1/*-------------------------------------------------------------------------
2 *
3 * pg_opclass.h
4 * definition of the "operator class" system catalog (pg_opclass)
5 *
6 * The primary key for this table is <opcmethod, opcname, opcnamespace> ---
7 * that is, there is a row for each valid combination of opclass name and
8 * index access method type. This row specifies the expected input data type
9 * for the opclass (the type of the heap column, or the expression output type
10 * in the case of an index expression). Note that types binary-coercible to
11 * the specified type will be accepted too.
12 *
13 * For a given <opcmethod, opcintype> pair, there can be at most one row that
14 * has opcdefault = true; this row is the default opclass for such data in
15 * such an index. (This is not currently enforced by an index, because we
16 * don't support partial indexes on system catalogs.)
17 *
18 * Normally opckeytype = InvalidOid (zero), indicating that the data stored
19 * in the index is the same as the data in the indexed column. If opckeytype
20 * is nonzero then it indicates that a conversion step is needed to produce
21 * the stored index data, which will be of type opckeytype (which might be
22 * the same or different from the input datatype). Performing such a
23 * conversion is the responsibility of the index access method --- not all
24 * AMs support this.
25 *
26 *
27 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
28 * Portions Copyright (c) 1994, Regents of the University of California
29 *
30 * src/include/catalog/pg_opclass.h
31 *
32 * NOTES
33 * The Catalog.pm module reads this file and derives schema
34 * information.
35 *
36 *-------------------------------------------------------------------------
37 */
38#ifndef PG_OPCLASS_H
39#define PG_OPCLASS_H
40
41#include "catalog/genbki.h"
42#include "catalog/pg_opclass_d.h"
43
44/* ----------------
45 * pg_opclass definition. cpp turns this into
46 * typedef struct FormData_pg_opclass
47 * ----------------
48 */
49CATALOG(pg_opclass,2616,OperatorClassRelationId)
50{
51 Oid oid; /* oid */
52
53 /* index access method opclass is for */
54 Oid opcmethod BKI_LOOKUP(pg_am);
55
56 /* name of this opclass */
57 NameData opcname;
58
59 /* namespace of this opclass */
60 Oid opcnamespace BKI_DEFAULT(PGNSP);
61
62 /* opclass owner */
63 Oid opcowner BKI_DEFAULT(PGUID);
64
65 /* containing operator family */
66 Oid opcfamily BKI_LOOKUP(pg_opfamily);
67
68 /* type of data indexed by opclass */
69 Oid opcintype BKI_LOOKUP(pg_type);
70
71 /* T if opclass is default for opcintype */
72 bool opcdefault BKI_DEFAULT(t);
73
74 /* type of data in index, or InvalidOid */
75 Oid opckeytype BKI_DEFAULT(0) BKI_LOOKUP(pg_type);
76} FormData_pg_opclass;
77
78/* ----------------
79 * Form_pg_opclass corresponds to a pointer to a tuple with
80 * the format of pg_opclass relation.
81 * ----------------
82 */
83typedef FormData_pg_opclass *Form_pg_opclass;
84
85#endif /* PG_OPCLASS_H */
86