/*
* Wait until the relation synchronization state is set in the catalog to the
* expected one.
*
* Used when transitioning from CATCHUP state to SYNCDONE.
*
* Returns false if the synchronization worker has disappeared or the table state
* has been reset.
*/
static bool
wait_for_relation_state_change(Oid relid, char expected_state)
{
char state;
for (;;)
{
LogicalRepWorker *worker;
XLogRecPtr statelsn;
CHECK_FOR_INTERRUPTS();
/* XXX use cache invalidation here to improve performance? */
PushActiveSnapshot(GetLatestSnapshot());
state = GetSubscriptionRelState(MyLogicalRepWorker->subid,
relid, &statelsn, true);
PopActiveSnapshot();
if (state == SUBREL_STATE_UNKNOWN)
return false;
if (state == expected_state)
return true;
/* Check if the sync worker is still running and bail if not. */
LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
/* Check if the opposite worker is still running and bail if not. */
worker = logicalrep_worker_find(MyLogicalRepWorker->subid,
am_tablesync_worker() ? InvalidOid : relid,
false);
LWLockRelease(LogicalRepWorkerLock);
if (!worker)
return false;
(void) WaitLatch(MyLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
1000L, WAIT_EVENT_LOGICAL_SYNC_STATE_CHANGE);
ResetLatch(MyLatch);
}
return false;
}
/*
* Open the local relation associated with the remote one.
*
* Optionally rebuilds the Relcache mapping if it was invalidated
* by local DDL.
*/
LogicalRepRelMapEntry *
logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
{
LogicalRepRelMapEntry *entry;
bool found;
if (LogicalRepRelMap == NULL)
logicalrep_relmap_init();
/* Search for existing entry. */
entry = hash_search(LogicalRepRelMap, (void *) &remoteid,
HASH_FIND, &found);
if (!found)
elog(ERROR, "no relation map entry for remote relation ID %u",
remoteid);
/* Need to update the local cache? */
if (!OidIsValid(entry->localreloid))
{
Oid relid;
int i;
int found;
Bitmapset *idkey;
TupleDesc desc;
LogicalRepRelation *remoterel;
MemoryContext oldctx;
remoterel = &entry->remoterel;
/* Try to find and lock the relation by name. */
relid = RangeVarGetRelid(makeRangeVar(remoterel->nspname,
remoterel->relname, -1),
lockmode, true);
if (!OidIsValid(relid))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("logical replication target relation \"%s.%s\" does not exist",
remoterel->nspname, remoterel->relname)));
entry->localrel = table_open(relid, NoLock);
/* Check for supported relkind. */
CheckSubscriptionRelkind(entry->localrel->rd_rel->relkind,
remoterel->nspname, remoterel->relname);
/*
* Build the mapping of local attribute numbers to remote attribute
* numbers and validate that we don't miss any replicated columns as
* that would result in potentially unwanted data loss.
*/
desc = RelationGetDescr(entry->localrel);
oldctx = MemoryContextSwitchTo(LogicalRepRelMapContext);
entry->attrmap = palloc(desc->natts * sizeof(int));
MemoryContextSwitchTo(oldctx);
found = 0;
for (i = 0; i < desc->natts; i++)
{
int attnum;
Form_pg_attribute attr = TupleDescAttr(desc, i);
if (attr->attisdropped || attr->attgenerated)
{
entry->attrmap[i] = -1;
continue;
}
attnum = logicalrep_rel_att_by_name(remoterel,
NameStr(attr->attname));
entry->attrmap[i] = attnum;
if (attnum >= 0)
found++;
}
/* TODO, detail message with names of missing columns */
if (found < remoterel->natts)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("logical replication target relation \"%s.%s\" is missing "
"some replicated columns",
remoterel->nspname, remoterel->relname)));
/*
* Check that replica identity matches. We allow for stricter replica
* identity (fewer columns) on subscriber as that will not stop us
* from finding unique tuple. IE, if publisher has identity
* (id,timestamp) and subscriber just (id) this will not be a problem,
* but in the opposite scenario it will.
*
* Don't throw any error here just mark the relation entry as not
* updatable, as replica identity is only for updates and deletes but
* inserts can be replicated even without it.
*/
entry->updatable = true;
idkey = RelationGetIndexAttrBitmap(entry->localrel,
INDEX_ATTR_BITMAP_IDENTITY_KEY);
/* fallback to PK if no replica identity */
if (idkey == NULL)
{
idkey = RelationGetIndexAttrBitmap(entry->localrel,
INDEX_ATTR_BITMAP_PRIMARY_KEY);
/*
* If no replica identity index and no PK, the published table
* must have replica identity FULL.
*/
if (idkey == NULL && remoterel->replident != REPLICA_IDENTITY_FULL)
entry->updatable = false;
}
i = -1;
while ((i = bms_next_member(idkey, i)) >= 0)
{
int attnum = i + FirstLowInvalidHeapAttributeNumber;
if (!AttrNumberIsForUserDefinedAttr(attnum))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("logical replication target relation \"%s.%s\" uses "
"system columns in REPLICA IDENTITY index",
remoterel->nspname, remoterel->relname)));
attnum = AttrNumberGetAttrOffset(attnum);
if (!bms_is_member(entry->attrmap[attnum], remoterel->attkeys))
{
entry->updatable = false;
break;
}
}
entry->localreloid = relid;
}
else
entry->localrel = table_open(entry->localreloid, lockmode);
if (entry->state != SUBREL_STATE_READY)
entry->state = GetSubscriptionRelState(MySubscription->oid,
entry->localreloid,
&entry->statelsn,
true);
return entry;
}