diff options
Diffstat (limited to 'src/include/nodes')
| -rw-r--r-- | src/include/nodes/parsenodes.h | 18 | ||||
| -rw-r--r-- | src/include/nodes/primnodes.h | 8 |
2 files changed, 21 insertions, 5 deletions
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 80230e34446..aff28bea08f 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.265 2004/08/04 21:34:24 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.266 2004/08/19 20:57:41 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -447,6 +447,22 @@ typedef struct DefElem * eref->aliasname is required to be present, and should generally be used * to identify the RTE for error messages etc. * + * In RELATION RTEs, the colnames in both alias and eref are indexed by + * physical attribute number; this means there must be colname entries for + * dropped columns. When building an RTE we insert empty strings ("") for + * dropped columns. Note however that a stored rule may have nonempty + * colnames for columns dropped since the rule was created (and for that + * matter the colnames might be out of date due to column renamings). + * The same comments apply to FUNCTION RTEs when the function's return type + * is a named composite type. + * + * In JOIN RTEs, the colnames in both alias and eref are one-to-one with + * joinaliasvars entries. A JOIN RTE will omit columns of its inputs when + * those columns are known to be dropped at parse time. Again, however, + * a stored rule might contain entries for columns dropped since the rule + * was created. (This is only possible for columns not actually referenced + * in the rule.) + * * inh is TRUE for relation references that should be expanded to include * inheritance children, if the rel has any. This *must* be FALSE for * RTEs other than RTE_RELATION entries. diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 5abdbd548fd..56f359978d4 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -10,7 +10,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.101 2004/08/17 18:47:09 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.102 2004/08/19 20:57:41 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -98,9 +98,9 @@ typedef struct Resdom * specifies an alias for a range variable; the alias might also * specify renaming of columns within the table. * - * Note: colnames is a list of Value nodes (always strings). In an RTE's - * eref Alias, the colnames list includes dropped columns, so that the - * colname list position matches the physical attribute number. + * Note: colnames is a list of Value nodes (always strings). In Alias structs + * associated with RTEs, there may be entries corresponding to dropped + * columns; these are normally empty strings (""). See parsenodes.h for info. */ typedef struct Alias { |