Refine nbtree = redundancy preprocessing comment.

[pgsql.git] / src / bin / pg_dump / pg_dump_sort.c

/*-------------------------------------------------------------------------
 *
 * pg_dump_sort.c
 *        Sort the items of a dump into a safe order for dumping
 *
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *        src/bin/pg_dump/pg_dump_sort.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres_fe.h"

#include "catalog/pg_class_d.h"
#include "common/int.h"
#include "lib/binaryheap.h"
#include "pg_backup_utils.h"
#include "pg_dump.h"

/*
 * Sort priority for database object types.
 * Objects are sorted by type, and within a type by name.
 *
 * Triggers, event triggers, and materialized views are intentionally sorted
 * late.  Triggers must be restored after all data modifications, so that
 * they don't interfere with loading data.  Event triggers are restored
 * next-to-last so that they don't interfere with object creations of any
 * kind.  Matview refreshes are last because they should execute in the
 * database's normal state (e.g., they must come after all ACLs are restored;
 * also, if they choose to look at system catalogs, they should see the final
 * restore state).  If you think to change this, see also the RestorePass
 * mechanism in pg_backup_archiver.c.
 *
 * On the other hand, casts are intentionally sorted earlier than you might
 * expect; logically they should come after functions, since they usually
 * depend on those.  This works around the backend's habit of recording
 * views that use casts as dependent on the cast's underlying function.
 * We initially sort casts first, and then any functions used by casts
 * will be hoisted above the casts, and in turn views that those functions
 * depend on will be hoisted above the functions.  But views not used that
 * way won't be hoisted.
 *
 * NOTE: object-type priorities must match the section assignments made in
 * pg_dump.c; that is, PRE_DATA objects must sort before DO_PRE_DATA_BOUNDARY,
 * POST_DATA objects must sort after DO_POST_DATA_BOUNDARY, and DATA objects
 * must sort between them.
 */

/* This enum lists the priority levels in order */
enum dbObjectTypePriorities
{
        PRIO_NAMESPACE = 1,
        PRIO_PROCLANG,
        PRIO_COLLATION,
        PRIO_TRANSFORM,
        PRIO_EXTENSION,
        PRIO_TYPE,                                      /* used for DO_TYPE and DO_SHELL_TYPE */
        PRIO_CAST,
        PRIO_FUNC,
        PRIO_AGG,
        PRIO_ACCESS_METHOD,
        PRIO_OPERATOR,
        PRIO_OPFAMILY,                          /* used for DO_OPFAMILY and DO_OPCLASS */
        PRIO_CONVERSION,
        PRIO_TSPARSER,
        PRIO_TSTEMPLATE,
        PRIO_TSDICT,
        PRIO_TSCONFIG,
        PRIO_FDW,
        PRIO_FOREIGN_SERVER,
        PRIO_TABLE,
        PRIO_TABLE_ATTACH,
        PRIO_DUMMY_TYPE,
        PRIO_ATTRDEF,
        PRIO_LARGE_OBJECT,
        PRIO_PRE_DATA_BOUNDARY,         /* boundary! */
        PRIO_TABLE_DATA,
        PRIO_SEQUENCE_SET,
        PRIO_LARGE_OBJECT_DATA,
        PRIO_POST_DATA_BOUNDARY,        /* boundary! */
        PRIO_CONSTRAINT,
        PRIO_INDEX,
        PRIO_INDEX_ATTACH,
        PRIO_STATSEXT,
        PRIO_RULE,
        PRIO_TRIGGER,
        PRIO_FK_CONSTRAINT,
        PRIO_POLICY,
        PRIO_PUBLICATION,
        PRIO_PUBLICATION_REL,
        PRIO_PUBLICATION_TABLE_IN_SCHEMA,
        PRIO_SUBSCRIPTION,
        PRIO_SUBSCRIPTION_REL,
        PRIO_DEFAULT_ACL,                       /* done in ACL pass */
        PRIO_EVENT_TRIGGER,                     /* must be next to last! */
        PRIO_REFRESH_MATVIEW            /* must be last! */
};

/* This table is indexed by enum DumpableObjectType */
static const int dbObjectTypePriority[] =
{
        [DO_NAMESPACE] = PRIO_NAMESPACE,
        [DO_EXTENSION] = PRIO_EXTENSION,
        [DO_TYPE] = PRIO_TYPE,
        [DO_SHELL_TYPE] = PRIO_TYPE,
        [DO_FUNC] = PRIO_FUNC,
        [DO_AGG] = PRIO_AGG,
        [DO_OPERATOR] = PRIO_OPERATOR,
        [DO_ACCESS_METHOD] = PRIO_ACCESS_METHOD,
        [DO_OPCLASS] = PRIO_OPFAMILY,
        [DO_OPFAMILY] = PRIO_OPFAMILY,
        [DO_COLLATION] = PRIO_COLLATION,
        [DO_CONVERSION] = PRIO_CONVERSION,
        [DO_TABLE] = PRIO_TABLE,
        [DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
        [DO_ATTRDEF] = PRIO_ATTRDEF,
        [DO_INDEX] = PRIO_INDEX,
        [DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
        [DO_STATSEXT] = PRIO_STATSEXT,
        [DO_RULE] = PRIO_RULE,
        [DO_TRIGGER] = PRIO_TRIGGER,
        [DO_CONSTRAINT] = PRIO_CONSTRAINT,
        [DO_FK_CONSTRAINT] = PRIO_FK_CONSTRAINT,
        [DO_PROCLANG] = PRIO_PROCLANG,
        [DO_CAST] = PRIO_CAST,
        [DO_TABLE_DATA] = PRIO_TABLE_DATA,
        [DO_SEQUENCE_SET] = PRIO_SEQUENCE_SET,
        [DO_DUMMY_TYPE] = PRIO_DUMMY_TYPE,
        [DO_TSPARSER] = PRIO_TSPARSER,
        [DO_TSDICT] = PRIO_TSDICT,
        [DO_TSTEMPLATE] = PRIO_TSTEMPLATE,
        [DO_TSCONFIG] = PRIO_TSCONFIG,
        [DO_FDW] = PRIO_FDW,
        [DO_FOREIGN_SERVER] = PRIO_FOREIGN_SERVER,
        [DO_DEFAULT_ACL] = PRIO_DEFAULT_ACL,
        [DO_TRANSFORM] = PRIO_TRANSFORM,
        [DO_LARGE_OBJECT] = PRIO_LARGE_OBJECT,
        [DO_LARGE_OBJECT_DATA] = PRIO_LARGE_OBJECT_DATA,
        [DO_PRE_DATA_BOUNDARY] = PRIO_PRE_DATA_BOUNDARY,
        [DO_POST_DATA_BOUNDARY] = PRIO_POST_DATA_BOUNDARY,
        [DO_EVENT_TRIGGER] = PRIO_EVENT_TRIGGER,
        [DO_REFRESH_MATVIEW] = PRIO_REFRESH_MATVIEW,
        [DO_POLICY] = PRIO_POLICY,
        [DO_PUBLICATION] = PRIO_PUBLICATION,
        [DO_PUBLICATION_REL] = PRIO_PUBLICATION_REL,
        [DO_PUBLICATION_TABLE_IN_SCHEMA] = PRIO_PUBLICATION_TABLE_IN_SCHEMA,
        [DO_SUBSCRIPTION] = PRIO_SUBSCRIPTION,
        [DO_SUBSCRIPTION_REL] = PRIO_SUBSCRIPTION_REL,
};

StaticAssertDecl(lengthof(dbObjectTypePriority) == (DO_SUBSCRIPTION_REL + 1),
                                 "array length mismatch");

static DumpId preDataBoundId;
static DumpId postDataBoundId;


static int      DOTypeNameCompare(const void *p1, const void *p2);
static bool TopoSort(DumpableObject **objs,
                                         int numObjs,
                                         DumpableObject **ordering,
                                         int *nOrdering);
static void findDependencyLoops(DumpableObject **objs, int nObjs, int totObjs);
static int      findLoop(DumpableObject *obj,
                                         DumpId startPoint,
                                         bool *processed,
                                         DumpId *searchFailed,
                                         DumpableObject **workspace,
                                         int depth);
static void repairDependencyLoop(DumpableObject **loop,
                                                                 int nLoop);
static void describeDumpableObject(DumpableObject *obj,
                                                                   char *buf, int bufsize);
static int      int_cmp(void *a, void *b, void *arg);


/*
 * Sort the given objects into a type/name-based ordering
 *
 * Normally this is just the starting point for the dependency-based
 * ordering.
 */
void
sortDumpableObjectsByTypeName(DumpableObject **objs, int numObjs)
{
        if (numObjs > 1)
                qsort(objs, numObjs, sizeof(DumpableObject *),
                          DOTypeNameCompare);
}

static int
DOTypeNameCompare(const void *p1, const void *p2)
{
        DumpableObject *obj1 = *(DumpableObject *const *) p1;
        DumpableObject *obj2 = *(DumpableObject *const *) p2;
        int                     cmpval;

        /* Sort by type's priority */
        cmpval = dbObjectTypePriority[obj1->objType] -
                dbObjectTypePriority[obj2->objType];

        if (cmpval != 0)
                return cmpval;

        /*
         * Sort by namespace.  Typically, all objects of the same priority would
         * either have or not have a namespace link, but there are exceptions.
         * Sort NULL namespace after non-NULL in such cases.
         */
        if (obj1->namespace)
        {
                if (obj2->namespace)
                {
                        cmpval = strcmp(obj1->namespace->dobj.name,
                                                        obj2->namespace->dobj.name);
                        if (cmpval != 0)
                                return cmpval;
                }
                else
                        return -1;
        }
        else if (obj2->namespace)
                return 1;

        /* Sort by name */
        cmpval = strcmp(obj1->name, obj2->name);
        if (cmpval != 0)
                return cmpval;

        /* To have a stable sort order, break ties for some object types */
        if (obj1->objType == DO_FUNC || obj1->objType == DO_AGG)
        {
                FuncInfo   *fobj1 = *(FuncInfo *const *) p1;
                FuncInfo   *fobj2 = *(FuncInfo *const *) p2;
                int                     i;

                /* Sort by number of arguments, then argument type names */
                cmpval = fobj1->nargs - fobj2->nargs;
                if (cmpval != 0)
                        return cmpval;
                for (i = 0; i < fobj1->nargs; i++)
                {
                        TypeInfo   *argtype1 = findTypeByOid(fobj1->argtypes[i]);
                        TypeInfo   *argtype2 = findTypeByOid(fobj2->argtypes[i]);

                        if (argtype1 && argtype2)
                        {
                                if (argtype1->dobj.namespace && argtype2->dobj.namespace)
                                {
                                        cmpval = strcmp(argtype1->dobj.namespace->dobj.name,
                                                                        argtype2->dobj.namespace->dobj.name);
                                        if (cmpval != 0)
                                                return cmpval;
                                }
                                cmpval = strcmp(argtype1->dobj.name, argtype2->dobj.name);
                                if (cmpval != 0)
                                        return cmpval;
                        }
                }
        }
        else if (obj1->objType == DO_OPERATOR)
        {
                OprInfo    *oobj1 = *(OprInfo *const *) p1;
                OprInfo    *oobj2 = *(OprInfo *const *) p2;

                /* oprkind is 'l', 'r', or 'b'; this sorts prefix, postfix, infix */
                cmpval = (oobj2->oprkind - oobj1->oprkind);
                if (cmpval != 0)
                        return cmpval;
        }
        else if (obj1->objType == DO_ATTRDEF)
        {
                AttrDefInfo *adobj1 = *(AttrDefInfo *const *) p1;
                AttrDefInfo *adobj2 = *(AttrDefInfo *const *) p2;

                /* Sort by attribute number */
                cmpval = (adobj1->adnum - adobj2->adnum);
                if (cmpval != 0)
                        return cmpval;
        }
        else if (obj1->objType == DO_POLICY)
        {
                PolicyInfo *pobj1 = *(PolicyInfo *const *) p1;
                PolicyInfo *pobj2 = *(PolicyInfo *const *) p2;

                /* Sort by table name (table namespace was considered already) */
                cmpval = strcmp(pobj1->poltable->dobj.name,
                                                pobj2->poltable->dobj.name);
                if (cmpval != 0)
                        return cmpval;
        }
        else if (obj1->objType == DO_RULE)
        {
                RuleInfo   *robj1 = *(RuleInfo *const *) p1;
                RuleInfo   *robj2 = *(RuleInfo *const *) p2;

                /* Sort by table name (table namespace was considered already) */
                cmpval = strcmp(robj1->ruletable->dobj.name,
                                                robj2->ruletable->dobj.name);
                if (cmpval != 0)
                        return cmpval;
        }
        else if (obj1->objType == DO_TRIGGER)
        {
                TriggerInfo *tobj1 = *(TriggerInfo *const *) p1;
                TriggerInfo *tobj2 = *(TriggerInfo *const *) p2;

                /* Sort by table name (table namespace was considered already) */
                cmpval = strcmp(tobj1->tgtable->dobj.name,
                                                tobj2->tgtable->dobj.name);
                if (cmpval != 0)
                        return cmpval;
        }

        /* Usually shouldn't get here, but if we do, sort by OID */
        return oidcmp(obj1->catId.oid, obj2->catId.oid);
}


/*
 * Sort the given objects into a safe dump order using dependency
 * information (to the extent we have it available).
 *
 * The DumpIds of the PRE_DATA_BOUNDARY and POST_DATA_BOUNDARY objects are
 * passed in separately, in case we need them during dependency loop repair.
 */
void
sortDumpableObjects(DumpableObject **objs, int numObjs,
                                        DumpId preBoundaryId, DumpId postBoundaryId)
{
        DumpableObject **ordering;
        int                     nOrdering;

        if (numObjs <= 0)                       /* can't happen anymore ... */
                return;

        /*
         * Saving the boundary IDs in static variables is a bit grotty, but seems
         * better than adding them to parameter lists of subsidiary functions.
         */
        preDataBoundId = preBoundaryId;
        postDataBoundId = postBoundaryId;

        ordering = (DumpableObject **) pg_malloc(numObjs * sizeof(DumpableObject *));
        while (!TopoSort(objs, numObjs, ordering, &nOrdering))
                findDependencyLoops(ordering, nOrdering, numObjs);

        memcpy(objs, ordering, numObjs * sizeof(DumpableObject *));

        free(ordering);
}

/*
 * TopoSort -- topological sort of a dump list
 *
 * Generate a re-ordering of the dump list that satisfies all the dependency
 * constraints shown in the dump list.  (Each such constraint is a fact of a
 * partial ordering.)  Minimize rearrangement of the list not needed to
 * achieve the partial ordering.
 *
 * The input is the list of numObjs objects in objs[].  This list is not
 * modified.
 *
 * Returns true if able to build an ordering that satisfies all the
 * constraints, false if not (there are contradictory constraints).
 *
 * On success (true result), ordering[] is filled with a sorted array of
 * DumpableObject pointers, of length equal to the input list length.
 *
 * On failure (false result), ordering[] is filled with an unsorted array of
 * DumpableObject pointers of length *nOrdering, listing the objects that
 * prevented the sort from being completed.  In general, these objects either
 * participate directly in a dependency cycle, or are depended on by objects
 * that are in a cycle.  (The latter objects are not actually problematic,
 * but it takes further analysis to identify which are which.)
 *
 * The caller is responsible for allocating sufficient space at *ordering.
 */
static bool
TopoSort(DumpableObject **objs,
                 int numObjs,
                 DumpableObject **ordering, /* output argument */
                 int *nOrdering)                /* output argument */
{
        DumpId          maxDumpId = getMaxDumpId();
        binaryheap *pendingHeap;
        int                *beforeConstraints;
        int                *idMap;
        DumpableObject *obj;
        int                     i,
                                j,
                                k;

        /*
         * This is basically the same algorithm shown for topological sorting in
         * Knuth's Volume 1.  However, we would like to minimize unnecessary
         * rearrangement of the input ordering; that is, when we have a choice of
         * which item to output next, we always want to take the one highest in
         * the original list.  Therefore, instead of maintaining an unordered
         * linked list of items-ready-to-output as Knuth does, we maintain a heap
         * of their item numbers, which we can use as a priority queue.  This
         * turns the algorithm from O(N) to O(N log N) because each insertion or
         * removal of a heap item takes O(log N) time.  However, that's still
         * plenty fast enough for this application.
         */

        *nOrdering = numObjs;           /* for success return */

        /* Eliminate the null case */
        if (numObjs <= 0)
                return true;

        /* Create workspace for the above-described heap */
        pendingHeap = binaryheap_allocate(numObjs, int_cmp, NULL);

        /*
         * Scan the constraints, and for each item in the input, generate a count
         * of the number of constraints that say it must be before something else.
         * The count for the item with dumpId j is stored in beforeConstraints[j].
         * We also make a map showing the input-order index of the item with
         * dumpId j.
         */
        beforeConstraints = (int *) pg_malloc0((maxDumpId + 1) * sizeof(int));
        idMap = (int *) pg_malloc((maxDumpId + 1) * sizeof(int));
        for (i = 0; i < numObjs; i++)
        {
                obj = objs[i];
                j = obj->dumpId;
                if (j <= 0 || j > maxDumpId)
                        pg_fatal("invalid dumpId %d", j);
                idMap[j] = i;
                for (j = 0; j < obj->nDeps; j++)
                {
                        k = obj->dependencies[j];
                        if (k <= 0 || k > maxDumpId)
                                pg_fatal("invalid dependency %d", k);
                        beforeConstraints[k]++;
                }
        }

        /*
         * Now initialize the heap of items-ready-to-output by filling it with the
         * indexes of items that already have beforeConstraints[id] == 0.
         *
         * We enter the indexes into pendingHeap in decreasing order so that the
         * heap invariant is satisfied at the completion of this loop.  This
         * reduces the amount of work that binaryheap_build() must do.
         */
        for (i = numObjs; --i >= 0;)
        {
                if (beforeConstraints[objs[i]->dumpId] == 0)
                        binaryheap_add_unordered(pendingHeap, (void *) (intptr_t) i);
        }
        binaryheap_build(pendingHeap);

        /*--------------------
         * Now emit objects, working backwards in the output list.  At each step,
         * we use the priority heap to select the last item that has no remaining
         * before-constraints.  We remove that item from the heap, output it to
         * ordering[], and decrease the beforeConstraints count of each of the
         * items it was constrained against.  Whenever an item's beforeConstraints
         * count is thereby decreased to zero, we insert it into the priority heap
         * to show that it is a candidate to output.  We are done when the heap
         * becomes empty; if we have output every element then we succeeded,
         * otherwise we failed.
         * i = number of ordering[] entries left to output
         * j = objs[] index of item we are outputting
         * k = temp for scanning constraint list for item j
         *--------------------
         */
        i = numObjs;
        while (!binaryheap_empty(pendingHeap))
        {
                /* Select object to output by removing largest heap member */
                j = (int) (intptr_t) binaryheap_remove_first(pendingHeap);
                obj = objs[j];
                /* Output candidate to ordering[] */
                ordering[--i] = obj;
                /* Update beforeConstraints counts of its predecessors */
                for (k = 0; k < obj->nDeps; k++)
                {
                        int                     id = obj->dependencies[k];

                        if ((--beforeConstraints[id]) == 0)
                                binaryheap_add(pendingHeap, (void *) (intptr_t) idMap[id]);
                }
        }

        /*
         * If we failed, report the objects that couldn't be output; these are the
         * ones with beforeConstraints[] still nonzero.
         */
        if (i != 0)
        {
                k = 0;
                for (j = 1; j <= maxDumpId; j++)
                {
                        if (beforeConstraints[j] != 0)
                                ordering[k++] = objs[idMap[j]];
                }
                *nOrdering = k;
        }

        /* Done */
        binaryheap_free(pendingHeap);
        free(beforeConstraints);
        free(idMap);

        return (i == 0);
}

/*
 * findDependencyLoops - identify loops in TopoSort's failure output,
 *              and pass each such loop to repairDependencyLoop() for action
 *
 * In general there may be many loops in the set of objects returned by
 * TopoSort; for speed we should try to repair as many loops as we can
 * before trying TopoSort again.  We can safely repair loops that are
 * disjoint (have no members in common); if we find overlapping loops
 * then we repair only the first one found, because the action taken to
 * repair the first might have repaired the other as well.  (If not,
 * we'll fix it on the next go-round.)
 *
 * objs[] lists the objects TopoSort couldn't sort
 * nObjs is the number of such objects
 * totObjs is the total number of objects in the universe
 */
static void
findDependencyLoops(DumpableObject **objs, int nObjs, int totObjs)
{
        /*
         * We use three data structures here:
         *
         * processed[] is a bool array indexed by dump ID, marking the objects
         * already processed during this invocation of findDependencyLoops().
         *
         * searchFailed[] is another array indexed by dump ID.  searchFailed[j] is
         * set to dump ID k if we have proven that there is no dependency path
         * leading from object j back to start point k.  This allows us to skip
         * useless searching when there are multiple dependency paths from k to j,
         * which is a common situation.  We could use a simple bool array for
         * this, but then we'd need to re-zero it for each start point, resulting
         * in O(N^2) zeroing work.  Using the start point's dump ID as the "true"
         * value lets us skip clearing the array before we consider the next start
         * point.
         *
         * workspace[] is an array of DumpableObject pointers, in which we try to
         * build lists of objects constituting loops.  We make workspace[] large
         * enough to hold all the objects in TopoSort's output, which is huge
         * overkill in most cases but could theoretically be necessary if there is
         * a single dependency chain linking all the objects.
         */
        bool       *processed;
        DumpId     *searchFailed;
        DumpableObject **workspace;
        bool            fixedloop;
        int                     i;

        processed = (bool *) pg_malloc0((getMaxDumpId() + 1) * sizeof(bool));
        searchFailed = (DumpId *) pg_malloc0((getMaxDumpId() + 1) * sizeof(DumpId));
        workspace = (DumpableObject **) pg_malloc(totObjs * sizeof(DumpableObject *));
        fixedloop = false;

        for (i = 0; i < nObjs; i++)
        {
                DumpableObject *obj = objs[i];
                int                     looplen;
                int                     j;

                looplen = findLoop(obj,
                                                   obj->dumpId,
                                                   processed,
                                                   searchFailed,
                                                   workspace,
                                                   0);

                if (looplen > 0)
                {
                        /* Found a loop, repair it */
                        repairDependencyLoop(workspace, looplen);
                        fixedloop = true;
                        /* Mark loop members as processed */
                        for (j = 0; j < looplen; j++)
                                processed[workspace[j]->dumpId] = true;
                }
                else
                {
                        /*
                         * There's no loop starting at this object, but mark it processed
                         * anyway.  This is not necessary for correctness, but saves later
                         * invocations of findLoop() from uselessly chasing references to
                         * such an object.
                         */
                        processed[obj->dumpId] = true;
                }
        }

        /* We'd better have fixed at least one loop */
        if (!fixedloop)
                pg_fatal("could not identify dependency loop");

        free(workspace);
        free(searchFailed);
        free(processed);
}

/*
 * Recursively search for a circular dependency loop that doesn't include
 * any already-processed objects.
 *
 *      obj: object we are examining now
 *      startPoint: dumpId of starting object for the hoped-for circular loop
 *      processed[]: flag array marking already-processed objects
 *      searchFailed[]: flag array marking already-unsuccessfully-visited objects
 *      workspace[]: work array in which we are building list of loop members
 *      depth: number of valid entries in workspace[] at call
 *
 * On success, the length of the loop is returned, and workspace[] is filled
 * with pointers to the members of the loop.  On failure, we return 0.
 *
 * Note: it is possible that the given starting object is a member of more
 * than one cycle; if so, we will find an arbitrary one of the cycles.
 */
static int
findLoop(DumpableObject *obj,
                 DumpId startPoint,
                 bool *processed,
                 DumpId *searchFailed,
                 DumpableObject **workspace,
                 int depth)
{
        int                     i;

        /*
         * Reject if obj is already processed.  This test prevents us from finding
         * loops that overlap previously-processed loops.
         */
        if (processed[obj->dumpId])
                return 0;

        /*
         * If we've already proven there is no path from this object back to the
         * startPoint, forget it.
         */
        if (searchFailed[obj->dumpId] == startPoint)
                return 0;

        /*
         * Reject if obj is already present in workspace.  This test prevents us
         * from going into infinite recursion if we are given a startPoint object
         * that links to a cycle it's not a member of, and it guarantees that we
         * can't overflow the allocated size of workspace[].
         */
        for (i = 0; i < depth; i++)
        {
                if (workspace[i] == obj)
                        return 0;
        }

        /*
         * Okay, tentatively add obj to workspace
         */
        workspace[depth++] = obj;

        /*
         * See if we've found a loop back to the desired startPoint; if so, done
         */
        for (i = 0; i < obj->nDeps; i++)
        {
                if (obj->dependencies[i] == startPoint)
                        return depth;
        }

        /*
         * Recurse down each outgoing branch
         */
        for (i = 0; i < obj->nDeps; i++)
        {
                DumpableObject *nextobj = findObjectByDumpId(obj->dependencies[i]);
                int                     newDepth;

                if (!nextobj)
                        continue;                       /* ignore dependencies on undumped objects */
                newDepth = findLoop(nextobj,
                                                        startPoint,
                                                        processed,
                                                        searchFailed,
                                                        workspace,
                                                        depth);
                if (newDepth > 0)
                        return newDepth;
        }

        /*
         * Remember there is no path from here back to startPoint
         */
        searchFailed[obj->dumpId] = startPoint;

        return 0;
}

/*
 * A user-defined datatype will have a dependency loop with each of its
 * I/O functions (since those have the datatype as input or output).
 * Similarly, a range type will have a loop with its canonicalize function,
 * if any.  Break the loop by making the function depend on the associated
 * shell type, instead.
 */
static void
repairTypeFuncLoop(DumpableObject *typeobj, DumpableObject *funcobj)
{
        TypeInfo   *typeInfo = (TypeInfo *) typeobj;

        /* remove function's dependency on type */
        removeObjectDependency(funcobj, typeobj->dumpId);

        /* add function's dependency on shell type, instead */
        if (typeInfo->shellType)
        {
                addObjectDependency(funcobj, typeInfo->shellType->dobj.dumpId);

                /*
                 * Mark shell type (always including the definition, as we need the
                 * shell type defined to identify the function fully) as to be dumped
                 * if any such function is
                 */
                if (funcobj->dump)
                        typeInfo->shellType->dobj.dump = funcobj->dump |
                                DUMP_COMPONENT_DEFINITION;
        }
}

/*
 * Because we force a view to depend on its ON SELECT rule, while there
 * will be an implicit dependency in the other direction, we need to break
 * the loop.  If there are no other objects in the loop then we can remove
 * the implicit dependency and leave the ON SELECT rule non-separate.
 * This applies to matviews, as well.
 */
static void
repairViewRuleLoop(DumpableObject *viewobj,
                                   DumpableObject *ruleobj)
{
        /* remove rule's dependency on view */
        removeObjectDependency(ruleobj, viewobj->dumpId);
        /* flags on the two objects are already set correctly for this case */
}

/*
 * However, if there are other objects in the loop, we must break the loop
 * by making the ON SELECT rule a separately-dumped object.
 *
 * Because findLoop() finds shorter cycles before longer ones, it's likely
 * that we will have previously fired repairViewRuleLoop() and removed the
 * rule's dependency on the view.  Put it back to ensure the rule won't be
 * emitted before the view.
 *
 * Note: this approach does *not* work for matviews, at the moment.
 */
static void
repairViewRuleMultiLoop(DumpableObject *viewobj,
                                                DumpableObject *ruleobj)
{
        TableInfo  *viewinfo = (TableInfo *) viewobj;
        RuleInfo   *ruleinfo = (RuleInfo *) ruleobj;

        /* remove view's dependency on rule */
        removeObjectDependency(viewobj, ruleobj->dumpId);
        /* mark view to be printed with a dummy definition */
        viewinfo->dummy_view = true;
        /* mark rule as needing its own dump */
        ruleinfo->separate = true;
        /* put back rule's dependency on view */
        addObjectDependency(ruleobj, viewobj->dumpId);
        /* now that rule is separate, it must be post-data */
        addObjectDependency(ruleobj, postDataBoundId);
}

/*
 * If a matview is involved in a multi-object loop, we can't currently fix
 * that by splitting off the rule.  As a stopgap, we try to fix it by
 * dropping the constraint that the matview be dumped in the pre-data section.
 * This is sufficient to handle cases where a matview depends on some unique
 * index, as can happen if it has a GROUP BY for example.
 *
 * Note that the "next object" is not necessarily the matview itself;
 * it could be the matview's rowtype, for example.  We may come through here
 * several times while removing all the pre-data linkages.  In particular,
 * if there are other matviews that depend on the one with the circularity
 * problem, we'll come through here for each such matview and mark them all
 * as postponed.  (This works because all MVs have pre-data dependencies
 * to begin with, so each of them will get visited.)
 */
static void
repairMatViewBoundaryMultiLoop(DumpableObject *boundaryobj,
                                                           DumpableObject *nextobj)
{
        /* remove boundary's dependency on object after it in loop */
        removeObjectDependency(boundaryobj, nextobj->dumpId);
        /* if that object is a matview, mark it as postponed into post-data */
        if (nextobj->objType == DO_TABLE)
        {
                TableInfo  *nextinfo = (TableInfo *) nextobj;

                if (nextinfo->relkind == RELKIND_MATVIEW)
                        nextinfo->postponed_def = true;
        }
}

/*
 * If a function is involved in a multi-object loop, we can't currently fix
 * that by splitting it into two DumpableObjects.  As a stopgap, we try to fix
 * it by dropping the constraint that the function be dumped in the pre-data
 * section.  This is sufficient to handle cases where a function depends on
 * some unique index, as can happen if it has a GROUP BY for example.
 */
static void
repairFunctionBoundaryMultiLoop(DumpableObject *boundaryobj,
                                                                DumpableObject *nextobj)
{
        /* remove boundary's dependency on object after it in loop */
        removeObjectDependency(boundaryobj, nextobj->dumpId);
        /* if that object is a function, mark it as postponed into post-data */
        if (nextobj->objType == DO_FUNC)
        {
                FuncInfo   *nextinfo = (FuncInfo *) nextobj;

                nextinfo->postponed_def = true;
        }
}

/*
 * Because we make tables depend on their CHECK constraints, while there
 * will be an automatic dependency in the other direction, we need to break
 * the loop.  If there are no other objects in the loop then we can remove
 * the automatic dependency and leave the CHECK constraint non-separate.
 */
static void
repairTableConstraintLoop(DumpableObject *tableobj,
                                                  DumpableObject *constraintobj)
{
        /* remove constraint's dependency on table */
        removeObjectDependency(constraintobj, tableobj->dumpId);
}

/*
 * However, if there are other objects in the loop, we must break the loop
 * by making the CHECK constraint a separately-dumped object.
 *
 * Because findLoop() finds shorter cycles before longer ones, it's likely
 * that we will have previously fired repairTableConstraintLoop() and
 * removed the constraint's dependency on the table.  Put it back to ensure
 * the constraint won't be emitted before the table...
 */
static void
repairTableConstraintMultiLoop(DumpableObject *tableobj,
                                                           DumpableObject *constraintobj)
{
        /* remove table's dependency on constraint */
        removeObjectDependency(tableobj, constraintobj->dumpId);
        /* mark constraint as needing its own dump */
        ((ConstraintInfo *) constraintobj)->separate = true;
        /* put back constraint's dependency on table */
        addObjectDependency(constraintobj, tableobj->dumpId);
        /* now that constraint is separate, it must be post-data */
        addObjectDependency(constraintobj, postDataBoundId);
}

/*
 * Attribute defaults behave exactly the same as CHECK constraints...
 */
static void
repairTableAttrDefLoop(DumpableObject *tableobj,
                                           DumpableObject *attrdefobj)
{
        /* remove attrdef's dependency on table */
        removeObjectDependency(attrdefobj, tableobj->dumpId);
}

static void
repairTableAttrDefMultiLoop(DumpableObject *tableobj,
                                                        DumpableObject *attrdefobj)
{
        /* remove table's dependency on attrdef */
        removeObjectDependency(tableobj, attrdefobj->dumpId);
        /* mark attrdef as needing its own dump */
        ((AttrDefInfo *) attrdefobj)->separate = true;
        /* put back attrdef's dependency on table */
        addObjectDependency(attrdefobj, tableobj->dumpId);
}

/*
 * CHECK constraints on domains work just like those on tables ...
 */
static void
repairDomainConstraintLoop(DumpableObject *domainobj,
                                                   DumpableObject *constraintobj)
{
        /* remove constraint's dependency on domain */
        removeObjectDependency(constraintobj, domainobj->dumpId);
}

static void
repairDomainConstraintMultiLoop(DumpableObject *domainobj,
                                                                DumpableObject *constraintobj)
{
        /* remove domain's dependency on constraint */
        removeObjectDependency(domainobj, constraintobj->dumpId);
        /* mark constraint as needing its own dump */
        ((ConstraintInfo *) constraintobj)->separate = true;
        /* put back constraint's dependency on domain */
        addObjectDependency(constraintobj, domainobj->dumpId);
        /* now that constraint is separate, it must be post-data */
        addObjectDependency(constraintobj, postDataBoundId);
}

static void
repairIndexLoop(DumpableObject *partedindex,
                                DumpableObject *partindex)
{
        removeObjectDependency(partedindex, partindex->dumpId);
}

/*
 * Fix a dependency loop, or die trying ...
 *
 * This routine is mainly concerned with reducing the multiple ways that
 * a loop might appear to common cases, which it passes off to the
 * "fixer" routines above.
 */
static void
repairDependencyLoop(DumpableObject **loop,
                                         int nLoop)
{
        int                     i,
                                j;

        /* Datatype and one of its I/O or canonicalize functions */
        if (nLoop == 2 &&
                loop[0]->objType == DO_TYPE &&
                loop[1]->objType == DO_FUNC)
        {
                repairTypeFuncLoop(loop[0], loop[1]);
                return;
        }
        if (nLoop == 2 &&
                loop[1]->objType == DO_TYPE &&
                loop[0]->objType == DO_FUNC)
        {
                repairTypeFuncLoop(loop[1], loop[0]);
                return;
        }

        /* View (including matview) and its ON SELECT rule */
        if (nLoop == 2 &&
                loop[0]->objType == DO_TABLE &&
                loop[1]->objType == DO_RULE &&
                (((TableInfo *) loop[0])->relkind == RELKIND_VIEW ||
                 ((TableInfo *) loop[0])->relkind == RELKIND_MATVIEW) &&
                ((RuleInfo *) loop[1])->ev_type == '1' &&
                ((RuleInfo *) loop[1])->is_instead &&
                ((RuleInfo *) loop[1])->ruletable == (TableInfo *) loop[0])
        {
                repairViewRuleLoop(loop[0], loop[1]);
                return;
        }
        if (nLoop == 2 &&
                loop[1]->objType == DO_TABLE &&
                loop[0]->objType == DO_RULE &&
                (((TableInfo *) loop[1])->relkind == RELKIND_VIEW ||
                 ((TableInfo *) loop[1])->relkind == RELKIND_MATVIEW) &&
                ((RuleInfo *) loop[0])->ev_type == '1' &&
                ((RuleInfo *) loop[0])->is_instead &&
                ((RuleInfo *) loop[0])->ruletable == (TableInfo *) loop[1])
        {
                repairViewRuleLoop(loop[1], loop[0]);
                return;
        }

        /* Indirect loop involving view (but not matview) and ON SELECT rule */
        if (nLoop > 2)
        {
                for (i = 0; i < nLoop; i++)
                {
                        if (loop[i]->objType == DO_TABLE &&
                                ((TableInfo *) loop[i])->relkind == RELKIND_VIEW)
                        {
                                for (j = 0; j < nLoop; j++)
                                {
                                        if (loop[j]->objType == DO_RULE &&
                                                ((RuleInfo *) loop[j])->ev_type == '1' &&
                                                ((RuleInfo *) loop[j])->is_instead &&
                                                ((RuleInfo *) loop[j])->ruletable == (TableInfo *) loop[i])
                                        {
                                                repairViewRuleMultiLoop(loop[i], loop[j]);
                                                return;
                                        }
                                }
                        }
                }
        }

        /* Indirect loop involving matview and data boundary */
        if (nLoop > 2)
        {
                for (i = 0; i < nLoop; i++)
                {
                        if (loop[i]->objType == DO_TABLE &&
                                ((TableInfo *) loop[i])->relkind == RELKIND_MATVIEW)
                        {
                                for (j = 0; j < nLoop; j++)
                                {
                                        if (loop[j]->objType == DO_PRE_DATA_BOUNDARY)
                                        {
                                                DumpableObject *nextobj;

                                                nextobj = (j < nLoop - 1) ? loop[j + 1] : loop[0];
                                                repairMatViewBoundaryMultiLoop(loop[j], nextobj);
                                                return;
                                        }
                                }
                        }
                }
        }

        /* Indirect loop involving function and data boundary */
        if (nLoop > 2)
        {
                for (i = 0; i < nLoop; i++)
                {
                        if (loop[i]->objType == DO_FUNC)
                        {
                                for (j = 0; j < nLoop; j++)
                                {
                                        if (loop[j]->objType == DO_PRE_DATA_BOUNDARY)
                                        {
                                                DumpableObject *nextobj;

                                                nextobj = (j < nLoop - 1) ? loop[j + 1] : loop[0];
                                                repairFunctionBoundaryMultiLoop(loop[j], nextobj);
                                                return;
                                        }
                                }
                        }
                }
        }

        /* Table and CHECK constraint */
        if (nLoop == 2 &&
                loop[0]->objType == DO_TABLE &&
                loop[1]->objType == DO_CONSTRAINT &&
                ((ConstraintInfo *) loop[1])->contype == 'c' &&
                ((ConstraintInfo *) loop[1])->contable == (TableInfo *) loop[0])
        {
                repairTableConstraintLoop(loop[0], loop[1]);
                return;
        }
        if (nLoop == 2 &&
                loop[1]->objType == DO_TABLE &&
                loop[0]->objType == DO_CONSTRAINT &&
                ((ConstraintInfo *) loop[0])->contype == 'c' &&
                ((ConstraintInfo *) loop[0])->contable == (TableInfo *) loop[1])
        {
                repairTableConstraintLoop(loop[1], loop[0]);
                return;
        }

        /* Indirect loop involving table and CHECK constraint */
        if (nLoop > 2)
        {
                for (i = 0; i < nLoop; i++)
                {
                        if (loop[i]->objType == DO_TABLE)
                        {
                                for (j = 0; j < nLoop; j++)
                                {
                                        if (loop[j]->objType == DO_CONSTRAINT &&
                                                ((ConstraintInfo *) loop[j])->contype == 'c' &&
                                                ((ConstraintInfo *) loop[j])->contable == (TableInfo *) loop[i])
                                        {
                                                repairTableConstraintMultiLoop(loop[i], loop[j]);
                                                return;
                                        }
                                }
                        }
                }
        }

        /* Table and attribute default */
        if (nLoop == 2 &&
                loop[0]->objType == DO_TABLE &&
                loop[1]->objType == DO_ATTRDEF &&
                ((AttrDefInfo *) loop[1])->adtable == (TableInfo *) loop[0])
        {
                repairTableAttrDefLoop(loop[0], loop[1]);
                return;
        }
        if (nLoop == 2 &&
                loop[1]->objType == DO_TABLE &&
                loop[0]->objType == DO_ATTRDEF &&
                ((AttrDefInfo *) loop[0])->adtable == (TableInfo *) loop[1])
        {
                repairTableAttrDefLoop(loop[1], loop[0]);
                return;
        }

        /* index on partitioned table and corresponding index on partition */
        if (nLoop == 2 &&
                loop[0]->objType == DO_INDEX &&
                loop[1]->objType == DO_INDEX)
        {
                if (((IndxInfo *) loop[0])->parentidx == loop[1]->catId.oid)
                {
                        repairIndexLoop(loop[0], loop[1]);
                        return;
                }
                else if (((IndxInfo *) loop[1])->parentidx == loop[0]->catId.oid)
                {
                        repairIndexLoop(loop[1], loop[0]);
                        return;
                }
        }

        /* Indirect loop involving table and attribute default */
        if (nLoop > 2)
        {
                for (i = 0; i < nLoop; i++)
                {
                        if (loop[i]->objType == DO_TABLE)
                        {
                                for (j = 0; j < nLoop; j++)
                                {
                                        if (loop[j]->objType == DO_ATTRDEF &&
                                                ((AttrDefInfo *) loop[j])->adtable == (TableInfo *) loop[i])
                                        {
                                                repairTableAttrDefMultiLoop(loop[i], loop[j]);
                                                return;
                                        }
                                }
                        }
                }
        }

        /* Domain and CHECK constraint */
        if (nLoop == 2 &&
                loop[0]->objType == DO_TYPE &&
                loop[1]->objType == DO_CONSTRAINT &&
                ((ConstraintInfo *) loop[1])->contype == 'c' &&
                ((ConstraintInfo *) loop[1])->condomain == (TypeInfo *) loop[0])
        {
                repairDomainConstraintLoop(loop[0], loop[1]);
                return;
        }
        if (nLoop == 2 &&
                loop[1]->objType == DO_TYPE &&
                loop[0]->objType == DO_CONSTRAINT &&
                ((ConstraintInfo *) loop[0])->contype == 'c' &&
                ((ConstraintInfo *) loop[0])->condomain == (TypeInfo *) loop[1])
        {
                repairDomainConstraintLoop(loop[1], loop[0]);
                return;
        }

        /* Indirect loop involving domain and CHECK constraint */
        if (nLoop > 2)
        {
                for (i = 0; i < nLoop; i++)
                {
                        if (loop[i]->objType == DO_TYPE)
                        {
                                for (j = 0; j < nLoop; j++)
                                {
                                        if (loop[j]->objType == DO_CONSTRAINT &&
                                                ((ConstraintInfo *) loop[j])->contype == 'c' &&
                                                ((ConstraintInfo *) loop[j])->condomain == (TypeInfo *) loop[i])
                                        {
                                                repairDomainConstraintMultiLoop(loop[i], loop[j]);
                                                return;
                                        }
                                }
                        }
                }
        }

        /*
         * Loop of table with itself --- just ignore it.
         *
         * (Actually, what this arises from is a dependency of a table column on
         * another column, which happened with generated columns before v15; or a
         * dependency of a table column on the whole table, which happens with
         * partitioning.  But we didn't pay attention to sub-object IDs while
         * collecting the dependency data, so we can't see that here.)
         */
        if (nLoop == 1)
        {
                if (loop[0]->objType == DO_TABLE)
                {
                        removeObjectDependency(loop[0], loop[0]->dumpId);
                        return;
                }
        }

        /*
         * If all the objects are TABLE_DATA items, what we must have is a
         * circular set of foreign key constraints (or a single self-referential
         * table).  Print an appropriate complaint and break the loop arbitrarily.
         */
        for (i = 0; i < nLoop; i++)
        {
                if (loop[i]->objType != DO_TABLE_DATA)
                        break;
        }
        if (i >= nLoop)
        {
                pg_log_warning(ngettext("there are circular foreign-key constraints on this table:",
                                                                "there are circular foreign-key constraints among these tables:",
                                                                nLoop));
                for (i = 0; i < nLoop; i++)
                        pg_log_warning_detail("%s", loop[i]->name);
                pg_log_warning_hint("You might not be able to restore the dump without using --disable-triggers or temporarily dropping the constraints.");
                pg_log_warning_hint("Consider using a full dump instead of a --data-only dump to avoid this problem.");
                if (nLoop > 1)
                        removeObjectDependency(loop[0], loop[1]->dumpId);
                else                                    /* must be a self-dependency */
                        removeObjectDependency(loop[0], loop[0]->dumpId);
                return;
        }

        /*
         * If we can't find a principled way to break the loop, complain and break
         * it in an arbitrary fashion.
         */
        pg_log_warning("could not resolve dependency loop among these items:");
        for (i = 0; i < nLoop; i++)
        {
                char            buf[1024];

                describeDumpableObject(loop[i], buf, sizeof(buf));
                pg_log_warning_detail("%s", buf);
        }

        if (nLoop > 1)
                removeObjectDependency(loop[0], loop[1]->dumpId);
        else                                            /* must be a self-dependency */
                removeObjectDependency(loop[0], loop[0]->dumpId);
}

/*
 * Describe a dumpable object usefully for errors
 *
 * This should probably go somewhere else...
 */
static void
describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
{
        switch (obj->objType)
        {
                case DO_NAMESPACE:
                        snprintf(buf, bufsize,
                                         "SCHEMA %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_EXTENSION:
                        snprintf(buf, bufsize,
                                         "EXTENSION %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TYPE:
                        snprintf(buf, bufsize,
                                         "TYPE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_SHELL_TYPE:
                        snprintf(buf, bufsize,
                                         "SHELL TYPE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_FUNC:
                        snprintf(buf, bufsize,
                                         "FUNCTION %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_AGG:
                        snprintf(buf, bufsize,
                                         "AGGREGATE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_OPERATOR:
                        snprintf(buf, bufsize,
                                         "OPERATOR %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_ACCESS_METHOD:
                        snprintf(buf, bufsize,
                                         "ACCESS METHOD %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_OPCLASS:
                        snprintf(buf, bufsize,
                                         "OPERATOR CLASS %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_OPFAMILY:
                        snprintf(buf, bufsize,
                                         "OPERATOR FAMILY %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_COLLATION:
                        snprintf(buf, bufsize,
                                         "COLLATION %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_CONVERSION:
                        snprintf(buf, bufsize,
                                         "CONVERSION %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TABLE:
                        snprintf(buf, bufsize,
                                         "TABLE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TABLE_ATTACH:
                        snprintf(buf, bufsize,
                                         "TABLE ATTACH %s  (ID %d)",
                                         obj->name, obj->dumpId);
                        return;
                case DO_ATTRDEF:
                        snprintf(buf, bufsize,
                                         "ATTRDEF %s.%s  (ID %d OID %u)",
                                         ((AttrDefInfo *) obj)->adtable->dobj.name,
                                         ((AttrDefInfo *) obj)->adtable->attnames[((AttrDefInfo *) obj)->adnum - 1],
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_INDEX:
                        snprintf(buf, bufsize,
                                         "INDEX %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_INDEX_ATTACH:
                        snprintf(buf, bufsize,
                                         "INDEX ATTACH %s  (ID %d)",
                                         obj->name, obj->dumpId);
                        return;
                case DO_STATSEXT:
                        snprintf(buf, bufsize,
                                         "STATISTICS %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_REFRESH_MATVIEW:
                        snprintf(buf, bufsize,
                                         "REFRESH MATERIALIZED VIEW %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_RULE:
                        snprintf(buf, bufsize,
                                         "RULE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TRIGGER:
                        snprintf(buf, bufsize,
                                         "TRIGGER %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_EVENT_TRIGGER:
                        snprintf(buf, bufsize,
                                         "EVENT TRIGGER %s (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_CONSTRAINT:
                        snprintf(buf, bufsize,
                                         "CONSTRAINT %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_FK_CONSTRAINT:
                        snprintf(buf, bufsize,
                                         "FK CONSTRAINT %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_PROCLANG:
                        snprintf(buf, bufsize,
                                         "PROCEDURAL LANGUAGE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_CAST:
                        snprintf(buf, bufsize,
                                         "CAST %u to %u  (ID %d OID %u)",
                                         ((CastInfo *) obj)->castsource,
                                         ((CastInfo *) obj)->casttarget,
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_TRANSFORM:
                        snprintf(buf, bufsize,
                                         "TRANSFORM %u lang %u  (ID %d OID %u)",
                                         ((TransformInfo *) obj)->trftype,
                                         ((TransformInfo *) obj)->trflang,
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_TABLE_DATA:
                        snprintf(buf, bufsize,
                                         "TABLE DATA %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_SEQUENCE_SET:
                        snprintf(buf, bufsize,
                                         "SEQUENCE SET %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_DUMMY_TYPE:
                        snprintf(buf, bufsize,
                                         "DUMMY TYPE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TSPARSER:
                        snprintf(buf, bufsize,
                                         "TEXT SEARCH PARSER %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TSDICT:
                        snprintf(buf, bufsize,
                                         "TEXT SEARCH DICTIONARY %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TSTEMPLATE:
                        snprintf(buf, bufsize,
                                         "TEXT SEARCH TEMPLATE %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_TSCONFIG:
                        snprintf(buf, bufsize,
                                         "TEXT SEARCH CONFIGURATION %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_FDW:
                        snprintf(buf, bufsize,
                                         "FOREIGN DATA WRAPPER %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_FOREIGN_SERVER:
                        snprintf(buf, bufsize,
                                         "FOREIGN SERVER %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_DEFAULT_ACL:
                        snprintf(buf, bufsize,
                                         "DEFAULT ACL %s  (ID %d OID %u)",
                                         obj->name, obj->dumpId, obj->catId.oid);
                        return;
                case DO_LARGE_OBJECT:
                        snprintf(buf, bufsize,
                                         "LARGE OBJECT  (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_LARGE_OBJECT_DATA:
                        snprintf(buf, bufsize,
                                         "LARGE OBJECT DATA  (ID %d)",
                                         obj->dumpId);
                        return;
                case DO_POLICY:
                        snprintf(buf, bufsize,
                                         "POLICY (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_PUBLICATION:
                        snprintf(buf, bufsize,
                                         "PUBLICATION (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_PUBLICATION_REL:
                        snprintf(buf, bufsize,
                                         "PUBLICATION TABLE (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_PUBLICATION_TABLE_IN_SCHEMA:
                        snprintf(buf, bufsize,
                                         "PUBLICATION TABLES IN SCHEMA (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_SUBSCRIPTION:
                        snprintf(buf, bufsize,
                                         "SUBSCRIPTION (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_SUBSCRIPTION_REL:
                        snprintf(buf, bufsize,
                                         "SUBSCRIPTION TABLE (ID %d OID %u)",
                                         obj->dumpId, obj->catId.oid);
                        return;
                case DO_PRE_DATA_BOUNDARY:
                        snprintf(buf, bufsize,
                                         "PRE-DATA BOUNDARY  (ID %d)",
                                         obj->dumpId);
                        return;
                case DO_POST_DATA_BOUNDARY:
                        snprintf(buf, bufsize,
                                         "POST-DATA BOUNDARY  (ID %d)",
                                         obj->dumpId);
                        return;
        }
        /* shouldn't get here */
        snprintf(buf, bufsize,
                         "object type %d  (ID %d OID %u)",
                         (int) obj->objType,
                         obj->dumpId, obj->catId.oid);
}

/* binaryheap comparator that compares "a" and "b" as integers */
static int
int_cmp(void *a, void *b, void *arg)
{
        int                     ai = (int) (intptr_t) a;
        int                     bi = (int) (intptr_t) b;

        return pg_cmp_s32(ai, bi);
}