greenplumn pg_depend 源码
greenplumn pg_depend 代码
文件路径：/src/include/catalog/pg_depend.h
/*-------------------------------------------------------------------------
*
* pg_depend.h
* definition of the "dependency" system catalog (pg_depend)
*
* pg_depend has no preloaded contents, so there is no pg_depend.dat
* file; system-defined dependencies are loaded into it during a late stage
* of the initdb process.
*
* NOTE: we do not represent all possible dependency pairs in pg_depend;
* for example, there's not much value in creating an explicit dependency
* from an attribute to its relation. Usually we make a dependency for
* cases where the relationship is conditional rather than essential
* (for example, not all triggers are dependent on constraints, but all
* attributes are dependent on relations) or where the dependency is not
* convenient to find from the contents of other catalogs.
*
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/catalog/pg_depend.h
*
* NOTES
* The Catalog.pm module reads this file and derives schema
* information.
*
*-------------------------------------------------------------------------
*/
#ifndef PG_DEPEND_H
#define PG_DEPEND_H
#include "catalog/genbki.h"
#include "catalog/pg_depend_d.h"
/* ----------------
* pg_depend definition. cpp turns this into
* typedef struct FormData_pg_depend
* ----------------
*/
CATALOG(pg_depend,2608,DependRelationId)
{
/*
* Identification of the dependent (referencing) object.
*
* These fields are all zeroes for a DEPENDENCY_PIN entry.
*/
Oid classid; /* OID of table containing object */
Oid objid; /* OID of object itself */
int32 objsubid; /* column number, or 0 if not used */
/*
* Identification of the independent (referenced) object.
*/
Oid refclassid; /* OID of table containing object */
Oid refobjid; /* OID of object itself */
int32 refobjsubid; /* column number, or 0 if not used */
/*
* Precise semantics of the relationship are specified by the deptype
* field. See DependencyType in catalog/dependency.h.
*/
char deptype; /* see codes in dependency.h */
} FormData_pg_depend;
/* GPDB added foreign key definitions for gpcheckcat. */
FOREIGN_KEY(classid REFERENCES pg_class(oid));
FOREIGN_KEY(refclassid REFERENCES pg_class(oid));
/* ----------------
* Form_pg_depend corresponds to a pointer to a row with
* the format of pg_depend relation.
* ----------------
*/
typedef FormData_pg_depend *Form_pg_depend;
#endif /* PG_DEPEND_H */
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