.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian
provided by Andrew.
2009-03-30Fix an oversight in the support for storing/retrieving "minimal tuples" inTom Lane
TupleTableSlots. We have functions for retrieving a minimal tuple from a slot after storing a regular tuple in it, or vice versa; but these were implemented by converting the internal storage from one format to the other. The problem with that is it invalidates any pass-by-reference Datums that were already fetched from the slot, since they'll be pointing into the just-freed version of the tuple. The known problem cases involve fetching both a whole-row variable and a pass-by-reference value from a slot that is fed from a tuplestore or tuplesort object. The added regression tests illustrate some simple cases, but there may be other failure scenarios traceable to the same bug. Note that the added tests probably only fail on unpatched code if it's built with --enable-cassert; otherwise the bug leads to fetching from freed memory, which will not have been overwritten without additional conditions. Fix by allowing a slot to contain both formats simultaneously; which turns out not to complicate the logic much at all, if anything it seems less contorted than before. Back-patch to 8.2, where minimal tuples were introduced.
2009-03-21Optimize multi-batch hash joins when the outer relation has a nonuniformTom Lane
distribution, by creating a special fast path for the (first few) most common values of the outer relation. Tuples having hashvalues matching the MCVs are effectively forced to be in the first batch, so that we never write them out to the batch temp files. Bryce Cutt and Ramon Lawrence, with some editorialization by me.
2009-01-21Add new SPI_OK_REWRITTEN return code to SPI_execute and friends, for theHeikki Linnakangas
case that the command is rewritten into another type of command. The old behavior to return the command tag of the last executed command was pretty surprising. In PL/pgSQL, for example, it meant that if a command was rewritten to a utility statement, FOUND wasn't set at all.
2009-01-07Insert conditional SPI_push/SPI_pop calls into InputFunctionCall,Tom Lane
OutputFunctionCall, and friends. This allows SPI-using functions to invoke datatype I/O without concern for the possibility that a SPI-using function will be called (which could be either the I/O function itself, or a function used in a domain check constraint). It's a tad ugly, but not nearly as ugly as what'd be needed to make this work via retail insertion of push/pop operations in all the PLs. This reverts my patch of 2007-01-30 that inserted some retail SPI_push/pop calls into plpgsql; that approach only fixed plpgsql, and not any other PLs. But the other PLs have the issue too, as illustrated by a recent gripe from Christian Schröder. Back-patch to 8.2, which is as far back as this solution will work. It's also as far back as we need to worry about the domain-constraint case, since earlier versions did not attempt to check domain constraints within datatype input. I'm not aware of any old I/O functions that use SPI themselves, so this should be sufficient for a back-patch.
2009-01-07Fix executor/spi.h to follow our usual conventions for include files, ie,Tom Lane
not include postgres.h nor anything else it doesn't directly need. Add #includes to calling files as needed to compensate. Per my proposal of yesterday. This should be noted as a source code change in the 8.4 release notes, since it's likely to require changes in add-on modules.
2009-01-02Include a pointer to the query's source text in QueryDesc structs. This isTom Lane
practically free given prior 8.4 changes in plancache and portal management, and it makes it a lot easier for ExecutorStart/Run/End hooks to get at the query text. Extracted from Itagaki Takahiro's pg_stat_statements patch, with minor editorialization.
2009-01-01Update copyright for 2009.Bruce Momjian
2008-12-28Support window functions a la SQL:2008.Tom Lane
Hitoshi Harada, with some kibitzing from Heikki and Tom.
2008-12-01Ensure that the contents of a holdable cursor don't depend on out-of-lineTom Lane
toasted values, since those could get dropped once the cursor's transaction is over. Per bug #4553 from Andrew Gierth. Back-patch as far as 8.1. The bug actually exists back to 7.4 when holdable cursors were introduced, but this patch won't work before 8.1 without significant adjustments. Given the lack of field complaints, it doesn't seem worth the work (and risk of introducing new bugs) to try to make a patch for the older branches.
2008-11-30Clean up the API for DestReceiver objects by eliminating the assumptionTom Lane
that a Portal is a useful and sufficient additional argument for CreateDestReceiver --- it just isn't, in most cases. Instead formalize the approach of passing any needed parameters to the receiver separately. One unexpected benefit of this change is that we can declare typedef Portal in a less surprising location. This patch is just code rearrangement and doesn't change any functionality. I'll tackle the HOLD-cursor-vs-toast problem in a follow-on patch.
2008-11-19Some infrastructure changes for the upcoming auto-explain contrib module:Tom Lane
* Refactor explain.c slightly to export a convenient-to-use subroutine for printing EXPLAIN results. * Provide hooks for plugins to get control at ExecutorStart and ExecutorEnd as well as ExecutorRun. * Add some minimal support for tracking the total runtime of ExecutorRun. This code won't actually do anything unless a plugin prods it to. * Change the API of the DefineCustomXXXVariable functions to allow nonzero "flags" to be specified for a custom GUC variable. While at it, also make the "bootstrap" default value for custom GUCs be explicitly specified as a parameter to these functions. This is to eliminate confusion over where the default comes from, as has been expressed in the past by some users of the custom-variable facility. * Refactor GUC code a bit to ensure that a custom variable gets initialized to something valid (like its default value) even if the placeholder value was invalid.
2008-10-31Simplify ExecutorRun's API and save some trivial number of cycles by havingTom Lane
it just return void instead of sometimes returning a TupleTableSlot. SQL functions don't need that anymore, and noplace else does either. Eliminating the return value also means one less hassle for the ExecutorRun hook functions that will be supported beginning in 8.4.
2008-10-31Allow SQL-language functions to return the output of an INSERT/UPDATE/DELETETom Lane
RETURNING clause, not just a SELECT as formerly. A side effect of this patch is that when a set-returning SQL function is used in a FROM clause, performance is improved because the output is collected into a tuplestore within the function, rather than using the less efficient value-per-call mechanism.
2008-10-29Be more tense about not creating tuplestores with randomAccess = true unlessTom Lane
backwards scan could actually happen. In particular, pass a flag to materialize-mode SRFs that tells them whether they need to require random access. In passing, also suppress unneeded backward-scan overhead for a Portal's holdStore tuplestore. Per my proposal about reducing I/O costs for tuplestores.
2008-10-28Extend ExecMakeFunctionResult() to support set-returning functions that returnTom Lane
via a tuplestore instead of value-per-call. Refactor a few things to reduce ensuing code duplication with nodeFunctionscan.c. This represents the reasonably noncontroversial part of my proposed patch to switch SQL functions over to returning tuplestores. For the moment, SQL functions still do things the old way. However, this change enables PL SRFs to be called in targetlists (observe changes in plperl regression results).
2008-10-04Implement SQL-standard WITH clauses, including WITH RECURSIVE.Tom Lane
There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane
2008-10-01Improve tuplestore.c to support multiple concurrent read positions.Tom Lane
This facility replaces the former mark/restore support but is otherwise upward-compatible with previous uses. It's expected to be needed for single evaluation of CTEs and also for window functions, so I'm committing it separately instead of waiting for either one of those patches to be finished. Per discussion with Greg Stark and Hitoshi Harada. Note: I removed nodeFunctionscan's mark/restore support, instead of bothering to update it for this change, because it was dead code anyway.
2008-09-17Allow ShowBufferUsage() to report the number of reads/writes that haveTom Lane
occurred to temporary files. This replaces the unused NDirectFileRead/NDirectFileWrite counters. Itagaki Takahiro
2008-09-15Fix caching of foreign-key-checking queries so that when a replan is needed,Tom Lane
we regenerate the SQL query text not merely the plan derived from it. This is needed to handle contingencies such as renaming of a table or column used in an FK. Pre-8.3, such cases worked despite the lack of replanning (because the cached plan needn't actually change), so this is a regression. Per bug #4417 from Benjamin Bihler.
2008-08-25Get rid of the last remaining uses of var_is_rel(), to wit some debuggingTom Lane
checks in ExecIndexBuildScanKeys() that were inadequate anyway: it's better to verify the correct varno on an expected index key, not just reject OUTER and INNER. This makes the entire current contents of nodeFuncs.c dead code. I'll be replacing it with some other stuff later, as per recent proposal.
2008-08-22Arrange to convert EXISTS subqueries that are equivalent to hashable INTom Lane
subqueries into the same thing you'd have gotten from IN (except always with unknownEqFalse = true, so as to get the proper semantics for an EXISTS). I believe this fixes the last case within CVS HEAD in which an EXISTS could give worse performance than an equivalent IN subquery. The tricky part of this is that if the upper query probes the EXISTS for only a few rows, the hashing implementation can actually be worse than the default, and therefore we need to make a cost-based decision about which way to use. But at the time when the planner generates plans for subqueries, it doesn't really know how many times the subquery will be executed. The least invasive solution seems to be to generate both plans and postpone the choice until execution. Therefore, in a query that has been optimized this way, EXPLAIN will show two subplans for the EXISTS, of which only one will actually get executed. There is a lot more that could be done based on this infrastructure: in particular it's interesting to consider switching to the hash plan if we start out using the non-hashed plan but find a lot more upper rows going by than we expected. I have therefore left some minor inefficiencies in place, such as initializing both subplans even though we will currently only use one.
2008-07-26As noted by Andrew Gierth, there's really no need any more to force a junkTom Lane
filter to be used when INSERT or SELECT INTO has a plan that returns raw disk tuples. The virtual-tuple-slot optimizations that were put in place awhile ago mean that ExecInsert has to do ExecMaterializeSlot, and that already copies the tuple if it's raw (and does so more efficiently than a junk filter, too). So get rid of that logic. This in turn means that we can throw away ExecMayReturnRawTuples, which wasn't used for any other purpose, and was always a kluge anyway. In passing, move a couple of SELECT-INTO-specific fields out of EState and into the private state of the SELECT INTO DestReceiver, as was foreseen in an old comment there. Also make intorel_receive use ExecMaterializeSlot not ExecCopySlotTuple, for consistency with ExecInsert and to possibly save a tuple copy step in some cases.
2008-07-18Provide a function hook to let plug-ins get control around ExecutorRun.Tom Lane
ITAGAKI Takahiro
2008-05-14Move the "instr_time" typedef and associated macros into a new headerTom Lane
file portability/instr_time.h, and add a couple more macros to eliminate some abstraction leakage we formerly had. Also update psql to use this header instead of its own copy of nearly the same code. This commit in itself is just code cleanup and shouldn't change anything. It lays some groundwork for the upcoming function-stats patch, though.
2008-04-13Since createplan.c no longer cares whether index operators are lossy, it hasTom Lane
no particular need to do get_op_opfamily_properties() while building an indexscan plan. Postpone that lookup until executor start. This simplifies createplan.c a lot more than it complicates nodeIndexscan.c, and makes things more uniform since we already had to do it that way for RowCompare expressions. Should be a bit faster too, at least for plans that aren't re-used many times, since we avoid palloc'ing and perhaps copying the intermediate list data structure.
2008-04-01Add SPI-level support for executing SQL commands with one-time-use plans,Tom Lane
that is commands that have out-of-line parameters but the plan is prepared assuming that the parameter values are constants. This is needed for the plpgsql EXECUTE USING patch, but will probably have use elsewhere. This commit includes the SPI functions and documentation, but no callers nor regression tests. The upcoming EXECUTE USING patch will provide regression-test coverage. I thought committing this separately made sense since it's logically a distinct feature.
2008-03-28Support statement-level ON TRUNCATE triggers. Simon RiggsTom Lane