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path: root/src/backend/commands/trigger.c
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2008-12-13Fix failure to ensure that a snapshot is available to datatype input functionsTom Lane
when they are invoked by the parser. We had been setting up a snapshot at plan time but really it needs to be done earlier, before parse analysis. Per report from Dmitry Koterov. Also fix two related problems discovered while poking at this one: exec_bind_message called datatype input functions without establishing a snapshot, and SET CONSTRAINTS IMMEDIATE could call trigger functions without establishing a snapshot. Backpatch to 8.2. The underlying problem goes much further back, but it is masked in 8.1 and before because we didn't attempt to invoke domain check constraints within datatype input. It would only be exposed if a C-language datatype input function used the snapshot; which evidently none do, or we'd have heard complaints sooner. Since this code has changed a lot over time, a back-patch is hardly risk-free, and so I'm disinclined to patch further than absolutely necessary.
2008-10-25Fix an old bug in after-trigger handling: AfterTriggerEndQuery took theTom Lane
address of afterTriggers->query_stack[afterTriggers->query_depth] and hung onto it through all its firings of triggers. However, if a trigger causes sufficiently many nested query executions, query_stack will get repalloc'd bigger, leaving AfterTriggerEndQuery --- and hence afterTriggerInvokeEvents --- using a stale pointer. So far as I can find, the only consequence of this error is to stomp on a couple of words of already-freed memory; which would lead to a failure only if that chunk had already gotten re-allocated for something else. So it's hard to exhibit a simple failure case, but this is surely a bug. I noticed this while working on my recent patch to reduce pending-trigger space usage. The present patch is mighty ugly, because it requires making afterTriggerInvokeEvents know about all the possible event lists it might get called on. Fortunately, this is only needed in back branches because CVS HEAD avoids the problem in a different way: afterTriggerInvokeEvents only touches the passed AfterTriggerEventList pointer once at startup. Back branches are stable enough that wiring in knowledge of all possible call usages doesn't seem like a killer problem. Back-patch to 8.0. 7.4's trigger code is completely different and doesn't seem to have the problem (it doesn't even use repalloc).
2008-05-27Back-patch the 8.3 fix that prohibits TRUNCATE, CLUSTER, and REINDEX when theTom Lane
current transaction has any open references to the target relation or index (implying it has an active query using the relation). Also back-patch the 8.2 fix that prohibits TRUNCATE and CLUSTER when there are pending AFTER-trigger events. Per suggestion from Heikki.
2007-08-15Repair problems occurring when multiple RI updates have to be done to the sameTom Lane
row within one query: we were firing check triggers before all the updates were done, leading to bogus failures. Fix by making the triggers queued by an RI update go at the end of the outer query's trigger event list, thereby effectively making the processing "breadth-first". This was indeed how it worked pre-8.0, so the bug does not occur in the 7.x branches. Per report from Pavel Stehule.
2007-07-17Fix incorrect optimization of foreign-key checks. When an UPDATE on theTom Lane
referencing table does not change the tuple's FK column(s), we don't bother to check the PK table since the constraint was presumably already valid. However, the check is still necessary if the tuple was inserted by our own transaction, since in that case the INSERT trigger will conclude it need not make the check (since its version of the tuple has been deleted). We got this right for simple cases, but not when the insert and update are in different subtransactions of the current top-level transaction; in such cases the FK check would never be made at all. (Hence, problem dates back to 8.0 when subtransactions were added --- it's actually the subtransaction version of a bug fixed in 7.3.5.) Fix, and add regression test cases. Report and fix by Affan Salman.
2007-07-01Avoid memory leakage when a series of subtransactions invoke AFTER triggersTom Lane
that are fired at end-of-statement (as is the normal case for foreign keys, for example). In this situation the per-subxact deferred trigger context is always empty when subtransaction exit is reached; so we could free it, but were not doing so, leading to an intratransaction leak of 8K or more per subtransaction. Per off-list example from Viatcheslav Kalinin subsequent to bug #3418 (his original bug report omitted a foreign key constraint needed to cause this leak). Back-patch to 8.2; prior versions were not using per-subxact contexts for deferred triggers, so did not have this leak.
2007-01-25Properly detoast access to bytea field pg_trigger.tgargs. Old codeBruce Momjian
might cause server crash. Backpatch to 8.2.X.
2006-11-23Several changes to reduce the probability of running out of memory duringTom Lane
AbortTransaction, which would lead to recursion and eventual PANIC exit as illustrated in recent report from Jeff Davis. First, in xact.c create a special dedicated memory context for AbortTransaction to run in. This solves the problem as long as AbortTransaction doesn't need more than 32K (or whatever other size we create the context with). But in corner cases it might. Second, in trigger.c arrange to keep pending after-trigger event records in separate contexts that can be freed near the beginning of AbortTransaction, rather than having them persist until CleanupTransaction as before. Third, in portalmem.c arrange to free executor state data earlier as well. These two changes should result in backing off the out-of-memory condition before AbortTransaction needs any significant amount of memory, at least in typical cases such as memory overrun due to too many trigger events or too big an executor hash table. And all the same for subtransaction abort too, of course.
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-10-03Make some sentences consistent with similar ones.Bruce Momjian
Euler Taveira de Oliveira
2006-09-04Disallow TRUNCATE when there are any pending after-trigger events forTom Lane
the target relation(s). There might be some cases where we could discard the pending event instead, but for the moment a conservative approach seems sufficient. Per report from Markus Schiltknecht and subsequent discussion.
2006-08-03Fix AfterTriggerExecute() to pass tg_trigtuple and tg_newtuple as NULLsTom Lane
rather than pointers to garbage, when calling AFTER STATEMENT triggers. Michael Fuhr
2006-07-31Change the relation_open protocol so that we obtain lock on a relationTom Lane
(table or index) before trying to open its relcache entry. This fixes race conditions in which someone else commits a change to the relation's catalog entries while we are in process of doing relcache load. Problems of that ilk have been reported sporadically for years, but it was not really practical to fix until recently --- for instance, the recent addition of WAL-log support for in-place updates helped. Along the way, remove pg_am.amconcurrent: all AMs are now expected to support concurrent update.
2006-07-14Remove 576 references of include files that were not needed.Bruce Momjian
2006-06-16DROP ... IF EXISTS for the following cases:Andrew Dunstan
language, tablespace, trigger, rule, opclass, function, aggregate. operator, and cast.
2006-05-30Make EXPLAIN sampling smarter, to avoid excessive sampling delay.Bruce Momjian
Martijn van Oosterhout
2006-04-27Use schema search path to find the first matching contraint name for SETBruce Momjian
CONSTRAINT, rather than affecting all constraints in all schemas (which is what we used to do). Also allow schema specifications. Kris Jurka
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
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.
2006-01-05Make all command-line options of postmaster and postgres the same. SeePeter Eisentraut
http://archives.postgresql.org/pgsql-hackers/2006-01/msg00151.php for the complete plan.
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.
2005-11-20Remove the t_datamcxt field of HeapTupleData. This was introduced forTom Lane
the convenience of tuptoaster.c and is no longer needed, so may as well get rid of some small amount of overhead.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-08-24Fix ExecBRDeleteTriggers so that deletion is not suppressed when deleteTom Lane
triggers exist but are all disabled. Problem noted by Gavin Sherry in original discussion of enable/disable trigger patch, but was never addressed.
2005-08-23Add ALTER TABLE ENABLE/DISABLE TRIGGER commands. Change pg_dump toTom Lane
use these instead of its previous hack of changing pg_class.reltriggers. Documentation is lacking, will add that later. Patch by Satoshi Nagayasu, review and some extra work by Tom Lane.
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.
2005-08-12Solve the problem of OID collisions by probing for duplicate OIDsTom Lane
whenever we generate a new OID. This prevents occasional duplicate-OID errors that can otherwise occur once the OID counter has wrapped around. Duplicate relfilenode values are also checked for when creating new physical files. Per my recent proposal.
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.
2005-05-30When enqueueing after-row triggers for updates of a table with a foreignNeil Conway
key, compare the new and old row versions. If the foreign key column has not changed, we needn't enqueue the trigger, since the update cannot violate the foreign key. This optimization was previously applied in the RI trigger function, but it is more efficient to avoid firing the trigger altogether. Per recent discussion on pgsql-hackers. Also add a regression test for some unintuitive foreign key behavior, and refactor some code that deals with the OIDs of the various RI trigger functions.
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.
2005-04-28Implement 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.
2005-04-14Completion of project to use fixed OIDs for all system catalogs andTom Lane
indexes. Replace all heap_openr and index_openr calls by heap_open and index_open. Remove runtime lookups of catalog OID numbers in various places. Remove relcache's support for looking up system catalogs by name. Bulky but mostly very boring patch ...
2005-04-14First phase of project to use fixed OIDs for all system catalogs andTom Lane
indexes. Extend the macros in include/catalog/*.h to carry the info about hand-assigned OIDs, and adjust the genbki script and bootstrap code to make the relations actually get those OIDs. Remove the small number of RelOid_pg_foo macros that we had in favor of a complete set named like the catname.h and indexing.h macros. Next phase will get rid of internal use of names for looking up catalogs and indexes; but this completes the changes forcing an initdb, so it looks like a good place to commit. Along the way, I made the shared relations (pg_database etc) not be 'bootstrap' relations any more, so as to reduce the number of hardwired entries and simplify changing those relations in future. I'm not sure whether they ever really needed to be handled as bootstrap relations, but it seems to work fine to not do so now.
2005-04-11Fix interaction between materializing holdable cursors and firingTom Lane
deferred triggers: either one can create more work for the other, so we have to loop till it's all gone. Per example from andrew@supernews. Add a regression test to help spot trouble in this area in future.
2005-03-29Officially decouple FUNC_MAX_ARGS from INDEX_MAX_KEYS, and set theTom Lane
former to 100 by default. Clean up some of the less necessary dependencies on FUNC_MAX_ARGS; however, the biggie (FunctionCallInfoData) remains.
2005-03-29Convert oidvector and int2vector into variable-length arrays. ThisTom Lane
change saves a great deal of space in pg_proc and its primary index, and it eliminates the former requirement that INDEX_MAX_KEYS and FUNC_MAX_ARGS have the same value. INDEX_MAX_KEYS is still embedded in the on-disk representation (because it affects index tuple header size), but FUNC_MAX_ARGS is not. I believe it would now be possible to increase FUNC_MAX_ARGS at little cost, but haven't experimented yet. There are still a lot of vestigial references to FUNC_MAX_ARGS, which I will clean up in a separate pass. However, getting rid of it altogether would require changing the FunctionCallInfoData struct, and I'm not sure I want to buy into that.
2005-03-25Improve EXPLAIN ANALYZE to show the time spent in each trigger whenTom Lane
executing a statement that fires triggers. Formerly this time was included in "Total runtime" but not otherwise accounted for. As a side benefit, we avoid re-opening relations when firing non-deferred AFTER triggers, because the trigger code can re-use the main executor's ResultRelInfo data structure.
2005-03-24Revert changes to CREATE TRIGGER and ALTER TABLE ADD FOREIGN KEY locking,Neil Conway
per request from Tom.
2005-03-23Adjust CREATE TRIGGER and ALTER TABLE ... ADD FOREIGN KEY to acquireNeil Conway
ExclusiveLock rather than AccessExclusiveLock. This will allow concurrent SELECT queries to proceed on the table. Per discussion with Andrew at SuperNews.
2005-03-20Change the return value of HeapTupleSatisfiesUpdate() to be an enum,Neil Conway
rather than an integer, and fix the associated fallout. From Alvaro Herrera.
2004-12-31Tag appropriate files for rc3PostgreSQL Daemon
Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
2004-12-06ActiveSnapshot must be set to something valid while running deferredTom Lane
triggers during COMMIT. Per trouble report from Frank van Vugt.
2004-11-14There is no need for ReadBuffer() call sites to check that the returnedNeil Conway
buffer is valid, as ReadBuffer() will elog on error. Most of the call sites of ReadBuffer() got this right, but this patch fixes those call sites that did not.
2004-10-30I found a corner case in which it is possible for RI_FKey_check's callTom Lane
of HeapTupleSatisfiesItself() to trigger a hint-bit update on the tuple: if the row was updated or deleted by a subtransaction of my own transaction that was later rolled back. This cannot occur in pre-8.0 of course, so the hint-bit patch applied a couple weeks ago is OK for existing releases. But for 8.0 it seems we had better fix things so that RI_FKey_check can pass the correct buffer number to HeapTupleSatisfiesItself. Accordingly, add fields to the TriggerData struct to carry the buffer ID(s) for the old and new tuple(s). There are other possible solutions but this one seems cleanest; it will allow other AFTER-trigger functions to safely do tqual.c calls if they want to. Put new fields at end of struct so that there is no API breakage.
2004-10-21Disallow referential integrity actions from being deferred; only theTom Lane
NO ACTION check is deferrable. This seems to be a closer approximation to what the SQL spec says than what we were doing before, and it prevents some anomalous behaviors that are possible now that triggers can fire during the execution of PL functions. Stephan Szabo.
2004-09-10Fire non-deferred AFTER triggers immediately upon query completion,Tom Lane
rather than when returning to the idle loop. This makes no particular difference for interactively-issued queries, but it makes a big difference for queries issued within functions: trigger execution now occurs before the calling function is allowed to proceed. This responds to numerous complaints about nonintuitive behavior of foreign key checking, such as http://archives.postgresql.org/pgsql-bugs/2004-09/msg00020.php, and appears to be required by the SQL99 spec. Also take the opportunity to simplify the data structures used for the pending-trigger list, rename them for more clarity, and squeeze out a bit of space.
2004-09-08Minor efficiency improvements in keeping track of trigger deferredTom Lane
status. In particular, I see no reason for deferredTriggerCheckState to make an explicit entry to note that a particular trigger has its default state --- that just clutters a list that should normally be empty or very short. I have plans to revise this module much more heavily, but this is a simple separable improvement.
2004-09-07Fix a couple of small errors in trigger-list management, as per recentTom Lane
discussion.
2004-09-06Fix a number of places where brittle data structures or overly strongTom Lane
Asserts would lead to a server core dump if an error occurred while trying to abort a failed subtransaction (thereby leading to re-execution of whatever parts of AbortSubTransaction had already run). This of course does not prevent such an error from creating an infinite loop, but at least we don't make the situation worse. Responds to an open item on the subtransactions to-do list.
2004-08-29Pgindent run for 8.0.Bruce Momjian