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path: root/src/backend/executor/nodeMergejoin.c
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* Repair failure to check that a table is still compatible with a previouslyTom Lane2007-02-02
| | | | | | | | | | | | | | | | | | | | | | 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
* Fix bug introduced into mergejoin logic by performance improvement patch ofTom Lane2006-03-17
| | | | | | | | | | | | | | 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.
* Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian2005-11-22
| | | | | | | | | 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.
* Standard pgindent run for 8.1.Bruce Momjian2005-10-15
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* Fix latent bug in ExecSeqRestrPos: it leaves the plan node's result slotTom Lane2005-05-15
| | | | | | | 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.
* Minor refactoring to eliminate duplicate code and make startup aTom Lane2005-05-14
| | | | tad faster.
* Revise nodeMergejoin in light of example provided by Guillaume Smet.Tom Lane2005-05-13
| | | | | | | | | | 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.
* For some reason access/tupmacs.h has been #including utils/memutils.h,Tom Lane2005-05-06
| | | | | | | 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.
* Revise TupleTableSlot code to avoid unnecessary construction and disassemblyTom Lane2005-03-16
| | | | | | | | | | | | | | | | | | | | | 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.
* Tag appropriate files for rc3PostgreSQL Daemon2004-12-31
| | | | | | | | 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 ...
* Pgindent run for 8.0.Bruce Momjian2004-08-29
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* Update copyright to 2004.Bruce Momjian2004-08-29
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* Use the new List API function names throughout the backend, and disable theNeil Conway2004-05-30
| | | | | list compatibility API by default. While doing this, I decided to keep the llast() macro around and introduce llast_int() and llast_oid() variants.
* Reimplement the linked list data structure used throughout the backend.Neil Conway2004-05-26
| | | | | | | | | | | | | | | | 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.
* Replace the switching function ExecEvalExpr() with a macro that jumpsTom Lane2004-03-17
| | | | | | | | | | | 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.
* $Header: -> $PostgreSQL Changes ...PostgreSQL Daemon2003-11-29
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* Message editing: remove gratuitous variations in message wording, standardizePeter Eisentraut2003-09-25
| | | | | terms, add some clarifications, fix some untranslatable attempts at dynamic message building.
* Another pgindent run with updated typedefs.Bruce Momjian2003-08-08
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* Update copyrights to 2003.Bruce Momjian2003-08-04
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* pgindent run.Bruce Momjian2003-08-04
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* Error message editing in backend/executor.Tom Lane2003-07-21
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* Ditch ExecGetTupType() in favor of the much simpler ExecGetResultType(),Tom Lane2003-05-05
| | | | | | which does the same thing. Perhaps at one time there was a reason to allow plan nodes to store their result types in different places, but AFAICT that's been unnecessary for a good while.
* IN clauses appearing at top level of WHERE can now be handled as joins.Tom Lane2003-01-20
| | | | | | | | | | There are two implementation techniques: the executor understands a new JOIN_IN jointype, which emits at most one matching row per left-hand row, or the result of the IN's sub-select can be fed through a DISTINCT filter and then joined as an ordinary relation. Along the way, some minor code cleanup in the optimizer; notably, break out most of the jointree-rearrangement preprocessing in planner.c and put it in a new file prep/prepjointree.c.
* Revise executor APIs so that all per-query state structure is built inTom Lane2002-12-15
| | | | | | a per-query memory context created by CreateExecutorState --- and destroyed by FreeExecutorState. This provides a final solution to the longstanding problem of memory leaked by various ExecEndNode calls.
* Phase 3 of read-only-plans project: ExecInitExpr now builds expressionTom Lane2002-12-13
| | | | | | | execution state trees, and ExecEvalExpr takes an expression state tree not an expression plan tree. The plan tree is now read-only as far as the executor is concerned. Next step is to begin actually exploiting this property.
* Phase 2 of read-only-plans project: restructure expression-tree nodesTom Lane2002-12-12
| | | | | | | | | so that all executable expression nodes inherit from a common supertype Expr. This is somewhat of an exercise in code purity rather than any real functional advance, but getting rid of the extra Oper or Func node formerly used in each operator or function call should provide at least a little space and speed improvement. initdb forced by changes in stored-rules representation.
* Phase 1 of read-only-plans project: cause executor state nodes to pointTom Lane2002-12-05
| | | | | | | | | | to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
* pgindent run.Bruce Momjian2002-09-04
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* Update copyright to 2002.Bruce Momjian2002-06-20
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* Change made to elog:Bruce Momjian2002-03-06
| | | | | | | | | | | | | | | | | | | o Change all current CVS messages of NOTICE to WARNING. We were going to do this just before 7.3 beta but it has to be done now, as you will see below. o Change current INFO messages that should be controlled by client_min_messages to NOTICE. o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc. to always go to the client. o Remove INFO from the client_min_messages options and add NOTICE. Seems we do need three non-ERROR elog levels to handle the various behaviors we need for these messages. Regression passed.
* Teach planner about the idea that a mergejoin won't necessarily readTom Lane2002-03-01
| | | | | | both input streams to the end. If one variable's range is much less than the other, an indexscan-based merge can win by not scanning all of the other table. Per example from Reinhard Max.
* Another pgindent run. Fixes enum indenting, and improves #endifBruce Momjian2001-10-28
| | | | spacing. Also adds space for one-line comments.
* pgindent run on all C files. Java run to follow. initdb/regressionBruce Momjian2001-10-25
| | | | tests pass.
* Fix comments that were mis-wrapped, for Tom Lane.Bruce Momjian2001-03-23
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* Remove dashes in comments that don't need them, rewrap with pgindent.Bruce Momjian2001-03-22
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* pgindent run. Make it all clean.Bruce Momjian2001-03-22
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* Clean up handling of tuple descriptors so that result-tuple descriptorsTom Lane2001-01-29
| | | | | | | | allocated by plan nodes are not leaked at end of query. This doesn't really matter for normal queries, but it sure does for queries invoked repetitively inside SQL functions. Clean up some other grotty code associated with tupdescs, and fix a few other memory leaks exposed by tests with simple SQL functions.
* Change Copyright from PostgreSQL, Inc to PostgreSQL Global Development Group.Bruce Momjian2001-01-24
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* Fix thinko for case of outer join where inner table is empty: shouldTom Lane2000-12-13
| | | | output first outer tuple before advancing...
* Change SearchSysCache coding conventions so that a reference count isTom Lane2000-11-16
| | | | | | | maintained for each cache entry. A cache entry will not be freed until the matching ReleaseSysCache call has been executed. This eliminates worries about cache entries getting dropped while still in use. See my posting to pg-hackers of even date for more info.
* First cut at full support for OUTER JOINs. There are still a few looseTom Lane2000-09-12
| | | | | ends to clean up (see my message of same date to pghackers), but mostly it works. INITDB REQUIRED!
* SQL-language functions are now callable in ordinary fmgr contexts ...Tom Lane2000-08-24
| | | | | | for example, an SQL function can be used in a functional index. (I make no promises about speed, but it'll work ;-).) Clean up and simplify handling of functions returning sets.
* First stage of reclaiming memory in executor by resetting short-termTom Lane2000-07-12
| | | | | | memory contexts. Currently, only leaks in expressions executed as quals or projections are handled. Clean up some old dead cruft in executor while at it --- unused fields in state nodes, that sort of thing.
* Final #include cleanup.Bruce Momjian2000-06-15
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* Add:Bruce Momjian2000-01-26
| | | | | | * Portions Copyright (c) 1996-2000, PostgreSQL, Inc to all files copyright Regents of Berkeley. Man, that's a lot of files.
* Fix handling of NULL constraint conditions: per SQL92 spec, a NULL resultTom Lane2000-01-19
| | | | | | | | | from a constraint condition does not violate the constraint (cf. discussion on pghackers 12/9/99). Implemented by adding a parameter to ExecQual, specifying whether to return TRUE or FALSE when the qual result is really NULL in three-valued boolean logic. Currently, ExecRelCheck is the only caller that asks for TRUE, but if we find any other places that have the wrong response to NULL, it'll be easy to fix them.
* Add system indexes to match all caches.Bruce Momjian1999-11-22
| | | | | | | Make all system indexes unique. Make all cache loads use system indexes. Rename *rel to *relid in inheritance tables. Rename cache names to be clearer.
* Actually, nodeMergejoin shouldn't include psort.h at all...Tom Lane1999-10-17
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* nodeMergejoin was depending on an inclusion from psort.h...Tom Lane1999-10-16
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* Several changes here, not very related but touching some of the same files.Tom Lane1999-09-24
| | | | | | | | | | | | | | | | | | | | | * Buffer refcount cleanup (per my "progress report" to pghackers, 9/22). * Add links to backend PROC structs to sinval's array of per-backend info, and use these links for routines that need to check the state of all backends (rather than the slow, complicated search of the ShmemIndex hashtable that was used before). Add databaseOID to PROC structs. * Use this to implement an interlock that prevents DESTROY DATABASE of a database containing running backends. (It's a little tricky to prevent a concurrently-starting backend from getting in there, since the new backend is not able to lock anything at the time it tries to look up its database in pg_database. My solution is to recheck that the DB is OK at the end of InitPostgres. It may not be a 100% solution, but it's a lot better than no interlock at all...) * In ALTER TABLE RENAME, flush buffers for the relation before doing the rename of the physical files, to ensure we don't get failures later from mdblindwrt(). * Update TRUNCATE patch so that it actually compiles against current sources :-(. You should do "make clean all" after pulling these changes.
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