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pg_opclass.h
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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) 1996-2018, 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  */
49 CATALOG(pg_opclass,2616,OperatorClassRelationId)
50 {
51  /* index access method opclass is for */
52  Oid opcmethod BKI_LOOKUP(pg_am);
53 
54  /* name of this opclass */
55  NameData opcname;
56 
57  /* namespace of this opclass */
58  Oid opcnamespace BKI_DEFAULT(PGNSP);
59 
60  /* opclass owner */
61  Oid opcowner BKI_DEFAULT(PGUID);
62 
63  /* containing operator family */
64  Oid opcfamily BKI_LOOKUP(pg_opfamily);
65 
66  /* type of data indexed by opclass */
67  Oid opcintype BKI_LOOKUP(pg_type);
68 
69  /* T if opclass is default for opcintype */
70  bool opcdefault BKI_DEFAULT(t);
71 
72  /* type of data in index, or InvalidOid */
73  Oid opckeytype BKI_DEFAULT(0) BKI_LOOKUP(pg_type);
75 
76 /* ----------------
77  * Form_pg_opclass corresponds to a pointer to a tuple with
78  * the format of pg_opclass relation.
79  * ----------------
80  */
82 
83 #endif /* PG_OPCLASS_H */
FormData_pg_opclass
Definition: pg_opclass.h:74
unsigned int Oid
Definition: postgres_ext.h:31
#define BKI_DEFAULT(value)
Definition: genbki.h:36
Definition: c.h:570
#define BKI_LOOKUP(catalog)
Definition: genbki.h:38
CATALOG(pg_opclass, 2616, OperatorClassRelationId)
Definition: pg_opclass.h:49
FormData_pg_opclass * Form_pg_opclass
Definition: pg_opclass.h:81