diff options
Diffstat (limited to 'src/include/nodes/parsenodes.h')
| -rw-r--r-- | src/include/nodes/parsenodes.h | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index e1fe6c0ddba..d11f9ae6ead 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.337 2007/01/05 22:19:55 momjian Exp $ + * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.338 2007/01/09 02:14:15 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -36,6 +36,22 @@ typedef enum OnCommitAction ONCOMMIT_DROP /* ON COMMIT DROP */ } OnCommitAction; +/* Sort ordering options for ORDER BY and CREATE INDEX */ +typedef enum SortByDir +{ + SORTBY_DEFAULT, + SORTBY_ASC, + SORTBY_DESC, + SORTBY_USING /* not allowed in CREATE INDEX ... */ +} SortByDir; + +typedef enum SortByNulls +{ + SORTBY_NULLS_DEFAULT, + SORTBY_NULLS_FIRST, + SORTBY_NULLS_LAST +} SortByNulls; + /* * Grantable rights are encoded so that we can OR them together in a bitmask. @@ -348,14 +364,11 @@ typedef struct ResTarget /* * SortBy - for ORDER BY clause */ -#define SORTBY_ASC 1 -#define SORTBY_DESC 2 -#define SORTBY_USING 3 - typedef struct SortBy { NodeTag type; - int sortby_kind; /* see codes above */ + SortByDir sortby_dir; /* ASC/DESC/USING */ + SortByNulls sortby_nulls; /* NULLS FIRST/LAST */ List *useOp; /* name of op to use, if SORTBY_USING */ Node *node; /* expression to sort on */ } SortBy; @@ -443,6 +456,8 @@ typedef struct IndexElem char *name; /* name of attribute to index, or NULL */ Node *expr; /* expression to index, or NULL */ List *opclass; /* name of desired opclass; NIL = default */ + SortByDir ordering; /* ASC/DESC/default */ + SortByNulls nulls_ordering; /* FIRST/LAST/default */ } IndexElem; /* @@ -614,7 +629,8 @@ typedef struct RangeTblEntry * * tleSortGroupRef must match ressortgroupref of exactly one entry of the * associated targetlist; that is the expression to be sorted (or grouped) by. - * sortop is the OID of the ordering operator. + * sortop is the OID of the ordering operator (a "<" or ">" operator). + * nulls_first does about what you'd expect. * * SortClauses are also used to identify targets that we will do a "Unique" * filter step on (for SELECT DISTINCT and SELECT DISTINCT ON). The @@ -627,16 +643,21 @@ typedef struct SortClause { NodeTag type; Index tleSortGroupRef; /* reference into targetlist */ - Oid sortop; /* the sort operator to use */ + Oid sortop; /* the ordering operator ('<' op) */ + bool nulls_first; /* do NULLs come before normal values? */ } SortClause; /* * GroupClause - * representation of GROUP BY clauses * - * GroupClause is exactly like SortClause except for the nodetag value - * (it's probably not even really necessary to have two different - * nodetags...). We have routines that operate interchangeably on both. + * GroupClause is exactly like SortClause except for the nodetag value. + * We have routines that operate interchangeably on both. + * + * XXX SortClause overspecifies the semantics so far as GROUP BY is concerned + * (ditto for DISTINCT). It'd be better to specify an equality operator not + * an ordering operator. However, the two implementations are tightly entwined + * at the moment ... breaking them apart is work for another day. */ typedef SortClause GroupClause; |