dependency.c File Reference

#include "postgres.h"
#include "access/htup_details.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/proclang.h"
#include "commands/publicationcmds.h"
#include "commands/schemacmds.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/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "utils/tqual.h"

Include dependency graph for dependency.c:

Go to the source code of this file.

Data Structures
struct	ObjectAddressExtra
struct	ObjectAddresses
struct	ObjectAddressStack
struct	find_expr_references_context

Macros
#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_EXTENSION   0x0010 /* reached via extension dependency */
#define	DEPFLAG_REVERSE   0x0020 /* reverse internal/extension link */
#define	MAX_REPORTED_DEPS   100

Typedefs
typedef struct ObjectAddressStack	ObjectAddressStack

Functions
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 void	AcquireDeletionLock (const ObjectAddress *object, int flags)
static void	ReleaseDeletionLock (const ObjectAddress *object)
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)
static void	deleteObjectsInList (ObjectAddresses *targetObjects, Relation *depRel, int flags)
void	performDeletion (const ObjectAddress *object, DropBehavior behavior, int flags)
void	performMultipleDeletions (const ObjectAddresses *objects, DropBehavior behavior, int flags)
static void	deleteOneObject (const ObjectAddress *object, Relation *depRel, int flags)
void	recordDependencyOnExpr (const ObjectAddress *depender, Node *expr, List *rtable, DependencyType behavior)
void	recordDependencyOnSingleRelExpr (const ObjectAddress *depender, Node *expr, Oid relId, DependencyType behavior, DependencyType self_behavior, bool ignore_self)
ObjectAddresses *	new_object_addresses (void)
void	add_exact_object_address (const ObjectAddress *object, ObjectAddresses *addrs)
bool	object_address_present (const ObjectAddress *object, const ObjectAddresses *addrs)
void	record_object_address_dependencies (const ObjectAddress *depender, ObjectAddresses *referenced, DependencyType behavior)
void	free_object_addresses (ObjectAddresses *addrs)
ObjectClass	getObjectClass (const ObjectAddress *object)

Variables
static const Oid	object_classes []

Macro Definition Documentation

DEPFLAG_AUTO

#define DEPFLAG_AUTO   0x0004 /* reached via auto dependency */

Definition at line 99 of file dependency.c.

Referenced by findDependentObjects(), and reportDependentObjects().

DEPFLAG_EXTENSION

#define DEPFLAG_EXTENSION   0x0010 /* reached via extension dependency */

Definition at line 101 of file dependency.c.

Referenced by findDependentObjects(), and reportDependentObjects().

DEPFLAG_INTERNAL

#define DEPFLAG_INTERNAL   0x0008 /* reached via internal dependency */

Definition at line 100 of file dependency.c.

Referenced by findDependentObjects(), and reportDependentObjects().

DEPFLAG_NORMAL

#define DEPFLAG_NORMAL   0x0002 /* reached via normal dependency */

Definition at line 98 of file dependency.c.

Referenced by deleteObjectsInList(), and findDependentObjects().

DEPFLAG_ORIGINAL

#define DEPFLAG_ORIGINAL   0x0001 /* an original deletion target */

Definition at line 97 of file dependency.c.

Referenced by deleteObjectsInList(), performDeletion(), performMultipleDeletions(), and reportDependentObjects().

DEPFLAG_REVERSE

#define DEPFLAG_REVERSE   0x0020 /* reverse internal/extension link */

Definition at line 102 of file dependency.c.

Referenced by deleteObjectsInList(), and findDependentObjects().

MAX_REPORTED_DEPS

#define MAX_REPORTED_DEPS   100

Referenced by reportDependentObjects().

Typedef Documentation

ObjectAddressStack

typedef struct ObjectAddressStack ObjectAddressStack

Function Documentation

AcquireDeletionLock()

static void AcquireDeletionLock ( const ObjectAddress *  object, int  flags  )

static

Definition at line 1308 of file dependency.c.

References AccessExclusiveLock, ObjectAddress::classId, LockDatabaseObject(), LockRelationOid(), ObjectAddress::objectId, PERFORM_DELETION_CONCURRENTLY, and ShareUpdateExclusiveLock.

Referenced by findDependentObjects(), performDeletion(), and performMultipleDeletions().

{
    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);
    }
}

add_exact_object_address()

void add_exact_object_address	(	const ObjectAddress *	object,
		ObjectAddresses *	addrs
	)

Definition at line 2185 of file dependency.c.

References Assert, ObjectAddresses::extras, ObjectAddresses::maxrefs, ObjectAddresses::numrefs, ObjectAddressStack::object, ObjectAddresses::refs, and repalloc().

Referenced by AlterConstraintNamespaces(), AlterIndexNamespaces(), AlterRelationNamespaceInternal(), AlterTypeNamespaceInternal(), makeConfigurationDependencies(), recordDependencyOnSingleRelExpr(), RemoveObjects(), RemoveRelations(), and shdepDropOwned().

{
    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_exact_object_address_extra()

static void add_exact_object_address_extra ( const ObjectAddress *  object, const ObjectAddressExtra *  extra, ObjectAddresses *  addrs  )

static

Definition at line 2210 of file dependency.c.

References ObjectAddresses::extras, ObjectAddresses::maxrefs, ObjectAddresses::numrefs, ObjectAddressStack::object, palloc(), ObjectAddresses::refs, and repalloc().

Referenced by findDependentObjects().

{
    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++;
}

add_object_address()

static void add_object_address ( ObjectClass  oclass, Oid  objectId, int32  subId, ObjectAddresses *  addrs  )

static

Definition at line 2152 of file dependency.c.

References Assert, ObjectAddress::classId, ObjectAddresses::extras, LAST_OCLASS, lengthof, ObjectAddresses::maxrefs, ObjectAddresses::numrefs, object_classes, ObjectAddress::objectId, ObjectAddress::objectSubId, ObjectAddresses::refs, repalloc(), and StaticAssertStmt.

Referenced by find_expr_references_walker().

{
    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++;
}

DeleteInitPrivs()

static void DeleteInitPrivs ( const ObjectAddress *  object )

static

Definition at line 2551 of file dependency.c.

References BTEqualStrategyNumber, CatalogTupleDelete(), ObjectAddress::classId, heap_close, heap_open(), HeapTupleIsValid, InitPrivsObjIndexId, Int32GetDatum, ObjectAddress::objectId, ObjectIdGetDatum, ObjectAddress::objectSubId, RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), and HeapTupleData::t_self.

Referenced by deleteOneObject().

{
    Relation    relation;
    ScanKeyData key[3];
    SysScanDesc scan;
    HeapTuple   oldtuple;

    relation = heap_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);

    heap_close(relation, RowExclusiveLock);
}

deleteObjectsInList()

static void deleteObjectsInList ( ObjectAddresses *  targetObjects, Relation *  depRel, int  flags  )

static

Definition at line 216 of file dependency.c.

References deleteOneObject(), DEPFLAG_NORMAL, DEPFLAG_ORIGINAL, DEPFLAG_REVERSE, EventTriggerSQLDropAddObject(), EventTriggerSupportsObjectClass(), ObjectAddresses::extras, ObjectAddressExtra::flags, getObjectClass(), i, ObjectAddresses::numrefs, PERFORM_DELETION_INTERNAL, PERFORM_DELETION_SKIP_ORIGINAL, ObjectAddresses::refs, and trackDroppedObjectsNeeded().

Referenced by performDeletion(), and performMultipleDeletions().

{
    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);
    }
}

deleteOneObject() [1/2]

static void deleteOneObject ( const ObjectAddress *  object, Relation *  depRel, int32  flags  )

static

Referenced by deleteObjectsInList().

deleteOneObject() [2/2]

static void deleteOneObject ( const ObjectAddress *  object, Relation *  depRel, int  flags  )

static

Definition at line 1008 of file dependency.c.

References BTEqualStrategyNumber, CatalogTupleDelete(), ObjectAddress::classId, CommandCounterIncrement(), DeleteComments(), DeleteInitPrivs(), DeleteSecurityLabel(), deleteSharedDependencyRecordsFor(), DependDependerIndexId, doDeletion(), heap_close, heap_open(), HeapTupleIsValid, Int32GetDatum, InvokeObjectDropHookArg, ObjectAddress::objectId, ObjectIdGetDatum, ObjectAddress::objectSubId, PERFORM_DELETION_CONCURRENTLY, RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), and HeapTupleData::t_self.

{
    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)
        heap_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 = heap_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()

static void doDeletion ( const ObjectAddress *  object, int  flags  )

static

Definition at line 1112 of file dependency.c.

References Assert, DeleteSequenceTuple(), DropCastById(), DropProceduralLanguageById(), DropTransformById(), elog, ERROR, get_rel_relkind(), getObjectClass(), heap_drop_with_catalog(), index_drop(), LargeObjectDrop(), ObjectAddress::objectId, ObjectAddress::objectSubId, OCLASS_AM, OCLASS_AMOP, OCLASS_AMPROC, OCLASS_CAST, OCLASS_CLASS, OCLASS_COLLATION, OCLASS_CONSTRAINT, OCLASS_CONVERSION, OCLASS_DATABASE, OCLASS_DEFACL, OCLASS_DEFAULT, OCLASS_EVENT_TRIGGER, OCLASS_EXTENSION, OCLASS_FDW, OCLASS_FOREIGN_SERVER, OCLASS_LANGUAGE, OCLASS_LARGEOBJECT, OCLASS_OPCLASS, OCLASS_OPERATOR, OCLASS_OPFAMILY, OCLASS_POLICY, OCLASS_PROC, OCLASS_PUBLICATION, OCLASS_PUBLICATION_REL, OCLASS_REWRITE, OCLASS_ROLE, OCLASS_SCHEMA, OCLASS_STATISTIC_EXT, OCLASS_SUBSCRIPTION, OCLASS_TBLSPACE, OCLASS_TRANSFORM, OCLASS_TRIGGER, OCLASS_TSCONFIG, OCLASS_TSDICT, OCLASS_TSPARSER, OCLASS_TSTEMPLATE, OCLASS_TYPE, OCLASS_USER_MAPPING, PERFORM_DELETION_CONCURRENTLY, RemoveAccessMethodById(), RemoveAmOpEntryById(), RemoveAmProcEntryById(), RemoveAttrDefaultById(), RemoveAttributeById(), RemoveCollationById(), RemoveConstraintById(), RemoveConversionById(), RemoveDefaultACLById(), RemoveEventTriggerById(), RemoveExtensionById(), RemoveForeignDataWrapperById(), RemoveForeignServerById(), RemoveFunctionById(), RemoveOpClassById(), RemoveOperatorById(), RemoveOpFamilyById(), RemovePolicyById(), RemovePublicationById(), RemovePublicationRelById(), RemoveRewriteRuleById(), RemoveSchemaById(), RemoveStatisticsById(), RemoveTriggerById(), RemoveTSConfigurationById(), RemoveTSDictionaryById(), RemoveTSParserById(), RemoveTSTemplateById(), RemoveTypeById(), and RemoveUserMappingById().

Referenced by deleteOneObject().

{
    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);

                    Assert(object->objectSubId == 0);
                    index_drop(object->objectId, concurrent);
                }
                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_CAST:
            DropCastById(object->objectId);
            break;

        case OCLASS_COLLATION:
            RemoveCollationById(object->objectId);
            break;

        case OCLASS_CONSTRAINT:
            RemoveConstraintById(object->objectId);
            break;

        case OCLASS_CONVERSION:
            RemoveConversionById(object->objectId);
            break;

        case OCLASS_DEFAULT:
            RemoveAttrDefaultById(object->objectId);
            break;

        case OCLASS_LANGUAGE:
            DropProceduralLanguageById(object->objectId);
            break;

        case OCLASS_LARGEOBJECT:
            LargeObjectDrop(object->objectId);
            break;

        case OCLASS_OPERATOR:
            RemoveOperatorById(object->objectId);
            break;

        case OCLASS_OPCLASS:
            RemoveOpClassById(object->objectId);
            break;

        case OCLASS_OPFAMILY:
            RemoveOpFamilyById(object->objectId);
            break;

        case OCLASS_AM:
            RemoveAccessMethodById(object->objectId);
            break;

        case OCLASS_AMOP:
            RemoveAmOpEntryById(object->objectId);
            break;

        case OCLASS_AMPROC:
            RemoveAmProcEntryById(object->objectId);
            break;

        case OCLASS_REWRITE:
            RemoveRewriteRuleById(object->objectId);
            break;

        case OCLASS_TRIGGER:
            RemoveTriggerById(object->objectId);
            break;

        case OCLASS_SCHEMA:
            RemoveSchemaById(object->objectId);
            break;

        case OCLASS_STATISTIC_EXT:
            RemoveStatisticsById(object->objectId);
            break;

        case OCLASS_TSPARSER:
            RemoveTSParserById(object->objectId);
            break;

        case OCLASS_TSDICT:
            RemoveTSDictionaryById(object->objectId);
            break;

        case OCLASS_TSTEMPLATE:
            RemoveTSTemplateById(object->objectId);
            break;

        case OCLASS_TSCONFIG:
            RemoveTSConfigurationById(object->objectId);
            break;

            /*
             * OCLASS_ROLE, OCLASS_DATABASE, OCLASS_TBLSPACE intentionally not
             * handled here
             */

        case OCLASS_FDW:
            RemoveForeignDataWrapperById(object->objectId);
            break;

        case OCLASS_FOREIGN_SERVER:
            RemoveForeignServerById(object->objectId);
            break;

        case OCLASS_USER_MAPPING:
            RemoveUserMappingById(object->objectId);
            break;

        case OCLASS_DEFACL:
            RemoveDefaultACLById(object->objectId);
            break;

        case OCLASS_EXTENSION:
            RemoveExtensionById(object->objectId);
            break;

        case OCLASS_EVENT_TRIGGER:
            RemoveEventTriggerById(object->objectId);
            break;

        case OCLASS_POLICY:
            RemovePolicyById(object->objectId);
            break;

        case OCLASS_PUBLICATION:
            RemovePublicationById(object->objectId);
            break;

        case OCLASS_PUBLICATION_REL:
            RemovePublicationRelById(object->objectId);
            break;

        case OCLASS_TRANSFORM:
            DropTransformById(object->objectId);
            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.
             */
    }
}

eliminate_duplicate_dependencies()

static void eliminate_duplicate_dependencies ( ObjectAddresses *  addrs )

static

Definition at line 2039 of file dependency.c.

References Assert, ObjectAddress::classId, ObjectAddresses::extras, ObjectAddresses::numrefs, object_address_comparator(), ObjectAddress::objectId, ObjectAddress::objectSubId, qsort, and ObjectAddresses::refs.

Referenced by record_object_address_dependencies(), recordDependencyOnExpr(), and recordDependencyOnSingleRelExpr().

{
    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;
}

find_expr_references_walker()

static bool find_expr_references_walker ( Node *  node, find_expr_references_context *  context  )

static

Definition at line 1496 of file dependency.c.

References add_object_address(), find_expr_references_context::addrs, Aggref::aggfnoid, FieldSelect::arg, CMD_INSERT, CMD_UPDATE, CollateExpr::collOid, Query::commandType, Const::constcollid, Const::constisnull, OnConflictExpr::constraint, Query::constraintDeps, Const::consttype, Const::constvalue, DatumGetObjectId, Query::distinctClause, elog, WindowClause::endInRangeFunc, SortGroupClause::eqop, ereport, errcode(), errmsg(), ERROR, expression_tree_walker(), exprType(), FieldSelect::fieldnum, FieldStore::fieldnums, RangeTblFunction::funccolcollations, RangeTblFunction::funccoltypes, FuncExpr::funcid, get_typ_typrelid(), getBaseType(), Query::groupClause, SetOperationStmt::groupClauses, WindowClause::inRangeColl, InvalidAttrNumber, IsA, RangeTblEntry::joinaliasvars, lcons(), lfirst, lfirst_int, lfirst_oid, list_copy_tail(), list_delete_first(), list_free(), list_length(), list_nth(), NAMESPACEOID, ObjectIdGetDatum, OCLASS_CLASS, OCLASS_COLLATION, OCLASS_CONSTRAINT, OCLASS_OPERATOR, OCLASS_OPFAMILY, OCLASS_PROC, OCLASS_SCHEMA, OCLASS_TSCONFIG, OCLASS_TSDICT, OCLASS_TYPE, OidIsValid, OPEROID, RowCompareExpr::opfamilies, OpExpr::opno, ScalarArrayOpExpr::opno, RowCompareExpr::opnos, Param::paramcollid, Param::paramtype, PROCOID, QTW_IGNORE_JOINALIASES, query_tree_walker(), RangeTblEntry::relid, RELOID, reltype, TargetEntry::resjunk, TargetEntry::resno, FieldSelect::resultcollid, RelabelType::resultcollid, CoerceViaIO::resultcollid, ArrayCoerceExpr::resultcollid, Query::resultRelation, FieldSelect::resulttype, FieldStore::resulttype, RelabelType::resulttype, CoerceViaIO::resulttype, ArrayCoerceExpr::resulttype, ConvertRowtypeExpr::resulttype, CoerceToDomain::resulttype, RowExpr::row_typeid, rt_fetch, Query::rtable, find_expr_references_context::rtables, RTE_JOIN, RTE_RELATION, RangeTblEntry::rtekind, SearchSysCacheExists1, NextValueExpr::seqid, Query::sortClause, SortGroupClause::sortop, WindowClause::startInRangeFunc, Query::targetList, TSCONFIGOID, TSDICTOID, TableSampleClause::tsmhandler, TYPEOID, Var::varattno, Var::varlevelsup, Var::varno, Query::windowClause, and WindowFunc::winfnoid.

Referenced by recordDependencyOnExpr(), and recordDependencyOnSingleRelExpr().

{
    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);
        }
        else if (rte->rtekind == RTE_JOIN)
        {
            /* Scan join output column to add references to join inputs */
            List       *save_rtables;

            /* We must make the context appropriate for join's level */
            save_rtables = context->rtables;
            context->rtables = list_copy_tail(context->rtables,
                                              var->varlevelsup);
            if (var->varattno <= 0 ||
                var->varattno > list_length(rte->joinaliasvars))
                elog(ERROR, "invalid varattno %d", var->varattno);
            find_expr_references_walker((Node *) list_nth(rte->joinaliasvars,
                                                          var->varattno - 1),
                                        context);
            list_free(context->rtables);
            context->rtables = save_rtables;
        }
        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 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, 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, 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.
         *
         * Note: query_tree_walker takes care of recursing into RTE_FUNCTION
         * RTEs, subqueries, etc, so no need to do that here.  But keep it
         * from looking at join alias lists.
         *
         * 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;
                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);
        }

        /* query_tree_walker ignores ORDER BY etc, but we need those opers */
        find_expr_references_walker((Node *) query->sortClause, context);
        find_expr_references_walker((Node *) query->groupClause, context);
        find_expr_references_walker((Node *) query->windowClause, context);
        find_expr_references_walker((Node *) query->distinctClause, context);

        /* 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);
        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, 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);
}

findDependentObjects()

static void findDependentObjects ( const ObjectAddress *  object, int  objflags, int  flags, ObjectAddressStack *  stack, ObjectAddresses *  targetObjects, const ObjectAddresses *  pendingObjects, Relation *  depRel  )

static

Definition at line 459 of file dependency.c.

References AcquireDeletionLock(), add_exact_object_address_extra(), BTEqualStrategyNumber, ObjectAddress::classId, creating_extension, CurrentExtensionObject, DependDependerIndexId, ObjectAddressExtra::dependee, DEPENDENCY_AUTO, DEPENDENCY_AUTO_EXTENSION, DEPENDENCY_EXTENSION, DEPENDENCY_INTERNAL, DEPENDENCY_INTERNAL_AUTO, DEPENDENCY_NORMAL, DEPENDENCY_PIN, DependReferenceIndexId, DEPFLAG_AUTO, DEPFLAG_EXTENSION, DEPFLAG_INTERNAL, DEPFLAG_NORMAL, DEPFLAG_REVERSE, elog, ereport, errcode(), errhint(), errmsg(), ERROR, ObjectAddressExtra::flags, ObjectAddressStack::flags, getObjectDescription(), GETSTRUCT, HeapTupleIsValid, Int32GetDatum, ObjectAddressStack::next, ObjectAddressStack::object, object_address_present(), object_address_present_add_flags(), ObjectAddress::objectId, ObjectIdGetDatum, ObjectAddress::objectSubId, PERFORM_DELETION_SKIP_EXTENSIONS, ReleaseDeletionLock(), ScanKeyInit(), stack_address_present_add_flags(), systable_beginscan(), systable_endscan(), systable_getnext(), and systable_recheck_tuple().

Referenced by performDeletion(), and performMultipleDeletions().

{
    ScanKeyData key[3];
    int         nkeys;
    SysScanDesc scan;
    HeapTuple   tup;
    ObjectAddress otherObject;
    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)
    {
        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)))
    {
        Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(tup);

        otherObject.classId = foundDep->refclassid;
        otherObject.objectId = foundDep->refobjid;
        otherObject.objectSubId = foundDep->refobjsubid;

        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:
            case DEPENDENCY_INTERNAL_AUTO:

                /*
                 * 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, disallow the DROP. (We
                 * just ereport here, rather than proceeding, since no other
                 * dependencies are likely to be interesting.)  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.
                 */
                if (stack == NULL)
                {
                    char       *otherObjDesc;

                    if (pendingObjects &&
                        object_address_present(&otherObject, pendingObjects))
                    {
                        systable_endscan(scan);
                        /* need to release caller's lock; see notes below */
                        ReleaseDeletionLock(object);
                        return;
                    }
                    otherObjDesc = getObjectDescription(&otherObject);
                    ereport(ERROR,
                            (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
                             errmsg("cannot drop %s because %s requires it",
                                    getObjectDescription(object),
                                    otherObjDesc),
                             errhint("You can drop %s instead.",
                                     otherObjDesc)));
                }

                /*
                 * 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.
                 *
                 * For INTERNAL_AUTO dependencies, we don't enforce this; in
                 * other words, we don't follow the links back to the owning
                 * object.
                 */
                if (foundDep->deptype == DEPENDENCY_INTERNAL_AUTO)
                    break;

                /*
                 * 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;
                }

                /*
                 * 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);
                /* And we're done here. */
                systable_endscan(scan);
                return;

            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));
                break;
            default:
                elog(ERROR, "unrecognized dependency type '%c' for %s",
                     foundDep->deptype, getObjectDescription(object));
                break;
        }
    }

    systable_endscan(scan);

    /*
     * Now recurse to any 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;

    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;

        /*
         * 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;
        }

        /* Recurse, passing objflags indicating 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_AUTO:
            case DEPENDENCY_INTERNAL:
                subflags = DEPFLAG_INTERNAL;
                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))));
                subflags = 0;   /* keep compiler quiet */
                break;
            default:
                elog(ERROR, "unrecognized dependency type '%c' for %s",
                     foundDep->deptype, getObjectDescription(object));
                subflags = 0;   /* keep compiler quiet */
                break;
        }

        findDependentObjects(&otherObject,
                             subflags,
                             flags,
                             &mystack,
                             targetObjects,
                             pendingObjects,
                             depRel);
    }

    systable_endscan(scan);

    /*
     * 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.
     */
    extra.flags = mystack.flags;
    if (stack)
        extra.dependee = *stack->object;
    else
        memset(&extra.dependee, 0, sizeof(extra.dependee));
    add_exact_object_address_extra(object, &extra, targetObjects);
}

free_object_addresses()

void free_object_addresses

(

ObjectAddresses *

addrs

)

Definition at line 2401 of file dependency.c.

References ObjectAddresses::extras, pfree(), and ObjectAddresses::refs.

Referenced by AlterTableNamespace(), AlterTypeNamespace(), makeConfigurationDependencies(), performDeletion(), performMultipleDeletions(), recordDependencyOnExpr(), recordDependencyOnSingleRelExpr(), RemoveObjects(), RemoveRelations(), and shdepDropOwned().

{
    pfree(addrs->refs);
    if (addrs->extras)
        pfree(addrs->extras);
    pfree(addrs);
}

getObjectClass()

ObjectClass getObjectClass

(

const ObjectAddress *

object

)

Definition at line 2416 of file dependency.c.

References ObjectAddress::classId, elog, ERROR, ObjectAddress::objectSubId, OCLASS_AM, OCLASS_AMOP, OCLASS_AMPROC, OCLASS_CAST, OCLASS_CLASS, OCLASS_COLLATION, OCLASS_CONSTRAINT, OCLASS_CONVERSION, OCLASS_DATABASE, OCLASS_DEFACL, OCLASS_DEFAULT, OCLASS_EVENT_TRIGGER, OCLASS_EXTENSION, OCLASS_FDW, OCLASS_FOREIGN_SERVER, OCLASS_LANGUAGE, OCLASS_LARGEOBJECT, OCLASS_OPCLASS, OCLASS_OPERATOR, OCLASS_OPFAMILY, OCLASS_POLICY, OCLASS_PROC, OCLASS_PUBLICATION, OCLASS_PUBLICATION_REL, OCLASS_REWRITE, OCLASS_ROLE, OCLASS_SCHEMA, OCLASS_STATISTIC_EXT, OCLASS_SUBSCRIPTION, OCLASS_TBLSPACE, OCLASS_TRANSFORM, OCLASS_TRIGGER, OCLASS_TSCONFIG, OCLASS_TSDICT, OCLASS_TSPARSER, OCLASS_TSTEMPLATE, OCLASS_TYPE, and OCLASS_USER_MAPPING.

Referenced by AlterObjectNamespace_oid(), ATExecAlterColumnType(), deleteObjectsInList(), doDeletion(), EventTriggerSQLDropAddObject(), getObjectDescription(), getObjectIdentityParts(), and getObjectTypeDescription().

{
    /* 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 */
}

new_object_addresses()

ObjectAddresses* new_object_addresses

(

void

)

Definition at line 2130 of file dependency.c.

References ObjectAddresses::extras, ObjectAddresses::maxrefs, ObjectAddresses::numrefs, palloc(), and ObjectAddresses::refs.

Referenced by AlterExtensionNamespace(), AlterTableNamespace(), AlterTypeNamespace(), makeConfigurationDependencies(), performDeletion(), performMultipleDeletions(), recordDependencyOnExpr(), recordDependencyOnSingleRelExpr(), RemoveObjects(), RemoveRelations(), and shdepDropOwned().

{
    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;
}

object_address_comparator()

static int object_address_comparator ( const void *  a, const void *  b  )

static

Definition at line 2099 of file dependency.c.

References ObjectAddress::classId, ObjectAddress::objectId, and ObjectAddress::objectSubId.

Referenced by eliminate_duplicate_dependencies().

{
    const ObjectAddress *obja = (const ObjectAddress *) a;
    const ObjectAddress *objb = (const ObjectAddress *) b;

    if (obja->classId < objb->classId)
        return -1;
    if (obja->classId > objb->classId)
        return 1;
    if (obja->objectId < objb->objectId)
        return -1;
    if (obja->objectId > objb->objectId)
        return 1;

    /*
     * We sort the subId as an unsigned int so that 0 will come first. See
     * logic in eliminate_duplicate_dependencies.
     */
    if ((unsigned int) obja->objectSubId < (unsigned int) objb->objectSubId)
        return -1;
    if ((unsigned int) obja->objectSubId > (unsigned int) objb->objectSubId)
        return 1;
    return 0;
}

object_address_present()

bool object_address_present	(	const ObjectAddress *	object,
		const ObjectAddresses *	addrs
	)

Definition at line 2245 of file dependency.c.

References ObjectAddress::classId, i, ObjectAddresses::numrefs, ObjectAddress::objectId, ObjectAddress::objectSubId, and ObjectAddresses::refs.

Referenced by AlterConstraintNamespaces(), AlterIndexNamespaces(), AlterRelationNamespaceInternal(), AlterTypeNamespaceInternal(), and findDependentObjects().

{
    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;
}

object_address_present_add_flags()

static bool object_address_present_add_flags ( const ObjectAddress *  object, int  flags, ObjectAddresses *  addrs  )

static

Definition at line 2271 of file dependency.c.

References ObjectAddress::classId, ObjectAddresses::extras, ObjectAddressExtra::flags, ObjectAddressStack::flags, i, ObjectAddresses::numrefs, ObjectAddress::objectId, ObjectAddress::objectSubId, and ObjectAddresses::refs.

Referenced by findDependentObjects().

{
    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.
                 *
                 * 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;

                thisextra->flags |= flags;
            }
        }
    }

    return result;
}

performDeletion()

void performDeletion	(	const ObjectAddress *	object,
		DropBehavior	behavior,
		int	flags
	)

Definition at line 300 of file dependency.c.

References AcquireDeletionLock(), deleteObjectsInList(), DEPFLAG_ORIGINAL, findDependentObjects(), free_object_addresses(), heap_close, heap_open(), new_object_addresses(), reportDependentObjects(), and RowExclusiveLock.

Referenced by AlterDomainDropConstraint(), ATExecDropColumn(), ATExecDropConstraint(), ATExecDropIdentity(), ATPostAlterTypeCleanup(), DefineQueryRewrite(), do_autovacuum(), dropOperators(), dropProcedures(), finish_heap_swap(), inv_drop(), PreCommit_on_commit_actions(), PublicationDropTables(), RemoveAttrDefault(), RemoveTempRelations(), RemoveUserMapping(), and SetDefaultACL().

{
    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 = heap_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);

    heap_close(depRel, RowExclusiveLock);
}

performMultipleDeletions()

void performMultipleDeletions	(	const ObjectAddresses *	objects,
		DropBehavior	behavior,
		int	flags
	)

Definition at line 359 of file dependency.c.

References AcquireDeletionLock(), deleteObjectsInList(), DEPFLAG_ORIGINAL, findDependentObjects(), free_object_addresses(), heap_close, heap_open(), i, new_object_addresses(), ObjectAddresses::numrefs, ObjectAddresses::refs, reportDependentObjects(), and RowExclusiveLock.

Referenced by RemoveObjects(), RemoveRelations(), and shdepDropOwned().

{
    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 = heap_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);

    heap_close(depRel, RowExclusiveLock);
}

record_object_address_dependencies()

void record_object_address_dependencies	(	const ObjectAddress *	depender,
		ObjectAddresses *	referenced,
		DependencyType	behavior
	)

Definition at line 2387 of file dependency.c.

References eliminate_duplicate_dependencies(), ObjectAddresses::numrefs, recordMultipleDependencies(), and ObjectAddresses::refs.

Referenced by makeConfigurationDependencies().

{
    eliminate_duplicate_dependencies(referenced);
    recordMultipleDependencies(depender,
                               referenced->refs, referenced->numrefs,
                               behavior);
}

recordDependencyOnExpr()

void recordDependencyOnExpr	(	const ObjectAddress *	depender,
		Node *	expr,
		List *	rtable,
		DependencyType	behavior
	)

Definition at line 1360 of file dependency.c.

References find_expr_references_context::addrs, eliminate_duplicate_dependencies(), find_expr_references_walker(), free_object_addresses(), list_make1, new_object_addresses(), ObjectAddresses::numrefs, recordMultipleDependencies(), ObjectAddresses::refs, and find_expr_references_context::rtables.

Referenced by AlterPolicy(), CreatePolicy(), CreateTrigger(), GenerateTypeDependencies(), InsertRule(), ProcedureCreate(), RemoveRoleFromObjectPolicy(), and StoreAttrDefault().

{
    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()

void recordDependencyOnSingleRelExpr	(	const ObjectAddress *	depender,
		Node *	expr,
		Oid	relId,
		DependencyType	behavior,
		DependencyType	self_behavior,
		bool	ignore_self
	)

Definition at line 1401 of file dependency.c.

References add_exact_object_address(), find_expr_references_context::addrs, ObjectAddress::classId, eliminate_duplicate_dependencies(), find_expr_references_walker(), free_object_addresses(), list_make1, MemSet, new_object_addresses(), ObjectAddresses::numrefs, ObjectAddress::objectId, recordMultipleDependencies(), ObjectAddresses::refs, RangeTblEntry::relid, RangeTblEntry::relkind, find_expr_references_context::rtables, RTE_RELATION, RangeTblEntry::rtekind, T_RangeTblEntry, and RangeTblEntry::type.

Referenced by CreateConstraintEntry(), index_create(), and StorePartitionKey().

{
    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 */

    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 && 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 */
        if (!ignore_self)
            recordMultipleDependencies(depender,
                                       self_addrs->refs, self_addrs->numrefs,
                                       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);
}

ReleaseDeletionLock()

static void ReleaseDeletionLock ( const ObjectAddress *  object )

static

Definition at line 1335 of file dependency.c.

References AccessExclusiveLock, ObjectAddress::classId, ObjectAddress::objectId, UnlockDatabaseObject(), and UnlockRelationOid().

Referenced by findDependentObjects().

{
    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);
}

reportDependentObjects()

static void reportDependentObjects ( const ObjectAddresses *  targetObjects, DropBehavior  behavior, int  flags, const ObjectAddress *  origObject  )

static

Definition at line 836 of file dependency.c.

References _, appendStringInfo(), appendStringInfoChar(), client_min_messages, StringInfoData::data, DEBUG2, ObjectAddressExtra::dependee, DEPFLAG_AUTO, DEPFLAG_EXTENSION, DEPFLAG_INTERNAL, DEPFLAG_ORIGINAL, DROP_CASCADE, DROP_RESTRICT, ereport, errcode(), errdetail(), errdetail_log(), errhint(), errmsg(), errmsg_internal(), errmsg_plural(), ERROR, ObjectAddresses::extras, ObjectAddressExtra::flags, getObjectDescription(), i, initStringInfo(), StringInfoData::len, LOG, log_min_messages, MAX_REPORTED_DEPS, ngettext, NOTICE, ObjectAddresses::numrefs, PERFORM_DELETION_QUIETLY, pfree(), and ObjectAddresses::refs.

Referenced by performDeletion(), and performMultipleDeletions().

{
    int         msglevel = (flags & PERFORM_DELETION_QUIETLY) ? DEBUG2 : NOTICE;
    bool        ok = true;
    StringInfoData clientdetail;
    StringInfoData logdetail;
    int         numReportedClient = 0;
    int         numNotReportedClient = 0;
    int         i;

    /*
     * 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 work.
     *
     * Note: this code doesn't know all there is to be known about elog
     * levels, but it works for NOTICE and DEBUG2, which are the only values
     * msglevel can currently have.  We also assume we are running in a normal
     * operating environment.
     */
    if (behavior == DROP_CASCADE &&
        msglevel < client_min_messages &&
        (msglevel < log_min_messages || log_min_messages == LOG))
        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;

        objDesc = getObjectDescription(obj);

        /*
         * If, at any stage of the recursive search, we reached the object via
         * an AUTO, INTERNAL, or EXTENSION dependency, then it's okay to
         * delete it even in RESTRICT mode.
         */
        if (extra->flags & (DEPFLAG_AUTO |
                            DEPFLAG_INTERNAL |
                            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("drop auto-cascades to %s",
                            objDesc)));
        }
        else if (behavior == DROP_RESTRICT)
        {
            char       *otherDesc = getObjectDescription(&extra->dependee);

            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);
            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)),
                     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);
}

stack_address_present_add_flags()

static bool stack_address_present_add_flags ( const ObjectAddress *  object, int  flags, ObjectAddressStack *  stack  )

static

Definition at line 2338 of file dependency.c.

References ObjectAddress::classId, ObjectAddressStack::flags, ObjectAddressStack::next, ObjectAddressStack::object, ObjectAddress::objectId, and ObjectAddress::objectSubId.

Referenced by findDependentObjects().

{
    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.
                 */
                stackptr->flags |= flags;
            }
        }
    }

    return result;
}

Variable Documentation

object_classes

const Oid object_classes[]

static

Definition at line 135 of file dependency.c.

Referenced by add_object_address().