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path: root/src/backend/commands/explain.c
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2006-10-04pgindent run for 8.2.Bruce Momjian
2006-09-06Change processing of extended-Query mode so that an unnamed statementTom Lane
that has parameters is always planned afresh for each Bind command, treating the parameter values as constants in the planner. This removes the performance penalty formerly often paid for using out-of-line parameters --- with this definition, the planner can do constant folding, LIKE optimization, etc. After a suggestion by Andrew@supernews.
2006-08-02Add support for multi-row VALUES clauses as part of INSERT statementsJoe Conway
(e.g. "INSERT ... VALUES (...), (...), ...") and elsewhere as allowed by the spec. (e.g. similar to a FROM clause subselect). initdb required. Joe Conway and Tom Lane.
2006-07-14Remove 576 references of include files that were not needed.Bruce Momjian
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.
2006-04-08Fix EXPLAIN so that it can drill down through multiple levels of subplanTom Lane
when trying to locate the referent of a RECORD variable. This fixes the 'record type has not been registered' failure reported by Stefan Kaltenbrunner about a month ago. A side effect of the way I chose to fix it is that most variable references in join conditions will now be properly labeled with the variable's source table name, instead of the not-too-helpful 'outer' or 'inner' we used to use.
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
2006-03-01Attached is a patch that replaces a bunch of places where StringInfosNeil Conway
are unnecessarily allocated on the heap rather than the stack. If the StringInfo doesn't outlive the stack frame in which it is created, there is no need to allocate it on the heap via makeStringInfo() -- stack allocation is faster. While it's not a big deal unless the code is in a critical path, I don't see a reason not to save a few cycles -- using stack allocation is not less readable. I also cleaned up a bit of code along the way: moved variable declarations into a more tightly-enclosing scope where possible, fixed some pointless copying of strings in dblink, etc.
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
2006-02-05Improve my initial, rather hacky implementation of joins to appendTom Lane
relations: fix the executor so that we can have an Append plan on the inside of a nestloop and still pass down outer index keys to index scans within the Append, then generate such plans as if they were regular inner indexscans. This avoids the need to evaluate the outer relation multiple times.
2005-11-29Fix EXPLAIN and EXECUTE commands to pass portal parameters through toTom Lane
the executor. This allows, for example, JDBC clients to use '?' bound parameters in these commands. Per gripe from Virag Saksena.
2005-11-26Teach tid-scan code to make use of "ctid = ANY (array)" clauses, so thatTom Lane
"ctid IN (list)" will still work after we convert IN to ScalarArrayOpExpr. Make some minor efficiency improvements while at it, such as ensuring that multiple TIDs are fetched in physical heap order. And fix EXPLAIN so that it shows what's really going on for a TID scan.
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.
2005-10-21Fix EXPLAIN ANALYZE bug noted by Wiebe Cazemier: although we wereTom Lane
properly advancing the CommandCounter between multiple sub-queries generated by rules, we forgot to update the snapshot being used, so that the successive sub-queries didn't actually see each others' results. This is still not *exactly* like the semantics of normal execution of the same queries, in that we don't take new transaction snapshots and hence don't see changes from concurrently committed commands, but I think that's OK and probably even preferable for EXPLAIN ANALYZE.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-06-04Remove unused 'printCost' field from ExplainState, and simplify the codeNeil Conway
accordingly (this field was always initialized to true). Patch from Alvaro Herrera.
2005-06-03Revise handling of dropped columns in JOIN alias lists to avoid aTom Lane
performance problem pointed out by phil@vodafone: to wit, we were spending O(N^2) time to check dropped-ness in an N-deep join tree, even in the case where the tree was freshly constructed and couldn't possibly mention any dropped columns. Instead of recursing in get_rte_attribute_is_dropped(), change the data structure definition: the joinaliasvars list of a JOIN RTE must have a NULL Const instead of a Var at any position that references a now-dropped column. This costs nothing during normal parse-rewrite-plan path, and instead we have a linear-time update to make when loading a stored rule that might contain now-dropped columns. While at it, move the responsibility for acquring locks on relations referenced by rules into this separate function (which I therefore chose to call AcquireRewriteLocks). This saves effort --- namely, duplicated lock grabs in parser and rewriter --- in the normal path at a cost of one extra non-locked heap_open() in the stored-rule path; seems a good tradeoff. A fringe benefit is that it is now *much* clearer that we acquire lock on relations referenced in rules before we make any rewriter decisions based on their properties. (I don't know of any bug of that ilk, but it wasn't exactly clear before.)
2005-04-25Remove support for OR'd indexscans internal to a single IndexScan planTom Lane
node, as this behavior is now better done as a bitmap OR indexscan. This allows considerable simplification in nodeIndexscan.c itself as well as several planner modules concerned with indexscan plan generation. Also we can improve the sharing of code between regular and bitmap indexscans, since they are now working with nigh-identical Plan nodes.
2005-04-22First cut at planner support for bitmap index scans. Lots to do yet,Tom Lane
but the code is basically working. Along the way, rewrite the entire approach to processing OR index conditions, and make it work in join cases for the first time ever. orindxpath.c is now basically obsolete, but I left it in for the time being to allow easy comparison testing against the old implementation.
2005-04-19Create executor and planner-backend support for decoupled heap and indexTom Lane
scans, using in-memory tuple ID bitmaps as the intermediary. The planner frontend (path creation and cost estimation) is not there yet, so none of this code can be executed. I have tested it using some hacked planner code that is far too ugly to see the light of day, however. Committing now so that the bulk of the infrastructure changes go in before the tree drifts under me.
2005-04-16Create a new 'MultiExecProcNode' call API for plan nodes that don'tTom Lane
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.
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.
2005-03-20On Windows, use QueryPerformanceCounter instead of gettimeofday forTom Lane
EXPLAIN ANALYZE instrumentation. Magnus Hagander
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 ...
2004-12-12PREPARE and EXPLAIN need to copy the source query just like we recentlyTom Lane
had to do in DECLARE CURSOR. AFAICS these are all the places affected. PREPARE case per example from Michael Fuhr, EXPLAIN case located by grepping for planner calls ...
2004-09-30Remove unnecessary use of index_open just to get the index name.Tom Lane
2004-09-13Redesign query-snapshot timing so that volatile functions in READ COMMITTEDTom Lane
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.
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.
2004-08-29Pgindent run for 8.0.Bruce Momjian
2004-08-29Update copyright to 2004.Bruce Momjian
2004-06-11When using extended-query protocol, postpone planning of unnamed statementsTom Lane
until Bind is received, so that actual parameter values are visible to the planner. Make use of the parameter values for estimation purposes (but don't fold them into the actual plan). This buys back most of the potential loss of plan quality that ensues from using out-of-line parameters instead of putting literal values right into the query text. This patch creates a notion of constant-folding expressions 'for estimation purposes only', in which case we can be more aggressive than the normal eval_const_expressions() logic can be. Right now the only difference in behavior is inserting bound values for Params, but it will be interesting to look at other possibilities. One that we've seen come up repeatedly is reducing now() and related functions to current values, so that queries like ... WHERE timestampcol > now() - '1 day' have some chance of being planned effectively. Oliver Jowett, with some kibitzing from Tom Lane.
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.
2004-04-01Replace 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.
2004-01-31Micro-opt: replace calls likeNeil Conway
appendStringInfo(buf, "%s", str); with appendStringInfoString(buf, str); as the latter form is slightly faster.
2003-11-29$Header: -> $PostgreSQL Changes ...PostgreSQL Daemon
2003-10-17Adjust display of actual runtimes in EXPLAIN output to use three fractionalTom Lane
digits, and label it 'ms' not 'msec', for consistency with psql's \timing display. Per recent discussions.
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.
2003-08-11Code cleanup inspired by recent resname bug report (doesn't fix the bugTom Lane
yet, though). Avoid using nth() to fetch tlist entries; provide a common routine get_tle_by_resno() to search a tlist for a particular resno. This replaces a couple uses of nth() and a dozen hand-coded search loops. Also, replace a few uses of nth(length-1, list) with llast().
2003-08-08Another pgindent run with updated typedefs.Bruce Momjian
2003-08-04Update copyrights to 2003.Bruce Momjian
2003-08-04pgindent run.Bruce Momjian
2003-07-20Another round of error message editing, covering backend/commands/.Tom Lane
2003-05-28Knock down a couple more lappend() hotspots for large WHERE clauses.Tom Lane
2003-05-08Update 3.0 protocol support to match recent agreements about how toTom Lane
handle multiple 'formats' for data I/O. Restructure CommandDest and DestReceiver stuff one more time (it's finally starting to look a bit clean though). Code now matches latest 3.0 protocol document as far as message formats go --- but there is no support for binary I/O yet.
2003-05-06Restructure command destination handling so that we pass aroundTom Lane
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.
2003-05-06Implement feature of new FE/BE protocol whereby RowDescription identifiesTom Lane
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.
2003-04-24Infrastructure for upgraded error reporting mechanism. elog.c isTom Lane
rewritten and the protocol is changed, but most elog calls are still elog calls. Also, we need to contemplate mechanisms for controlling all this functionality --- eg, how much stuff should appear in the postmaster log? And what API should libpq expose for it?
2003-04-03Prevent EXPLAIN (without ANALYZE) SELECT ... INTO from creating an INTOTom Lane
table. Needed due to recent change that makes us call ExecutorStart even when not planning to carry out the query.
2003-03-10Restructure parsetree representation of DECLARE CURSOR: now it's aTom Lane
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.
2003-02-10Add code to show join rule (for outer and IN joins) in join type name.Tom Lane