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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
commit | 46651ce6fe013220ed397add242004d764fc0153 (patch) | |
tree | 6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/access/attmap.h | |
parent | Initial commit. (diff) | |
download | postgresql-14-upstream.tar.xz postgresql-14-upstream.zip |
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/access/attmap.h')
-rw-r--r-- | src/include/access/attmap.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/include/access/attmap.h b/src/include/access/attmap.h new file mode 100644 index 0000000..778fa27 --- /dev/null +++ b/src/include/access/attmap.h @@ -0,0 +1,52 @@ +/*------------------------------------------------------------------------- + * + * attmap.h + * Definitions for PostgreSQL attribute mappings + * + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/access/attmap.h + * + *------------------------------------------------------------------------- + */ +#ifndef ATTMAP_H +#define ATTMAP_H + +#include "access/attnum.h" +#include "access/tupdesc.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); +extern AttrMap *build_attrmap_by_name_if_req(TupleDesc indesc, + TupleDesc outdesc); +extern AttrMap *build_attrmap_by_position(TupleDesc indesc, + TupleDesc outdesc, + const char *msg); + +#endif /* ATTMAP_H */ |