pg_amop.h

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/*-------------------------------------------------------------------------
 *
 * pg_amop.h
 *    definition of the "access method operator" system catalog (pg_amop)
 *
 * The amop table identifies the operators associated with each index operator
 * family and operator class (classes are subsets of families).  An associated
 * operator can be either a search operator or an ordering operator, as
 * identified by amoppurpose.
 *
 * The primary key for this table is <amopfamily, amoplefttype, amoprighttype,
 * amopstrategy>.  amoplefttype and amoprighttype are just copies of the
 * operator's oprleft/oprright, ie its declared input data types.  The
 * "default" operators for a particular opclass within the family are those
 * with amoplefttype = amoprighttype = opclass's opcintype.  An opfamily may
 * also contain other operators, typically cross-data-type operators.  All the
 * operators within a family are supposed to be compatible, in a way that is
 * defined by each individual index AM.
 *
 * We also keep a unique index on <amopopr, amoppurpose, amopfamily>, so that
 * we can use a syscache to quickly answer questions of the form "is this
 * operator in this opfamily, and if so what are its semantics with respect to
 * the family?"  This implies that the same operator cannot be listed for
 * multiple strategy numbers within a single opfamily, with the exception that
 * it's possible to list it for both search and ordering purposes (with
 * different strategy numbers for the two purposes).
 *
 * amopmethod is a copy of the owning opfamily's opfmethod field.  This is an
 * intentional denormalization of the catalogs to buy lookup speed.
 *
 *
 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_amop.h
 *
 * NOTES
 *    The Catalog.pm module reads this file and derives schema
 *    information.
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_AMOP_H
#define PG_AMOP_H
 
#include "catalog/genbki.h"
#include "catalog/pg_amop_d.h"
 
/* ----------------
 *      pg_amop definition.  cpp turns this into
 *      typedef struct FormData_pg_amop
 * ----------------
 */
CATALOG(pg_amop,2602,AccessMethodOperatorRelationId)
{
    Oid         oid;            /* oid */
 
    /* the index opfamily this entry is for */
    Oid         amopfamily BKI_LOOKUP(pg_opfamily);
 
    /* operator's left input data type */
    Oid         amoplefttype BKI_LOOKUP(pg_type);
 
    /* operator's right input data type */
    Oid         amoprighttype BKI_LOOKUP(pg_type);
 
    /* operator strategy number */
    int16       amopstrategy;
 
    /* is operator for 's'earch or 'o'rdering? */
    char        amoppurpose BKI_DEFAULT(s);
 
    /* the operator's pg_operator OID */
    Oid         amopopr BKI_LOOKUP(pg_operator);
 
    /* the index access method this entry is for */
    Oid         amopmethod BKI_LOOKUP(pg_am);
 
    /* ordering opfamily OID, or 0 if search op */
    Oid         amopsortfamily BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_opfamily);
} FormData_pg_amop;
 
/* ----------------
 *      Form_pg_amop corresponds to a pointer to a tuple with
 *      the format of pg_amop relation.
 * ----------------
 */
typedef FormData_pg_amop *Form_pg_amop;
 
DECLARE_UNIQUE_INDEX(pg_amop_fam_strat_index, 2653, AccessMethodStrategyIndexId, on pg_amop using btree(amopfamily oid_ops, amoplefttype oid_ops, amoprighttype oid_ops, amopstrategy int2_ops));
DECLARE_UNIQUE_INDEX(pg_amop_opr_fam_index, 2654, AccessMethodOperatorIndexId, on pg_amop using btree(amopopr oid_ops, amoppurpose char_ops, amopfamily oid_ops));
DECLARE_UNIQUE_INDEX_PKEY(pg_amop_oid_index, 2756, AccessMethodOperatorOidIndexId, on pg_amop using btree(oid oid_ops));
 
#ifdef EXPOSE_TO_CLIENT_CODE
 
/* allowed values of amoppurpose: */
#define AMOP_SEARCH     's'     /* operator is for search */
#define AMOP_ORDER      'o'     /* operator is for ordering */
 
#endif                          /* EXPOSE_TO_CLIENT_CODE */
 
#endif                          /* PG_AMOP_H */