/*
* Per-tuple callback from IndexBuildHeapScan
*/
static void
hashbuildCallback(Relation index,
HeapTuple htup,
Datum *values,
bool *isnull,
bool tupleIsAlive,
void *state)
{
HashBuildState *buildstate = (HashBuildState *) state;
IndexTuple itup;
/* Hash indexes don't index nulls, see notes in hashinsert */
if (isnull[0])
return;
/* Either spool the tuple for sorting, or just put it into the index */
if (buildstate->spool)
_h_spool(buildstate->spool, &htup->t_self, values, isnull);
else
{
/* form an index tuple and point it at the heap tuple */
itup = _hash_form_tuple(index, values, isnull);
itup->t_tid = htup->t_self;
_hash_doinsert(index, itup);
pfree(itup);
}
buildstate->indtuples += 1;
}
/*
* hashinsert() -- insert an index tuple into a hash table.
*
* Hash on the heap tuple's key, form an index tuple with hash code.
* Find the appropriate location for the new tuple, and put it there.
*/
bool
hashinsert(Relation rel, Datum *values, bool *isnull,
ItemPointer ht_ctid, Relation heapRel,
IndexUniqueCheck checkUnique)
{
IndexTuple itup;
/*
* If the single index key is null, we don't insert it into the index.
* Hash tables support scans on '='. Relational algebra says that A = B
* returns null if either A or B is null. This means that no
* qualification used in an index scan could ever return true on a null
* attribute. It also means that indices can't be used by ISNULL or
* NOTNULL scans, but that's an artifact of the strategy map architecture
* chosen in 1986, not of the way nulls are handled here.
*/
if (isnull[0])
return false;
/* generate an index tuple */
itup = _hash_form_tuple(rel, values, isnull);
itup->t_tid = *ht_ctid;
_hash_doinsert(rel, itup);
pfree(itup);
return false;
}
/*
* hashinsert() -- insert an index tuple into a hash table.
*
* Hash on the heap tuple's key, form an index tuple with hash code.
* Find the appropriate location for the new tuple, and put it there.
*/
Datum
hashinsert(PG_FUNCTION_ARGS)
{
Relation rel = (Relation) PG_GETARG_POINTER(0);
Datum *values = (Datum *) PG_GETARG_POINTER(1);
bool *isnull = (bool *) PG_GETARG_POINTER(2);
ItemPointer ht_ctid = (ItemPointer) PG_GETARG_POINTER(3);
#ifdef NOT_USED
Relation heapRel = (Relation) PG_GETARG_POINTER(4);
IndexUniqueCheck checkUnique = (IndexUniqueCheck) PG_GETARG_INT32(5);
#endif
IndexTuple itup;
/* generate an index tuple */
itup = _hash_form_tuple(rel, values, isnull);
itup->t_tid = *ht_ctid;
/*
* If the single index key is null, we don't insert it into the index.
* Hash tables support scans on '='. Relational algebra says that A = B
* returns null if either A or B is null. This means that no
* qualification used in an index scan could ever return true on a null
* attribute. It also means that indices can't be used by ISNULL or
* NOTNULL scans, but that's an artifact of the strategy map architecture
* chosen in 1986, not of the way nulls are handled here.
*/
if (IndexTupleHasNulls(itup))
{
pfree(itup);
PG_RETURN_BOOL(false);
}
_hash_doinsert(rel, itup);
pfree(itup);
PG_RETURN_BOOL(false);
}
