| /*------------------------------------------------------------------------- | |
| * | |
| * attmap.h | |
| * Definitions for PostgreSQL attribute mappings | |
| * | |
| * | |
| * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group | |
| * Portions Copyright (c) 1994, Regents of the University of California | |
| * | |
| * src/include/access/attmap.h | |
| * | |
| *------------------------------------------------------------------------- | |
| */ | |
| /* | |
| * Attribute mapping structure | |
| * | |
| * This maps attribute numbers between a pair of relations, designated | |
| * 'input' and 'output' (most typically inheritance parent and child | |
| * relations), whose common columns may have different attribute numbers. | |
| * Such difference may arise due to the columns being ordered differently | |
| * in the two relations or the two relations having dropped columns at | |
| * different positions. | |
| * | |
| * 'maplen' is set to the number of attributes of the 'output' relation, | |
| * taking into account any of its dropped attributes, with the corresponding | |
| * elements of the 'attnums' array set to 0. | |
| */ | |
| typedef struct AttrMap | |
| { | |
| AttrNumber *attnums; | |
| int maplen; | |
| } AttrMap; | |
| extern AttrMap *make_attrmap(int maplen); | |
| extern void free_attrmap(AttrMap *map); | |
| /* Conversion routines to build mappings */ | |
| extern AttrMap *build_attrmap_by_name(TupleDesc indesc, | |
| TupleDesc outdesc, | |
| bool missing_ok); | |
| extern AttrMap *build_attrmap_by_name_if_req(TupleDesc indesc, | |
| TupleDesc outdesc, | |
| bool missing_ok); | |
| extern AttrMap *build_attrmap_by_position(TupleDesc indesc, | |
| TupleDesc outdesc, | |
| const char *msg); | |