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pg_dump_sort.c
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pg_dump_sort.c
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/*-------------------------------------------------------------------------
*
* pg_dump_sort.c
* Sort the items of a dump into a safe order for dumping
*
*
* Portions Copyright (c) 1996-2023, 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 "lib/binaryheap.h"
#include "pg_backup_archiver.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_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[] =
{
PRIO_NAMESPACE, /* DO_NAMESPACE */
PRIO_EXTENSION, /* DO_EXTENSION */
PRIO_TYPE, /* DO_TYPE */
PRIO_TYPE, /* DO_SHELL_TYPE */
PRIO_FUNC, /* DO_FUNC */
PRIO_AGG, /* DO_AGG */
PRIO_OPERATOR, /* DO_OPERATOR */
PRIO_ACCESS_METHOD, /* DO_ACCESS_METHOD */
PRIO_OPFAMILY, /* DO_OPCLASS */
PRIO_OPFAMILY, /* DO_OPFAMILY */
PRIO_COLLATION, /* DO_COLLATION */
PRIO_CONVERSION, /* DO_CONVERSION */
PRIO_TABLE, /* DO_TABLE */
PRIO_TABLE_ATTACH, /* DO_TABLE_ATTACH */
PRIO_ATTRDEF, /* DO_ATTRDEF */
PRIO_INDEX, /* DO_INDEX */
PRIO_INDEX_ATTACH, /* DO_INDEX_ATTACH */
PRIO_STATSEXT, /* DO_STATSEXT */
PRIO_RULE, /* DO_RULE */
PRIO_TRIGGER, /* DO_TRIGGER */
PRIO_CONSTRAINT, /* DO_CONSTRAINT */
PRIO_FK_CONSTRAINT, /* DO_FK_CONSTRAINT */
PRIO_PROCLANG, /* DO_PROCLANG */
PRIO_CAST, /* DO_CAST */
PRIO_TABLE_DATA, /* DO_TABLE_DATA */
PRIO_SEQUENCE_SET, /* DO_SEQUENCE_SET */
PRIO_DUMMY_TYPE, /* DO_DUMMY_TYPE */
PRIO_TSPARSER, /* DO_TSPARSER */
PRIO_TSDICT, /* DO_TSDICT */
PRIO_TSTEMPLATE, /* DO_TSTEMPLATE */
PRIO_TSCONFIG, /* DO_TSCONFIG */
PRIO_FDW, /* DO_FDW */
PRIO_FOREIGN_SERVER, /* DO_FOREIGN_SERVER */
PRIO_DEFAULT_ACL, /* DO_DEFAULT_ACL */
PRIO_TRANSFORM, /* DO_TRANSFORM */
PRIO_LARGE_OBJECT, /* DO_LARGE_OBJECT */
PRIO_LARGE_OBJECT_DATA, /* DO_LARGE_OBJECT_DATA */
PRIO_PRE_DATA_BOUNDARY, /* DO_PRE_DATA_BOUNDARY */
PRIO_POST_DATA_BOUNDARY, /* DO_POST_DATA_BOUNDARY */
PRIO_EVENT_TRIGGER, /* DO_EVENT_TRIGGER */
PRIO_REFRESH_MATVIEW, /* DO_REFRESH_MATVIEW */
PRIO_POLICY, /* DO_POLICY */
PRIO_PUBLICATION, /* DO_PUBLICATION */
PRIO_PUBLICATION_REL, /* DO_PUBLICATION_REL */
PRIO_PUBLICATION_TABLE_IN_SCHEMA, /* DO_PUBLICATION_TABLE_IN_SCHEMA */
PRIO_SUBSCRIPTION /* DO_SUBSCRIPTION */
};
StaticAssertDecl(lengthof(dbObjectTypePriority) == (DO_SUBSCRIPTION + 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_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)