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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 copyrights for 2013 Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
2013-01-01 17:15:01 -05:00
* Portions Copyright (c) 1996-2013, 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
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/parser/parse_clause.h
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);
Fix problems with incomplete attempt to prohibit OIDS with MVs. Problem with assertion failure in restoring from pg_dump output reported by Joachim Wieland. Review and suggestions by Tom Lane and Robert Haas.
2013-03-22 13:27:34 -05:00
extern bool interpretOidsOption(List *defList, char relkind);
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,
Centralize the logic for detecting misplaced aggregates, window funcs, etc. Formerly we relied on checking after-the-fact to see if an expression contained aggregates, window functions, or sub-selects when it shouldn't. This is grotty, easily forgotten (indeed, we had forgotten to teach DefineIndex about rejecting window functions), and none too efficient since it requires extra traversals of the parse tree. To improve matters, define an enum type that classifies all SQL sub-expressions, store it in ParseState to show what kind of expression we are currently parsing, and make transformAggregateCall, transformWindowFuncCall, and transformSubLink check the expression type and throw error if the type indicates the construct is disallowed. This allows removal of a large number of ad-hoc checks scattered around the code base. The enum type is sufficiently fine-grained that we can still produce error messages of at least the same specificity as before. Bringing these error checks together revealed that we'd been none too consistent about phrasing of the error messages, so standardize the wording a bit. Also, rewrite checking of aggregate arguments so that it requires only one traversal of the arguments, rather than up to three as before. In passing, clean up some more comments left over from add_missing_from support, and annotate some tests that I think are dead code now that that's gone. (I didn't risk actually removing said dead code, though.)
2012-08-10 11:35:33 -04:00
ParseExprKind exprKind, 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,
Centralize the logic for detecting misplaced aggregates, window funcs, etc. Formerly we relied on checking after-the-fact to see if an expression contained aggregates, window functions, or sub-selects when it shouldn't. This is grotty, easily forgotten (indeed, we had forgotten to teach DefineIndex about rejecting window functions), and none too efficient since it requires extra traversals of the parse tree. To improve matters, define an enum type that classifies all SQL sub-expressions, store it in ParseState to show what kind of expression we are currently parsing, and make transformAggregateCall, transformWindowFuncCall, and transformSubLink check the expression type and throw error if the type indicates the construct is disallowed. This allows removal of a large number of ad-hoc checks scattered around the code base. The enum type is sufficiently fine-grained that we can still produce error messages of at least the same specificity as before. Bringing these error checks together revealed that we'd been none too consistent about phrasing of the error messages, so standardize the wording a bit. Also, rewrite checking of aggregate arguments so that it requires only one traversal of the arguments, rather than up to three as before. In passing, clean up some more comments left over from add_missing_from support, and annotate some tests that I think are dead code now that that's gone. (I didn't risk actually removing said dead code, though.)
2012-08-10 11:35:33 -04:00
ParseExprKind exprKind, 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,
Centralize the logic for detecting misplaced aggregates, window funcs, etc. Formerly we relied on checking after-the-fact to see if an expression contained aggregates, window functions, or sub-selects when it shouldn't. This is grotty, easily forgotten (indeed, we had forgotten to teach DefineIndex about rejecting window functions), and none too efficient since it requires extra traversals of the parse tree. To improve matters, define an enum type that classifies all SQL sub-expressions, store it in ParseState to show what kind of expression we are currently parsing, and make transformAggregateCall, transformWindowFuncCall, and transformSubLink check the expression type and throw error if the type indicates the construct is disallowed. This allows removal of a large number of ad-hoc checks scattered around the code base. The enum type is sufficiently fine-grained that we can still produce error messages of at least the same specificity as before. Bringing these error checks together revealed that we'd been none too consistent about phrasing of the error messages, so standardize the wording a bit. Also, rewrite checking of aggregate arguments so that it requires only one traversal of the arguments, rather than up to three as before. In passing, clean up some more comments left over from add_missing_from support, and annotate some tests that I think are dead code now that that's gone. (I didn't risk actually removing said dead code, though.)
2012-08-10 11:35:33 -04:00
ParseExprKind exprKind, bool useSQL99);
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,
Centralize the logic for detecting misplaced aggregates, window funcs, etc. Formerly we relied on checking after-the-fact to see if an expression contained aggregates, window functions, or sub-selects when it shouldn't. This is grotty, easily forgotten (indeed, we had forgotten to teach DefineIndex about rejecting window functions), and none too efficient since it requires extra traversals of the parse tree. To improve matters, define an enum type that classifies all SQL sub-expressions, store it in ParseState to show what kind of expression we are currently parsing, and make transformAggregateCall, transformWindowFuncCall, and transformSubLink check the expression type and throw error if the type indicates the construct is disallowed. This allows removal of a large number of ad-hoc checks scattered around the code base. The enum type is sufficiently fine-grained that we can still produce error messages of at least the same specificity as before. Bringing these error checks together revealed that we'd been none too consistent about phrasing of the error messages, so standardize the wording a bit. Also, rewrite checking of aggregate arguments so that it requires only one traversal of the arguments, rather than up to three as before. In passing, clean up some more comments left over from add_missing_from support, and annotate some tests that I think are dead code now that that's gone. (I didn't risk actually removing said dead code, though.)
2012-08-10 11:35:33 -04:00
List **targetlist, ParseExprKind exprKind,
bool resolveUnknown, bool useSQL99);
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,
8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list provided by Andrew.
2009-06-11 14:49:15 +00:00
List *windowdefs,
List **targetlist);
Support window functions a la SQL:2008. Hitoshi Harada, with some kibitzing from Heikki and Tom.
2008-12-28 18:54:01 +00:00
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,
Support ORDER BY within aggregate function calls, at long last providing a 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
2009-12-15 17:57:48 +00:00
List **targetlist, List *sortClause, bool is_agg);
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 *transformDistinctOnClause(ParseState *pstate, List *distinctlist,
8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list provided by Andrew.
2009-06-11 14:49:15 +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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