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2007-02-02Repair insufficiently careful type checking for SQL-language functions:Tom Lane
we should check that the function code returns the claimed result datatype every time we parse the function for execution. Formerly, for simple scalar result types we assumed the creation-time check was sufficient, but this fails if the function selects from a table that's been redefined since then, and even more obviously fails if check_function_bodies had been OFF. This is a significant security hole: not only can one trivially crash the backend, but with appropriate misuse of pass-by-reference datatypes it is possible to read out arbitrary locations in the server process's memory, which could allow retrieving database content the user should not be able to see. Our thanks to Jeff Trout for the initial report. Security: CVE-2007-0555
2007-01-24Relax an Assert() that has been found to be too strict in some situationsTom Lane
involving unions of types having typmods. Variants of the failure are known to occur in 8.1 and up; not sure if it's possible in 8.0 and 7.4, but since the code exists that far back, I'll just patch 'em all. Per report from Brian Hurt.
2006-12-26Repair bug #2839: the various ExecReScan functions need to resetTom Lane
ps_TupFromTlist in plan nodes that make use of it. This was being done correctly in join nodes and Result nodes but not in any relation-scan nodes. Bug would lead to bogus results if a set-returning function appeared in the targetlist of a subquery that could be rescanned after partial execution, for example a subquery within EXISTS(). Bug has been around forever :-( ... surprising it wasn't reported before.
2006-11-06Repair bug #2694 concerning an ARRAY[] construct whose inputs are emptyTom Lane
sub-arrays. Per discussion, if all inputs are empty arrays then result must be an empty array too, whereas a mix of empty and nonempty arrays should (and already did) draw an error. In the back branches, the construct was strict: any NULL input immediately yielded a NULL output; so I left that behavior alone. HEAD was simply ignoring NULL sub-arrays, which doesn't seem very sensible. For lack of a better idea it now treats NULL sub-arrays the same as empty ones.
2006-10-12Fix mishandling of after-trigger state when a SQL function returns multipleTom Lane
rows --- if the surrounding query queued any trigger events between the rows, the events would be fired at the wrong time, leading to bizarre behavior. Per report from Merlin Moncure. This is a simple patch that should solve the problem fully in the back branches, but in HEAD we also need to consider the possibility of queries with RETURNING clauses. Will look into a fix for that separately.
2006-04-26Fix SELECT INTO and CREATE TABLE AS to create tables in the defaultBruce Momjian
tablespace, not the base directory. Kris Jurka
2006-03-17Fix bug introduced into mergejoin logic by performance improvement patch ofTom Lane
2005-05-13. When we find that a new inner tuple can't possibly match any outer tuple (because it contains a NULL), we can't immediately skip the tuple when we are in NEXTINNER state. Doing so can lead to emitting multiple copies of the tuple in FillInner mode, because we may rescan the tuple after returning to a previous marked tuple. Instead, proceed to NEXTOUTER state the same as we used to do. After we've found that there's no need to return to the marked position, we can go to SKIPINNER_ADVANCE state instead of SKIP_TEST when the inner tuple is unmatchable; this preserves the performance improvement. Per bug report from Bruce. I also made a couple of cosmetic code rearrangements and added a regression test for the problem.
2006-03-10Add a CHECK_FOR_INTERRUPTS() to the loop in ExecMakeTableFunctionResult.Tom Lane
Otherwise you can't cancel queries like select ... from generate_series(1,1000000).
2006-01-12Repair "Halloween problem" in EvalPlanQual: a tuple that's been inserted byTom Lane
our own command (or more generally, xmin = our xact and cmin >= current command ID) should not be seen as good. Else we may try to update rows we already updated. This error was inserted last August while fixing the even bigger problem that the old coding wouldn't see *any* tuples inserted by our own transaction as good. Per report from Euler Taveira de Oliveira.
2005-12-14Fix problem with whole-row Vars referencing sub-select outputs, perTom Lane
example from Jim Dew. Add some simple regression tests, since this is an area we seem to break regularly :-(
2005-12-02Rearrange code in ExecInitBitmapHeapScan so that we don't initialize theTom Lane
child plan nodes until we have acquired lock on the relation to scan. The relative order of initialization of plan nodes isn't real important in other cases, but it's critical here because one is supposed to lock a relation before its indexes, not vice versa. The original coding was at least vulnerable to deadlock against DROP INDEX, and perhaps worse things.
2005-11-28Tweak hash join code to use an additional heuristic for deciding whetherTom Lane
it's worth probing the outer relation for emptiness before building the hash table. To wit, if we're rescanning a join previously performed, remember whether we found it nonempty the previous time, and don't bother with the probe if it was nonempty. This buys back the performance lost in examples like Mario Weilguni's.
2005-11-28Recent changes to allow hash join to exit early given empty input fromTom Lane
one child or the other had a problem: they did not leave the node in a state that ExecReScanHashJoin would understand. In particular it would tend to fail to reset the child plans when needed. Per report from Mario Weilguni.
2005-11-23Get rid of ExecAssignResultTypeFromOuterPlan() and make all plan node typesTom Lane
generate their output tuple descriptors from their target lists (ie, using ExecAssignResultTypeFromTL()). We long ago fixed things so that all node types have minimally valid tlists, so there's no longer any good reason to have two different ways of doing it. This change is needed to fix bug reported by Hayden James: the fix of 2005-11-03 to emit the correct column names after optimizing away a SubqueryScan node didn't work if the new top-level plan node used ExecAssignResultTypeFromOuterPlan to generate its tupdesc, since the next plan node down won't have the correct column labels.
2005-11-22Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian
comment line where output as too long, and update typedefs for /lib directory. Also fix case where identifiers were used as variable names in the backend, but as typedefs in ecpg (favor the backend for indenting). Backpatch to 8.1.X.
2005-11-20Modify tuptoaster's API so that it does not try to modify the passedTom Lane
tuple in-place, but instead passes back an all-new tuple structure if any changes are needed. This is a much cleaner and more robust solution for the bug discovered by Alexey Beschiokov; accordingly, revert the quick hack I installed yesterday. With this change, HeapTupleData.t_datamcxt is no longer needed; will remove it in a separate commit in HEAD only.
2005-11-19Stopgap solution for problem reported by Alexey Beschiokov: afterTom Lane
doing heap_insert or heap_update, wipe out any extracted fields in the TupleTableSlot containing the tuple, because they might not be valid anymore if tuptoaster.c changed the tuple. Safe because slot must be in the materialized state, but mighty ugly --- find a better answer!
2005-11-14Prevent ExecInsert() and ExecUpdate() from scribbling on the result tupleTom Lane
slot of the topmost plan node when a trigger returns a modified tuple. These appear to be the only places where a plan node's caller did not treat the result slot as read-only, which is an assumption that nodeUnique makes as of 8.1. Fixes trigger-vs-DISTINCT bug reported by Frank van Vugt.
2005-11-03Rename the members of CommandDest enum so they don't collide with other uses ofAlvaro Herrera
those names. (Debug and None were pretty bad names anyway.) I hope I catched all uses of the names in comments too.
2005-10-19Better solution to the problem of labeling whole-row Datums that areTom Lane
generated from subquery outputs: use the type info stored in the Var itself. To avoid making ExecEvalVar and slot_getattr more complex and slower, I split out the whole-row case into a separate ExecEval routine.
2005-10-19Ensure that the Datum generated from a whole-row Var contains validTom Lane
type ID information even when it's a record type. This is needed to handle whole-row Vars referencing subquery outputs. Per example from Richard Huxton.
2005-10-18A few trivial code cleanups motivated by reading warnings generatedTom Lane
by a recent HP C compiler. Mostly, get rid of useless local variables that are assigned to but never used.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-10-06Revise pgstats stuff to fix the problems with not counting accessesTom Lane
generated by bitmap index scans. Along the way, simplify and speed up the code for counting sequential and index scans; it was both confusing and inefficient to be taking care of that in the per-tuple loops, IMHO. initdb forced because of internal changes in pg_stat view definitions.
2005-10-01_SPI_execute_plan failed to return result tuple table to caller inTom Lane
the ProcessUtility case, resulting in an intratransaction memory leak if a utility command actually did return any tuples, as reported by Dmitry Karasik. Fix this and also make the behavior more consistent for cases involving nested SPI operations and multiple query trees, by ensuring that we store the state locally until it is ready to be returned to the caller.
2005-09-25The original patch to avoid building a hash join's hashtable when theTom Lane
outer relation is empty did not work, per test case from Patrick Welche. It tried to use nodeHashjoin.c's high-level mechanisms for fetching an outer-relation tuple, but that code expected the hash table to be filled already. As patched, the code failed in corner cases such as having no outer-relation tuples for the first hash batch. Revert and rewrite.
2005-09-22Remove some dead code.Tom Lane
2005-08-28Tweak nodeBitmapAnd to stop evaluating sub-plan scans if it finds it'sTom Lane
got an empty bitmap after any step; the remaining subplans can no longer affect the result. Per a suggestion from Ilia Kantor.
2005-08-26Arrange for indexes and toast tables to inherit their ownership fromTom Lane
the parent table, even if the command that creates them is executed by someone else (such as a superuser or a member of the owning role). Per gripe from Michael Fuhr.
2005-08-20Repair problems with VACUUM destroying t_ctid chains too soon, and withTom Lane
insufficient paranoia in code that follows t_ctid links. (We must do both because even with VACUUM doing it properly, the intermediate state with a dangling t_ctid link is visible concurrently during lazy VACUUM, and could be seen afterwards if either type of VACUUM crashes partway through.) Also try to improve documentation about what's going on. Patch is a bit bulky because passing the XMAX information around required changing the APIs of some low-level heapam.c routines, but it's not conceptually very complicated. Per trouble report from Teodor and subsequent analysis. This needs to be back-patched, but I'll do that after 8.1 beta is out.
2005-08-18Update some obsolete comments --- code is using t_self now, not t_ctid.Tom Lane
2005-08-01Add NOWAIT option to SELECT FOR UPDATE/SHARE.Tom Lane
Original patch by Hans-Juergen Schoenig, revisions by Karel Zak and Tom Lane.
2005-06-28Replace pg_shadow and pg_group by new role-capable catalogs pg_authidTom Lane
and pg_auth_members. There are still many loose ends to finish in this patch (no documentation, no regression tests, no pg_dump support for instance). But I'm going to commit it now anyway so that Alvaro can make some progress on shared dependencies. The catalog changes should be pretty much done.
2005-06-26Add Oracle-compatible GREATEST and LEAST functions. Pavel StehuleTom Lane
2005-06-20Avoid WAL-logging individual tuple insertions during CREATE TABLE ASTom Lane
(a/k/a SELECT INTO). Instead, flush and fsync the whole relation before committing. We do still need the WAL log when PITR is active, however. Simon Riggs and Tom Lane.
2005-06-15Change the implementation of hash join to attempt to avoid unnecessaryNeil Conway
work if either of the join relations are empty. The logic is: (1) if the inner relation's startup cost is less than the outer relation's startup cost and this is not an outer join, read a single tuple from the inner relation via ExecHash() - if NULL, we're done (2) read a single tuple from the outer relation - if NULL, we're done (3) build the hash table on the inner relation - if hash table is empty and this is not an outer join, we're done (4) otherwise, do hash join as usual The implementation uses the new MultiExecProcNode API, per a suggestion from Tom: invoking ExecHash() now produces the first tuple from the Hash node's child node, whereas MultiExecHash() builds the hash table. I had to put in a bit of a kludge to get the row count returned for EXPLAIN ANALYZE to be correct: since ExecHash() is invoked to return a tuple, and then MultiExecHash() is invoked, we would return one too many tuples to EXPLAIN ANALYZE. I hacked around this by just manually detecting this situation and subtracting 1 from the EXPLAIN ANALYZE row count.
2005-06-09Make SPI set SPI_processed for CREATE TABLE AS / SELECT INTO commands;Tom Lane
this in turn causes CREATE TABLE AS in plpgsql to set ROW_COUNT. This is how it behaved before 7.4; I had unintentionally changed the behavior in a bit of sloppy micro-optimization.
2005-05-29Modify hash_search() API to prevent future occurrences of the errorTom Lane
spotted by Qingqing Zhou. The HASH_ENTER action now automatically fails with elog(ERROR) on out-of-memory --- which incidentally lets us eliminate duplicate error checks in quite a bunch of places. If you really need the old return-NULL-on-out-of-memory behavior, you can ask for HASH_ENTER_NULL. But there is now an Assert in that path checking that you aren't hoping to get that behavior in a palloc-based hash table. Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions, which were not being used anywhere anymore, and were surely too ugly and unsafe to want to see revived again.
2005-05-22Teach the planner to remove SubqueryScan nodes from the plan if theyTom Lane
aren't doing anything useful (ie, neither selection nor projection). Also, extend to SubqueryScan the hacks already in place to avoid unnecessary ExecProject calls when the result would just be the same tuple the subquery already delivered. This saves some overhead in UNION and other set operations, as well as avoiding overhead for unflatten-able subqueries. Per example from Sokolov Yura.
2005-05-15Fix latent bug in ExecSeqRestrPos: it leaves the plan node's result slotTom Lane
in an inconsistent state. (This is only latent because in reality ExecSeqRestrPos is dead code at the moment ... but someday maybe it won't be.) Add some comments about what the API for plan node mark/restore actually is, because it's not immediately obvious.
2005-05-14Minor refactoring to eliminate duplicate code and make startup aTom Lane
tad faster.
2005-05-13Revise nodeMergejoin in light of example provided by Guillaume Smet.Tom Lane
When one side of the join has a NULL, we don't want to uselessly try to match it against every remaining tuple of the other side. While at it, rewrite the comparison machinery to avoid multiple evaluations of the left and right input expressions and to use a btree comparator where available, instead of double operator calls. Also revise the state machine to eliminate redundant comparisons and hopefully make it more readable too.
2005-05-12Remove some unnecessary code: since ExecMakeFunctionResultNoSets does notTom Lane
want to handle set inputs, it should just pass NULL for isDone, not make its own failure check.
2005-05-09Add some defenses against functions declared to return set that don'tTom Lane
actually follow the protocol; per example from Kris Jurka.
2005-05-06For some reason access/tupmacs.h has been #including utils/memutils.h,Tom Lane
which is neither needed by nor related to that header. Remove the bogus inclusion and instead include the header in those C files that actually need it. Also fix unnecessary inclusions and bad inclusion order in tsearch2 files.
2005-05-05Adjust nodeBitmapIndexscan to keep the target index opened from planTom Lane
startup to end, rather than re-opening it in each MultiExecBitmapIndexScan call. I had foolishly thought that opening/closing wouldn't be much more expensive than a rescan call, but that was sheer brain fade. This seems to fix about half of the performance lossage reported by Sergey Koposov. I'm still not sure where the other half went.
2005-05-02Change SPI functions to use a `long' when specifying the number of tuplesNeil Conway
to produce when running the executor. This is consistent with the internal executor APIs (such as ExecutorRun), which also use a long for this purpose. It also allows FETCH_ALL to be passed -- since FETCH_ALL is defined as LONG_MAX, this wouldn't have worked on platforms where int and long are of different sizes. Per report from Tzahi Fadida.
2005-05-01Change CREATE TYPE to require datatype output and send functions to haveTom Lane
only one argument. (Per recent discussion, the option to accept multiple arguments is pretty useless for user-defined types, and would be a likely source of security holes if it was used.) Simplify call sites of output/send functions to not bother passing more than one argument.
2005-04-28Implement sharable row-level locks, and use them for foreign key referencesTom Lane
to eliminate unnecessary deadlocks. This commit adds SELECT ... FOR SHARE paralleling SELECT ... FOR UPDATE. The implementation uses a new SLRU data structure (managed much like pg_subtrans) to represent multiple- transaction-ID sets. When more than one transaction is holding a shared lock on a particular row, we create a MultiXactId representing that set of transactions and store its ID in the row's XMAX. This scheme allows an effectively unlimited number of row locks, just as we did before, while not costing any extra overhead except when a shared lock actually has to be shared. Still TODO: use the regular lock manager to control the grant order when multiple backends are waiting for a row lock. Alvaro Herrera and Tom Lane.
2005-04-25Remove support for OR'd indexscans internal to a single IndexScan planTom Lane
node, as this behavior is now better done as a bitmap OR indexscan. This allows considerable simplification in nodeIndexscan.c itself as well as several planner modules concerned with indexscan plan generation. Also we can improve the sharing of code between regular and bitmap indexscans, since they are now working with nigh-identical Plan nodes.