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* Get rid of the separate EState for subplans, and just let them share theTom Lane2007-02-271-4/+1
| | | | | | | | | 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.
* Turn the rangetable used by the executor into a flat list, and avoid storingTom Lane2007-02-221-2/+1
| | | | | | | | | | | | | | | | | 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.
* Remove the Query structure from the executor's API. This allows us to stopTom Lane2007-02-201-1/+2
| | | | | | | | | | | | | | | storing mostly-redundant Query trees in prepared statements, portals, etc. To replace Query, a new node type called PlannedStmt is inserted by the planner at the top of a completed plan tree; this carries just the fields of Query that are still needed at runtime. The statement lists kept in portals etc. now consist of intermixed PlannedStmt and bare utility-statement nodes --- no Query. This incidentally allows us to remove some fields from Query and Plan nodes that shouldn't have been there in the first place. Still to do: simplify the execution-time range table; at the moment the range table passed to the executor still contains Query trees for subqueries. initdb forced due to change of stored rules.
* Add support for cross-type hashing in hashed subplans (hashed IN/NOT IN casesTom Lane2007-02-061-1/+5
| | | | | | | 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 ...
* Repair failure to check that a table is still compatible with a previouslyTom Lane2007-02-021-3/+5
| | | | | | | | | | | | | | | | | | | | | | 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
* Change the planner-to-executor API so that the planner tells the executorTom Lane2007-01-101-9/+7
| | | | | | | | | | | | | | | | which comparison operators to use for plan nodes involving tuple comparison (Agg, Group, Unique, SetOp). Formerly the executor looked up the default equality operator for the datatype, which was really pretty shaky, since it's possible that the data being fed to the node is sorted according to some nondefault operator class that could have an incompatible idea of equality. The planner knows what it has sorted by and therefore can provide the right equality operator to use. Also, this change moves a couple of catalog lookups out of the executor and into the planner, which should help startup time for pre-planned queries by some small amount. Modify the planner to remove some other cavalier assumptions about always being able to use the default operators. Also add "nulls first/last" info to the Plan node for a mergejoin --- neither the executor nor the planner can cope yet, but at least the API is in place.
* Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian2007-01-051-2/+2
| | | | back-stamped for this.
* Fix failure due to accessing an already-freed tuple descriptor in a planTom Lane2006-12-261-1/+2
| | | | | | | | | | | | 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.
* Refactor ExecGetJunkAttribute to avoid searching for junk attributesTom Lane2006-12-041-3/+5
| | | | | | by name on each and every row processed. Profiling suggests this may buy a percent or two for simple UPDATE scenarios, which isn't huge, but when it's so easy to get ...
* pgindent run for 8.2.Bruce Momjian2006-10-041-6/+6
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* Add INSERT/UPDATE/DELETE RETURNING, with basic docs and regression tests.Tom Lane2006-08-121-1/+2
| | | | | | | | plpgsql support to come later. Along the way, convert execMain's SELECT INTO support into a DestReceiver, in order to eliminate some ugly special cases. Jonah Harris and Tom Lane
* Fix domain_in() bug exhibited by Darcy Buskermolen. The idea of an EStateTom Lane2006-08-041-1/+2
| | | | | | | | | | | | | that's shorter-lived than the expression state being evaluated in it really doesn't work :-( --- we end up with fn_extra caches getting deleted while still in use. Rather than abandon the notion of caching expression state across domain_in calls altogether, I chose to make domain_in a bit cozier with ExprContext. All we really need for evaluating variable-free expressions is an ExprContext, not an EState, so I invented the notion of a "standalone" ExprContext. domain_in can prevent resource leakages by doing a ReScanExprContext on this rather than having to free it entirely; so we can make the ExprContext have the same lifespan (and particularly the same per_query memory context) as the expression state structs.
* Fix problems with cached tuple descriptors disappearing while still in useTom Lane2006-06-161-5/+3
| | | | | | | | | | 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
* Update copyright for 2006. Update scripts.Bruce Momjian2006-03-051-2/+2
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* Extend the ExecInitNode API so that plan nodes receive a set of flagTom Lane2006-02-281-3/+36
| | | | | | | | | | | | 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
* Repair "Halloween problem" in EvalPlanQual: a tuple that's been inserted byTom Lane2006-01-121-2/+2
| | | | | | | | 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.
* Tweak indexscan machinery to avoid taking an AccessShareLock on an indexTom Lane2005-12-031-1/+3
| | | | | | | if we already have a stronger lock due to the index's table being the update target table of the query. Same optimization I applied earlier at the table level. There doesn't seem to be much interest in the more radical idea of not locking indexes at all, so do what we can ...
* Adjust scan plan nodes to avoid getting an extra AccessShareLock on aTom Lane2005-12-021-1/+4
| | | | | | relation if it's already been locked by execMain.c as either a result relation or a FOR UPDATE/SHARE relation. This avoids an extra trip to the shared lock manager state. Per my suggestion yesterday.
* Get rid of ExecAssignResultTypeFromOuterPlan() and make all plan node typesTom Lane2005-11-231-2/+1
| | | | | | | | | | | 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.
* Standard pgindent run for 8.1.Bruce Momjian2005-10-151-15/+15
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* Repair problems with VACUUM destroying t_ctid chains too soon, and withTom Lane2005-08-201-2/+2
| | | | | | | | | | | | 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.
* Create a new 'MultiExecProcNode' call API for plan nodes that don'tTom Lane2005-04-161-1/+2
| | | | | | | return just a single tuple at a time. Currently the only such node type is Hash, but I expect we will soon have indexscans that can return tuple bitmaps. A side benefit is that EXPLAIN ANALYZE now shows the correct tuple count for a Hash node.
* Revise TupleTableSlot code to avoid unnecessary construction and disassemblyTom Lane2005-03-161-37/+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.
* Avoid O(N^2) overhead in repeated nocachegetattr calls when columns ofTom Lane2005-03-141-4/+3
| | | | | | | | 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.
* Tag appropriate files for rc3PostgreSQL Daemon2004-12-311-2/+2
| | | | | | | | 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 ...
* Fix problems with SQL functions returning rowtypes that have droppedTom Lane2004-10-071-2/+5
| | | | | | | | | | | | columns. The returned tuple needs to have appropriate NULL columns inserted so that it actually matches the declared rowtype. It seemed convenient to use a JunkFilter for this, so I made some cleanups and simplifications in the JunkFilter code to allow it to support this additional functionality. (That in turn exposed a latent bug in nodeAppend.c, which is that it was returning a tuple slot whose descriptor didn't match its data.) Also, move check_sql_fn_retval out of pg_proc.c and into functions.c, where it seems to more naturally belong.
* Redesign query-snapshot timing so that volatile functions in READ COMMITTEDTom Lane2004-09-131-3/+2
| | | | | | | | | | | | | mode see a fresh snapshot for each command in the function, rather than using the latest interactive command's snapshot. Also, suppress fresh snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE functions, instead using the snapshot taken for the most closely nested regular query. (This behavior is only sane for read-only functions, so the patch also enforces that such functions contain only SELECT commands.) As per my proposal of 6-Sep-2004; I note that I floated essentially the same proposal on 19-Jun-2002, but that discussion tailed off without any action. Since 8.0 seems like the right place to be taking possibly nontrivial backwards compatibility hits, let's get it done now.
* Pgindent run for 8.0.Bruce Momjian2004-08-291-2/+2
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* Update copyright to 2004.Bruce Momjian2004-08-291-2/+2
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* Promote row expressions to full-fledged citizens of the expression syntax,Tom Lane2004-05-101-1/+2
| | | | | | | | | | 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.
* Replace TupleTableSlot convention for whole-row variables and functionTom Lane2004-04-011-3/+3
| | | | | | | | 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.
* Replace the switching function ExecEvalExpr() with a macro that jumpsTom Lane2004-03-171-6/+13
| | | | | | | | | | | 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.
* Junkfilter logic to force a projection step during SELECT INTO was tooTom Lane2004-03-021-1/+2
| | | | | simplistic; it recognized SELECT * FROM but not SELECT * FROM LIMIT. Per bug report from Jeff Bohmer.
* Fix oversight in optimization that avoids an unnecessary projection stepTom Lane2004-01-221-1/+2
| | | | | | when scanning a table that we need all the columns from. In case of SELECT INTO, we have to check that the hasoids flag matches the desired output type, too. Per report from Mike Mascari.
* Fix permission-checking bug reported by Tim Burgess 10-Feb-03 (this timeTom Lane2004-01-141-2/+2
| | | | | | | | | 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.
* Ensure set-returning functions in the targetlist of a plan node will beTom Lane2003-12-181-1/+2
| | | | | | shut down cleanly if the plan node is ReScanned before the SRFs are run to completion. This fixes the problem for SQL-language functions, but still need work on functions using the SRF_XXX() macros.
* make sure the $Id tags are converted to $PostgreSQL as well ...PostgreSQL Daemon2003-11-291-1/+1
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* Repair RI trigger visibility problems (this time for sure ;-)) per recentTom Lane2003-10-011-2/+2
| | | | | | | 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.
* Get rid of ReferentialIntegritySnapshotOverride by extending Executor APITom Lane2003-09-251-2/+3
| | | | | | 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.
* Improve dynahash.c's API so that caller can specify the comparison functionTom Lane2003-08-191-3/+1
| | | | | | | | | | | | | 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.
* Another pgindent run with updated typedefs.Bruce Momjian2003-08-081-31/+31
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* Update copyrights to 2003.Bruce Momjian2003-08-041-2/+2
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* pgindent run.Bruce Momjian2003-08-041-52/+52
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* Error message editing in backend/executor.Tom Lane2003-07-211-2/+2
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* Revise hash join and hash aggregation code to use the same datatype-Tom Lane2003-06-221-2/+7
| | | | | | | | 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.
* Restructure command destination handling so that we pass aroundTom Lane2003-05-061-3/+5
| | | | | | | | | | | | | | DestReceiver pointers instead of just CommandDest values. The DestReceiver is made at the point where the destination is selected, rather than deep inside the executor. This cleans up the original kluge implementation of tstoreReceiver.c, and makes it easy to support retrieving results from utility statements inside portals. Thus, you can now do fun things like Bind and Execute a FETCH or EXPLAIN command, and it'll all work as expected (e.g., you can Describe the portal, or use Execute's count parameter to suspend the output partway through). Implementation involves stuffing the utility command's output into a Tuplestore, which would be kind of annoying for huge output sets, but should be quite acceptable for typical uses of utility commands.
* Implement feature of new FE/BE protocol whereby RowDescription identifiesTom Lane2003-05-061-2/+2
| | | | | | | | | the column by table OID and column number, if it's a simple column reference. Along the way, get rid of reskey/reskeyop fields in Resdoms. Turns out that representation was not convenient for either the planner or the executor; we can make the planner deliver exactly what the executor wants with no more effort. initdb forced due to change in stored rule representation.
* Ditch ExecGetTupType() in favor of the much simpler ExecGetResultType(),Tom Lane2003-05-051-2/+1
| | | | | | 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.
* Implement SQL92-compatible FIRST, LAST, ABSOLUTE n, RELATIVE n optionsTom Lane2003-03-111-1/+2
| | | | for FETCH and MOVE.
* Restructure parsetree representation of DECLARE CURSOR: now it's aTom Lane2003-03-101-1/+2
| | | | | | | | | | | | utility statement (DeclareCursorStmt) with a SELECT query dangling from it, rather than a SELECT query with a few unusual fields in it. Add code to determine whether a planned query can safely be run backwards. If DECLARE CURSOR specifies SCROLL, ensure that the plan can be run backwards by adding a Materialize plan node if it can't. Without SCROLL, you get an error if you try to fetch backwards from a cursor that can't handle it. (There is still some discussion about what the exact behavior should be, but this is necessary infrastructure in any case.) Along the way, make EXPLAIN DECLARE CURSOR work.
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