Function bmbuild

src/backend/access/bitmap/bitmap.c:119–161

* bmbuild() -- Build a new bitmap index. */

 * bmbuild() -- Build a new bitmap index.
 */
IndexBuildResult *
bmbuild(Relation heap, Relation index, IndexInfo *indexInfo)
{
	double      reltuples;
	BMBuildState bmstate;
	IndexBuildResult *result;
	TupleDesc	tupDesc;

	if (indexInfo->ii_Concurrent)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("CONCURRENTLY is not supported when creating bitmap indexes")));

	/* We expect this to be called exactly once. */
	if (RelationGetNumberOfBlocks(index) != 0)
		ereport (ERROR,
				(errcode(ERRCODE_INDEX_CORRUPTED),
				errmsg("index \"%s\" already contains data",
				RelationGetRelationName(index))));

	tupDesc = RelationGetDescr(index);

	/* initialize the bitmap index for MAIN_FORKNUM. */
	_bitmap_init(index, RelationNeedsWAL(index), false);

	/* initialize the build state. */
	_bitmap_init_buildstate(index, &bmstate);

	/* do the heap scan */
	reltuples = table_index_build_scan(heap, index, indexInfo, false, true,
									   bmbuildCallback, (void *) &bmstate,
									   NULL);
	/* clean up the build state */
	_bitmap_cleanup_buildstate(index, &bmstate);
	
	/* return statistics */
	result = (IndexBuildResult *) palloc0(sizeof(IndexBuildResult));

	result->heap_tuples = reltuples;
	result->index_tuples = bmstate.ituples;

	return result;
}

/*
 *	bmbuildempty() -- build an empty bitmap index in the initialization fork