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path: root/src/backend/executor/execQual.c
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2007-08-31Extend whole-row Var evaluation to cope with the case that the sub-planTom Lane
generating the tuples has resjunk output columns. This is not possible for simple table scans but can happen when evaluating a whole-row Var for a view. Per example from Patryk Kordylewski. The problem exists back to 8.0 but I'm not going to risk back-patching further than 8.2 because of the many changes in this area.
2007-02-06Remove typmod checking from the recent security-related patches. It turnsTom Lane
out that ExecEvalVar and friends don't necessarily have access to a tuple descriptor with correct typmod: it definitely can contain -1, and possibly might contain other values that are different from the Var's value. Arguably this should be cleaned up someday, but it's not a simple change, and in any case typmod discrepancies don't pose a security hazard. Per reports from numerous people :-( I'm not entirely sure whether the failure can occur in 8.0 --- the simple test cases reported so far don't trigger it there. But back-patch the change all the way anyway.
2007-02-02Repair failure to check that a table is still compatible with a previouslyTom Lane
made query plan. Use of ALTER COLUMN TYPE creates a hazard for cached query plans: they could contain Vars that claim a column has a different type than it now has. Fix this by checking during plan startup that Vars at relation scan level match the current relation tuple descriptor. Since at that point we already have at least AccessShareLock, we can be sure the column type will not change underneath us later in the query. However, since a backend's locks do not conflict against itself, there is still a hole for an attacker to exploit: he could try to execute ALTER COLUMN TYPE while a query is in progress in the current backend. Seal that hole by rejecting ALTER TABLE whenever the target relation is already open in the current backend. 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-2007-0556
2006-11-17Small message equalization fixPeter Eisentraut
2006-11-08Remove a 15-year old comment questioning behavior that is now well-Neil Conway
established: referencing an undefined parameter should result in an error, not NULL.
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.
2006-10-06Message style improvementsPeter Eisentraut
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-09-28Fix IS NULL and IS NOT NULL tests on row-valued expressions to conform toTom Lane
the SQL spec, viz IS NULL is true if all the row's fields are null, IS NOT NULL is true if all the row's fields are not null. The former coding got this right for a limited number of cases with IS NULL (ie, those where it could disassemble a ROW constructor at parse time), but was entirely wrong for IS NOT NULL. Per report from Teodor. I desisted from changing the behavior for arrays, since on closer inspection it's not clear that there's any support for that in the SQL spec. This probably needs more consideration.
2006-07-27Aggregate functions now support multiple input arguments. I also tookTom Lane
the opportunity to treat COUNT(*) as a zero-argument aggregate instead of the old hack that equated it to COUNT(1); this is materially cleaner (no more weird ANYOID cases) and ought to be at least a tiny bit faster. Original patch by Sergey Koposov; review, documentation, simple regression tests, pg_dump and psql support by moi.
2006-07-14Remove 576 references of include files that were not needed.Bruce Momjian
2006-06-16Fix problems with cached tuple descriptors disappearing while still in useTom Lane
by creating a reference-count mechanism, similar to what we did a long time ago for catcache entries. The back branches have an ugly solution involving lots of extra copies, but this way is more efficient. Reference counting is only applied to tupdescs that are actually in caches --- there seems no need to use it for tupdescs that are generated in the executor, since they'll go away during plan shutdown by virtue of being in the per-query memory context. Neil Conway and Tom Lane
2006-04-22Simplify ParamListInfo data structure to support only numbered parameters,Tom Lane
not named ones, and replace linear searches of the list with array indexing. The named-parameter support has been dead code for many years anyway, and recent profiling suggests that the searching was costing a noticeable amount of performance for complex queries.
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).
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
2005-12-28Implement SQL-compliant treatment of row comparisons for < <= > >= casesTom Lane
(previously we only did = and <> correctly). Also, allow row comparisons with any operators that are in btree opclasses, not only those with these specific names. This gets rid of a whole lot of indefensible assumptions about the behavior of particular operators based on their names ... though it's still true that IN and NOT IN expand to "= ANY". The patch adds a RowCompareExpr expression node type, and makes some changes in the representation of ANY/ALL/ROWCOMPARE SubLinks so that they can share code with RowCompareExpr. I have not yet done anything about making RowCompareExpr an indexable operator, but will look at that soon. initdb forced due to changes in stored rules.
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 :-(
2005-11-22Re-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.
2005-11-17Make SQL arrays support null elements. This commit fixes the core arrayTom Lane
functionality, but I still need to make another pass looking at places that incidentally use arrays (such as ACL manipulation) to make sure they are null-safe. Contrib needs work too. I have not changed the behaviors that are still under discussion about array comparison and what to do with lower bounds.
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.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-06-26Add Oracle-compatible GREATEST and LEAST functions. Pavel StehuleTom Lane
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.
2005-04-06Merge Resdom nodes into TargetEntry nodes to simplify code and save aTom Lane
few palloc's. I also chose to eliminate the restype and restypmod fields entirely, since they are redundant with information stored in the node's contained expression; re-examining the expression at need seems simpler and more reliable than trying to keep restype/restypmod up to date. initdb forced due to change in contents of stored rules.
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.
2005-03-22Use InitFunctionCallInfoData() macro instead of MemSet in performanceTom Lane
critical places in execQual. By Atsushi Ogawa; some minor cleanup by moi.
2005-03-16Revise TupleTableSlot code to avoid unnecessary construction and disassemblyTom Lane
of tuples when passing data up through multiple plan nodes. A slot can now hold either a normal "physical" HeapTuple, or a "virtual" tuple consisting of Datum/isnull arrays. Upper plan levels can usually just copy the Datum arrays, avoiding heap_formtuple() and possible subsequent nocachegetattr() calls to extract the data again. This work extends Atsushi Ogawa's earlier patch, which provided the key idea of adding Datum arrays to TupleTableSlots. (I believe however that something like this was foreseen way back in Berkeley days --- see the old comment on ExecProject.) A test case involving many levels of join of fairly wide tables (about 80 columns altogether) showed about 3x overall speedup, though simple queries will probably not be helped very much. I have also duplicated some code in heaptuple.c in order to provide versions of heap_formtuple and friends that use "bool" arrays to indicate null attributes, instead of the old convention of "char" arrays containing either 'n' or ' '. This provides a better match to the convention used by ExecEvalExpr. While I have not made a concerted effort to get rid of uses of the old routines, I think they should be deprecated and eventually removed.
2005-03-14Avoid O(N^2) overhead in repeated nocachegetattr calls when columns ofTom Lane
a tuple are being accessed via ExecEvalVar and the attcacheoff shortcut isn't usable (due to nulls and/or varlena columns). To do this, cache Datums extracted from a tuple in the associated TupleTableSlot. Also some code cleanup in and around the TupleTable handling. Atsushi Ogawa with some kibitzing by Tom Lane.
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 ...
2004-12-11Instead of supposing (wrongly, in the general case) that the rowtypeTom Lane
of an inheritance child table is binary-compatible with the rowtype of its parent, invent an expression node type that does the conversion correctly. Fixes the new bug exhibited by Kris Shannon as well as a lot of old bugs that would only show up when using multiple inheritance or after altering the parent table.
2004-09-22Adjust ExecMakeTableFunctionResult to produce a single all-nulls rowTom Lane
when a function that returns a single tuple (not a setof tuple) returns NULL. This seems to be the most consistent behavior. It would have taken a bit less code to make it return an empty table (zero rows) but ISTM a non-SETOF function ought always return exactly one row. Per bug report from Ivan-Sun1.
2004-08-29Pgindent run for 8.0.Bruce Momjian
2004-08-29Update copyright to 2004.Bruce Momjian
2004-08-17Standardize on the assumption that the arguments of a RowExpr correspondTom Lane
to the physical layout of the rowtype, ie, there are dummy arguments corresponding to any dropped columns in the rowtype. We formerly had a couple of places that did it this way and several others that did not. Fixes Gaetano Mendola's "cache lookup failed for type 0" bug of 5-Aug.
2004-08-02Allow DECLARE CURSOR to take parameters from the portal in which it isTom Lane
executed. Previously, the DECLARE would succeed but subsequent FETCHes would fail since the parameter values supplied to DECLARE were not propagated to the portal created for the cursor. In support of this, add type Oids to ParamListInfo entries, which seems like a good idea anyway since code that extracts a value can double-check that it got the type of value it was expecting. Oliver Jowett, with minor editorialization by Tom Lane.
2004-06-09Support assignment to subfields of composite columns in UPDATE and INSERT.Tom Lane
As a side effect, cause subscripts in INSERT targetlists to do something more or less sensible; previously we evaluated such subscripts and then effectively ignored them. Another side effect is that UPDATE-ing an element or slice of an array value that is NULL now produces a non-null result, namely an array containing just the assigned-to positions.
2004-06-05Tweak palloc/repalloc to allow zero bytes to be requested, as per recentTom Lane
proposal. Eliminate several dozen now-unnecessary hacks to avoid palloc(0). (It's likely there are more that I didn't find.)
2004-06-01Some more de-FastList-ification.Tom Lane
2004-05-30Use the new List API function names throughout the backend, and disable theNeil Conway
list compatibility API by default. While doing this, I decided to keep the llast() macro around and introduce llast_int() and llast_oid() variants.
2004-05-26Reimplement the linked list data structure used throughout the backend.Neil Conway
In the past, we used a 'Lispy' linked list implementation: a "list" was merely a pointer to the head node of the list. The problem with that design is that it makes lappend() and length() linear time. This patch fixes that problem (and others) by maintaining a count of the list length and a pointer to the tail node along with each head node pointer. A "list" is now a pointer to a structure containing some meta-data about the list; the head and tail pointers in that structure refer to ListCell structures that maintain the actual linked list of nodes. The function names of the list API have also been changed to, I hope, be more logically consistent. By default, the old function names are still available; they will be disabled-by-default once the rest of the tree has been updated to use the new API names.
2004-05-10Promote row expressions to full-fledged citizens of the expression syntax,Tom Lane
rather than allowing them only in a few special cases as before. In particular you can now pass a ROW() construct to a function that accepts a rowtype parameter. Internal generation of RowExprs fixes a number of corner cases that used to not work very well, such as referencing the whole-row result of a JOIN or subquery. This represents a further step in the work I started a month or so back to make rowtype values into first-class citizens.
2004-04-01Replace TupleTableSlot convention for whole-row variables and functionTom Lane
results with tuples as ordinary varlena Datums. This commit does not in itself do much for us, except eliminate the horrid memory leak associated with evaluation of whole-row variables. However, it lays the groundwork for allowing composite types as table columns, and perhaps some other useful features as well. Per my proposal of a few days ago.
2004-03-24Replace max_expr_depth parameter with a max_stack_depth parameter thatTom Lane
is measured in kilobytes and checked against actual physical execution stack depth, as per my proposal of 30-Dec. This gives us a fairly bulletproof defense against crashing due to runaway recursive functions.
2004-03-17Reimplement CASE val WHEN compval1 THEN ... WHEN compval2 THEN ... ENDTom Lane
so that the 'val' is computed only once, per recent discussion. The speedup is not much when 'val' is just a simple variable, but could be significant for larger expressions. More importantly this avoids issues with multiple evaluations of a volatile 'val', and it allows the CASE expression to be reverse-listed in its original form by ruleutils.c.
2004-03-17Replace the switching function ExecEvalExpr() with a macro that jumpsTom Lane
directly to the appropriate per-node execution function, using a function pointer stored by ExecInitExpr. This speeds things up by eliminating one level of function call. The function-pointer technique also enables further small improvements such as only making one-time tests once (and then changing the function pointer). Overall this seems to gain about 10% on evaluation of simple expressions, which isn't earthshaking but seems a worthwhile gain for a relatively small hack. Per recent discussion on pghackers.
2004-02-03Rename SortMem and VacuumMem to work_mem and maintenance_work_mem.Tom Lane
Make btree index creation and initial validation of foreign-key constraints use maintenance_work_mem rather than work_mem as their memory limit. Add some code to guc.c to allow these variables to be referenced by their old names in SHOW and SET commands, for backwards compatibility.
2004-01-07More janitorial work: remove the explicit casting of NULL literals to aNeil Conway
pointer type when it is not necessary to do so. For future reference, casting NULL to a pointer type is only necessary when (a) invoking a function AND either (b) the function has no prototype OR (c) the function is a varargs function.