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Diffstat (limited to 'src/include/catalog/pg_amop.h')
-rw-r--r-- | src/include/catalog/pg_amop.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/include/catalog/pg_amop.h b/src/include/catalog/pg_amop.h new file mode 100644 index 0000000..81a7eb6 --- /dev/null +++ b/src/include/catalog/pg_amop.h @@ -0,0 +1,98 @@ +/*------------------------------------------------------------------------- + * + * 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) 1996-2020, 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(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; + +#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 */ |