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path: root/src/backend/executor/nodeSubplan.c
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2008-05-12Restructure some header files a bit, in particular heapam.h, by removing someAlvaro Herrera
unnecessary #include lines in it. Also, move some tuple routine prototypes and macros to htup.h, which allows removal of heapam.h inclusion from some .c files. For this to work, a new header file access/sysattr.h needed to be created, initially containing attribute numbers of system columns, for pg_dump usage. While at it, make contrib ltree, intarray and hstore header files more consistent with our header style.
2008-01-01Update copyrights in source tree to 2008.Bruce Momjian
2007-11-15pgindent run for 8.3.Bruce Momjian
2007-08-26Make ARRAY(SELECT ...) return an empty array, rather than a NULL, when theTom Lane
sub-select returns zero rows. Per complaint from Jens Schicke. Since this is more in the nature of a definition change than a bug, not back-patched.
2007-05-17Fix parameter recalculation for Limit nodes: during a ReScan call we mustTom Lane
recompute the limit/offset immediately, so that the updated values are available when the child's ReScan function is invoked. Add a regression test for this, too. Bug is new in HEAD (due to the bounded-sorting patch) so no need for back-patch. I did not do anything about merging this signaling with chgParam processing, but if we were to do that we'd still need to compute the updated values at this point rather than during the first ProcNode call. Per observation and test case from Greg Stark, though I didn't use his patch.
2007-04-26Fix dynahash.c to suppress hash bucket splits while a hash_seq_search() scanTom Lane
is in progress on the same hashtable. This seems the least invasive way to fix the recently-recognized problem that a split could cause the scan to visit entries twice or (with much lower probability) miss them entirely. The only field-reported problem caused by this is the "failed to re-find shared lock object" PANIC in COMMIT PREPARED reported by Michel Dorochevsky, which was caused by multiply visited entries. However, it seems certain that mdsync() is vulnerable to missing required fsync's due to missed entries, and I am fearful that RelationCacheInitializePhase2() might be at risk as well. Because of that and the generalized hazard presented by this bug, back-patch all the supported branches. Along the way, fix pg_prepared_statement() and pg_cursor() to not assume that the hashtables they are examining will stay static between calls. This is risky regardless of the newly noted dynahash problem, because hash_seq_search() has never promised to cope with deletion of table entries other than the just-returned one. There may be no bug here because the only supported way to call these functions is via ExecMakeTableFunctionResult() which will cycle them to completion before doing anything very interesting, but it seems best to get rid of the assumption. This affects 8.2 and HEAD only, since those functions weren't there earlier.
2007-02-27Get rid of the separate EState for subplans, and just let them share theTom Lane
parent query's EState. Now that there's a single flat rangetable for both the main plan and subplans, there's no need anymore for a separate EState, and removing it allows cleaning up some crufty code in nodeSubplan.c and nodeSubqueryscan.c. Should be a tad faster too, although any difference will probably be hard to measure. This is the last bit of subsidiary mop-up work from changing to a flat rangetable.
2007-02-22Turn the rangetable used by the executor into a flat list, and avoid storingTom Lane
useless substructure for its RangeTblEntry nodes. (I chose to keep using the same struct node type and just zero out the link fields for unneeded info, rather than making a separate ExecRangeTblEntry type --- it seemed too fragile to have two different rangetable representations.) Along the way, put subplans into a list in the toplevel PlannedStmt node, and have SubPlan nodes refer to them by list index instead of direct pointers. Vadim wanted to do that years ago, but I never understood what he was on about until now. It makes things a *whole* lot more robust, because we can stop worrying about duplicate processing of subplans during expression tree traversals. That's been a constant source of bugs, and it's finally gone. There are some consequent simplifications yet to be made, like not using a separate EState for subplans in the executor, but I'll tackle that later.
2007-02-06Add support for cross-type hashing in hashed subplans (hashed IN/NOT IN casesTom Lane
that aren't turned into true joins). Since this is the last missing bit of infrastructure, go ahead and fill out the hash integer_ops and float_ops opfamilies with cross-type operators. The operator family project is now DONE ... er, except for documentation ...
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
2007-01-30Add support for cross-type hashing in hash index searches and hash joins.Tom Lane
Hashing for aggregation purposes still needs work, so it's not time to mark any cross-type operators as hashable for general use, but these cases work if the operators are so marked by hand in the system catalogs.
2007-01-05Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian
back-stamped for this.
2006-12-26Fix failure due to accessing an already-freed tuple descriptor in a planTom Lane
involving HashAggregate over SubqueryScan (this is the known case, there may well be more). The bug is only latent in releases before 8.2 since they didn't try to access tupletable slots' descriptors during ExecDropTupleTable. The least bogus fix seems to be to make subqueries share the parent query's memory context, so that tupdescs they create will have the same lifespan as those of the parent query. There are comments in the code envisioning going even further by not having a separate child EState at all, but that will require rethinking executor access to range tables, which I don't want to tackle right now. Per bug report from Jean-Pierre Pelletier.
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-07-14Remove 576 references of include files that were not needed.Bruce Momjian
2006-07-14Fix a passel of recently-committed violations of the rule 'thou shaltTom Lane
have no other gods before c.h'. Also remove some demonstrably redundant #include lines, mostly of <errno.h> which was added to c.h years ago.
2006-07-13Allow include files to compile own their own.Bruce Momjian
Strip unused include files out unused include files, and add needed includes to C files. The next step is to remove unused include files in C files.
2006-06-28Adjust TupleHashTables to use MinimalTuple format for contained tuples.Tom Lane
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
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
2006-02-28Extend the ExecInitNode API so that plan nodes receive a set of flagTom Lane
bits indicating which optional capabilities can actually be exercised at runtime. This will allow Sort and Material nodes, and perhaps later other nodes, to avoid unnecessary overhead in common cases. This commit just adds the infrastructure and arranges to pass the correct flag values down to plan nodes; none of the actual optimizations are here yet. I'm committing this separately in case anyone wants to measure the added overhead. (It should be negligible.) Simon Riggs and Tom Lane
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.
2005-11-22Re-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.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
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.
2005-03-16Revise 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.
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 ...
2004-08-29Pgindent run for 8.0.Bruce Momjian
2004-08-29Update copyright to 2004.Bruce Momjian
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.
2004-03-17Replace 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.
2004-01-14Fix permission-checking bug reported by Tim Burgess 10-Feb-03 (this timeTom Lane
for sure...). Rather than relying on the query context of a rangetable entry to identify what permissions it wants checked, store a full AclMode mask in each RTE, and check exactly those bits. This allows an RTE specifying, say, INSERT privilege on a view to be copied into a derived UPDATE query without changing meaning. Per recent discussion thread. initdb forced due to change of stored rule representation.
2003-11-29$Header: -> $PostgreSQL Changes ...PostgreSQL Daemon
2003-10-01Repair RI trigger visibility problems (this time for sure ;-)) per recentTom Lane
discussion on pgsql-hackers: in READ COMMITTED mode we just have to force a QuerySnapshot update in the trigger, but in SERIALIZABLE mode we have to run the scan under a current snapshot and then complain if any rows would be updated/deleted that are not visible in the transaction snapshot.
2003-09-25Get rid of ReferentialIntegritySnapshotOverride by extending Executor APITom Lane
to allow es_snapshot to be set to SnapshotNow rather than a query snapshot. This solves a bug reported by Wade Klaver, wherein triggers fired as a result of RI cascade updates could misbehave.
2003-09-25Message editing: remove gratuitous variations in message wording, standardizePeter Eisentraut
terms, add some clarifications, fix some untranslatable attempts at dynamic message building.
2003-08-19Improve dynahash.c's API so that caller can specify the comparison functionTom Lane
as well as the hash function (formerly the comparison function was hardwired as memcmp()). This makes it possible to eliminate the special-purpose hashtable management code in execGrouping.c in favor of using dynahash to manage tuple hashtables; which is a win because dynahash knows how to expand a hashtable when the original size estimate was too small, whereas the special-purpose code was too stupid to do that. (See recent gripe from Stephan Szabo about poor performance when hash table size estimate is way off.) Free side benefit: when using string_hash, the default comparison function is now strncmp() instead of memcmp(). This should eliminate some part of the overhead associated with larger NAMEDATALEN values.
2003-08-08Another pgindent run with updated typedefs.Bruce Momjian
2003-08-04Update copyrights to 2003.Bruce Momjian
2003-08-04pgindent run.Bruce Momjian
2003-07-21Error message editing in backend/executor.Tom Lane
2003-06-27Create real array comparison functions (that use the element datatype'sTom Lane
comparison functions), replacing the highly bogus bitwise array_eq. Create a btree index opclass for ANYARRAY --- it is now possible to create indexes on array columns. Arrange to cache the results of catalog lookups across multiple array operations, instead of repeating the lookups on every call. Add string_to_array and array_to_string functions. Remove singleton_array, array_accum, array_assign, and array_subscript functions, since these were for proof-of-concept and not intended to become supported functions. Minor adjustments to behavior in some corner cases with empty or zero-dimensional arrays. Joe Conway (with some editorializing by Tom Lane).
2003-06-25Back out array mega-patch.Bruce Momjian
Joe Conway
2003-06-24Array mega-patch.Bruce Momjian
Joe Conway
2003-06-22Revise hash join and hash aggregation code to use the same datatype-Tom Lane
specific hash functions used by hash indexes, rather than the old not-datatype-aware ComputeHashFunc routine. This makes it safe to do hash joining on several datatypes that previously couldn't use hashing. The sets of datatypes that are hash indexable and hash joinable are now exactly the same, whereas before each had some that weren't in the other.
2003-06-06Implement outer-level aggregates to conform to the SQL spec, withTom Lane
extensions to support our historical behavior. An aggregate belongs to the closest query level of any of the variables in its argument, or the current query level if there are no variables (e.g., COUNT(*)). The implementation involves adding an agglevelsup field to Aggref, and treating outer aggregates like outer variables at planning time.
2003-04-08First phase of work on array improvements. ARRAY[x,y,z] constructorTom Lane
expressions, ARRAY(sub-SELECT) expressions, some array functions. Polymorphic functions using ANYARRAY/ANYELEMENT argument and return types. Some regression tests in place, documentation is lacking. Joe Conway, with some kibitzing from Tom Lane.
2003-02-09Make further use of new bitmapset code: executor's chgParam, extParam,Tom Lane
locParam lists can be converted to bitmapsets to speed updating. Also, replace 'locParam' with 'allParam', which contains all the paramIDs relevant to the node (i.e., the union of extParam and locParam); this saves a step during SetChangedParamList() without costing anything elsewhere.