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postgres/src/include/parser/parse_clause.h

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Break parser functions into smaller files, group together.
1997-11-25 22:07:18 +00:00
/*-------------------------------------------------------------------------
*
* parse_clause.h
Adjust subquery qual pushdown rules to be more forgiving: if a qual refers to a non-DISTINCT output column of a DISTINCT ON subquery, or if it refers to a function-returning-set, we cannot push it down. But the old implementation refused to push down *any* quals if the subquery had any such 'dangerous' outputs. Now we just look at the output columns actually referenced by each qual expression. More code than before, but probably no slower since we don't make unnecessary checks.
2003-03-22 01:49:38 +00:00
* handle clauses in parser
Break parser functions into smaller files, group together.
1997-11-25 22:07:18 +00:00
*
*
Update copyright for 2009.
2009-01-01 17:24:05 +00:00
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
Add: * Portions Copyright (c) 1996-2000, PostgreSQL, Inc to all files copyright Regents of Berkeley. Man, that's a lot of files.
2000-01-26 05:58:53 +00:00
* Portions Copyright (c) 1994, Regents of the University of California
Break parser functions into smaller files, group together.
1997-11-25 22:07:18 +00:00
*
Update copyright for 2009.
2009-01-01 17:24:05 +00:00
* $PostgreSQL: pgsql/src/include/parser/parse_clause.h,v 1.54 2009/01/01 17:24:00 momjian Exp $
Break parser functions into smaller files, group together.
1997-11-25 22:07:18 +00:00
*
*-------------------------------------------------------------------------
*/
#ifndef PARSE_CLAUSE_H
#define PARSE_CLAUSE_H
Change #include's to use <> and "" as appropriate.
1999-07-15 23:04:24 +00:00
#include "parser/parse_node.h"
Break parser functions into smaller files, group together.
1997-11-25 22:07:18 +00:00
Change scoping of table and join refnames to conform to SQL92: a JOIN clause with an alias is a <subquery> and therefore hides table references appearing within it, according to the spec. This is the same as the preliminary patch I posted to pgsql-patches yesterday, plus some really grotty code in ruleutils.c to reverse-list a query tree with the correct alias name depending on context. I'd rather not have done that, but unless we want to force another initdb for 7.1, there's no other way for now.
2001-02-14 21:35:07 +00:00
extern void transformFromClause(ParseState *pstate, List *frmList);
A little further progress on schemas: push down RangeVars into addRangeTableEntry calls. Remove relname field from RTEs, since it will no longer be a useful unique identifier of relations; we want to encourage people to rely on the relation OID instead. Further work on dumping qual expressions in EXPLAIN, too.
2002-03-22 02:56:37 +00:00
extern int setTargetTable(ParseState *pstate, RangeVar *relation,
Fix permission-checking bug reported by Tim Burgess 10-Feb-03 (this time 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.
2004-01-14 23:01:55 +00:00
bool inh, bool alsoSource, AclMode requiredPerms);
Remove not-really-standard implementation of CREATE TABLE's UNDER clause, and revert documentation to describe the existing INHERITS clause instead, per recent discussion in pghackers. Also fix implementation of SQL_inheritance SET variable: it is not cool to look at this var during the initial parsing phase, only during parse_analyze(). See recent bug report concerning misinterpretation of date constants just after a SET TIMEZONE command. gram.y really has to be an invariant transformation of the query string to a raw parsetree; anything that can vary with time must be done during parse analysis.
2001-01-05 06:34:23 +00:00
extern bool interpretInhOption(InhOption inhOpt);
Code review for FILLFACTOR patch. Change WITH grammar as per earlier 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.
2006-07-03 22:45:41 +00:00
extern bool interpretOidsOption(List *defList);
Allow GROUP BY, ORDER BY, DISTINCT targets to be unknown literals, silently resolving them to type TEXT. This is comparable to what we do when faced with UNKNOWN in CASE, UNION, and other contexts. It gets rid of this and related annoyances: select distinct f1, '' from int4_tbl; ERROR: Unable to identify an ordering operator '<' for type unknown This was discussed many moons ago, but no one got round to fixing it.
2003-06-16 02:03:38 +00:00
Do honest transformation and preprocessing of LIMIT/OFFSET clauses, instead of the former kluge whereby gram.y emitted already-transformed expressions. This is needed so that Params appearing in these clauses actually work correctly. I suppose some might claim that the side effect of 'SELECT ... LIMIT 2+2' working is a new feature, but I say this is a bug fix.
2003-07-03 19:07:54 +00:00
extern Node *transformWhereClause(ParseState *pstate, Node *clause,
pgindent run.
2003-08-04 00:43:34 +00:00
const char *constructName);
Do honest transformation and preprocessing of LIMIT/OFFSET clauses, instead of the former kluge whereby gram.y emitted already-transformed expressions. This is needed so that Params appearing in these clauses actually work correctly. I suppose some might claim that the side effect of 'SELECT ... LIMIT 2+2' working is a new feature, but I say this is a bug fix.
2003-07-03 19:07:54 +00:00
extern Node *transformLimitClause(ParseState *pstate, Node *clause,
pgindent run.
2003-08-04 00:43:34 +00:00
const char *constructName);
OK, folks, here is the pgindent output.
1998-09-01 04:40:42 +00:00
extern List *transformGroupClause(ParseState *pstate, List *grouplist,
Support window functions a la SQL:2008. Hitoshi Harada, with some kibitzing from Heikki and Tom.
2008-12-28 18:54:01 +00:00
List **targetlist, List *sortClause,
bool isPartition);
Major revision of sort-node handling: push knowledge of query sort order down into planner, instead of handling it only at the very top level of the planner. This fixes many things. An explicit sort is now avoided if there is a cheaper alternative (typically an indexscan) not only for ORDER BY, but also for the internal sort of GROUP BY. It works even when there is no other reason (such as a WHERE condition) to consider the indexscan. It works for indexes on functions. It works for indexes on functions, backwards. It's just so cool... CAUTION: I have changed the representation of SortClause nodes, therefore THIS UPDATE BREAKS STORED RULES. You will need to initdb.
1999-08-21 03:49:17 +00:00
extern List *transformSortClause(ParseState *pstate, List *orderlist,
Still another place to make the world safe for zero-column tables: remove the ancient (and always pretty dodgy) assumption in parse_clause.c that a query can't have an empty targetlist.
2004-05-23 17:10:54 +00:00
List **targetlist, bool resolveUnknown);
Support window functions a la SQL:2008. Hitoshi Harada, with some kibitzing from Heikki and Tom.
2008-12-28 18:54:01 +00:00
extern List *transformWindowDefinitions(ParseState *pstate,
List *windowdefs,
List **targetlist);
Rearrange the querytree representation of ORDER BY/GROUP BY/DISTINCT items 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.
2008-08-02 21:32:01 +00:00
extern List *transformDistinctClause(ParseState *pstate,
List **targetlist, List *sortClause);
extern List *transformDistinctOnClause(ParseState *pstate, List *distinctlist,
Fix parser so that we don't modify the user-written ORDER BY list in order 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.
2008-07-31 22:47:56 +00:00
List **targetlist, List *sortClause);
Major revision of sort-node handling: push knowledge of query sort order down into planner, instead of handling it only at the very top level of the planner. This fixes many things. An explicit sort is now avoided if there is a cheaper alternative (typically an indexscan) not only for ORDER BY, but also for the internal sort of GROUP BY. It works even when there is no other reason (such as a WHERE condition) to consider the indexscan. It works for indexes on functions. It works for indexes on functions, backwards. It's just so cool... CAUTION: I have changed the representation of SortClause nodes, therefore THIS UPDATE BREAKS STORED RULES. You will need to initdb.
1999-08-21 03:49:17 +00:00
extern Index assignSortGroupRef(TargetEntry *tle, List *tlist);
Support ORDER BY ... NULLS FIRST/LAST, and add ASC/DESC/NULLS FIRST/NULLS LAST 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.
2007-01-09 02:14:16 +00:00
extern bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList);
Another pgindent run. Fixes enum indenting, and improves #endif spacing. Also adds space for one-line comments.
2001-10-28 06:26:15 +00:00
New pgindent run with fixes suggested by Tom. Patch manually reviewed, initdb/regression tests pass.
2001-11-05 17:46:40 +00:00
#endif /* PARSE_CLAUSE_H */
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