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path: root/src/backend/parser/parse_clause.c
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2010-02-26pgindent run for 9.0Bruce Momjian
2010-02-12Extend the set of frame options supported for window functions.Tom Lane
This patch allows the frame to start from CURRENT ROW (in either RANGE or ROWS mode), and it also adds support for ROWS n PRECEDING and ROWS n FOLLOWING start and end points. (RANGE value PRECEDING/FOLLOWING isn't there yet --- the grammar works, but that's all.) Hitoshi Harada, reviewed by Pavel Stehule
2010-02-07Create a "relation mapping" infrastructure to support changing the relfilenodesTom Lane
of shared or nailed system catalogs. This has two key benefits: * The new CLUSTER-based VACUUM FULL can be applied safely to all catalogs. * We no longer have to use an unsafe reindex-in-place approach for reindexing shared catalogs. CLUSTER on nailed catalogs now works too, although I left it disabled on shared catalogs because the resulting pg_index.indisclustered update would only be visible in one database. Since reindexing shared system catalogs is now fully transactional and crash-safe, the former special cases in REINDEX behavior have been removed; shared catalogs are treated the same as non-shared. This commit does not do anything about the recently-discussed problem of deadlocks between VACUUM FULL/CLUSTER on a system catalog and other concurrent queries; will address that in a separate patch. As a stopgap, parallel_schedule has been tweaked to run vacuum.sql by itself, to avoid such failures during the regression tests.
2010-01-02Update copyright for the year 2010.Bruce Momjian
2009-12-15Support ORDER BY within aggregate function calls, at long last providing aTom Lane
non-kluge method for controlling the order in which values are fed to an aggregate function. At the same time eliminate the old implementation restriction that DISTINCT was only supported for single-argument aggregates. Possibly release-notable behavioral change: formerly, agg(DISTINCT x) dropped null values of x unconditionally. Now, it does so only if the agg transition function is strict; otherwise nulls are treated as DISTINCT normally would, ie, you get one copy. Andrew Gierth, reviewed by Hitoshi Harada
2009-10-27Make FOR UPDATE/SHARE in the primary query not propagate into WITH queries;Tom Lane
for example in WITH w AS (SELECT * FROM foo) SELECT * FROM w, bar ... FOR UPDATE the FOR UPDATE will now affect bar but not foo. This is more useful and consistent than the original 8.4 behavior, which tried to propagate FOR UPDATE into the WITH query but always failed due to assorted implementation restrictions. Even though we are in process of removing those restrictions, it seems correct on philosophical grounds to not let the outer query's FOR UPDATE affect the WITH query. In passing, fix isLockedRel which frequently got things wrong in nested-subquery cases: "FOR UPDATE OF foo" applies to an alias foo in the current query level, not subqueries. This has been broken for a long time, but it doesn't seem worth back-patching further than 8.4 because the actual consequences are minimal. At worst the parser would sometimes get RowShareLock on a relation when it should be AccessShareLock or vice versa. That would only make a difference if someone were using ExclusiveLock concurrently, which no standard operation does, and anyway FOR UPDATE doesn't result in visible changes so it's not clear that the someone would notice any problem. Between that and the fact that FOR UPDATE barely works with subqueries at all in existing releases, I'm not excited about worrying about it.
2009-09-09Fix bug with WITH RECURSIVE immediately inside WITH RECURSIVE. 99% of theTom Lane
code was already okay with this, but the hack that obtained the output column types of a recursive union in advance of doing real parse analysis of the recursive union forgot to handle the case where there was an inner WITH clause available to the non-recursive term. Best fix seems to be to refactor so that we don't need the "throwaway" parse analysis step at all. Instead, teach the transformSetOperationStmt code to set up the CTE's output column information after it's processed the non-recursive term normally. Per report from David Fetter.
2009-08-27Modify the definition of window-function PARTITION BY and ORDER BY clausesTom Lane
so that their elements are always taken as simple expressions over the query's input columns. It originally seemed like a good idea to make them act exactly like GROUP BY and ORDER BY, right down to the SQL92-era behavior of accepting output column names or numbers. However, that was not such a great idea, for two reasons: 1. It permits circular references, as exhibited in bug #5018: the output column could be the one containing the window function itself. (We actually had a regression test case illustrating this, but nobody thought twice about how confusing that would be.) 2. It doesn't seem like a good idea for, eg, "lead(foo) OVER (ORDER BY foo)" to potentially use two completely different meanings for "foo". Accordingly, narrow down the behavior of window clauses to use only the SQL99-compliant interpretation that the expressions are simple expressions.
2009-07-16Make backend header files C++ safePeter Eisentraut
This alters various incidental uses of C++ key words to use other similar identifiers, so that a C++ compiler won't choke outright. You still (probably) need extern "C" { }; around the inclusion of backend headers. based on a patch by Kurt Harriman <harriman@acm.org> Also add a script cpluspluscheck to check for C++ compatibility in the future. As of right now, this passes without error for me.
2009-06-118.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian
provided by Andrew.
2009-04-04Remove the recently added node types ReloptElem and OptionDefElem in favorTom Lane
of adding optional namespace and action fields to DefElem. Having three node types that do essentially the same thing bloats the code and leads to errors of confusion, such as in yesterday's bug report from Khee Chin.
2009-02-02Allow reloption names to have qualifiers, initially supporting a TOASTAlvaro Herrera
qualifier, and add support for this in pg_dump. This allows TOAST tables to have user-defined fillfactor, and will also enable us to move the autovacuum parameters to reloptions without taking away the possibility of setting values for TOAST tables.
2009-01-22Support column-level privileges, as required by SQL standard.Tom Lane
Stephen Frost, with help from KaiGai Kohei and others
2009-01-01Update copyright for 2009.Bruce Momjian
2008-12-31Throw error if a <window definition> references a window that already has aTom Lane
frame clause, as appears to be required by the fine print in the SQL spec. Per discussion with Pavel, not doing so risks user confusion.
2008-12-31Add some basic support for window frame clauses to the window-functionsTom Lane
patch. This includes the ability to force the frame to cover the whole partition, and the ability to make the frame end exactly on the current row rather than its last ORDER BY peer. Supporting any more of the full SQL frame-clause syntax will require nontrivial hacking on the window aggregate code, so it'll have to wait for 8.5 or beyond.
2008-12-28Support window functions a la SQL:2008.Tom Lane
Hitoshi Harada, with some kibitzing from Heikki and Tom.
2008-10-06Fix the implicit-RTE code to be able to handle implicit RTEs for CTEs, asTom Lane
well as regular tables. Per discussion, this seems necessary to meet the principle of least astonishment. In passing, simplify the error messages in warnAutoRange(). Now that we have parser error position info for these errors, it doesn't seem very useful to word the error message differently depending on whether we are inside a sub-select or not.
2008-10-04Implement SQL-standard WITH clauses, including WITH RECURSIVE.Tom Lane
There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane
2008-09-01Add a bunch of new error location reports to parse-analysis error messages.Tom Lane
There are still some weak spots around JOIN USING and relation alias lists, but most errors reported within backend/parser/ now have locations.
2008-08-30Fix the raw-parsetree representation of star (as in SELECT * FROM orTom Lane
SELECT foo.*) so that it cannot be confused with a quoted identifier "*". Instead create a separate node type A_Star to represent this notation. Per pgsql-hackers discussion of 2007-Sep-27.
2008-08-28Extend the parser location infrastructure to include a location field inTom Lane
most node types used in expression trees (both before and after parse analysis). This allows us to place an error cursor in many situations where we formerly could not, because the information wasn't available beyond the very first level of parse analysis. There's a fair amount of work still to be done to persuade individual ereport() calls to actually include an error location, but this gets the initdb-forcing part of the work out of the way; and the situation is already markedly better than before for complaints about unimplementable implicit casts, such as CASE and UNION constructs with incompatible alternative data types. Per my proposal of a few days ago.
2008-08-25Move exprType(), exprTypmod(), expression_tree_walker(), and related routinesTom Lane
into nodes/nodeFuncs, so as to reduce wanton cross-subsystem #includes inside the backend. There's probably more that should be done along this line, but this is a start anyway.
2008-08-07Teach the system how to use hashing for UNION. (INTERSECT/EXCEPT will follow,Tom Lane
but seem like a separate patch since most of the remaining work is on the executor side.) I took the opportunity to push selection of the grouping operators for set operations into the parser where it belongs. Otherwise this is just a small exercise in making prepunion.c consider both alternatives. As with the recent DISTINCT patch, this means we can UNION on datatypes that can hash but not sort, and it means that UNION without ORDER BY is no longer certain to produce sorted output.
2008-08-05Improve SELECT DISTINCT to consider hash aggregation, as well as sort/uniq,Tom Lane
as methods for implementing the DISTINCT step. This eliminates the former performance gap between DISTINCT and GROUP BY, and also makes it possible to do SELECT DISTINCT on datatypes that only support hashing not sorting. SELECT DISTINCT ON is still always implemented by sorting; it would take executor changes to support hashing that, and it's not clear it's worth the trouble. This is a release-note-worthy incompatibility from previous PG versions, since SELECT DISTINCT can no longer be counted on to deliver sorted output without explicitly saying ORDER BY. (Anyone who can't cope with that can consider turning off enable_hashagg.) Several regression test queries needed to have ORDER BY added to preserve stable output order. I fixed the ones that manifested here, but there might be some other cases that show up on other platforms.
2008-08-03Make GROUP BY work properly for datatypes that only support hashing and notTom Lane
sorting. The infrastructure for this was all in place already; it's only necessary to fix the planner to not assume that sorting is always an available option.
2008-08-02Rearrange the querytree representation of ORDER BY/GROUP BY/DISTINCT itemsTom Lane
as per my recent proposal: 1. Fold SortClause and GroupClause into a single node type SortGroupClause. We were already relying on them to be struct-equivalent, so using two node tags wasn't accomplishing much except to get in the way of comparing items with equal(). 2. Add an "eqop" field to SortGroupClause to carry the associated equality operator. This is cheap for the parser to get at the same time it's looking up the sort operator, and storing it eliminates the need for repeated not-so-cheap lookups during planning. In future this will also let us represent GROUP/DISTINCT operations on datatypes that have hash opclasses but no btree opclasses (ie, they have equality but no natural sort order). The previous representation simply didn't work for that, since its only indicator of comparison semantics was a sort operator. 3. Add a hasDistinctOn boolean to struct Query to explicitly record whether the distinctClause came from DISTINCT or DISTINCT ON. This allows removing some complicated and not 100% bulletproof code that attempted to figure that out from the distinctClause alone. This patch doesn't in itself create any new capability, but it's necessary infrastructure for future attempts to use hash-based grouping for DISTINCT and UNION/INTERSECT/EXCEPT.
2008-07-31Fix parser so that we don't modify the user-written ORDER BY list in orderTom Lane
to represent DISTINCT or DISTINCT ON. This gets rid of a longstanding annoyance that a view or rule using SELECT DISTINCT will be dumped out with an overspecified ORDER BY list, and is one small step along the way to decoupling DISTINCT and ORDER BY enough so that hash-based implementation of DISTINCT will be possible. In passing, improve transformDistinctClause so that it doesn't reject duplicate DISTINCT ON items, as was reported by Steve Midgley a couple weeks ago.
2008-06-19Improve our #include situation by moving pointer types away from theAlvaro Herrera
corresponding struct definitions. This allows other headers to avoid including certain highly-loaded headers such as rel.h and relscan.h, instead using just relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less unnecessary dependencies.
2008-02-15Remove ancient restriction that LIMIT/OFFSET can't contain a sub-select.Tom Lane
This was probably protecting some implementation limitation when it was put in, but as far as I can tell the planner and executor have no such assumption anymore; the case seems to work fine. Per a gripe from Grzegorz Jaskiewicz.
2008-01-01Update copyrights in source tree to 2008.Bruce Momjian
2007-11-15pgindent run for 8.3.Bruce Momjian
2007-06-23Separate parse-analysis for utility commands out of parser/analyze.cTom Lane
(which now deals only in optimizable statements), and put that code into a new file parser/parse_utilcmd.c. This helps clarify and enforce the design rule that utility statements shouldn't be processed during the regular parse analysis phase; all interpretation of their meaning should happen after they are given to ProcessUtility to execute. (We need this because we don't retain any locks for a utility statement that's in a plan cache, nor have any way to detect that it's stale.) We are also able to simplify the API for parse_analyze() and related routines, because they will now always return exactly one Query structure. In passing, fix bug #3403 concerning trying to add a serial column to an existing temp table (this is largely Heikki's work, but we needed all that restructuring to make it safe).
2007-04-27Modify processing of DECLARE CURSOR and EXPLAIN so that they can resolve theTom Lane
types of unspecified parameters when submitted via extended query protocol. This worked in 8.2 but I had broken it during plancache changes. DECLARE CURSOR is now treated almost exactly like a plain SELECT through parse analysis, rewrite, and planning; only just before sending to the executor do we divert it away to ProcessUtility. This requires a special-case check in a number of places, but practically all of them were already special-casing SELECT INTO, so it's not too ugly. (Maybe it would be a good idea to merge the two by treating IntoClause as a form of utility statement? Not going to worry about that now, though.) That approach doesn't work for EXPLAIN, however, so for that I punted and used a klugy solution of running parse analysis an extra time if under extended query protocol.
2007-02-01Wording cleanup for error messages. Also change can't -> cannot.Bruce Momjian
Standard English uses "may", "can", and "might" in different ways: may - permission, "You may borrow my rake." can - ability, "I can lift that log." might - possibility, "It might rain today." Unfortunately, in conversational English, their use is often mixed, as in, "You may use this variable to do X", when in fact, "can" is a better choice. Similarly, "It may crash" is better stated, "It might crash".
2007-01-10Change the planner-to-executor API so that the planner tells the executorTom Lane
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.
2007-01-09Support ORDER BY ... NULLS FIRST/LAST, and add ASC/DESC/NULLS FIRST/NULLS LASTTom Lane
per-column options for btree indexes. The planner's support for this is still pretty rudimentary; it does not yet know how to plan mergejoins with nondefault ordering options. The documentation is pretty rudimentary, too. I'll work on improving that stuff later. Note incompatible change from prior behavior: ORDER BY ... USING will now be rejected if the operator is not a less-than or greater-than member of some btree opclass. This prevents less-than-sane behavior if an operator that doesn't actually define a proper sort ordering is selected.
2007-01-05Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian
back-stamped for this.
2006-12-24Code review for XML patch. Instill a bit of sanity in the location ofTom Lane
the XmlExpr code in various lists, use a representation that has some hope of reverse-listing correctly (though it's still a de-escaping function shy of correctness), generally try to make it look more like Postgres coding conventions.
2006-11-28Fix some translator comments so that xgettext finds them and pgindent doesPeter Eisentraut
not destroy them. Maybe we can adjust pgindent sometime.
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-08-14Cause '*' and 'foo.*' notations to mark the referenced RTE(s) asTom Lane
requiring read permissions. Up till now there was no possible case in which the RTEs wouldn't already have ACL_SELECT set ... but now that you can say something like 'INSERT INTO foo ... RETURNING *' this is an essential step. With this commit, a RETURNING clause adds the requirement for SELECT permissions on the target table if and only if the clause actually reads the value of at least one target-table column.
2006-08-12Tweak SPI_cursor_open to allow INSERT/UPDATE/DELETE RETURNING; this wasTom Lane
merely a matter of fixing the error check, since the underlying Portal infrastructure already handles it. This in turn allows these statements to be used in some existing plpgsql and plperl contexts, such as a plpgsql FOR loop. Also, do some marginal code cleanup in places that were being sloppy about distinguishing SELECT from SELECT INTO.
2006-07-26Code review for bigint-LIMIT patch. Fix missed planner dependency,Tom Lane
eliminate unnecessary code, force initdb because stored rules change (limit nodes are now supposed to be int8 not int4 expressions). Update comments and error messages, which still all said 'integer'.
2006-07-26Change LIMIT/OFFSET to use int8Bruce Momjian
Dhanaraj M
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.
2006-07-03Code review for FILLFACTOR patch. Change WITH grammar as per earlierTom Lane
discussion (including making def_arg allow reserved words), add missed opt_definition for UNIQUE case. Put the reloptions support code in a less random place (I chose to make a new file access/common/reloptions.c). Eliminate header inclusion creep. Make the index options functions safely user-callable (seems like client apps might like to be able to test validity of options before trying to make an index). Reduce overhead for normal case with no options by allowing rd_options to be NULL. Fix some unmaintainably klugy code, including getting rid of Natts_pg_class_fixed at long last. Some stylistic cleanup too, and pay attention to keeping comments in sync with code. Documentation still needs work, though I did fix the omissions in catalogs.sgml and indexam.sgml.
2006-07-02Add FILLFACTOR to CREATE INDEX.Bruce Momjian
ITAGAKI Takahiro
2006-03-16Clean up representation of function RTEs for functions returning RECORD.Tom Lane
The original coding stored the raw parser output (ColumnDef and TypeName nodes) which was ugly, bulky, and wrong because it failed to create any dependency on the referenced datatype --- and in fact would not track type renamings and suchlike. Instead store a list of column type OIDs in the RTE. Also fix up general failure of recordDependencyOnExpr to do anything sane about recording dependencies on datatypes. While there are many cases where there will be an indirect dependency (eg if an operator returns a datatype, the dependency on the operator is enough), we do have to record the datatype as a separate dependency in examples like CoerceToDomain. initdb forced because of change of stored rules.