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2009-11-09Fix WHERE CURRENT OF to work as designed within plpgsql. The argumentTom Lane
can be the name of a plpgsql cursor variable, which formerly was converted to $N before the core parser saw it, but that's no longer the case. Deal with plain name references to plpgsql variables, and add a regression test case that exposes the failure.
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.
2009-10-30Make the overflow guards in ExecChooseHashTableSize be more protective.Tom Lane
The original coding ensured nbuckets and nbatch didn't exceed INT_MAX, which while not insane on its own terms did nothing to protect subsequent code like "palloc(nbatch * sizeof(BufFile *))". Since enormous join size estimates might well be planner error rather than reality, it seems best to constrain the initial sizes to be not more than work_mem/sizeof(pointer), thus ensuring the allocated arrays don't exceed work_mem. We will allow nbatch to get bigger than that during subsequent ExecHashIncreaseNumBatches calls, but we should still guard against integer overflow in those palloc requests. Per bug #5145 from Bernt Marius Johnsen. Although the given test case only seems to fail back to 8.2, previous releases have variants of this issue, so patch all supported branches.
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.
2009-10-05Create an ALTER DEFAULT PRIVILEGES command, which allows users to adjustTom Lane
the privileges that will be applied to subsequently-created objects. Such adjustments are always per owning role, and can be restricted to objects created in particular schemas too. A notable benefit is that users can override the traditional default privilege settings, eg, the PUBLIC EXECUTE privilege traditionally granted by default for functions. Petr Jelinek
2009-10-02Ensure that a cursor has an immutable snapshot throughout its lifespan.Alvaro Herrera
The old coding was using a regular snapshot, referenced elsewhere, that was subject to having its command counter updated. Fix by creating a private copy of the snapshot exclusively for the cursor. Backpatch to 8.4, which is when the bug was introduced during the snapshot management rewrite.
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.
2009-09-26Extend the BKI infrastructure to allow system catalogs to be givenTom Lane
hand-assigned rowtype OIDs, even when they are not "bootstrapped" catalogs that have handmade type rows in pg_type.h. Give pg_database such an OID. Restore the availability of C macros for the rowtype OIDs of the bootstrapped catalogs. (These macros are now in the individual catalogs' .h files, though, not in pg_type.h.) This commit doesn't do anything especially useful by itself, but it's necessary infrastructure for reverting some ill-considered changes in relcache.c.
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.
2009-08-23Tweak ExecIndexEvalRuntimeKeys to forcibly detoast any toasted comparisonTom Lane
values before they get passed to the index access method. This avoids repeated detoastings that will otherwise ensue as the comparison value is examined by various index support functions. We have seen a couple of reports of cases where repeated detoastings result in an order-of-magnitude slowdown, so it seems worth adding a bit of extra logic to prevent this. I had previously proposed trying to avoid duplicate detoastings in general, but this fix takes care of what seems the most important case in practice with very little effort or risk. Back-patch to 8.4 so that the PostGIS folk won't have to wait a year to have this fix in a production release. (The issue exists further back, of course, but the code's diverged enough to make backpatching further a higher-risk action. Also it appears that the possible gains may be limited in prior releases because of different handling of lossy operators.)
2009-08-06Improve plpgsql's ability to cope with rowtypes containing dropped columns,Tom Lane
by supporting conversions in places that used to demand exact rowtype match. Since this issue is certain to come up elsewhere (in fact, already has, in ExecEvalConvertRowtype), factor out the support code into new core functions for tuple conversion. I chose to put these in a new source file since heaptuple.c is already overly long. Heavily revised version of a patch by Pavel Stehule.
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
2009-07-23Save a few cycles in EXPLAIN and related commands by not bothering to formTom Lane
a physical tuple in do_tup_output(). A virtual tuple is easier to set up and also easier for most tuple receivers to process. Per my comment on Robert Haas' recent patch in this code.
2009-07-23In a non-hashed Agg node, reset the "aggcontext" at group boundaries, insteadTom Lane
of individually pfree'ing pass-by-reference transition values. This should be at least as fast as the prior coding, and it has the major advantage of clearing out any working data an aggregate function may have stored in or underneath the aggcontext. This avoids memory leakage when an aggregate such as array_agg() is used in GROUP BY mode. Per report from Chris Spotts. Back-patch to 8.4. In principle the problem could arise in prior versions, but since they didn't have array_agg the issue seems not critical.
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.
2009-06-20Fix things so that array_agg_finalfn does not modify or free its inputTom Lane
ArrayBuildState, per trouble report from Merlin Moncure. By adopting this fix, we are essentially deciding that aggregate final-functions should not modify their inputs ever. Adjust documentation and comments to match that conclusion.
2009-06-17ExecAgg() failed to finish running out set-returning functions in the lastTom Lane
aggregated tuple of a run. Per report from Laurenz Albe. This is a new bug in 8.4, but only because prior versions rejected SRFs in an Agg plan node altogether.
2009-06-11Revisit AlterTableCreateToastTable's API once again, hoping to make it whatTom Lane
pg_migrator actually needs and not just a partial solution. We have to be able to specify the OID that the new toast table should be created with.
2009-06-11Fix things so that you can still do "select foo()" where foo is a SQLTom Lane
function returning setof record. This used to work, more or less accidentally, but I had broken it while extending the code to allow materialize-mode functions to be called in select lists. Add a regression test case so it doesn't get broken again. Per gripe from Greg Davidson.
2009-06-118.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian
provided by Andrew.
2009-06-09Fix xmlattribute escaping XML special characters twice (bug #4822).Peter Eisentraut
Author: Itagaki Takahiro <itagaki.takahiro@oss.ntt.co.jp>
2009-06-04Improve the recently-added support for properly pluralized error messagesTom Lane
by extending the ereport() API to cater for pluralization directly. This is better than the original method of calling ngettext outside the elog.c code because (1) it avoids double translation, which wastes cycles and in the worst case could give a wrong result; and (2) it avoids having to use a different coding method in PL code than in the core backend. The client-side uses of ngettext are not touched since neither of these concerns is very pressing in the client environment. Per my proposal of yesterday.
2009-05-07Add an option to AlterTableCreateToastTable() to allow its caller to forceTom Lane
a toast table to be built, even if the sum-of-column-widths calculation indicates one isn't needed. This is needed by pg_migrator because if the old table has a toast table, we have to migrate over the toast table since it might contain some live data, even though subsequent column drops could mean that no recently-added rows could require toasting.
2009-04-08XMLATTRIBUTES() should send the attribute values throughPeter Eisentraut
map_sql_value_to_xml_value() instead of directly through the data type output function. This is per SQL standard, and consistent with XMLELEMENT().
2009-04-05Make ExecInitExpr build the list of SubPlans found in a plan tree in orderTom Lane
of discovery, rather than reverse order. This doesn't matter functionally (I suppose the previous coding dates from the time when lcons was markedly cheaper than lappend). However now that EXPLAIN is labeling subplans with IDs that are based on order of creation, this may help produce a slightly less surprising printout.
2009-04-02Refactor ExecProject and associated routines so that fast-path code is usedTom Lane
for simple Var targetlist entries all the time, even when there are other entries that are not simple Vars. Also, ensure that we prefetch attributes (with slot_getsomeattrs) for all Vars in the targetlist, even those buried within expressions. In combination these changes seem to significantly reduce the runtime for cases where tlists are mostly but not exclusively Vars. Per my proposal of yesterday.
2009-04-02Revert DTrace patch from Robert LorBruce Momjian
2009-04-02Add support for additional DTrace probes.Bruce Momjian
Robert Lor
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.
2009-03-27Fix possible failures when a tuplestore switches from in-memory to on-diskTom Lane
mode while callers hold pointers to in-memory tuples. I reported this for the case of nodeWindowAgg's primary scan tuple, but inspection of the code shows that all of the calls in nodeWindowAgg and nodeCtescan are at risk. For the moment, fix it with a rather brute-force approach of copying whenever one of the at-risk callers requests a tuple. Later we might think of some sort of reference-count approach to reduce tuple copying.
2009-03-26Gettext plural supportPeter Eisentraut
In the backend, I changed only a handful of exemplary or important-looking instances to make use of the plural support; there is probably more work there. For the rest of the source, this should cover all relevant cases.
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.
2009-03-04Add new SQL:2008 error codes for invalid LIMIT and OFFSET values. RemovePeter Eisentraut
unused nonstandard error code that was perhaps intended for this but never used.
2009-02-08Ensure that INSERT ... SELECT into a table with OIDs never copies row OIDsTom Lane
from the source table. This could never happen anyway before 8.4 because the executor invariably applied a "junk filter" to rows due to be inserted; but now that we skip doing that when it's not necessary, the case can occur. Problem noted 2008-11-27 by KaiGai Kohei, though I misunderstood what he was on about at the time (the opacity of the patch he proposed didn't help).
2009-02-02Allow reloption names to have qualifiers, initially supporting a TOASTAlvaro Herrera
qualifier, and add support for this in pg_dump. This allows TOAST tables to have user-defined fillfactor, and will also enable us to move the autovacuum parameters to reloptions without taking away the possibility of setting values for TOAST tables.
2009-01-22Support column-level privileges, as required by SQL standard.Tom Lane
Stephen Frost, with help from KaiGai Kohei and others
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.
2009-01-12Tweak order of operations in BitmapHeapNext() to avoid the case of prefetchingTom Lane
the same page we are nanoseconds away from reading for real. There should be something left to do on the current page before we consider issuing a prefetch.
2009-01-12Implement prefetching via posix_fadvise() for bitmap index scans. A newTom Lane
GUC variable effective_io_concurrency controls how many concurrent block prefetch requests will be issued. (The best way to handle this for plain index scans is still under debate, so that part is not applied yet --- tgl) Greg Stark
2009-01-10Revise the TIDBitmap API to support multiple concurrent iterations over aTom Lane
bitmap. This is extracted from Greg Stark's posix_fadvise patch; it seems worth committing separately, since it's potentially useful independently of posix_fadvise.
2009-01-09Arrange for function default arguments to be processed properly in expressionsTom Lane
that are set up for execution with ExecPrepareExpr rather than going through the full planner process. By introducing an explicit notion of "expression planning", this patch also lays a bit of groundwork for maybe someday allowing sub-selects in standalone expressions.
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