/*------------------------------------------------------------------------- * * dependency.c * Routines to support inter-object dependencies. * * * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION * src/backend/catalog/dependency.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/genam.h" #include "access/htup_details.h" #include "access/table.h" #include "access/xact.h" #include "catalog/dependency.h" #include "catalog/heap.h" #include "catalog/index.h" #include "catalog/objectaccess.h" #include "catalog/pg_am.h" #include "catalog/pg_amop.h" #include "catalog/pg_amproc.h" #include "catalog/pg_attrdef.h" #include "catalog/pg_authid.h" #include "catalog/pg_cast.h" #include "catalog/pg_collation.h" #include "catalog/pg_constraint.h" #include "catalog/pg_conversion.h" #include "catalog/pg_database.h" #include "catalog/pg_default_acl.h" #include "catalog/pg_depend.h" #include "catalog/pg_event_trigger.h" #include "catalog/pg_extension.h" #include "catalog/pg_foreign_data_wrapper.h" #include "catalog/pg_foreign_server.h" #include "catalog/pg_init_privs.h" #include "catalog/pg_language.h" #include "catalog/pg_largeobject.h" #include "catalog/pg_namespace.h" #include "catalog/pg_opclass.h" #include "catalog/pg_operator.h" #include "catalog/pg_opfamily.h" #include "catalog/pg_policy.h" #include "catalog/pg_proc.h" #include "catalog/pg_publication.h" #include "catalog/pg_publication_rel.h" #include "catalog/pg_rewrite.h" #include "catalog/pg_statistic_ext.h" #include "catalog/pg_subscription.h" #include "catalog/pg_tablespace.h" #include "catalog/pg_transform.h" #include "catalog/pg_trigger.h" #include "catalog/pg_ts_config.h" #include "catalog/pg_ts_dict.h" #include "catalog/pg_ts_parser.h" #include "catalog/pg_ts_template.h" #include "catalog/pg_type.h" #include "catalog/pg_user_mapping.h" #include "commands/comment.h" #include "commands/defrem.h" #include "commands/event_trigger.h" #include "commands/extension.h" #include "commands/policy.h" #include "commands/publicationcmds.h" #include "commands/seclabel.h" #include "commands/sequence.h" #include "commands/trigger.h" #include "commands/typecmds.h" #include "nodes/nodeFuncs.h" #include "parser/parsetree.h" #include "rewrite/rewriteRemove.h" #include "storage/lmgr.h" #include "utils/acl.h" #include "utils/fmgroids.h" #include "utils/guc.h" #include "utils/lsyscache.h" #include "utils/syscache.h" /* * Deletion processing requires additional state for each ObjectAddress that * it's planning to delete. For simplicity and code-sharing we make the * ObjectAddresses code support arrays with or without this extra state. */ typedef struct { int flags; /* bitmask, see bit definitions below */ ObjectAddress dependee; /* object whose deletion forced this one */ } ObjectAddressExtra; /* ObjectAddressExtra flag bits */ #define DEPFLAG_ORIGINAL 0x0001 /* an original deletion target */ #define DEPFLAG_NORMAL 0x0002 /* reached via normal dependency */ #define DEPFLAG_AUTO 0x0004 /* reached via auto dependency */ #define DEPFLAG_INTERNAL 0x0008 /* reached via internal dependency */ #define DEPFLAG_PARTITION 0x0010 /* reached via partition dependency */ #define DEPFLAG_EXTENSION 0x0020 /* reached via extension dependency */ #define DEPFLAG_REVERSE 0x0040 /* reverse internal/extension link */ #define DEPFLAG_IS_PART 0x0080 /* has a partition dependency */ #define DEPFLAG_SUBOBJECT 0x0100 /* subobject of another deletable object */ /* expansible list of ObjectAddresses */ struct ObjectAddresses { ObjectAddress *refs; /* => palloc'd array */ ObjectAddressExtra *extras; /* => palloc'd array, or NULL if not used */ int numrefs; /* current number of references */ int maxrefs; /* current size of palloc'd array(s) */ }; /* typedef ObjectAddresses appears in dependency.h */ /* threaded list of ObjectAddresses, for recursion detection */ typedef struct ObjectAddressStack { const ObjectAddress *object; /* object being visited */ int flags; /* its current flag bits */ struct ObjectAddressStack *next; /* next outer stack level */ } ObjectAddressStack; /* temporary storage in findDependentObjects */ typedef struct { ObjectAddress obj; /* object to be deleted --- MUST BE FIRST */ int subflags; /* flags to pass down when recursing to obj */ } ObjectAddressAndFlags; /* for find_expr_references_walker */ typedef struct { ObjectAddresses *addrs; /* addresses being accumulated */ List *rtables; /* list of rangetables to resolve Vars */ } find_expr_references_context; /* * This constant table maps ObjectClasses to the corresponding catalog OIDs. * See also getObjectClass(). */ static const Oid object_classes[] = { RelationRelationId, /* OCLASS_CLASS */ ProcedureRelationId, /* OCLASS_PROC */ TypeRelationId, /* OCLASS_TYPE */ CastRelationId, /* OCLASS_CAST */ CollationRelationId, /* OCLASS_COLLATION */ ConstraintRelationId, /* OCLASS_CONSTRAINT */ ConversionRelationId, /* OCLASS_CONVERSION */ AttrDefaultRelationId, /* OCLASS_DEFAULT */ LanguageRelationId, /* OCLASS_LANGUAGE */ LargeObjectRelationId, /* OCLASS_LARGEOBJECT */ OperatorRelationId, /* OCLASS_OPERATOR */ OperatorClassRelationId, /* OCLASS_OPCLASS */ OperatorFamilyRelationId, /* OCLASS_OPFAMILY */ AccessMethodRelationId, /* OCLASS_AM */ AccessMethodOperatorRelationId, /* OCLASS_AMOP */ AccessMethodProcedureRelationId, /* OCLASS_AMPROC */ RewriteRelationId, /* OCLASS_REWRITE */ TriggerRelationId, /* OCLASS_TRIGGER */ NamespaceRelationId, /* OCLASS_SCHEMA */ StatisticExtRelationId, /* OCLASS_STATISTIC_EXT */ TSParserRelationId, /* OCLASS_TSPARSER */ TSDictionaryRelationId, /* OCLASS_TSDICT */ TSTemplateRelationId, /* OCLASS_TSTEMPLATE */ TSConfigRelationId, /* OCLASS_TSCONFIG */ AuthIdRelationId, /* OCLASS_ROLE */ DatabaseRelationId, /* OCLASS_DATABASE */ TableSpaceRelationId, /* OCLASS_TBLSPACE */ ForeignDataWrapperRelationId, /* OCLASS_FDW */ ForeignServerRelationId, /* OCLASS_FOREIGN_SERVER */ UserMappingRelationId, /* OCLASS_USER_MAPPING */ DefaultAclRelationId, /* OCLASS_DEFACL */ ExtensionRelationId, /* OCLASS_EXTENSION */ EventTriggerRelationId, /* OCLASS_EVENT_TRIGGER */ PolicyRelationId, /* OCLASS_POLICY */ PublicationRelationId, /* OCLASS_PUBLICATION */ PublicationRelRelationId, /* OCLASS_PUBLICATION_REL */ SubscriptionRelationId, /* OCLASS_SUBSCRIPTION */ TransformRelationId /* OCLASS_TRANSFORM */ }; static void findDependentObjects(const ObjectAddress *object, int objflags, int flags, ObjectAddressStack *stack, ObjectAddresses *targetObjects, const ObjectAddresses *pendingObjects, Relation *depRel); static void reportDependentObjects(const ObjectAddresses *targetObjects, DropBehavior behavior, int flags, const ObjectAddress *origObject); static void deleteOneObject(const ObjectAddress *object, Relation *depRel, int32 flags); static void doDeletion(const ObjectAddress *object, int flags); static bool find_expr_references_walker(Node *node, find_expr_references_context *context); static void eliminate_duplicate_dependencies(ObjectAddresses *addrs); static int object_address_comparator(const void *a, const void *b); static void add_object_address(ObjectClass oclass, Oid objectId, int32 subId, ObjectAddresses *addrs); static void add_exact_object_address_extra(const ObjectAddress *object, const ObjectAddressExtra *extra, ObjectAddresses *addrs); static bool object_address_present_add_flags(const ObjectAddress *object, int flags, ObjectAddresses *addrs); static bool stack_address_present_add_flags(const ObjectAddress *object, int flags, ObjectAddressStack *stack); static void DeleteInitPrivs(const ObjectAddress *object); /* * Go through the objects given running the final actions on them, and execute * the actual deletion. */ static void deleteObjectsInList(ObjectAddresses *targetObjects, Relation *depRel, int flags) { int i; /* * Keep track of objects for event triggers, if necessary. */ if (trackDroppedObjectsNeeded() && !(flags & PERFORM_DELETION_INTERNAL)) { for (i = 0; i < targetObjects->numrefs; i++) { const ObjectAddress *thisobj = &targetObjects->refs[i]; const ObjectAddressExtra *extra = &targetObjects->extras[i]; bool original = false; bool normal = false; if (extra->flags & DEPFLAG_ORIGINAL) original = true; if (extra->flags & DEPFLAG_NORMAL) normal = true; if (extra->flags & DEPFLAG_REVERSE) normal = true; if (EventTriggerSupportsObjectClass(getObjectClass(thisobj))) { EventTriggerSQLDropAddObject(thisobj, original, normal); } } } /* * Delete all the objects in the proper order, except that if told to, we * should skip the original object(s). */ for (i = 0; i < targetObjects->numrefs; i++) { ObjectAddress *thisobj = targetObjects->refs + i; ObjectAddressExtra *thisextra = targetObjects->extras + i; if ((flags & PERFORM_DELETION_SKIP_ORIGINAL) && (thisextra->flags & DEPFLAG_ORIGINAL)) continue; deleteOneObject(thisobj, depRel, flags); } } /* * performDeletion: attempt to drop the specified object. If CASCADE * behavior is specified, also drop any dependent objects (recursively). * If RESTRICT behavior is specified, error out if there are any dependent * objects, except for those that should be implicitly dropped anyway * according to the dependency type. * * This is the outer control routine for all forms of DROP that drop objects * that can participate in dependencies. Note that performMultipleDeletions * is a variant on the same theme; if you change anything here you'll likely * need to fix that too. * * Bits in the flags argument can include: * * PERFORM_DELETION_INTERNAL: indicates that the drop operation is not the * direct result of a user-initiated action. For example, when a temporary * schema is cleaned out so that a new backend can use it, or when a column * default is dropped as an intermediate step while adding a new one, that's * an internal operation. On the other hand, when we drop something because * the user issued a DROP statement against it, that's not internal. Currently * this suppresses calling event triggers and making some permissions checks. * * PERFORM_DELETION_CONCURRENTLY: perform the drop concurrently. This does * not currently work for anything except dropping indexes; don't set it for * other object types or you may get strange results. * * PERFORM_DELETION_QUIETLY: reduce message level from NOTICE to DEBUG2. * * PERFORM_DELETION_SKIP_ORIGINAL: do not delete the specified object(s), * but only what depends on it/them. * * PERFORM_DELETION_SKIP_EXTENSIONS: do not delete extensions, even when * deleting objects that are part of an extension. This should generally * be used only when dropping temporary objects. * * PERFORM_DELETION_CONCURRENT_LOCK: perform the drop normally but with a lock * as if it were concurrent. This is used by REINDEX CONCURRENTLY. * */ void performDeletion(const ObjectAddress *object, DropBehavior behavior, int flags) { Relation depRel; ObjectAddresses *targetObjects; /* * We save some cycles by opening pg_depend just once and passing the * Relation pointer down to all the recursive deletion steps. */ depRel = table_open(DependRelationId, RowExclusiveLock); /* * Acquire deletion lock on the target object. (Ideally the caller has * done this already, but many places are sloppy about it.) */ AcquireDeletionLock(object, 0); /* * Construct a list of objects to delete (ie, the given object plus * everything directly or indirectly dependent on it). */ targetObjects = new_object_addresses(); findDependentObjects(object, DEPFLAG_ORIGINAL, flags, NULL, /* empty stack */ targetObjects, NULL, /* no pendingObjects */ &depRel); /* * Check if deletion is allowed, and report about cascaded deletes. */ reportDependentObjects(targetObjects, behavior, flags, object); /* do the deed */ deleteObjectsInList(targetObjects, &depRel, flags); /* And clean up */ free_object_addresses(targetObjects); table_close(depRel, RowExclusiveLock); } /* * performMultipleDeletions: Similar to performDeletion, but act on multiple * objects at once. * * The main difference from issuing multiple performDeletion calls is that the * list of objects that would be implicitly dropped, for each object to be * dropped, is the union of the implicit-object list for all objects. This * makes each check be more relaxed. */ void performMultipleDeletions(const ObjectAddresses *objects, DropBehavior behavior, int flags) { Relation depRel; ObjectAddresses *targetObjects; int i; /* No work if no objects... */ if (objects->numrefs <= 0) return; /* * We save some cycles by opening pg_depend just once and passing the * Relation pointer down to all the recursive deletion steps. */ depRel = table_open(DependRelationId, RowExclusiveLock); /* * Construct a list of objects to delete (ie, the given objects plus * everything directly or indirectly dependent on them). Note that * because we pass the whole objects list as pendingObjects context, we * won't get a failure from trying to delete an object that is internally * dependent on another one in the list; we'll just skip that object and * delete it when we reach its owner. */ targetObjects = new_object_addresses(); for (i = 0; i < objects->numrefs; i++) { const ObjectAddress *thisobj = objects->refs + i; /* * Acquire deletion lock on each target object. (Ideally the caller * has done this already, but many places are sloppy about it.) */ AcquireDeletionLock(thisobj, flags); findDependentObjects(thisobj, DEPFLAG_ORIGINAL, flags, NULL, /* empty stack */ targetObjects, objects, &depRel); } /* * Check if deletion is allowed, and report about cascaded deletes. * * If there's exactly one object being deleted, report it the same way as * in performDeletion(), else we have to be vaguer. */ reportDependentObjects(targetObjects, behavior, flags, (objects->numrefs == 1 ? objects->refs : NULL)); /* do the deed */ deleteObjectsInList(targetObjects, &depRel, flags); /* And clean up */ free_object_addresses(targetObjects); table_close(depRel, RowExclusiveLock); } /* * findDependentObjects - find all objects that depend on 'object' * * For every object that depends on the starting object, acquire a deletion * lock on the object, add it to targetObjects (if not already there), * and recursively find objects that depend on it. An object's dependencies * will be placed into targetObjects before the object itself; this means * that the finished list's order represents a safe deletion order. * * The caller must already have a deletion lock on 'object' itself, * but must not have added it to targetObjects. (Note: there are corner * cases where we won't add the object either, and will also release the * caller-taken lock. This is a bit ugly, but the API is set up this way * to allow easy rechecking of an object's liveness after we lock it. See * notes within the function.) * * When dropping a whole object (subId = 0), we find dependencies for * its sub-objects too. * * object: the object to add to targetObjects and find dependencies on * objflags: flags to be ORed into the object's targetObjects entry * flags: PERFORM_DELETION_xxx flags for the deletion operation as a whole * stack: list of objects being visited in current recursion; topmost item * is the object that we recursed from (NULL for external callers) * targetObjects: list of objects that are scheduled to be deleted * pendingObjects: list of other objects slated for destruction, but * not necessarily in targetObjects yet (can be NULL if none) * *depRel: already opened pg_depend relation * * Note: objflags describes the reason for visiting this particular object * at this time, and is not passed down when recursing. The flags argument * is passed down, since it describes what we're doing overall. */ static void findDependentObjects(const ObjectAddress *object, int objflags, int flags, ObjectAddressStack *stack, ObjectAddresses *targetObjects, const ObjectAddresses *pendingObjects, Relation *depRel) { ScanKeyData key[3]; int nkeys; SysScanDesc scan; HeapTuple tup; ObjectAddress otherObject; ObjectAddress owningObject; ObjectAddress partitionObject; ObjectAddressAndFlags *dependentObjects; int numDependentObjects; int maxDependentObjects; ObjectAddressStack mystack; ObjectAddressExtra extra; /* * If the target object is already being visited in an outer recursion * level, just report the current objflags back to that level and exit. * This is needed to avoid infinite recursion in the face of circular * dependencies. * * The stack check alone would result in dependency loops being broken at * an arbitrary point, ie, the first member object of the loop to be * visited is the last one to be deleted. This is obviously unworkable. * However, the check for internal dependency below guarantees that we * will not break a loop at an internal dependency: if we enter the loop * at an "owned" object we will switch and start at the "owning" object * instead. We could probably hack something up to avoid breaking at an * auto dependency, too, if we had to. However there are no known cases * where that would be necessary. */ if (stack_address_present_add_flags(object, objflags, stack)) return; /* * It's also possible that the target object has already been completely * processed and put into targetObjects. If so, again we just add the * specified objflags to its entry and return. * * (Note: in these early-exit cases we could release the caller-taken * lock, since the object is presumably now locked multiple times; but it * seems not worth the cycles.) */ if (object_address_present_add_flags(object, objflags, targetObjects)) return; /* * The target object might be internally dependent on some other object * (its "owner"), and/or be a member of an extension (also considered its * owner). If so, and if we aren't recursing from the owning object, we * have to transform this deletion request into a deletion request of the * owning object. (We'll eventually recurse back to this object, but the * owning object has to be visited first so it will be deleted after.) The * way to find out about this is to scan the pg_depend entries that show * what this object depends on. */ ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->classId)); ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId)); if (object->objectSubId != 0) { /* Consider only dependencies of this sub-object */ ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(object->objectSubId)); nkeys = 3; } else { /* Consider dependencies of this object and any sub-objects it has */ nkeys = 2; } scan = systable_beginscan(*depRel, DependDependerIndexId, true, NULL, nkeys, key); /* initialize variables that loop may fill */ memset(&owningObject, 0, sizeof(owningObject)); memset(&partitionObject, 0, sizeof(partitionObject)); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(tup); otherObject.classId = foundDep->refclassid; otherObject.objectId = foundDep->refobjid; otherObject.objectSubId = foundDep->refobjsubid; /* * When scanning dependencies of a whole object, we may find rows * linking sub-objects of the object to the object itself. (Normally, * such a dependency is implicit, but we must make explicit ones in * some cases involving partitioning.) We must ignore such rows to * avoid infinite recursion. */ if (otherObject.classId == object->classId && otherObject.objectId == object->objectId && object->objectSubId == 0) continue; switch (foundDep->deptype) { case DEPENDENCY_NORMAL: case DEPENDENCY_AUTO: case DEPENDENCY_AUTO_EXTENSION: /* no problem */ break; case DEPENDENCY_EXTENSION: /* * If told to, ignore EXTENSION dependencies altogether. This * flag is normally used to prevent dropping extensions during * temporary-object cleanup, even if a temp object was created * during an extension script. */ if (flags & PERFORM_DELETION_SKIP_EXTENSIONS) break; /* * If the other object is the extension currently being * created/altered, ignore this dependency and continue with * the deletion. This allows dropping of an extension's * objects within the extension's scripts, as well as corner * cases such as dropping a transient object created within * such a script. */ if (creating_extension && otherObject.classId == ExtensionRelationId && otherObject.objectId == CurrentExtensionObject) break; /* Otherwise, treat this like an internal dependency */ /* FALL THRU */ case DEPENDENCY_INTERNAL: /* * This object is part of the internal implementation of * another object, or is part of the extension that is the * other object. We have three cases: * * 1. At the outermost recursion level, we must disallow the * DROP. However, if the owning object is listed in * pendingObjects, just release the caller's lock and return; * we'll eventually complete the DROP when we reach that entry * in the pending list. * * Note: the above statement is true only if this pg_depend * entry still exists by then; in principle, therefore, we * could miss deleting an item the user told us to delete. * However, no inconsistency can result: since we're at outer * level, there is no object depending on this one. */ if (stack == NULL) { if (pendingObjects && object_address_present(&otherObject, pendingObjects)) { systable_endscan(scan); /* need to release caller's lock; see notes below */ ReleaseDeletionLock(object); return; } /* * We postpone actually issuing the error message until * after this loop, so that we can make the behavior * independent of the ordering of pg_depend entries, at * least if there's not more than one INTERNAL and one * EXTENSION dependency. (If there's more, we'll complain * about a random one of them.) Prefer to complain about * EXTENSION, since that's generally a more important * dependency. */ if (!OidIsValid(owningObject.classId) || foundDep->deptype == DEPENDENCY_EXTENSION) owningObject = otherObject; break; } /* * 2. When recursing from the other end of this dependency, * it's okay to continue with the deletion. This holds when * recursing from a whole object that includes the nominal * other end as a component, too. Since there can be more * than one "owning" object, we have to allow matches that are * more than one level down in the stack. */ if (stack_address_present_add_flags(&otherObject, 0, stack)) break; /* * 3. Not all the owning objects have been visited, so * transform this deletion request into a delete of this * owning object. * * First, release caller's lock on this object and get * deletion lock on the owning object. (We must release * caller's lock to avoid deadlock against a concurrent * deletion of the owning object.) */ ReleaseDeletionLock(object); AcquireDeletionLock(&otherObject, 0); /* * The owning object might have been deleted while we waited * to lock it; if so, neither it nor the current object are * interesting anymore. We test this by checking the * pg_depend entry (see notes below). */ if (!systable_recheck_tuple(scan, tup)) { systable_endscan(scan); ReleaseDeletionLock(&otherObject); return; } /* * One way or the other, we're done with the scan; might as * well close it down before recursing, to reduce peak * resource consumption. */ systable_endscan(scan); /* * Okay, recurse to the owning object instead of proceeding. * * We do not need to stack the current object; we want the * traversal order to be as if the original reference had * linked to the owning object instead of this one. * * The dependency type is a "reverse" dependency: we need to * delete the owning object if this one is to be deleted, but * this linkage is never a reason for an automatic deletion. */ findDependentObjects(&otherObject, DEPFLAG_REVERSE, flags, stack, targetObjects, pendingObjects, depRel); /* * The current target object should have been added to * targetObjects while processing the owning object; but it * probably got only the flag bits associated with the * dependency we're looking at. We need to add the objflags * that were passed to this recursion level, too, else we may * get a bogus failure in reportDependentObjects (if, for * example, we were called due to a partition dependency). * * If somehow the current object didn't get scheduled for * deletion, bleat. (That would imply that somebody deleted * this dependency record before the recursion got to it.) * Another idea would be to reacquire lock on the current * object and resume trying to delete it, but it seems not * worth dealing with the race conditions inherent in that. */ if (!object_address_present_add_flags(object, objflags, targetObjects)) elog(ERROR, "deletion of owning object %s failed to delete %s", getObjectDescription(&otherObject, false), getObjectDescription(object, false)); /* And we're done here. */ return; case DEPENDENCY_PARTITION_PRI: /* * Remember that this object has a partition-type dependency. * After the dependency scan, we'll complain if we didn't find * a reason to delete one of its partition dependencies. */ objflags |= DEPFLAG_IS_PART; /* * Also remember the primary partition owner, for error * messages. If there are multiple primary owners (which * there should not be), we'll report a random one of them. */ partitionObject = otherObject; break; case DEPENDENCY_PARTITION_SEC: /* * Only use secondary partition owners in error messages if we * find no primary owner (which probably shouldn't happen). */ if (!(objflags & DEPFLAG_IS_PART)) partitionObject = otherObject; /* * Remember that this object has a partition-type dependency. * After the dependency scan, we'll complain if we didn't find * a reason to delete one of its partition dependencies. */ objflags |= DEPFLAG_IS_PART; break; case DEPENDENCY_PIN: /* * Should not happen; PIN dependencies should have zeroes in * the depender fields... */ elog(ERROR, "incorrect use of PIN dependency with %s", getObjectDescription(object, false)); break; default: elog(ERROR, "unrecognized dependency type '%c' for %s", foundDep->deptype, getObjectDescription(object, false)); break; } } systable_endscan(scan); /* * If we found an INTERNAL or EXTENSION dependency when we're at outer * level, complain about it now. If we also found a PARTITION dependency, * we prefer to report the PARTITION dependency. This is arbitrary but * seems to be more useful in practice. */ if (OidIsValid(owningObject.classId)) { char *otherObjDesc; if (OidIsValid(partitionObject.classId)) otherObjDesc = getObjectDescription(&partitionObject, false); else otherObjDesc = getObjectDescription(&owningObject, false); ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot drop %s because %s requires it", getObjectDescription(object, false), otherObjDesc), errhint("You can drop %s instead.", otherObjDesc))); } /* * Next, identify all objects that directly depend on the current object. * To ensure predictable deletion order, we collect them up in * dependentObjects and sort the list before actually recursing. (The * deletion order would be valid in any case, but doing this ensures * consistent output from DROP CASCADE commands, which is helpful for * regression testing.) */ maxDependentObjects = 128; /* arbitrary initial allocation */ dependentObjects = (ObjectAddressAndFlags *) palloc(maxDependentObjects * sizeof(ObjectAddressAndFlags)); numDependentObjects = 0; ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->classId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId)); if (object->objectSubId != 0) { ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(object->objectSubId)); nkeys = 3; } else nkeys = 2; scan = systable_beginscan(*depRel, DependReferenceIndexId, true, NULL, nkeys, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(tup); int subflags; otherObject.classId = foundDep->classid; otherObject.objectId = foundDep->objid; otherObject.objectSubId = foundDep->objsubid; /* * If what we found is a sub-object of the current object, just ignore * it. (Normally, such a dependency is implicit, but we must make * explicit ones in some cases involving partitioning.) */ if (otherObject.classId == object->classId && otherObject.objectId == object->objectId && object->objectSubId == 0) continue; /* * Must lock the dependent object before recursing to it. */ AcquireDeletionLock(&otherObject, 0); /* * The dependent object might have been deleted while we waited to * lock it; if so, we don't need to do anything more with it. We can * test this cheaply and independently of the object's type by seeing * if the pg_depend tuple we are looking at is still live. (If the * object got deleted, the tuple would have been deleted too.) */ if (!systable_recheck_tuple(scan, tup)) { /* release the now-useless lock */ ReleaseDeletionLock(&otherObject); /* and continue scanning for dependencies */ continue; } /* * We do need to delete it, so identify objflags to be passed down, * which depend on the dependency type. */ switch (foundDep->deptype) { case DEPENDENCY_NORMAL: subflags = DEPFLAG_NORMAL; break; case DEPENDENCY_AUTO: case DEPENDENCY_AUTO_EXTENSION: subflags = DEPFLAG_AUTO; break; case DEPENDENCY_INTERNAL: subflags = DEPFLAG_INTERNAL; break; case DEPENDENCY_PARTITION_PRI: case DEPENDENCY_PARTITION_SEC: subflags = DEPFLAG_PARTITION; break; case DEPENDENCY_EXTENSION: subflags = DEPFLAG_EXTENSION; break; case DEPENDENCY_PIN: /* * For a PIN dependency we just ereport immediately; there * won't be any others to report. */ ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot drop %s because it is required by the database system", getObjectDescription(object, false)))); subflags = 0; /* keep compiler quiet */ break; default: elog(ERROR, "unrecognized dependency type '%c' for %s", foundDep->deptype, getObjectDescription(object, false)); subflags = 0; /* keep compiler quiet */ break; } /* And add it to the pending-objects list */ if (numDependentObjects >= maxDependentObjects) { /* enlarge array if needed */ maxDependentObjects *= 2; dependentObjects = (ObjectAddressAndFlags *) repalloc(dependentObjects, maxDependentObjects * sizeof(ObjectAddressAndFlags)); } dependentObjects[numDependentObjects].obj = otherObject; dependentObjects[numDependentObjects].subflags = subflags; numDependentObjects++; } systable_endscan(scan); /* * Now we can sort the dependent objects into a stable visitation order. * It's safe to use object_address_comparator here since the obj field is * first within ObjectAddressAndFlags. */ if (numDependentObjects > 1) qsort((void *) dependentObjects, numDependentObjects, sizeof(ObjectAddressAndFlags), object_address_comparator); /* * Now recurse to the dependent objects. We must visit them first since * they have to be deleted before the current object. */ mystack.object = object; /* set up a new stack level */ mystack.flags = objflags; mystack.next = stack; for (int i = 0; i < numDependentObjects; i++) { ObjectAddressAndFlags *depObj = dependentObjects + i; findDependentObjects(&depObj->obj, depObj->subflags, flags, &mystack, targetObjects, pendingObjects, depRel); } pfree(dependentObjects); /* * Finally, we can add the target object to targetObjects. Be careful to * include any flags that were passed back down to us from inner recursion * levels. Record the "dependee" as being either the most important * partition owner if there is one, else the object we recursed from, if * any. (The logic in reportDependentObjects() is such that it can only * need one of those objects.) */ extra.flags = mystack.flags; if (extra.flags & DEPFLAG_IS_PART) extra.dependee = partitionObject; else if (stack) extra.dependee = *stack->object; else memset(&extra.dependee, 0, sizeof(extra.dependee)); add_exact_object_address_extra(object, &extra, targetObjects); } /* * reportDependentObjects - report about dependencies, and fail if RESTRICT * * Tell the user about dependent objects that we are going to delete * (or would need to delete, but are prevented by RESTRICT mode); * then error out if there are any and it's not CASCADE mode. * * targetObjects: list of objects that are scheduled to be deleted * behavior: RESTRICT or CASCADE * flags: other flags for the deletion operation * origObject: base object of deletion, or NULL if not available * (the latter case occurs in DROP OWNED) */ static void reportDependentObjects(const ObjectAddresses *targetObjects, DropBehavior behavior, int flags, const ObjectAddress *origObject) { int msglevel = (flags & PERFORM_DELETION_QUIETLY) ? DEBUG2 : NOTICE; bool ok = true; StringInfoData clientdetail; StringInfoData logdetail; int numReportedClient = 0; int numNotReportedClient = 0; int i; /* * If we need to delete any partition-dependent objects, make sure that * we're deleting at least one of their partition dependencies, too. That * can be detected by checking that we reached them by a PARTITION * dependency at some point. * * We just report the first such object, as in most cases the only way to * trigger this complaint is to explicitly try to delete one partition of * a partitioned object. */ for (i = 0; i < targetObjects->numrefs; i++) { const ObjectAddressExtra *extra = &targetObjects->extras[i]; if ((extra->flags & DEPFLAG_IS_PART) && !(extra->flags & DEPFLAG_PARTITION)) { const ObjectAddress *object = &targetObjects->refs[i]; char *otherObjDesc = getObjectDescription(&extra->dependee, false); ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot drop %s because %s requires it", getObjectDescription(object, false), otherObjDesc), errhint("You can drop %s instead.", otherObjDesc))); } } /* * If no error is to be thrown, and the msglevel is too low to be shown to * either client or server log, there's no need to do any of the rest of * the work. */ if (behavior == DROP_CASCADE && !message_level_is_interesting(msglevel)) return; /* * We limit the number of dependencies reported to the client to * MAX_REPORTED_DEPS, since client software may not deal well with * enormous error strings. The server log always gets a full report. */ #define MAX_REPORTED_DEPS 100 initStringInfo(&clientdetail); initStringInfo(&logdetail); /* * We process the list back to front (ie, in dependency order not deletion * order), since this makes for a more understandable display. */ for (i = targetObjects->numrefs - 1; i >= 0; i--) { const ObjectAddress *obj = &targetObjects->refs[i]; const ObjectAddressExtra *extra = &targetObjects->extras[i]; char *objDesc; /* Ignore the original deletion target(s) */ if (extra->flags & DEPFLAG_ORIGINAL) continue; /* Also ignore sub-objects; we'll report the whole object elsewhere */ if (extra->flags & DEPFLAG_SUBOBJECT) continue; objDesc = getObjectDescription(obj, false); /* An object being dropped concurrently doesn't need to be reported */ if (objDesc == NULL) continue; /* * If, at any stage of the recursive search, we reached the object via * an AUTO, INTERNAL, PARTITION, or EXTENSION dependency, then it's * okay to delete it even in RESTRICT mode. */ if (extra->flags & (DEPFLAG_AUTO | DEPFLAG_INTERNAL | DEPFLAG_PARTITION | DEPFLAG_EXTENSION)) { /* * auto-cascades are reported at DEBUG2, not msglevel. We don't * try to combine them with the regular message because the * results are too confusing when client_min_messages and * log_min_messages are different. */ ereport(DEBUG2, (errmsg_internal("drop auto-cascades to %s", objDesc))); } else if (behavior == DROP_RESTRICT) { char *otherDesc = getObjectDescription(&extra->dependee, false); if (otherDesc) { if (numReportedClient < MAX_REPORTED_DEPS) { /* separate entries with a newline */ if (clientdetail.len != 0) appendStringInfoChar(&clientdetail, '\n'); appendStringInfo(&clientdetail, _("%s depends on %s"), objDesc, otherDesc); numReportedClient++; } else numNotReportedClient++; /* separate entries with a newline */ if (logdetail.len != 0) appendStringInfoChar(&logdetail, '\n'); appendStringInfo(&logdetail, _("%s depends on %s"), objDesc, otherDesc); pfree(otherDesc); } else numNotReportedClient++; ok = false; } else { if (numReportedClient < MAX_REPORTED_DEPS) { /* separate entries with a newline */ if (clientdetail.len != 0) appendStringInfoChar(&clientdetail, '\n'); appendStringInfo(&clientdetail, _("drop cascades to %s"), objDesc); numReportedClient++; } else numNotReportedClient++; /* separate entries with a newline */ if (logdetail.len != 0) appendStringInfoChar(&logdetail, '\n'); appendStringInfo(&logdetail, _("drop cascades to %s"), objDesc); } pfree(objDesc); } if (numNotReportedClient > 0) appendStringInfo(&clientdetail, ngettext("\nand %d other object " "(see server log for list)", "\nand %d other objects " "(see server log for list)", numNotReportedClient), numNotReportedClient); if (!ok) { if (origObject) ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot drop %s because other objects depend on it", getObjectDescription(origObject, false)), errdetail("%s", clientdetail.data), errdetail_log("%s", logdetail.data), errhint("Use DROP ... CASCADE to drop the dependent objects too."))); else ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot drop desired object(s) because other objects depend on them"), errdetail("%s", clientdetail.data), errdetail_log("%s", logdetail.data), errhint("Use DROP ... CASCADE to drop the dependent objects too."))); } else if (numReportedClient > 1) { ereport(msglevel, /* translator: %d always has a value larger than 1 */ (errmsg_plural("drop cascades to %d other object", "drop cascades to %d other objects", numReportedClient + numNotReportedClient, numReportedClient + numNotReportedClient), errdetail("%s", clientdetail.data), errdetail_log("%s", logdetail.data))); } else if (numReportedClient == 1) { /* we just use the single item as-is */ ereport(msglevel, (errmsg_internal("%s", clientdetail.data))); } pfree(clientdetail.data); pfree(logdetail.data); } /* * Drop an object by OID. Works for most catalogs, if no special processing * is needed. */ static void DropObjectById(const ObjectAddress *object) { int cacheId; Relation rel; HeapTuple tup; cacheId = get_object_catcache_oid(object->classId); rel = table_open(object->classId, RowExclusiveLock); /* * Use the system cache for the oid column, if one exists. */ if (cacheId >= 0) { tup = SearchSysCache1(cacheId, ObjectIdGetDatum(object->objectId)); if (!HeapTupleIsValid(tup)) elog(ERROR, "cache lookup failed for %s %u", get_object_class_descr(object->classId), object->objectId); CatalogTupleDelete(rel, &tup->t_self); ReleaseSysCache(tup); } else { ScanKeyData skey[1]; SysScanDesc scan; ScanKeyInit(&skey[0], get_object_attnum_oid(object->classId), BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId)); scan = systable_beginscan(rel, get_object_oid_index(object->classId), true, NULL, 1, skey); /* we expect exactly one match */ tup = systable_getnext(scan); if (!HeapTupleIsValid(tup)) elog(ERROR, "could not find tuple for %s %u", get_object_class_descr(object->classId), object->objectId); CatalogTupleDelete(rel, &tup->t_self); systable_endscan(scan); } table_close(rel, RowExclusiveLock); } /* * deleteOneObject: delete a single object for performDeletion. * * *depRel is the already-open pg_depend relation. */ static void deleteOneObject(const ObjectAddress *object, Relation *depRel, int flags) { ScanKeyData key[3]; int nkeys; SysScanDesc scan; HeapTuple tup; /* DROP hook of the objects being removed */ InvokeObjectDropHookArg(object->classId, object->objectId, object->objectSubId, flags); /* * Close depRel if we are doing a drop concurrently. The object deletion * subroutine will commit the current transaction, so we can't keep the * relation open across doDeletion(). */ if (flags & PERFORM_DELETION_CONCURRENTLY) table_close(*depRel, RowExclusiveLock); /* * Delete the object itself, in an object-type-dependent way. * * We used to do this after removing the outgoing dependency links, but it * seems just as reasonable to do it beforehand. In the concurrent case * we *must* do it in this order, because we can't make any transactional * updates before calling doDeletion() --- they'd get committed right * away, which is not cool if the deletion then fails. */ doDeletion(object, flags); /* * Reopen depRel if we closed it above */ if (flags & PERFORM_DELETION_CONCURRENTLY) *depRel = table_open(DependRelationId, RowExclusiveLock); /* * Now remove any pg_depend records that link from this object to others. * (Any records linking to this object should be gone already.) * * When dropping a whole object (subId = 0), remove all pg_depend records * for its sub-objects too. */ ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->classId)); ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId)); if (object->objectSubId != 0) { ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(object->objectSubId)); nkeys = 3; } else nkeys = 2; scan = systable_beginscan(*depRel, DependDependerIndexId, true, NULL, nkeys, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { CatalogTupleDelete(*depRel, &tup->t_self); } systable_endscan(scan); /* * Delete shared dependency references related to this object. Again, if * subId = 0, remove records for sub-objects too. */ deleteSharedDependencyRecordsFor(object->classId, object->objectId, object->objectSubId); /* * Delete any comments, security labels, or initial privileges associated * with this object. (This is a convenient place to do these things, * rather than having every object type know to do it.) */ DeleteComments(object->objectId, object->classId, object->objectSubId); DeleteSecurityLabel(object); DeleteInitPrivs(object); /* * CommandCounterIncrement here to ensure that preceding changes are all * visible to the next deletion step. */ CommandCounterIncrement(); /* * And we're done! */ } /* * doDeletion: actually delete a single object */ static void doDeletion(const ObjectAddress *object, int flags) { switch (getObjectClass(object)) { case OCLASS_CLASS: { char relKind = get_rel_relkind(object->objectId); if (relKind == RELKIND_INDEX || relKind == RELKIND_PARTITIONED_INDEX) { bool concurrent = ((flags & PERFORM_DELETION_CONCURRENTLY) != 0); bool concurrent_lock_mode = ((flags & PERFORM_DELETION_CONCURRENT_LOCK) != 0); Assert(object->objectSubId == 0); index_drop(object->objectId, concurrent, concurrent_lock_mode); } else { if (object->objectSubId != 0) RemoveAttributeById(object->objectId, object->objectSubId); else heap_drop_with_catalog(object->objectId); } /* * for a sequence, in addition to dropping the heap, also * delete pg_sequence tuple */ if (relKind == RELKIND_SEQUENCE) DeleteSequenceTuple(object->objectId); break; } case OCLASS_PROC: RemoveFunctionById(object->objectId); break; case OCLASS_TYPE: RemoveTypeById(object->objectId); break; case OCLASS_CONSTRAINT: RemoveConstraintById(object->objectId); break; case OCLASS_DEFAULT: RemoveAttrDefaultById(object->objectId); break; case OCLASS_LARGEOBJECT: LargeObjectDrop(object->objectId); break; case OCLASS_OPERATOR: RemoveOperatorById(object->objectId); break; case OCLASS_REWRITE: RemoveRewriteRuleById(object->objectId); break; case OCLASS_TRIGGER: RemoveTriggerById(object->objectId); break; case OCLASS_STATISTIC_EXT: RemoveStatisticsById(object->objectId); break; case OCLASS_TSCONFIG: RemoveTSConfigurationById(object->objectId); break; case OCLASS_EXTENSION: RemoveExtensionById(object->objectId); break; case OCLASS_POLICY: RemovePolicyById(object->objectId); break; case OCLASS_PUBLICATION_REL: RemovePublicationRelById(object->objectId); break; case OCLASS_PUBLICATION: RemovePublicationById(object->objectId); break; case OCLASS_CAST: case OCLASS_COLLATION: case OCLASS_CONVERSION: case OCLASS_LANGUAGE: case OCLASS_OPCLASS: case OCLASS_OPFAMILY: case OCLASS_AM: case OCLASS_AMOP: case OCLASS_AMPROC: case OCLASS_SCHEMA: case OCLASS_TSPARSER: case OCLASS_TSDICT: case OCLASS_TSTEMPLATE: case OCLASS_FDW: case OCLASS_FOREIGN_SERVER: case OCLASS_USER_MAPPING: case OCLASS_DEFACL: case OCLASS_EVENT_TRIGGER: case OCLASS_TRANSFORM: DropObjectById(object); break; /* * These global object types are not supported here. */ case OCLASS_ROLE: case OCLASS_DATABASE: case OCLASS_TBLSPACE: case OCLASS_SUBSCRIPTION: elog(ERROR, "global objects cannot be deleted by doDeletion"); break; /* * There's intentionally no default: case here; we want the * compiler to warn if a new OCLASS hasn't been handled above. */ } } /* * AcquireDeletionLock - acquire a suitable lock for deleting an object * * Accepts the same flags as performDeletion (though currently only * PERFORM_DELETION_CONCURRENTLY does anything). * * We use LockRelation for relations, LockDatabaseObject for everything * else. Shared-across-databases objects are not currently supported * because no caller cares, but could be modified to use LockSharedObject. */ void AcquireDeletionLock(const ObjectAddress *object, int flags) { if (object->classId == RelationRelationId) { /* * In DROP INDEX CONCURRENTLY, take only ShareUpdateExclusiveLock on * the index for the moment. index_drop() will promote the lock once * it's safe to do so. In all other cases we need full exclusive * lock. */ if (flags & PERFORM_DELETION_CONCURRENTLY) LockRelationOid(object->objectId, ShareUpdateExclusiveLock); else LockRelationOid(object->objectId, AccessExclusiveLock); } else { /* assume we should lock the whole object not a sub-object */ LockDatabaseObject(object->classId, object->objectId, 0, AccessExclusiveLock); } } /* * ReleaseDeletionLock - release an object deletion lock * * Companion to AcquireDeletionLock. */ void ReleaseDeletionLock(const ObjectAddress *object) { if (object->classId == RelationRelationId) UnlockRelationOid(object->objectId, AccessExclusiveLock); else /* assume we should lock the whole object not a sub-object */ UnlockDatabaseObject(object->classId, object->objectId, 0, AccessExclusiveLock); } /* * recordDependencyOnExpr - find expression dependencies * * This is used to find the dependencies of rules, constraint expressions, * etc. * * Given an expression or query in node-tree form, find all the objects * it refers to (tables, columns, operators, functions, etc). Record * a dependency of the specified type from the given depender object * to each object mentioned in the expression. * * rtable is the rangetable to be used to interpret Vars with varlevelsup=0. * It can be NIL if no such variables are expected. */ void recordDependencyOnExpr(const ObjectAddress *depender, Node *expr, List *rtable, DependencyType behavior) { find_expr_references_context context; context.addrs = new_object_addresses(); /* Set up interpretation for Vars at varlevelsup = 0 */ context.rtables = list_make1(rtable); /* Scan the expression tree for referenceable objects */ find_expr_references_walker(expr, &context); /* Remove any duplicates */ eliminate_duplicate_dependencies(context.addrs); /* And record 'em */ recordMultipleDependencies(depender, context.addrs->refs, context.addrs->numrefs, behavior); free_object_addresses(context.addrs); } /* * recordDependencyOnSingleRelExpr - find expression dependencies * * As above, but only one relation is expected to be referenced (with * varno = 1 and varlevelsup = 0). Pass the relation OID instead of a * range table. An additional frammish is that dependencies on that * relation's component columns will be marked with 'self_behavior', * whereas 'behavior' is used for everything else; also, if 'reverse_self' * is true, those dependencies are reversed so that the columns are made * to depend on the table not vice versa. * * NOTE: the caller should ensure that a whole-table dependency on the * specified relation is created separately, if one is needed. In particular, * a whole-row Var "relation.*" will not cause this routine to emit any * dependency item. This is appropriate behavior for subexpressions of an * ordinary query, so other cases need to cope as necessary. */ void recordDependencyOnSingleRelExpr(const ObjectAddress *depender, Node *expr, Oid relId, DependencyType behavior, DependencyType self_behavior, bool reverse_self) { find_expr_references_context context; RangeTblEntry rte; context.addrs = new_object_addresses(); /* We gin up a rather bogus rangetable list to handle Vars */ MemSet(&rte, 0, sizeof(rte)); rte.type = T_RangeTblEntry; rte.rtekind = RTE_RELATION; rte.relid = relId; rte.relkind = RELKIND_RELATION; /* no need for exactness here */ rte.rellockmode = AccessShareLock; context.rtables = list_make1(list_make1(&rte)); /* Scan the expression tree for referenceable objects */ find_expr_references_walker(expr, &context); /* Remove any duplicates */ eliminate_duplicate_dependencies(context.addrs); /* Separate self-dependencies if necessary */ if ((behavior != self_behavior || reverse_self) && context.addrs->numrefs > 0) { ObjectAddresses *self_addrs; ObjectAddress *outobj; int oldref, outrefs; self_addrs = new_object_addresses(); outobj = context.addrs->refs; outrefs = 0; for (oldref = 0; oldref < context.addrs->numrefs; oldref++) { ObjectAddress *thisobj = context.addrs->refs + oldref; if (thisobj->classId == RelationRelationId && thisobj->objectId == relId) { /* Move this ref into self_addrs */ add_exact_object_address(thisobj, self_addrs); } else { /* Keep it in context.addrs */ *outobj = *thisobj; outobj++; outrefs++; } } context.addrs->numrefs = outrefs; /* Record the self-dependencies with the appropriate direction */ if (!reverse_self) recordMultipleDependencies(depender, self_addrs->refs, self_addrs->numrefs, self_behavior); else { /* Can't use recordMultipleDependencies, so do it the hard way */ int selfref; for (selfref = 0; selfref < self_addrs->numrefs; selfref++) { ObjectAddress *thisobj = self_addrs->refs + selfref; recordDependencyOn(thisobj, depender, self_behavior); } } free_object_addresses(self_addrs); } /* Record the external dependencies */ recordMultipleDependencies(depender, context.addrs->refs, context.addrs->numrefs, behavior); free_object_addresses(context.addrs); } /* * Recursively search an expression tree for object references. * * Note: in many cases we do not need to create dependencies on the datatypes * involved in an expression, because we'll have an indirect dependency via * some other object. For instance Var nodes depend on a column which depends * on the datatype, and OpExpr nodes depend on the operator which depends on * the datatype. However we do need a type dependency if there is no such * indirect dependency, as for example in Const and CoerceToDomain nodes. * * Similarly, we don't need to create dependencies on collations except where * the collation is being freshly introduced to the expression. */ static bool find_expr_references_walker(Node *node, find_expr_references_context *context) { if (node == NULL) return false; if (IsA(node, Var)) { Var *var = (Var *) node; List *rtable; RangeTblEntry *rte; /* Find matching rtable entry, or complain if not found */ if (var->varlevelsup >= list_length(context->rtables)) elog(ERROR, "invalid varlevelsup %d", var->varlevelsup); rtable = (List *) list_nth(context->rtables, var->varlevelsup); if (var->varno <= 0 || var->varno > list_length(rtable)) elog(ERROR, "invalid varno %d", var->varno); rte = rt_fetch(var->varno, rtable); /* * A whole-row Var references no specific columns, so adds no new * dependency. (We assume that there is a whole-table dependency * arising from each underlying rangetable entry. While we could * record such a dependency when finding a whole-row Var that * references a relation directly, it's quite unclear how to extend * that to whole-row Vars for JOINs, so it seems better to leave the * responsibility with the range table. Note that this poses some * risks for identifying dependencies of stand-alone expressions: * whole-table references may need to be created separately.) */ if (var->varattno == InvalidAttrNumber) return false; if (rte->rtekind == RTE_RELATION) { /* If it's a plain relation, reference this column */ add_object_address(OCLASS_CLASS, rte->relid, var->varattno, context->addrs); } /* * Vars referencing other RTE types require no additional work. In * particular, a join alias Var can be ignored, because it must * reference a merged USING column. The relevant join input columns * will also be referenced in the join qual, and any type coercion * functions involved in the alias expression will be dealt with when * we scan the RTE itself. */ return false; } else if (IsA(node, Const)) { Const *con = (Const *) node; Oid objoid; /* A constant must depend on the constant's datatype */ add_object_address(OCLASS_TYPE, con->consttype, 0, context->addrs); /* * We must also depend on the constant's collation: it could be * different from the datatype's, if a CollateExpr was const-folded to * a simple constant. However we can save work in the most common * case where the collation is "default", since we know that's pinned. */ if (OidIsValid(con->constcollid) && con->constcollid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, con->constcollid, 0, context->addrs); /* * If it's a regclass or similar literal referring to an existing * object, add a reference to that object. (Currently, only the * regclass and regconfig cases have any likely use, but we may as * well handle all the OID-alias datatypes consistently.) */ if (!con->constisnull) { switch (con->consttype) { case REGPROCOID: case REGPROCEDUREOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(PROCOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_PROC, objoid, 0, context->addrs); break; case REGOPEROID: case REGOPERATOROID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(OPEROID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_OPERATOR, objoid, 0, context->addrs); break; case REGCLASSOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(RELOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_CLASS, objoid, 0, context->addrs); break; case REGTYPEOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(TYPEOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_TYPE, objoid, 0, context->addrs); break; case REGCOLLATIONOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(COLLOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_COLLATION, objoid, 0, context->addrs); break; case REGCONFIGOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(TSCONFIGOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_TSCONFIG, objoid, 0, context->addrs); break; case REGDICTIONARYOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(TSDICTOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_TSDICT, objoid, 0, context->addrs); break; case REGNAMESPACEOID: objoid = DatumGetObjectId(con->constvalue); if (SearchSysCacheExists1(NAMESPACEOID, ObjectIdGetDatum(objoid))) add_object_address(OCLASS_SCHEMA, objoid, 0, context->addrs); break; /* * Dependencies for regrole should be shared among all * databases, so explicitly inhibit to have dependencies. */ case REGROLEOID: ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("constant of the type %s cannot be used here", "regrole"))); break; } } return false; } else if (IsA(node, Param)) { Param *param = (Param *) node; /* A parameter must depend on the parameter's datatype */ add_object_address(OCLASS_TYPE, param->paramtype, 0, context->addrs); /* and its collation, just as for Consts */ if (OidIsValid(param->paramcollid) && param->paramcollid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, param->paramcollid, 0, context->addrs); } else if (IsA(node, FuncExpr)) { FuncExpr *funcexpr = (FuncExpr *) node; add_object_address(OCLASS_PROC, funcexpr->funcid, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, OpExpr)) { OpExpr *opexpr = (OpExpr *) node; add_object_address(OCLASS_OPERATOR, opexpr->opno, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, DistinctExpr)) { DistinctExpr *distinctexpr = (DistinctExpr *) node; add_object_address(OCLASS_OPERATOR, distinctexpr->opno, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, NullIfExpr)) { NullIfExpr *nullifexpr = (NullIfExpr *) node; add_object_address(OCLASS_OPERATOR, nullifexpr->opno, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, ScalarArrayOpExpr)) { ScalarArrayOpExpr *opexpr = (ScalarArrayOpExpr *) node; add_object_address(OCLASS_OPERATOR, opexpr->opno, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, Aggref)) { Aggref *aggref = (Aggref *) node; add_object_address(OCLASS_PROC, aggref->aggfnoid, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, WindowFunc)) { WindowFunc *wfunc = (WindowFunc *) node; add_object_address(OCLASS_PROC, wfunc->winfnoid, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, SubscriptingRef)) { SubscriptingRef *sbsref = (SubscriptingRef *) node; /* * The refexpr should provide adequate dependency on refcontainertype, * and that type in turn depends on refelemtype. However, a custom * subscripting handler might set refrestype to something different * from either of those, in which case we'd better record it. */ if (sbsref->refrestype != sbsref->refcontainertype && sbsref->refrestype != sbsref->refelemtype) add_object_address(OCLASS_TYPE, sbsref->refrestype, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, SubPlan)) { /* Extra work needed here if we ever need this case */ elog(ERROR, "already-planned subqueries not supported"); } else if (IsA(node, FieldSelect)) { FieldSelect *fselect = (FieldSelect *) node; Oid argtype = getBaseType(exprType((Node *) fselect->arg)); Oid reltype = get_typ_typrelid(argtype); /* * We need a dependency on the specific column named in FieldSelect, * assuming we can identify the pg_class OID for it. (Probably we * always can at the moment, but in future it might be possible for * argtype to be RECORDOID.) If we can make a column dependency then * we shouldn't need a dependency on the column's type; but if we * can't, make a dependency on the type, as it might not appear * anywhere else in the expression. */ if (OidIsValid(reltype)) add_object_address(OCLASS_CLASS, reltype, fselect->fieldnum, context->addrs); else add_object_address(OCLASS_TYPE, fselect->resulttype, 0, context->addrs); /* the collation might not be referenced anywhere else, either */ if (OidIsValid(fselect->resultcollid) && fselect->resultcollid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, fselect->resultcollid, 0, context->addrs); } else if (IsA(node, FieldStore)) { FieldStore *fstore = (FieldStore *) node; Oid reltype = get_typ_typrelid(fstore->resulttype); /* similar considerations to FieldSelect, but multiple column(s) */ if (OidIsValid(reltype)) { ListCell *l; foreach(l, fstore->fieldnums) add_object_address(OCLASS_CLASS, reltype, lfirst_int(l), context->addrs); } else add_object_address(OCLASS_TYPE, fstore->resulttype, 0, context->addrs); } else if (IsA(node, RelabelType)) { RelabelType *relab = (RelabelType *) node; /* since there is no function dependency, need to depend on type */ add_object_address(OCLASS_TYPE, relab->resulttype, 0, context->addrs); /* the collation might not be referenced anywhere else, either */ if (OidIsValid(relab->resultcollid) && relab->resultcollid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, relab->resultcollid, 0, context->addrs); } else if (IsA(node, CoerceViaIO)) { CoerceViaIO *iocoerce = (CoerceViaIO *) node; /* since there is no exposed function, need to depend on type */ add_object_address(OCLASS_TYPE, iocoerce->resulttype, 0, context->addrs); /* the collation might not be referenced anywhere else, either */ if (OidIsValid(iocoerce->resultcollid) && iocoerce->resultcollid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, iocoerce->resultcollid, 0, context->addrs); } else if (IsA(node, ArrayCoerceExpr)) { ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) node; /* as above, depend on type */ add_object_address(OCLASS_TYPE, acoerce->resulttype, 0, context->addrs); /* the collation might not be referenced anywhere else, either */ if (OidIsValid(acoerce->resultcollid) && acoerce->resultcollid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, acoerce->resultcollid, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, ConvertRowtypeExpr)) { ConvertRowtypeExpr *cvt = (ConvertRowtypeExpr *) node; /* since there is no function dependency, need to depend on type */ add_object_address(OCLASS_TYPE, cvt->resulttype, 0, context->addrs); } else if (IsA(node, CollateExpr)) { CollateExpr *coll = (CollateExpr *) node; add_object_address(OCLASS_COLLATION, coll->collOid, 0, context->addrs); } else if (IsA(node, RowExpr)) { RowExpr *rowexpr = (RowExpr *) node; add_object_address(OCLASS_TYPE, rowexpr->row_typeid, 0, context->addrs); } else if (IsA(node, RowCompareExpr)) { RowCompareExpr *rcexpr = (RowCompareExpr *) node; ListCell *l; foreach(l, rcexpr->opnos) { add_object_address(OCLASS_OPERATOR, lfirst_oid(l), 0, context->addrs); } foreach(l, rcexpr->opfamilies) { add_object_address(OCLASS_OPFAMILY, lfirst_oid(l), 0, context->addrs); } /* fall through to examine arguments */ } else if (IsA(node, CoerceToDomain)) { CoerceToDomain *cd = (CoerceToDomain *) node; add_object_address(OCLASS_TYPE, cd->resulttype, 0, context->addrs); } else if (IsA(node, NextValueExpr)) { NextValueExpr *nve = (NextValueExpr *) node; add_object_address(OCLASS_CLASS, nve->seqid, 0, context->addrs); } else if (IsA(node, OnConflictExpr)) { OnConflictExpr *onconflict = (OnConflictExpr *) node; if (OidIsValid(onconflict->constraint)) add_object_address(OCLASS_CONSTRAINT, onconflict->constraint, 0, context->addrs); /* fall through to examine arguments */ } else if (IsA(node, SortGroupClause)) { SortGroupClause *sgc = (SortGroupClause *) node; add_object_address(OCLASS_OPERATOR, sgc->eqop, 0, context->addrs); if (OidIsValid(sgc->sortop)) add_object_address(OCLASS_OPERATOR, sgc->sortop, 0, context->addrs); return false; } else if (IsA(node, WindowClause)) { WindowClause *wc = (WindowClause *) node; if (OidIsValid(wc->startInRangeFunc)) add_object_address(OCLASS_PROC, wc->startInRangeFunc, 0, context->addrs); if (OidIsValid(wc->endInRangeFunc)) add_object_address(OCLASS_PROC, wc->endInRangeFunc, 0, context->addrs); if (OidIsValid(wc->inRangeColl) && wc->inRangeColl != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, wc->inRangeColl, 0, context->addrs); /* fall through to examine substructure */ } else if (IsA(node, CTECycleClause)) { CTECycleClause *cc = (CTECycleClause *) node; if (OidIsValid(cc->cycle_mark_type)) add_object_address(OCLASS_TYPE, cc->cycle_mark_type, 0, context->addrs); if (OidIsValid(cc->cycle_mark_collation)) add_object_address(OCLASS_COLLATION, cc->cycle_mark_collation, 0, context->addrs); if (OidIsValid(cc->cycle_mark_neop)) add_object_address(OCLASS_OPERATOR, cc->cycle_mark_neop, 0, context->addrs); /* fall through to examine substructure */ } else if (IsA(node, Query)) { /* Recurse into RTE subquery or not-yet-planned sublink subquery */ Query *query = (Query *) node; ListCell *lc; bool result; /* * Add whole-relation refs for each plain relation mentioned in the * subquery's rtable, and ensure we add refs for any type-coercion * functions used in join alias lists. * * Note: query_tree_walker takes care of recursing into RTE_FUNCTION * RTEs, subqueries, etc, so no need to do that here. But we must * tell it not to visit join alias lists, or we'll add refs for join * input columns whether or not they are actually used in our query. * * Note: we don't need to worry about collations mentioned in * RTE_VALUES or RTE_CTE RTEs, because those must just duplicate * collations referenced in other parts of the Query. We do have to * worry about collations mentioned in RTE_FUNCTION, but we take care * of those when we recurse to the RangeTblFunction node(s). */ foreach(lc, query->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc); switch (rte->rtekind) { case RTE_RELATION: add_object_address(OCLASS_CLASS, rte->relid, 0, context->addrs); break; case RTE_JOIN: /* * Examine joinaliasvars entries only for merged JOIN * USING columns. Only those entries could contain * type-coercion functions. Also, their join input * columns must be referenced in the join quals, so this * won't accidentally add refs to otherwise-unused join * input columns. (We want to ref the type coercion * functions even if the merged column isn't explicitly * used anywhere, to protect possible expansion of the * join RTE as a whole-row var, and because it seems like * a bad idea to allow dropping a function that's present * in our query tree, whether or not it could get called.) */ context->rtables = lcons(query->rtable, context->rtables); for (int i = 0; i < rte->joinmergedcols; i++) { Node *aliasvar = list_nth(rte->joinaliasvars, i); if (!IsA(aliasvar, Var)) find_expr_references_walker(aliasvar, context); } context->rtables = list_delete_first(context->rtables); break; default: break; } } /* * If the query is an INSERT or UPDATE, we should create a dependency * on each target column, to prevent the specific target column from * being dropped. Although we will visit the TargetEntry nodes again * during query_tree_walker, we won't have enough context to do this * conveniently, so do it here. */ if (query->commandType == CMD_INSERT || query->commandType == CMD_UPDATE) { RangeTblEntry *rte; if (query->resultRelation <= 0 || query->resultRelation > list_length(query->rtable)) elog(ERROR, "invalid resultRelation %d", query->resultRelation); rte = rt_fetch(query->resultRelation, query->rtable); if (rte->rtekind == RTE_RELATION) { foreach(lc, query->targetList) { TargetEntry *tle = (TargetEntry *) lfirst(lc); if (tle->resjunk) continue; /* ignore junk tlist items */ add_object_address(OCLASS_CLASS, rte->relid, tle->resno, context->addrs); } } } /* * Add dependencies on constraints listed in query's constraintDeps */ foreach(lc, query->constraintDeps) { add_object_address(OCLASS_CONSTRAINT, lfirst_oid(lc), 0, context->addrs); } /* Examine substructure of query */ context->rtables = lcons(query->rtable, context->rtables); result = query_tree_walker(query, find_expr_references_walker, (void *) context, QTW_IGNORE_JOINALIASES | QTW_EXAMINE_SORTGROUP); context->rtables = list_delete_first(context->rtables); return result; } else if (IsA(node, SetOperationStmt)) { SetOperationStmt *setop = (SetOperationStmt *) node; /* we need to look at the groupClauses for operator references */ find_expr_references_walker((Node *) setop->groupClauses, context); /* fall through to examine child nodes */ } else if (IsA(node, RangeTblFunction)) { RangeTblFunction *rtfunc = (RangeTblFunction *) node; ListCell *ct; /* * Add refs for any datatypes and collations used in a column * definition list for a RECORD function. (For other cases, it should * be enough to depend on the function itself.) */ foreach(ct, rtfunc->funccoltypes) { add_object_address(OCLASS_TYPE, lfirst_oid(ct), 0, context->addrs); } foreach(ct, rtfunc->funccolcollations) { Oid collid = lfirst_oid(ct); if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, collid, 0, context->addrs); } } else if (IsA(node, TableFunc)) { TableFunc *tf = (TableFunc *) node; ListCell *ct; /* * Add refs for the datatypes and collations used in the TableFunc. */ foreach(ct, tf->coltypes) { add_object_address(OCLASS_TYPE, lfirst_oid(ct), 0, context->addrs); } foreach(ct, tf->colcollations) { Oid collid = lfirst_oid(ct); if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID) add_object_address(OCLASS_COLLATION, collid, 0, context->addrs); } } else if (IsA(node, TableSampleClause)) { TableSampleClause *tsc = (TableSampleClause *) node; add_object_address(OCLASS_PROC, tsc->tsmhandler, 0, context->addrs); /* fall through to examine arguments */ } return expression_tree_walker(node, find_expr_references_walker, (void *) context); } /* * Given an array of dependency references, eliminate any duplicates. */ static void eliminate_duplicate_dependencies(ObjectAddresses *addrs) { ObjectAddress *priorobj; int oldref, newrefs; /* * We can't sort if the array has "extra" data, because there's no way to * keep it in sync. Fortunately that combination of features is not * needed. */ Assert(!addrs->extras); if (addrs->numrefs <= 1) return; /* nothing to do */ /* Sort the refs so that duplicates are adjacent */ qsort((void *) addrs->refs, addrs->numrefs, sizeof(ObjectAddress), object_address_comparator); /* Remove dups */ priorobj = addrs->refs; newrefs = 1; for (oldref = 1; oldref < addrs->numrefs; oldref++) { ObjectAddress *thisobj = addrs->refs + oldref; if (priorobj->classId == thisobj->classId && priorobj->objectId == thisobj->objectId) { if (priorobj->objectSubId == thisobj->objectSubId) continue; /* identical, so drop thisobj */ /* * If we have a whole-object reference and a reference to a part * of the same object, we don't need the whole-object reference * (for example, we don't need to reference both table foo and * column foo.bar). The whole-object reference will always appear * first in the sorted list. */ if (priorobj->objectSubId == 0) { /* replace whole ref with partial */ priorobj->objectSubId = thisobj->objectSubId; continue; } } /* Not identical, so add thisobj to output set */ priorobj++; *priorobj = *thisobj; newrefs++; } addrs->numrefs = newrefs; } /* * qsort comparator for ObjectAddress items */ static int object_address_comparator(const void *a, const void *b) { const ObjectAddress *obja = (const ObjectAddress *) a; const ObjectAddress *objb = (const ObjectAddress *) b; /* * Primary sort key is OID descending. Most of the time, this will result * in putting newer objects before older ones, which is likely to be the * right order to delete in. */ if (obja->objectId > objb->objectId) return -1; if (obja->objectId < objb->objectId) return 1; /* * Next sort on catalog ID, in case identical OIDs appear in different * catalogs. Sort direction is pretty arbitrary here. */ if (obja->classId < objb->classId) return -1; if (obja->classId > objb->classId) return 1; /* * Last, sort on object subId. * * We sort the subId as an unsigned int so that 0 (the whole object) will * come first. This is essential for eliminate_duplicate_dependencies, * and is also the best order for findDependentObjects. */ if ((unsigned int) obja->objectSubId < (unsigned int) objb->objectSubId) return -1; if ((unsigned int) obja->objectSubId > (unsigned int) objb->objectSubId) return 1; return 0; } /* * Routines for handling an expansible array of ObjectAddress items. * * new_object_addresses: create a new ObjectAddresses array. */ ObjectAddresses * new_object_addresses(void) { ObjectAddresses *addrs; addrs = palloc(sizeof(ObjectAddresses)); addrs->numrefs = 0; addrs->maxrefs = 32; addrs->refs = (ObjectAddress *) palloc(addrs->maxrefs * sizeof(ObjectAddress)); addrs->extras = NULL; /* until/unless needed */ return addrs; } /* * Add an entry to an ObjectAddresses array. * * It is convenient to specify the class by ObjectClass rather than directly * by catalog OID. */ static void add_object_address(ObjectClass oclass, Oid objectId, int32 subId, ObjectAddresses *addrs) { ObjectAddress *item; /* * Make sure object_classes is kept up to date with the ObjectClass enum. */ StaticAssertStmt(lengthof(object_classes) == LAST_OCLASS + 1, "object_classes[] must cover all ObjectClasses"); /* enlarge array if needed */ if (addrs->numrefs >= addrs->maxrefs) { addrs->maxrefs *= 2; addrs->refs = (ObjectAddress *) repalloc(addrs->refs, addrs->maxrefs * sizeof(ObjectAddress)); Assert(!addrs->extras); } /* record this item */ item = addrs->refs + addrs->numrefs; item->classId = object_classes[oclass]; item->objectId = objectId; item->objectSubId = subId; addrs->numrefs++; } /* * Add an entry to an ObjectAddresses array. * * As above, but specify entry exactly. */ void add_exact_object_address(const ObjectAddress *object, ObjectAddresses *addrs) { ObjectAddress *item; /* enlarge array if needed */ if (addrs->numrefs >= addrs->maxrefs) { addrs->maxrefs *= 2; addrs->refs = (ObjectAddress *) repalloc(addrs->refs, addrs->maxrefs * sizeof(ObjectAddress)); Assert(!addrs->extras); } /* record this item */ item = addrs->refs + addrs->numrefs; *item = *object; addrs->numrefs++; } /* * Add an entry to an ObjectAddresses array. * * As above, but specify entry exactly and provide some "extra" data too. */ static void add_exact_object_address_extra(const ObjectAddress *object, const ObjectAddressExtra *extra, ObjectAddresses *addrs) { ObjectAddress *item; ObjectAddressExtra *itemextra; /* allocate extra space if first time */ if (!addrs->extras) addrs->extras = (ObjectAddressExtra *) palloc(addrs->maxrefs * sizeof(ObjectAddressExtra)); /* enlarge array if needed */ if (addrs->numrefs >= addrs->maxrefs) { addrs->maxrefs *= 2; addrs->refs = (ObjectAddress *) repalloc(addrs->refs, addrs->maxrefs * sizeof(ObjectAddress)); addrs->extras = (ObjectAddressExtra *) repalloc(addrs->extras, addrs->maxrefs * sizeof(ObjectAddressExtra)); } /* record this item */ item = addrs->refs + addrs->numrefs; *item = *object; itemextra = addrs->extras + addrs->numrefs; *itemextra = *extra; addrs->numrefs++; } /* * Test whether an object is present in an ObjectAddresses array. * * We return "true" if object is a subobject of something in the array, too. */ bool object_address_present(const ObjectAddress *object, const ObjectAddresses *addrs) { int i; for (i = addrs->numrefs - 1; i >= 0; i--) { const ObjectAddress *thisobj = addrs->refs + i; if (object->classId == thisobj->classId && object->objectId == thisobj->objectId) { if (object->objectSubId == thisobj->objectSubId || thisobj->objectSubId == 0) return true; } } return false; } /* * As above, except that if the object is present then also OR the given * flags into its associated extra data (which must exist). */ static bool object_address_present_add_flags(const ObjectAddress *object, int flags, ObjectAddresses *addrs) { bool result = false; int i; for (i = addrs->numrefs - 1; i >= 0; i--) { ObjectAddress *thisobj = addrs->refs + i; if (object->classId == thisobj->classId && object->objectId == thisobj->objectId) { if (object->objectSubId == thisobj->objectSubId) { ObjectAddressExtra *thisextra = addrs->extras + i; thisextra->flags |= flags; result = true; } else if (thisobj->objectSubId == 0) { /* * We get here if we find a need to delete a column after * having already decided to drop its whole table. Obviously * we no longer need to drop the subobject, so report that we * found the subobject in the array. But don't plaster its * flags on the whole object. */ result = true; } else if (object->objectSubId == 0) { /* * We get here if we find a need to delete a whole table after * having already decided to drop one of its columns. We * can't report that the whole object is in the array, but we * should mark the subobject with the whole object's flags. * * It might seem attractive to physically delete the column's * array entry, or at least mark it as no longer needing * separate deletion. But that could lead to, e.g., dropping * the column's datatype before we drop the table, which does * not seem like a good idea. This is a very rare situation * in practice, so we just take the hit of doing a separate * DROP COLUMN action even though we know we're gonna delete * the table later. * * What we can do, though, is mark this as a subobject so that * we don't report it separately, which is confusing because * it's unpredictable whether it happens or not. But do so * only if flags != 0 (flags == 0 is a read-only probe). * * Because there could be other subobjects of this object in * the array, this case means we always have to loop through * the whole array; we cannot exit early on a match. */ ObjectAddressExtra *thisextra = addrs->extras + i; if (flags) thisextra->flags |= (flags | DEPFLAG_SUBOBJECT); } } } return result; } /* * Similar to above, except we search an ObjectAddressStack. */ static bool stack_address_present_add_flags(const ObjectAddress *object, int flags, ObjectAddressStack *stack) { bool result = false; ObjectAddressStack *stackptr; for (stackptr = stack; stackptr; stackptr = stackptr->next) { const ObjectAddress *thisobj = stackptr->object; if (object->classId == thisobj->classId && object->objectId == thisobj->objectId) { if (object->objectSubId == thisobj->objectSubId) { stackptr->flags |= flags; result = true; } else if (thisobj->objectSubId == 0) { /* * We're visiting a column with whole table already on stack. * As in object_address_present_add_flags(), we can skip * further processing of the subobject, but we don't want to * propagate flags for the subobject to the whole object. */ result = true; } else if (object->objectSubId == 0) { /* * We're visiting a table with column already on stack. As in * object_address_present_add_flags(), we should propagate * flags for the whole object to each of its subobjects. */ if (flags) stackptr->flags |= (flags | DEPFLAG_SUBOBJECT); } } } return result; } /* * Record multiple dependencies from an ObjectAddresses array, after first * removing any duplicates. */ void record_object_address_dependencies(const ObjectAddress *depender, ObjectAddresses *referenced, DependencyType behavior) { eliminate_duplicate_dependencies(referenced); recordMultipleDependencies(depender, referenced->refs, referenced->numrefs, behavior); } /* * Sort the items in an ObjectAddresses array. * * The major sort key is OID-descending, so that newer objects will be listed * first in most cases. This is primarily useful for ensuring stable outputs * from regression tests; it's not recommended if the order of the objects is * determined by user input, such as the order of targets in a DROP command. */ void sort_object_addresses(ObjectAddresses *addrs) { if (addrs->numrefs > 1) qsort((void *) addrs->refs, addrs->numrefs, sizeof(ObjectAddress), object_address_comparator); } /* * Clean up when done with an ObjectAddresses array. */ void free_object_addresses(ObjectAddresses *addrs) { pfree(addrs->refs); if (addrs->extras) pfree(addrs->extras); pfree(addrs); } /* * Determine the class of a given object identified by objectAddress. * * This function is essentially the reverse mapping for the object_classes[] * table. We implement it as a function because the OIDs aren't consecutive. */ ObjectClass getObjectClass(const ObjectAddress *object) { /* only pg_class entries can have nonzero objectSubId */ if (object->classId != RelationRelationId && object->objectSubId != 0) elog(ERROR, "invalid non-zero objectSubId for object class %u", object->classId); switch (object->classId) { case RelationRelationId: /* caller must check objectSubId */ return OCLASS_CLASS; case ProcedureRelationId: return OCLASS_PROC; case TypeRelationId: return OCLASS_TYPE; case CastRelationId: return OCLASS_CAST; case CollationRelationId: return OCLASS_COLLATION; case ConstraintRelationId: return OCLASS_CONSTRAINT; case ConversionRelationId: return OCLASS_CONVERSION; case AttrDefaultRelationId: return OCLASS_DEFAULT; case LanguageRelationId: return OCLASS_LANGUAGE; case LargeObjectRelationId: return OCLASS_LARGEOBJECT; case OperatorRelationId: return OCLASS_OPERATOR; case OperatorClassRelationId: return OCLASS_OPCLASS; case OperatorFamilyRelationId: return OCLASS_OPFAMILY; case AccessMethodRelationId: return OCLASS_AM; case AccessMethodOperatorRelationId: return OCLASS_AMOP; case AccessMethodProcedureRelationId: return OCLASS_AMPROC; case RewriteRelationId: return OCLASS_REWRITE; case TriggerRelationId: return OCLASS_TRIGGER; case NamespaceRelationId: return OCLASS_SCHEMA; case StatisticExtRelationId: return OCLASS_STATISTIC_EXT; case TSParserRelationId: return OCLASS_TSPARSER; case TSDictionaryRelationId: return OCLASS_TSDICT; case TSTemplateRelationId: return OCLASS_TSTEMPLATE; case TSConfigRelationId: return OCLASS_TSCONFIG; case AuthIdRelationId: return OCLASS_ROLE; case DatabaseRelationId: return OCLASS_DATABASE; case TableSpaceRelationId: return OCLASS_TBLSPACE; case ForeignDataWrapperRelationId: return OCLASS_FDW; case ForeignServerRelationId: return OCLASS_FOREIGN_SERVER; case UserMappingRelationId: return OCLASS_USER_MAPPING; case DefaultAclRelationId: return OCLASS_DEFACL; case ExtensionRelationId: return OCLASS_EXTENSION; case EventTriggerRelationId: return OCLASS_EVENT_TRIGGER; case PolicyRelationId: return OCLASS_POLICY; case PublicationRelationId: return OCLASS_PUBLICATION; case PublicationRelRelationId: return OCLASS_PUBLICATION_REL; case SubscriptionRelationId: return OCLASS_SUBSCRIPTION; case TransformRelationId: return OCLASS_TRANSFORM; } /* shouldn't get here */ elog(ERROR, "unrecognized object class: %u", object->classId); return OCLASS_CLASS; /* keep compiler quiet */ } /* * delete initial ACL for extension objects */ static void DeleteInitPrivs(const ObjectAddress *object) { Relation relation; ScanKeyData key[3]; SysScanDesc scan; HeapTuple oldtuple; relation = table_open(InitPrivsRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_init_privs_objoid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId)); ScanKeyInit(&key[1], Anum_pg_init_privs_classoid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->classId)); ScanKeyInit(&key[2], Anum_pg_init_privs_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(object->objectSubId)); scan = systable_beginscan(relation, InitPrivsObjIndexId, true, NULL, 3, key); while (HeapTupleIsValid(oldtuple = systable_getnext(scan))) CatalogTupleDelete(relation, &oldtuple->t_self); systable_endscan(scan); table_close(relation, RowExclusiveLock); }