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/*-------------------------------------------------------------------------
*
* dependency.h
* Routines to support inter-object dependencies.
*
*
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/dependency.h,v 1.38 2009/01/01 17:23:56 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef DEPENDENCY_H
#define DEPENDENCY_H
#include "nodes/parsenodes.h" /* for DropBehavior */
/*
* Precise semantics of a dependency relationship are specified by the
* DependencyType code (which is stored in a "char" field in pg_depend,
* so we assign ASCII-code values to the enumeration members).
*
* In all cases, a dependency relationship indicates that the referenced
* object may not be dropped without also dropping the dependent object.
* However, there are several subflavors:
*
* DEPENDENCY_NORMAL ('n'): normal relationship between separately-created
* objects. The dependent object may be dropped without affecting the
* referenced object. The referenced object may only be dropped by
* specifying CASCADE, in which case the dependent object is dropped too.
* Example: a table column has a normal dependency on its datatype.
*
* DEPENDENCY_AUTO ('a'): the dependent object can be dropped separately
* from the referenced object, and should be automatically dropped
* (regardless of RESTRICT or CASCADE mode) if the referenced object
* is dropped.
* Example: a named constraint on a table is made auto-dependent on
* the table, so that it will go away if the table is dropped.
*
* DEPENDENCY_INTERNAL ('i'): the dependent object was created as part
* of creation of the referenced object, and is really just a part of
* its internal implementation. A DROP of the dependent object will be
* disallowed outright (we'll tell the user to issue a DROP against the
* referenced object, instead). A DROP of the referenced object will be
* propagated through to drop the dependent object whether CASCADE is
* specified or not.
* Example: a trigger that's created to enforce a foreign-key constraint
* is made internally dependent on the constraint's pg_constraint entry.
*
* DEPENDENCY_PIN ('p'): there is no dependent object; this type of entry
* is a signal that the system itself depends on the referenced object,
* and so that object must never be deleted. Entries of this type are
* created only during initdb. The fields for the dependent object
* contain zeroes.
*
* Other dependency flavors may be needed in future.
*/
typedef enum DependencyType
{
DEPENDENCY_NORMAL = 'n',
DEPENDENCY_AUTO = 'a',
DEPENDENCY_INTERNAL = 'i',
DEPENDENCY_PIN = 'p'
} DependencyType;
/*
* There is also a SharedDependencyType enum type that determines the exact
* semantics of an entry in pg_shdepend. Just like regular dependency entries,
* any pg_shdepend entry means that the referenced object cannot be dropped
* unless the dependent object is dropped at the same time. There are some
* additional rules however:
*
* (a) For a SHARED_DEPENDENCY_PIN entry, there is no dependent object --
* rather, the referenced object is an essential part of the system. This
* applies to the initdb-created superuser. Entries of this type are only
* created by initdb; objects in this category don't need further pg_shdepend
* entries if more objects come to depend on them.
*
* (b) a SHARED_DEPENDENCY_OWNER entry means that the referenced object is
* the role owning the dependent object. The referenced object must be
* a pg_authid entry.
*
* (c) a SHARED_DEPENDENCY_ACL entry means that the referenced object is
* a role mentioned in the ACL field of the dependent object. The referenced
* object must be a pg_authid entry. (SHARED_DEPENDENCY_ACL entries are not
* created for the owner of an object; hence two objects may be linked by
* one or the other, but not both, of these dependency types.)
*
* SHARED_DEPENDENCY_INVALID is a value used as a parameter in internal
* routines, and is not valid in the catalog itself.
*/
typedef enum SharedDependencyType
{
SHARED_DEPENDENCY_PIN = 'p',
SHARED_DEPENDENCY_OWNER = 'o',
SHARED_DEPENDENCY_ACL = 'a',
SHARED_DEPENDENCY_INVALID = 0
} SharedDependencyType;
/*
* The two objects related by a dependency are identified by ObjectAddresses.
*/
typedef struct ObjectAddress
{
Oid classId; /* Class Id from pg_class */
Oid objectId; /* OID of the object */
int32 objectSubId; /* Subitem within the object (column of table) */
} ObjectAddress;
/* expansible list of ObjectAddresses (private in dependency.c) */
typedef struct ObjectAddresses ObjectAddresses;
/*
* This enum covers all system catalogs whose OIDs can appear in
* pg_depend.classId or pg_shdepend.classId.
*/
typedef enum ObjectClass
{
OCLASS_CLASS, /* pg_class */
OCLASS_PROC, /* pg_proc */
OCLASS_TYPE, /* pg_type */
OCLASS_CAST, /* pg_cast */
OCLASS_CONSTRAINT, /* pg_constraint */
OCLASS_CONVERSION, /* pg_conversion */
OCLASS_DEFAULT, /* pg_attrdef */
OCLASS_LANGUAGE, /* pg_language */
OCLASS_OPERATOR, /* pg_operator */
OCLASS_OPCLASS, /* pg_opclass */
OCLASS_OPFAMILY, /* pg_opfamily */
OCLASS_AMOP, /* pg_amop */
OCLASS_AMPROC, /* pg_amproc */
OCLASS_REWRITE, /* pg_rewrite */
OCLASS_TRIGGER, /* pg_trigger */
OCLASS_SCHEMA, /* pg_namespace */
OCLASS_TSPARSER, /* pg_ts_parser */
OCLASS_TSDICT, /* pg_ts_dict */
OCLASS_TSTEMPLATE, /* pg_ts_template */
OCLASS_TSCONFIG, /* pg_ts_config */
OCLASS_ROLE, /* pg_authid */
OCLASS_DATABASE, /* pg_database */
OCLASS_TBLSPACE, /* pg_tablespace */
OCLASS_FDW, /* pg_foreign_data_wrapper */
OCLASS_FOREIGN_SERVER, /* pg_foreign_server */
OCLASS_USER_MAPPING, /* pg_user_mapping */
MAX_OCLASS /* MUST BE LAST */
} ObjectClass;
/* in dependency.c */
extern void performDeletion(const ObjectAddress *object,
DropBehavior behavior);
extern void performMultipleDeletions(const ObjectAddresses *objects,
DropBehavior behavior);
extern void deleteWhatDependsOn(const ObjectAddress *object,
bool showNotices);
extern void recordDependencyOnExpr(const ObjectAddress *depender,
Node *expr, List *rtable,
DependencyType behavior);
extern void recordDependencyOnSingleRelExpr(const ObjectAddress *depender,
Node *expr, Oid relId,
DependencyType behavior,
DependencyType self_behavior);
extern ObjectClass getObjectClass(const ObjectAddress *object);
extern char *getObjectDescription(const ObjectAddress *object);
extern ObjectAddresses *new_object_addresses(void);
extern void add_exact_object_address(const ObjectAddress *object,
ObjectAddresses *addrs);
extern bool object_address_present(const ObjectAddress *object,
const ObjectAddresses *addrs);
extern void record_object_address_dependencies(const ObjectAddress *depender,
ObjectAddresses *referenced,
DependencyType behavior);
extern void free_object_addresses(ObjectAddresses *addrs);
/* in pg_depend.c */
extern void recordDependencyOn(const ObjectAddress *depender,
const ObjectAddress *referenced,
DependencyType behavior);
extern void recordMultipleDependencies(const ObjectAddress *depender,
const ObjectAddress *referenced,
int nreferenced,
DependencyType behavior);
extern long deleteDependencyRecordsFor(Oid classId, Oid objectId);
extern long changeDependencyFor(Oid classId, Oid objectId,
Oid refClassId, Oid oldRefObjectId,
Oid newRefObjectId);
extern bool sequenceIsOwned(Oid seqId, Oid *tableId, int32 *colId);
extern void markSequenceUnowned(Oid seqId);
extern List *getOwnedSequences(Oid relid);
extern Oid get_constraint_index(Oid constraintId);
extern Oid get_index_constraint(Oid indexId);
/* in pg_shdepend.c */
extern void recordSharedDependencyOn(ObjectAddress *depender,
ObjectAddress *referenced,
SharedDependencyType deptype);
extern void deleteSharedDependencyRecordsFor(Oid classId, Oid objectId);
extern void recordDependencyOnOwner(Oid classId, Oid objectId, Oid owner);
extern void changeDependencyOnOwner(Oid classId, Oid objectId,
Oid newOwnerId);
extern void updateAclDependencies(Oid classId, Oid objectId,
Oid ownerId, bool isGrant,
int noldmembers, Oid *oldmembers,
int nnewmembers, Oid *newmembers);
extern bool checkSharedDependencies(Oid classId, Oid objectId,
char **detail_msg, char **detail_log_msg);
extern void copyTemplateDependencies(Oid templateDbId, Oid newDbId);
extern void dropDatabaseDependencies(Oid databaseId);
extern void shdepDropOwned(List *relids, DropBehavior behavior);
extern void shdepReassignOwned(List *relids, Oid newrole);
#endif /* DEPENDENCY_H */
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