1/*-------------------------------------------------------------------------
2 *
3 * pg_amop.h
4 * definition of the "access method operator" system catalog (pg_amop)
5 *
6 * The amop table identifies the operators associated with each index operator
7 * family and operator class (classes are subsets of families). An associated
8 * operator can be either a search operator or an ordering operator, as
9 * identified by amoppurpose.
10 *
11 * The primary key for this table is <amopfamily, amoplefttype, amoprighttype,
12 * amopstrategy>. amoplefttype and amoprighttype are just copies of the
13 * operator's oprleft/oprright, ie its declared input data types. The
14 * "default" operators for a particular opclass within the family are those
15 * with amoplefttype = amoprighttype = opclass's opcintype. An opfamily may
16 * also contain other operators, typically cross-data-type operators. All the
17 * operators within a family are supposed to be compatible, in a way that is
18 * defined by each individual index AM.
19 *
20 * We also keep a unique index on <amopopr, amoppurpose, amopfamily>, so that
21 * we can use a syscache to quickly answer questions of the form "is this
22 * operator in this opfamily, and if so what are its semantics with respect to
23 * the family?" This implies that the same operator cannot be listed for
24 * multiple strategy numbers within a single opfamily, with the exception that
25 * it's possible to list it for both search and ordering purposes (with
26 * different strategy numbers for the two purposes).
27 *
28 * amopmethod is a copy of the owning opfamily's opfmethod field. This is an
29 * intentional denormalization of the catalogs to buy lookup speed.
30 *
31 *
32 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
33 * Portions Copyright (c) 1994, Regents of the University of California
34 *
35 * src/include/catalog/pg_amop.h
36 *
37 * NOTES
38 * The Catalog.pm module reads this file and derives schema
39 * information.
40 *
41 *-------------------------------------------------------------------------
42 */
43#ifndef PG_AMOP_H
44#define PG_AMOP_H
45
46#include "catalog/genbki.h"
47#include "catalog/pg_amop_d.h"
48
49/* ----------------
50 * pg_amop definition. cpp turns this into
51 * typedef struct FormData_pg_amop
52 * ----------------
53 */
54CATALOG(pg_amop,2602,AccessMethodOperatorRelationId)
55{
56 Oid oid; /* oid */
57
58 /* the index opfamily this entry is for */
59 Oid amopfamily BKI_LOOKUP(pg_opfamily);
60
61 /* operator's left input data type */
62 Oid amoplefttype BKI_LOOKUP(pg_type);
63
64 /* operator's right input data type */
65 Oid amoprighttype BKI_LOOKUP(pg_type);
66
67 /* operator strategy number */
68 int16 amopstrategy;
69
70 /* is operator for 's'earch or 'o'rdering? */
71 char amoppurpose BKI_DEFAULT(s);
72
73 /* the operator's pg_operator OID */
74 Oid amopopr BKI_LOOKUP(pg_operator);
75
76 /* the index access method this entry is for */
77 Oid amopmethod BKI_LOOKUP(pg_am);
78
79 /* ordering opfamily OID, or 0 if search op */
80 Oid amopsortfamily BKI_DEFAULT(0) BKI_LOOKUP(pg_opfamily);
81} FormData_pg_amop;
82
83/* ----------------
84 * Form_pg_amop corresponds to a pointer to a tuple with
85 * the format of pg_amop relation.
86 * ----------------
87 */
88typedef FormData_pg_amop *Form_pg_amop;
89
90#ifdef EXPOSE_TO_CLIENT_CODE
91
92/* allowed values of amoppurpose: */
93#define AMOP_SEARCH 's' /* operator is for search */
94#define AMOP_ORDER 'o' /* operator is for ordering */
95
96#endif /* EXPOSE_TO_CLIENT_CODE */
97
98#endif /* PG_AMOP_H */
99