/* ----------------
* RelationGetIndexScan -- Create and fill an IndexScanDesc.
*
* This routine creates an index scan structure and sets its contents
* up correctly. This routine calls AMrescan to set up the scan with
* the passed key.
*
* Parameters:
* indexRelation -- index relation for scan.
* nkeys -- count of scan keys.
* key -- array of scan keys to restrict the index scan.
*
* Returns:
* An initialized IndexScanDesc.
* ----------------
*/
IndexScanDesc
RelationGetIndexScan(Relation indexRelation,
int nkeys, ScanKey key)
{
IndexScanDesc scan;
scan = (IndexScanDesc) palloc(sizeof(IndexScanDescData));
scan->heapRelation = NULL; /* may be set later */
scan->indexRelation = indexRelation;
scan->xs_snapshot = SnapshotNow; /* may be set later */
scan->numberOfKeys = nkeys;
/*
* We allocate the key space here, but the AM is responsible for
* actually filling it from the passed key array.
*/
if (nkeys > 0)
scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * nkeys);
else
scan->keyData = NULL;
scan->kill_prior_tuple = false;
scan->ignore_killed_tuples = true; /* default setting */
scan->keys_are_unique = false; /* may be set by index AM */
scan->got_tuple = false;
scan->opaque = NULL;
ItemPointerSetInvalid(&scan->currentItemData);
ItemPointerSetInvalid(&scan->currentMarkData);
ItemPointerSetInvalid(&scan->xs_ctup.t_self);
scan->xs_ctup.t_datamcxt = NULL;
scan->xs_ctup.t_data = NULL;
scan->xs_cbuf = InvalidBuffer;
/* mark cached function lookup data invalid; it will be set later */
scan->fn_getnext.fn_oid = InvalidOid;
scan->unique_tuple_pos = 0;
scan->unique_tuple_mark = 0;
pgstat_initstats(&scan->xs_pgstat_info, indexRelation);
/*
* Let the AM fill in the key and any opaque data it wants.
*/
index_rescan(scan, key);
return scan;
}
/* ----------------
* index_openr - open a system index relation specified by name.
*
* As above, but the relation is specified by an unqualified name;
* it is assumed to live in the system catalog namespace.
* ----------------
*/
Relation
index_openr(const char *sysRelationName)
{
Relation r;
r = relation_openr(sysRelationName, NoLock);
if (r->rd_rel->relkind != RELKIND_INDEX)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not an index",
RelationGetRelationName(r))));
pgstat_initstats(&r->pgstat_info, r);
return r;
}
/* ----------------
* RelationGetIndexScan -- Create and fill an IndexScanDesc.
*
* This routine creates an index scan structure and sets its contents
* up correctly. This routine calls AMrescan to set up the scan with
* the passed key.
*
* Parameters:
* indexRelation -- index relation for scan.
* nkeys -- count of scan keys.
* key -- array of scan keys to restrict the index scan.
*
* Returns:
* An initialized IndexScanDesc.
* ----------------
*/
IndexScanDesc
RelationGetIndexScan(Relation indexRelation,
int nkeys, ScanKey key)
{
IndexScanDesc scan;
scan = (IndexScanDesc) palloc(sizeof(IndexScanDescData));
scan->heapRelation = NULL; /* may be set later */
scan->indexRelation = indexRelation;
scan->xs_snapshot = SnapshotNow; /* may be set later */
scan->numberOfKeys = nkeys;
/*
* We allocate the key space here, but the AM is responsible for actually
* filling it from the passed key array.
*/
if (nkeys > 0)
scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * nkeys);
else
scan->keyData = NULL;
scan->is_multiscan = false; /* caller may change this */
scan->kill_prior_tuple = false;
scan->ignore_killed_tuples = true; /* default setting */
scan->opaque = NULL;
ItemPointerSetInvalid(&scan->currentItemData);
ItemPointerSetInvalid(&scan->currentMarkData);
ItemPointerSetInvalid(&scan->xs_ctup.t_self);
scan->xs_ctup.t_data = NULL;
scan->xs_cbuf = InvalidBuffer;
pgstat_initstats(&scan->xs_pgstat_info, indexRelation);
/*
* Let the AM fill in the key and any opaque data it wants.
*/
index_rescan(scan, key);
return scan;
}
