Function utilizeIndices

src/execution_plan/optimizations/utilize_indices.c:511–552

}

void utilizeIndices
(
	ExecutionPlan *plan
) {
	GraphContext *gc = QueryCtx_GetGraphCtx();
	// return immediately if the graph has no indices
	if(!GraphContext_HasIndices(gc)) return;

	// collect all label scans
	OpBase **scanOps = ExecutionPlan_CollectOps(plan->root,
			OPType_NODE_BY_LABEL_SCAN);

	int scanOpCount = array_len(scanOps);
	for(int i = 0; i < scanOpCount; i++) {
		NodeByLabelScan *scanOp = (NodeByLabelScan *)scanOps[i];

		// make sure scan is followed by filter(s)
		OpBase *parent = scanOp->op.parent;
		if(parent->type != OPType_FILTER) {
			// no filters to utilize
			continue;
		}

		// try to reduce label scan + filter(s) to a single IndexScan operation
		reduce_scan_op(plan, scanOp);
	}

	// collect all conditional traverse
	OpBase **condOps = ExecutionPlan_CollectOps(plan->root,
			OPType_CONDITIONAL_TRAVERSE);

	uint condOpCount = array_len(condOps);
	for(uint i = 0; i < condOpCount; i++) {
		OpCondTraverse *condOp = (OpCondTraverse *)condOps[i];
		// try to reduce conditional travers + filter(s) to a single IndexScan operation
		reduce_cond_op(plan, condOp);
	}

	// cleanup
	array_free(scanOps);
	array_free(condOps);
}